Re: [RE-wrenches] Fed tax credit?
Roof work (including shingles, flashing, strengthening rafters, etc.), structural work, civil work (excavating, trenching, etc.), fencing and signage, electrical changes and upgrade, design work, permit costs, interconnection costs, etc. everything required to install the system should be specified in writing so that customers or their accountants can determine tax incentives eligibility. Joel Davidson - Original Message - From: Dave Click davecl...@fsec.ucf.edu To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Thursday, May 17, 2012 6:38 AM Subject: Re: [RE-wrenches] Fed tax credit? It's my understanding that shingles would not be included, just as you can't build a house and then claim that it's a 5kW PV rack, for an $80,000 tax credit. The act of installing PV doesn't necessarily require that the shingles be replaced. Electrical panel work may be OK if, say, you're putting a 30A PV breaker in a 100A panel-- the addition of the PV likely requires a change to the panel to remain code compliant. Similarly, if code requires you to upgrade the service for your interconnection to be legal, then I would say that that change is eligible for that ITC. On 2012/5/17 0:46, Alex Cozine wrote: To add to the question, what about electrical panel work, or even service upgrade? On Wed, May 16, 2012 at 5:17 PM, Jesse Dahl dahlso...@gmail.com mailto:dahlso...@gmail.com wrote: Hello, I remember someone asking something kind of similar before, but couldn't find it in the archives. Can replacing the shingles be considered when calculating the total cost of a PV system for Federal tax credit? Thanks as always! Jesse Sent from my iPad!!! ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org mailto:RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org http://www.members.re-wrenches.org -- Alex Cozine NABCEP Certified Solar PV Installer™ Journeyman Electrician Brothers Electric Solar brotherselectricsolar.com http://brotherselectricsolar.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Transformerless inverters
A Los Angeles contractor replied off-list that transformerless inverters cannot get permitted through LA Department of Building Safety's new express permit process that uses boilerplate drawings. They can get permitted through regular plan check. This would not be an issue, but LADWP and the LA Department of Building Safety are very influential nationally. They have teamed up to spearhead a statewide effort to standardize system designs to expedite permitting PV systems under 10 kW. Other utilities have their eyes on what LADWP is doing. Joel Davidson - Original Message - From: William Korthof To: re-wrenches@lists.re-wrenches.org Sent: Wednesday, April 18, 2012 11:44 PM Subject: Re: [RE-wrenches] RE-wrenches Digest, Vol 5, Issue 113 Interesting update I've installed dozens of non-isolated transformerless inverters with LADWP customers since those genius inverters first became available from Power-One's inverter ancestor, Magnetek. I don't remember ever having a conflict or technical issue with an engineer or inspector questioning the suitability of that class of inverter, or even looking for the double-insulated solar wire that is supposed to be required for the exposed solar wires. /wk On 4/16/2012 9:05 AM, Joel Davidson wrote: Wrenches, Los Angeles Department of Water Power (LADWP), the largest and most influential municipal utility in the US is finally going to allow transformerless inverters for residential PV systems. Are there any design, installation or reliability issues to consider with the SMA and other high-frequency transformerless inverters. Can they be mounted on a hot south or west wall or do the have to be kept cool in the shade? Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Transformerless inverter reliability
Wrenches, Los Angeles Department of Water Power (LADWP), the largest and most influential municipal utility in the US is finally going to allow transformerless inverters for residential PV systems. Are there any design, installation or reliability issues to consider with the SMA and other high-frequency transformerless inverters. Can they be mounted on a hot south or west wall or do the have to be kept cool in the shade? Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] AC PV module with battery backup?
Wrenches, I have a customer who wants solar modules and Enphase inverters, but he also wants PV and battery backup power during a grid outage. Are any wrenches doing this? How? Thanks for sharing your knowledge. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] embedded energy in pv
It takes energy to produce, deliver and install PV. In 1981, Bill Yerkes was asked how much energy is consumed to produce a photovoltaic cell. Bill was one of the 3 Spectrolab engineers who developed low-cost, single-crystal silicon solar cells in 1974 and founded the company that became Arco Solar in 1978. From the September 1981 issue of the Arco Solar News: The major raw material for most solar arrays is silicon in which the newer processes consume a total of less than 2 kWh per eventual watt of solar array (compared to older processes which consumed about 19 kWh/watt). Converting metallurgical grade silicon (97 percent pure) to the high purity required for the solar cell remains the major energy investment. Fabricating the cell and manufacturing the module adds about 1 kWh per eventual watt of solar array-about 30 percent-to the energy investment. This energy investment is then returned at the rate of about 2 kWh per watt per year. The energy payback period for 1981 solar arrays, using newer processes, is two to three years. PV production and solar cell efficiency have improved dramatically during the past 31 years. See http://www.nrel.gov/docs/fy04osti/35489.pdf Some people use 180 kWh/day to power their home. And some wrench will use gasoline to power their pickup truck to transport people, tools and equipment to that home to install PV. Both adversely affect the environment. With patient guidance both will improve dramatically over time. Joel Davidson - Original Message - From: toddc...@finestplanet.com To: RE-wrenches Sent: Thursday, March 15, 2012 12:42 PM Subject: [RE-wrenches] embedded energy in pv i recently read that it takes the equivalent energy of between 1 and 4 tons of coal to make a single pv module. this is why i insist my customers do their efficiency upgrades and learn how to be frugal/conserve before i will even talk about pv with them. renewables powering waste is old paradigm thinking. consuming less is always a win win. unfortunately (now that there is an incentive program) the new solar experts coming on the scene here make more $$ with bigger systems, so lipstick on pigs is becoming the norm. one customer wanted pv because her electric bill was over $600.00/month or 180 kWh/day!! i said there was something wrong with a power bill that high. maybe a duct on her heat pump had come loose and was blowing hot air into the attic and that should be investigated first with an energy audit. she hired another expert who put in a massive system. personally, i find it difficult to support this kind of resource use. todd On Thursday, March 15, 2012 6:26am, Solarguy nt...@1scom.net said: William Attached is a Power Point slide I made that shows the 'energy payback' from PV. The Swiss based IEA Photovoltaic Power Systems Programme takes a very serious look at the PV industry and its long term effects on the planet and PV is already pretty benign. While I don't know the logic behind their calculations my first thought is that with the volume of aluminum being extracted and produced for all industry world-wide, the impact by the PV industry is probably next to nothing. And using a plastic compound would mean using a crude oil based product which is even a bigger environmental blight than aluminum production-imo. Besides, with the PV industries rush to lower prices someone would have discovered a cheaper non-metallic replacement for aluminum if it is out there. Having worked for many years in the composite/plastics industry I can say that the production of a substitute fiber re-enforced compression molded composite for PV frames would be more costly than aluminum and most likely still never match the rigidity of aluminum. Now if the PV industry trended back to smaller modules a 'plastic' frame could become workable but I don't see that moving out of RD as long as prices and margins are so low. And I don't see a corrosion resistant module becoming a niche market any time soon unless another Silicon Energy type entrepreneur decides there is a market. Jim Duncan -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of William Miller Sent: Wednesday, March 14, 2012 9:13 PM To: RE-wrenches Cc: 'RE-wrenches' Subject: Re: [RE-wrenches] Installations in High Salt Spray Environments Marco: Are we in need of a new generation of PV modules with plastic frames? How about frame-less modules on recycled plastic racking? What is the energy cost for aluminum frame modules versus plastic or recycled plastic? What is the energy cost of anodizing aluminum frames and racking? There is a need here folks, that is not being filled. Entrepreneurs, where are you? William Miller At 06:51 PM 3/14/2012, Marco Mangelsdorf wrote: Living here
Re: [RE-wrenches] Community says farewell to solar pioneer Gottlieb - Brattleboro Reformer
Dear Richard, I'll miss you. I still got that 1961 newspaper article with your picture when you were a teenager working on the Vanguard satellite solar cells. It's around here somewhere. But there is your photo in The New Solar Electric Home book on page 369 lifting one more solar panel onto one more roof. Thanks for turning so many people onto PV. Your friend, Joel Davidson - Original Message - From: d...@foxfire-energy.com To: RE-wrenches@lists.re-wrenches.org Sent: Friday, February 24, 2012 7:05 AM Subject: [RE-wrenches] Community says farewell to solar pioneer Gottlieb - Brattleboro Reformer For those of you who knew Richard http://www.reformer.com/localnews/ci_20024575#.T0enKNp5zOw.email --- This message was sent by d...@foxfire-energy.com via http://addthis.com. Please note that AddThis does not verify email addresses. Make sharing easier with the AddThis Toolbar: http://www.addthis.com/go/toolbar-em To stop receiving any emails from AddThis please visit: http://www.addthis.com/privacy/email-opt-out?e=mAPxS4550WvNbctr0E7PZ9B60CDRa4550WvNbctr0CDMfMQ in your web browser. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Absolyte recovery
Chris, Look for hair-like cracks around the cell terminals. The cracks are failure indicators caused by temperature swings. In Malibu California, a 75 kWh, 48-volt Absolyte battery bank failed after 4 years. Malibu has a very mild climate but temperature in the uninsulated equipment room ranged from 40 F in winter to 90 F in summer. The PV system is grid connected with battery backup. Absolytes were used to replace an IBE battery bank because no one was watering the IBE cells. Two years ago, the Absolytes were replaced with a new IBE battery bank that is inspected and watered every 6 months. Joel Davidson - Original Message - From: mac Lewis To: RE-wrenches Sent: Friday, February 17, 2012 7:08 AM Subject: Re: [RE-wrenches] Absolyte recovery Hi Chris, I suspect that the charger in the Apollo Inverter/Charger is undersized, especially since all of the loads are -48V. Conversely, the array is very oversized and the controllers float most of the time. The charge controllers were working fine last I checked. It's difficult to access the site right now, it includes a 30 mile snow mobile ride. We intended to put a comprehensive remote monitoring system but it didn't get put in before the snow came. I want to get up there and help the system limp along until snow melt when we can do a thorough assessment. The generator guy went up there and someone had pulled the stop switch on the genset. The battery voltage was around 5V on a 48V bank. Yikes! Thanks for the contact info. On Thu, Feb 16, 2012 at 2:13 PM, Chris ch...@solarwindworks.com wrote: Hi Mac, We had a cell failure on an Absolyte system we inherited and contacted; Jeff Lambert Product Support and Warranty East Penn Mfg. Co., Inc. - Unigy Battery Division ( Office: (610) 682 – 6361 ext. 2848 | ÈCell: (484) 955 – 2899 | ÇPage: 888-797-8039 (If no answer on Cell) | * Email: jlamb...@eastpennunigy.com Jeff was very helpful. I do wonder if your charge controllers are getting the array power out to the battery bank, was there any damage to them too? Is the Apollo 4048 inverter/charger doing its job, is it undersized for the size of battery bank? Sincerely, Chris Worcester Solar Wind Works NABCEP Certified PV Installer Phone: 530-582-4503 Fax: 530-582-4603 www.solarwindworks.com ch...@solarwindworks.com Proven Energy Solutions From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of mac Lewis Sent: Thursday, February 16, 2012 12:43 PM To: RE-wrenches Subject: Re: [RE-wrenches] Absolyte recovery Wrenches, We have inherited a Telecomm system in which the batteries have had a very hard life. A lighting strike knocked the system off line for about 5 months, and ground fault dragged the batteries way down about a month ago. Now, we are seeing about 10h of generator run time/day indicating to me that the batteries are not holding voltage at all. I am uncertain of the exact specs at this moment, but it is a 24 Absolyte IIP batteries (5 years old), with a 5 kW array, two Apollo T80HV charge controllers and an Apollo 4048 inverter charger. I don't have experience with these batteries. Is there any way to try to recover these batteries? Any good contacts with GNB would be useful. Thanks Wrenches, We have inherited a Telecomm system in which the batteries have had a very hard life. -- Mac Lewis Yo solo sé que no sé nada. -Sócrates -- Mac Lewis Yo solo sé que no sé nada. -Sócrates ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- Mac Lewis Yo solo sé que no sé nada. -Sócrates -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org
Re: [RE-wrenches] 110Vac LED resistance to weak grids in developingworld
LED teardown at http://www.edn.com/blog/PowerSource/41611-Samsung_LED_light_bulb_teardown_includes_objective_dimming_numbers.php?cid=EDNToday_20120210 - Original Message - From: Jesse Dahl To: RE-wrenches Sent: Friday, February 10, 2012 5:32 AM Subject: Re: [RE-wrenches] 110Vac LED resistance to weak grids in developingworld I don't know about spikes or grid events, but my home is 3/4 LED and have zero complaints. The warranty on them is a little weak compared to life cycle.. All of mine vary in K rating and lumens and work beautifully. Sent from my iPhone On Feb 9, 2012, at 7:45 PM, Ray Walters r...@solarray.com wrote: Personally I love my latest LED lights. They have gotten substantially better just in the past year. We have some 8 watt units in our kitchen that illuminate just like a 35 watt halogen, beautiful color rendition, not that blue they used to have. I especially like my new 1000 lumen spotlight that lights up brighter than a car head light in a package slightly larger than the old mini mag flash lights. However, I have no experience with ham radio, or theRF interference issue. We're WiFi, and cell at our house. I do some audio recording, etc. and haven't noticed any extra buzz from the several LEDs I have in my basement studio. Ray On 2/9/2012 4:54 PM, toddc...@finestplanet.com wrote: i have some personal experience with led light bulbs. i put them outside because the cfl floodlights are very s-l-o-w to warm up to full brightness. 1) leds are still slightly less efficient (lumens per watt) than cfl's 2) led light bulbs (2 different brands) throw out an ungodly amount of rfi... want to listen to a conversation on the 2 meter ham radio or listen to a weak fm broadcast station or watch channel 6 on the tee-vee? go shut off the led lights off first. my conclusion? led light bulbs are not ready for prime time. todd (still using my 25+ year old phillips dulux cfls) On Thursday, February 9, 2012 1:44pm, Jim MacDonald j...@solaresystems.com said: Hello wrenches I am in Central America and looking to suggest customers buy efficient LEDs for illumination in their 120V-wired homes, connected to local power grids with less-than-desirable power quality. I see that so many manus claim long life for the LEDs, in the tens of thousands of hours, yet so few if any back it up with a decent warranty. Folks are hesitant to make this investment, believing that voltage surges or dips could destroy the LEDs. Has anyone heard of LED lights' lives ending prematurely due to grid events? Would inline surge protectors [something small to be installed immediately downstream of the breaker in the home's main panel) be helpful, and if so, does anyone have any recommended brands? thanks Jim MacDonald Sent from Finest Planet WebMail. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] SMA SWR2500 inverters
Wrenches, Does someone have any SMA SWR2500 inverters for sale? Please contact me off-list. Thank you very much ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] DC power for LED lighting
Jeff, I suggest another approach with the LED supplier. See if you can work with them. Tell them you can design their product to operate off-grid and that the new design will cost them nothing to develop and open up a whole new market for them. They make the lights (their expertise) and you design the power for the lighting systems (your expertise). I did that with a beautiful outdoor and landscape lighting product. See http://www.blisslights.com/index.php?option=com_phocagalleryview=categoryid=2:blisslights-outdoorsItemid=99 Joel Davidson - Original Message - From: Jeff Yago To: conr...@cape.com ; 'RE-wrenches' Sent: Friday, December 16, 2011 10:24 AM Subject: Re: [RE-wrenches] DC power for LED lighting I have a local sign company that asked is to provide a solar lighting system for a double sided sign they were building for a large retirement community entrance. We have provided many solar lighting systems just like this over the years and sent them several examples. All our systems have been turn-key in that we provided the 12 VDC ground mounted LED flood lights with the separately pole mounted solar module(S) and battery/controller box. We assumed when we told them our system includes the LED lights that they understood that we were providing the lighting. Unfortunately, when we arrived on the site to install the solar system, they said they did not need our LED lights, they wanted us to power the LED lights inside the sign. We opened up the signs and found two 120 VAC electronic LED power supplies. Each was clearly labeled as providing a maximum of 5 amps at 12 VDC output, and each powered a separate string of about 150 tiny plastic blocks and each block contained 2 small LED lamps. We immediately advised the client that the solar system was designed to power our two 12 VDC flood lights and we would have to totally tear out what we had just installed and go to a much larger system that included an inverter, larger array, 120 VAC timing device, and replace the 2 conductor DC underground wiring with 3-conductor AC wire and all this would really increase $$$. I said as an alternative, why can't we just cut out the two electronic120 VAC input LED drivers since we are providing well regulated 12 VDC power direct from the GEL battery. He checked with their LED lamp supplier and they said they strongly disagree and will void warranty. Since we are talking about almost 300 total LED devices my client is afraid to give us the OK, even though we did run them overnight and everything worked just fine. As I recall, an LED needs something in the circuit to limit the amp current, not the voltage flowing through it, or it will just get brighter and brighter and then fail. However, I thought almost all strings of separate LED lights already had some kind of regulator built into each light block otherwise those near the end of the string would be less bright than those near the power source.Is this correct?? Finally, if strings of LEDs require some kind of voltage or current regulator, I can't believe they all have to run on 120 VAC as indicated by this LED manufacturer who offers no alternative.Any LED experts out there that can point me to some type of DC-to-DC converter or current regulator that can replace these 120VAC LED drivers? Thanks, Jeff Yago -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Standard sizing
William, Almost everyone, including manufacturers, wants standard module sizes. There are a lot of similar modules, but manufacturers produce different size and shape cells (everything from 4-inch square on up and semi-square, round, etc.) and customers have different voltage and current needs (everything from 18 to 144 cell modules and up). It's like car tires. Lots of sizes and models for all different kinds of cars and applications. Our best course of action continues to be keep a file of the published module lists. Then ask fellow wrenches what replacements will work and where to find them. Joel Davidson - Original Message - From: William Miller will...@millersolar.com To: al...@positiveenergysolar.com; RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Wednesday, December 07, 2011 9:30 AM Subject: [RE-wrenches] Standard sizing Friends: Why can't the industry create a list of standard module sizes, sort of like the battery industry has (http://www.rtpnet.org/teaa/bcigroup.html)? This would be a big benefit to the consumer and the installer. If a module of Group X size breaks, you are far more likely to find a replacement if other manufacturers make modules of the same physical size. Then the only challenge is to match electrical characteristics, but if you find the same crystal type and cell count, you have succeeded. Who can we advocate to? William Miller PS: I have been saying this for years! wm At 09:04 AM 12/7/2011, you wrote: One or two Matrix/Photowatt PWX1250 needed, new or used, to replace shattered module in a school demonstration system from 2005. Odd size and shape, matches nothing else. Please reply offlist if you can help. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] SMA Sunny Design temperature/voltage calculations
Howie, Thank you for speaking up. SMA, please bring back the old string sizing program. Please. When John Berdner introduced the SunnyBoy and showed us the spreadsheet (I got version X3.13 in 2003), it answered all our temperature, voltage and power questions. When the string sizing program went on-line, it literally changed system design. You could quickly do what-ifs and try different inverter, module and strings to meet site and requirements. Wrenches speak up. Hopefully SMA will do the right thing and put that oldie-but-goodie back on-line. Fröhliche Weihnachten Joel Davidson - Original Message - From: Howie Michaelson ho...@suncatchervt.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Thursday, December 01, 2011 9:17 PM Subject: [RE-wrenches] SMA Sunny Design temperature/voltage calculations Apropos to the great discussion about temperature voltage calculations, has anyone else been frustrated by the removal of output information on the Sunny Design tool compared to the old on-line string sizing calculator? It was very useful to me to have the string sizer show the temperature voltage calculations for low and high temperature - as far as I know the only string sizing application that showed this info. The defunct online sizer allowed me to quickly look at a variety stringing options, see the impact on voltage, narrow down the possibilities and then run my own voltage calculations to verify. Sunny Design makes quickly scanning various string options not so easy, and it buries the results behind more obscure output info. It is quite a sophisticated program, but I wish they gave a way to see the calculations behind the choices it makes. Or am I just missing something? Howie -- Howie Michaelson NABCEP Certified Solar PV InstallerT Catamount Solar, LLC Renewable Energy Systems Sales and Service VT Solar Electric Hot Water Incentive Partner http://www.CatamountSolar.com 802-272-0004 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Liability
Hello Mac, I can understand not wanting to get involved in some people's problems, but electricians, plumbers and other tradespeople make a good living fixing people's problems. I have examined, tested and repaired PV systems for over 25 years. Sometimes I work with subcontractors or partner up with other experts on some jobs. I have never been sued by a client or a subcontractor because I make it a point to avoid problem people. Almost all my problem-solving work comes from phone inquiries, but some come by email. I telephone interview the prospect to determine the problem and to get a feel for how they will be as a client. I will not work for or with disturbed people or trouble-makers. I always ask who did the work and why he or she is not fixing it. The prospect's answers tell a lot about how the prospect will be as a client. If I can not do the work and know someone good who can do the work, I make a courtesy referral. If I can do what the caller wants or needs, I will tell the caller what I will do and how much I will charge. If they agree, I go to the site. If I do not feel good about the prospect or the place, I tell them I can not help them and leave. If the prospect is reasonable and I can do the work, I examine what needs to be done, show and tell the prospect what I will do, how much it will cost and the payment terms. If the client agrees, then in writing I specify the problem, my solution, list pre-existing conditions and exclusions for which I am not responsible. I also indemnify myself from any and all unspecified and undiscovered pre-existing conditions. Then I get the client to agree in writing that I will not be held responsible for the listed and undiscovered pre-existing conditions and exclusions. Then I do the work. Upon completion of the work, I show and tell the client what I did and get their acknowledgement that I performed the work that they expected to their complete satisfaction. If there are any unfinished issues, I finish them to their complete satisfaction. Then in writing, I list the work performed, reiterate the exclusions, have them sign off that the work is completed to their complete satisfaction and give them the invoice. I am thankful that many customers have become references and friends. Happy Thanksgiving. Joel Davidson - Original Message - From: mac Lewis To: RE-wrenches Sent: Wednesday, November 23, 2011 8:43 AM Subject: [RE-wrenches] Liability Hey wrenches, Wanted to see what everyone does in a case like I just encountered. I got a call from a tenant for an off-grid system installed by the landlord (supposedly an electrician). I went up there to look at the site and it was a mess. System lacked OCPDs, there were gouges in the insulation of the wires, loose terminals, nothing ran in conduit, etc... I was called up there to see why the generator was not auto starting. I got the auto start working, expressed my concern to the tenant about the workmanship and left. Now I'm wondering whether I should have touched the system at all. What would you do? Is there liability here? Thanks -- Mac Lewis Yo solo sé que no sé nada. -Sócrates -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Convert Grid Tie SW4048 to Backup System; Add New Inverter, AC Coupled
Allan, Thanks for reprinting the discussion. The retired engineer and his SW4048 are still both alive and doing well. Aside from the Trace SW4048 grid-tie low dc-to-ac efficiency (~65%), it is still one of the finest inverters ever made. In case I outlast my 13 year old SW4048, what new inverter has the same rugged durability but higher grid-tie efficiency? Joel Davidson - Original Message - From: Allan Sindelar To: re-wrenches@lists.re-wrenches.org Sent: Tuesday, November 22, 2011 8:07 AM Subject: Re: [RE-wrenches] Convert Grid Tie SW4048 to Backup System; Add New Inverter, AC Coupled Nathan, I neither stated nor implied that the SW series could be AC-coupled, because I don't know, friend. I have never had reason to try this. The issue was discussed on this forum several years ago, and I have found two key posts from David Katz of AEE about this topic in my email Wrenches archives. David only addresses compatibility with early Sunny Boys. The SW is true modified sine waveform, so whether is would be capable of providing a reference signal to which a modern grid-tie inverter could latch would be subject to several variables, and would likely vary among inverter brands and models. Here's what David wrote on 4/15/2005, excerpted: I have connected Sunny Boy inverters directly to the output of Xantrex SW inverters and Outback inverters. It works well. The Sunny Boy operates when it sees the SW or Outback output. Sometimes it shuts off when a large load, like a pump is applied to the circuit, because it looks like a grid failure. If the SB shuts off, it waits 5 minutes to turn on. If there is no AC load on the system and the SB is supplying power, you will charge the batteries connected to the SW. You need to put a voltage controlled switch to turn of the AC between the Sunny Boy and the sub panel if the battery voltage gets too high. The SW is bi-directional. if you put ac into the output, it charges the battery. The AC in terminal is connected directly to the output through a relay. The inverter is quite amazing. If you connect the output of the SB and the SW to the same sub panel and turn off all loads you will see it charge the battery. If you turn on loads to the point you are drawing more than the SB is supplying, it will begin to draw power from the battery and supply the excess that the SB is not supplying. I use an outback for backup power on my grid connected house this way. As long as the SW in turned on, there is a sine wave present at the AC output. This makes the SB think the grid is present. I hope this answers your question. If not let me know and I will try to draw a diagram. By the way, if you connect the AC input of the SW or (FX) to a breaker in the main panel in a grid connected system it will become your connection from the main panel to the sub panel (120VAC) and the inverter will turn on whenever the grid fails and keep the SB running. If you are using a 240 V SB, you will need an autotransformer or a second SW. David You mention the GTI below, but have not indicated whether the SW you are considering is or isn't a GTI-equipped model. If it is 4.10/GTI-equipped, I'd suspect it's incompatible with AC-coupling. When one of these is not selling (such as at night), has no loads on it but is grid-connected, it is continually drifting between buy and sell by an amp or two. Note that I have only observed this on the SW's meter display, which is a pretty crude measurement. But I would expect that this would interfere with any GT inverter's latching function, given the mandatory 5-minute waiting period. This is all based on observing one system that we installed around 2002 for a well-known retired movie star. The system remains fully operational today. We had an SW5548 (for most loads) and an SW 4048 (for background loads with surge, like pumps) that were not series-stacked, in a GTWB system, small by today's standards at 4.4kW of PV. Both inverters had GTIs, but only one was set to sell, in order for the two SWs not to argue with each other and to minimize their inherent float inefficiency previously noted. I'd guess your chances of AC-coupling would be better with a pre-GTI unit. Others here may have had more experience with this question. Just to stir the pot some more, here is an email from Lloyd Gomm, then at Xantrex, about the GTI/listing issue from 11/17/2003: Joel Davidson Wrote: November 15, 2003 one of our customers (maybe more) with a line-tie SW in Southern California Edison territory got a notice from Xantrex dated October 22, 2003 about a required firmware update. Anyone else get this notice? Joel, this firmware update is necessary for SW inverters tested / listed by UL. This batch of SW's were produced by Xantrex between Q4 2000 and Q4 2001 and, to be clear, were de-listed by UL in November 2001. This firmware update is NOT required
Re: [RE-wrenches] What inverter? (was Faulty PM-60 circuit board)
So far William and Maverick say Enphase 190 and Darryl says Solar Edge. My experience is that one SMA inverter costs less and is more reliable than multiple inverters. Joel Davidson - Original Message - From: Darryl Thayer To: RE-wrenches Sent: Wednesday, November 09, 2011 8:29 PM Subject: Re: [RE-wrenches] What inverter? (was Faulty PM-60 circuit board) I think you shoud go with Solar Edge, and modules optimizers From: William Miller will...@millersolar.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Wednesday, November 9, 2011 7:42 PM Subject: Re: [RE-wrenches] What inverter? (was Faulty PM-60 circuit board) Joel: 24 Enphase M190s. William Miller At 09:33 AM 11/9/2011, you wrote: Wrenches, After telling my customer to upgrade to an MPPT charge controller (thanks Ray Walters and John Blittersdorf), he decided to really optimize his PV array and retire his Trace SW4048 inverter. He has 48 Siemens SP75 modules (67.5 W DC PTC) that are ground mounted in full sun and easy to re-wire. With so many new batteryless grid-tie inverters on the market, this is a good time to ask this sage group with over 3,000 combined years of experience what inverter do you prefer? Joel Davidson - Original Message - From: Joel Davidson joel.david...@sbcglobal.net To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Saturday, November 05, 2011 4:50 PM Subject: Faulty PM-60 circuit board Wrenches, My customer has a circa 2001 Pulse PC250 with a faulty PM-60 circuit board TC-750, REV D2 (the microprocessor U1 has v2.5 and v1.01 written on a label on it). Does anyone repair or have replacements for PC250 PM-60 circuit boards? If not, what do you recommend? Thank you in advance for your help. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.454 / Virus Database: 271.1.1/4005 - Release Date: 11/08/11 19:34:00 Miller Solar Voice :805-438-5600 email: will...@millersolar.com http://millersolar.com License No. C-10-773985 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] What inverter? (was Faulty PM-60 circuit board)
Wrenches, After telling my customer to upgrade to an MPPT charge controller (thanks Ray Walters and John Blittersdorf), he decided to really optimize his PV array and retire his Trace SW4048 inverter. He has 48 Siemens SP75 modules (67.5 W DC PTC) that are ground mounted in full sun and easy to re-wire. With so many new batteryless grid-tie inverters on the market, this is a good time to ask this sage group with over 3,000 combined years of experience what inverter do you prefer? Joel Davidson - Original Message - From: Joel Davidson joel.david...@sbcglobal.net To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Saturday, November 05, 2011 4:50 PM Subject: Faulty PM-60 circuit board Wrenches, My customer has a circa 2001 Pulse PC250 with a faulty PM-60 circuit board TC-750, REV D2 (the microprocessor U1 has v2.5 and v1.01 written on a label on it). Does anyone repair or have replacements for PC250 PM-60 circuit boards? If not, what do you recommend? Thank you in advance for your help. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] What inverter? (was Faulty PM-60 circuit board)
Hello Ray, He has had almost no utility power outages since he got his PV system in 2001. By going batteryless, his dc-to-ac conversion efficiency and kWh production should increase by over 15%. He has not decided if he wants to keep the SW4048 and float charge his batteries with the grid for emergency power. Joel Davidson - Original Message - From: Ray Walters r...@solarray.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Wednesday, November 09, 2011 12:59 PM Subject: Re: [RE-wrenches] What inverter? (was Faulty PM-60 circuit board) He doesn't want battery backup? Ray On 11/9/2011 10:33 AM, Joel Davidson wrote: Wrenches, After telling my customer to upgrade to an MPPT charge controller (thanks Ray Walters and John Blittersdorf), he decided to really optimize his PV array and retire his Trace SW4048 inverter. He has 48 Siemens SP75 modules (67.5 W DC PTC) that are ground mounted in full sun and easy to re-wire. With so many new batteryless grid-tie inverters on the market, this is a good time to ask this sage group with over 3,000 combined years of experience what inverter do you prefer? Joel Davidson - Original Message - From: Joel Davidson joel.david...@sbcglobal.net To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Saturday, November 05, 2011 4:50 PM Subject: Faulty PM-60 circuit board Wrenches, My customer has a circa 2001 Pulse PC250 with a faulty PM-60 circuit board TC-750, REV D2 (the microprocessor U1 has v2.5 and v1.01 written on a label on it). Does anyone repair or have replacements for PC250 PM-60 circuit boards? If not, what do you recommend? Thank you in advance for your help. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Faulty PM-60 circuit board
Wrenches, My customer has a circa 2001 Pulse PC250 with a faulty PM-60 circuit board TC-750, REV D2 (the microprocessor U1 has v2.5 and v1.01 written on a label on it). Does anyone repair or have replacements for PC250 PM-60 circuit boards? If not, what do you recommend? Thank you in advance for your help. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Faulty PM-60 circuit board
Hello Ray, Thank you for the quick reply. You are right. It's time to move on from the Pulse stuff. I will recommend this solution to my customer. I did something similar to my Trace system when I replaced the C40 that came with the Trace Modular Cabinet with an externally mounted Outback MX60, but I did not rewire the array. Best regards, Joel Davidson - Original Message - From: Ray Walters r...@solarray.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Monday, November 07, 2011 10:16 AM Subject: Re: [RE-wrenches] Faulty PM-60 circuit board Today's controllers are so much better both in terms of battery management, and power efficiency, that I replace the old Pulse stuff even if they're not dead. I usually keep the PC250 as a DC load center, and pop a new controller off the top. This is often a good time to add a few modules to the array, and rewire the existing array to higher voltage. This allows the existing home run wiring to be reused, even with the additional modules. I've found that if the original array wiring was good, that it takes very little work to jump up the voltage. Definitely don't need to redo every connection. People are used to upgrading to better electronics: who still uses their computer, modem, or cell phone from 10 years ago? Today's controllers will pay for themselves in extended battery life alone. Ray On 11/5/2011 6:50 PM, Joel Davidson wrote: Wrenches, My customer has a circa 2001 Pulse PC250 with a faulty PM-60 circuit board TC-750, REV D2 (the microprocessor U1 has v2.5 and v1.01 written on a label on it). Does anyone repair or have replacements for PC250 PM-60 circuit boards? If not, what do you recommend? Thank you in advance for your help. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Bifacial modules
See-thru solar cells have been around for decades. Arco Solar made 4% efficient amorphous silicon modules and car sunroofs in 1984 that were tinted brown like sunglasses. I got a 12-inch square see-thru laminate that still works. I also have a 6.75-inch square sample of MSK Corp's amorphous silicon PV-TV solar panels. They were developed in conjunction with Kaneka and Japanese architects Taiyo Industries. The full-size glass panels, measure 1-meter square. In addition to producing electricity, they provide thermal insulation, solar heat gain protection and protection from ultra violet rays. During the manufacturing process, a laser inscribes a series of ultra fine lines onto the panel to allow 10 percent of visible light to be transmitted through the glass, enough for sufficient light to enter a building even during cloudy conditions while protecting against excessive solar gain. Amorphous silicon solar cells with 10 percent, 5 percent or 1 percent transparency are placed between two sheets of glass to generate power. This solar panel is called PV-TV because it is also used as a display screen on the outside of buildings. See http://www.metropolismag.com/story/20040727/pv-tv-a-multifunctional-eco-friendly-building-material The Tiger Woods Learning Center in Anaheim and other buildings have see-thru Schott solar modules with different amounts of transparency. See http://www.solardesign.com/library/pdf/tiger-woods-solar-curtain-wall.pdf Also, opaque cell solar modules are manufactured with various cell spacings for BIPV applications. I have a Mastech Light Meter LX1010B in my tool kit for measuring lux. This handy tool costs around $20. Joel Davidson - Original Message - From: Keith Cronin To: Phil Undercuffler ; RE-wrenches Sent: Wednesday, November 02, 2011 9:50 PM Subject: Re: [RE-wrenches] Bifacial modules Thanks everyone for the feedback! Thinking that the manu's can space cells accordingly on the surface of the glass and create whatever % light the end user wants to seep through. The % of light must slide between 5-15%, depending on manu's specs. Architecture can meet solar and increase the applicability of the products. Perhaps someday, they can make the cells see-through (or almost), like glass...? Now that opens up possibilities! Aloha, Keith -- From: Phil Undercuffler solarp...@gmail.com To: Keith Cronin electrich...@yahoo.com; RE-wrenches re-wrenches@lists.re-wrenches.org Cc: Bill Brooks billbroo...@yahoo.com Sent: Wednesday, November 2, 2011 9:18 AM Subject: Re: [RE-wrenches] Bifacial modules We've got an array of Silicon Energy modules out back, and in the interests of scientific discovery and procrastinating from what I really am supposed to be doing, Kelly, Seth and I just ran a few experiments to see if we can quantify the amount of irradiation that makes it through the array. Using a Kyocera module as our reference, we measured ISC with the module in the plane of the array, then moved the module to the same orientation but approximately 12 feet behind and in the shade of the SE array, and again measured ISC. Sun conditions were light wispy clouds, guesstimated 800 W/M2 (pretty darned good for Arlington WA this time o' year), 10:30 local time. We measured 5.9A ISC in front of the array, and 610 milliamps when in the shade the array, leading us to say that just over 10% of the available sun will make it to your orchids. It should be noted that there is a opaque backing behind each SE cell, so the only light that makes it through is through the intercell gaps. I've used Sanyo doubles before, and in those modules the cells are slightly translucent, so the sun is somewhat visible through the body of the cell itself as well -- sort of like looking through very dark sunglasses. In either case, the illumination on objects behind the array is a dappled, dynamic light. As Bill says, it's pretty cool from an aesthetic point of view. My personal .02 is that there is no finer place to put an array than a shade structure using clear modules. It keeps everything off the roof, gives shade and makes for a premium installation option. Phil --- When we learn how to store electricity, we will cease being apes ourselves; until then we are tailless orangutans. You see, we should utilize natural forces and thus get all of our power. Sunshine is a form of energy, and the winds and the tides are manifestations of energy. Do we use them? Oh, no! We burn up wood and coal, as renters burn up the front fence for fuel. We live like squatters, not as if we owned the property. There must surely come a time when heat and power will be stored in unlimited quantities in every community, all gathered by natural forces. -- Thomas Edison -- On Tue, Nov 1, 2011 at 7:48 PM, Keith Cronin
Re: [RE-wrenches] Bifacial modules
I also like Bill Brooks' test. I use a Daystar irradiance meter to determine light levels through glazing or PV modules by measuring the light throughout the day and at the distance from the glazing and height of whatever is being illuminated. - Original Message - From: Ray Walters To: RE-wrenches Sent: Thursday, November 03, 2011 11:54 AM Subject: Re: [RE-wrenches] Bifacial modules Geez Joel, we need to start a solar museum for all the cool old stuff you have. I just did a bit of research, and it seems lux is a weighted measure based on visible light present, while irradiation is more a total power measurement. I guess we really need to have two different meters to measure how much light passes through a module. If we were to go a step further and characterize the quality of light present, we might need a spectral analyzer to determine whether its cool white or daylight, etc. As always, the more you think about something, the more complicated it becomes. Ray Walters On 11/3/2011 11:39 AM, Joel Davidson wrote: See-thru solar cells have been around for decades. Arco Solar made 4% efficient amorphous silicon modules and car sunroofs in 1984 that were tinted brown like sunglasses. I got a 12-inch square see-thru laminate that still works. I also have a 6.75-inch square sample of MSK Corp's amorphous silicon PV-TV solar panels. They were developed in conjunction with Kaneka and Japanese architects Taiyo Industries. The full-size glass panels, measure 1-meter square. In addition to producing electricity, they provide thermal insulation, solar heat gain protection and protection from ultra violet rays. During the manufacturing process, a laser inscribes a series of ultra fine lines onto the panel to allow 10 percent of visible light to be transmitted through the glass, enough for sufficient light to enter a building even during cloudy conditions while protecting against excessive solar gain. Amorphous silicon solar cells with 10 percent, 5 percent or 1 percent transparency are placed between two sheets of glass to generate power. This solar panel is called PV-TV because it is also used as a display screen on the outside of buildings. See http://www.metropolismag.com/story/20040727/pv-tv-a-multifunctional-eco-friendly-building-material The Tiger Woods Learning Center in Anaheim and other buildings have see-thru Schott solar modules with different amounts of transparency. See http://www.solardesign.com/library/pdf/tiger-woods-solar-curtain-wall.pdf Also, opaque cell solar modules are manufactured with various cell spacings for BIPV applications. I have a Mastech Light Meter LX1010B in my tool kit for measuring lux. This handy tool costs around $20. Joel Davidson - Original Message - From: Keith Cronin To: Phil Undercuffler ; RE-wrenches Sent: Wednesday, November 02, 2011 9:50 PM Subject: Re: [RE-wrenches] Bifacial modules Thanks everyone for the feedback! Thinking that the manu's can space cells accordingly on the surface of the glass and create whatever % light the end user wants to seep through. The % of light must slide between 5-15%, depending on manu's specs. Architecture can meet solar and increase the applicability of the products. Perhaps someday, they can make the cells see-through (or almost), like glass...? Now that opens up possibilities! Aloha, Keith -- From: Phil Undercuffler solarp...@gmail.com To: Keith Cronin electrich...@yahoo.com; RE-wrenches re-wrenches@lists.re-wrenches.org Cc: Bill Brooks billbroo...@yahoo.com Sent: Wednesday, November 2, 2011 9:18 AM Subject: Re: [RE-wrenches] Bifacial modules We've got an array of Silicon Energy modules out back, and in the interests of scientific discovery and procrastinating from what I really am supposed to be doing, Kelly, Seth and I just ran a few experiments to see if we can quantify the amount of irradiation that makes it through the array. Using a Kyocera module as our reference, we measured ISC with the module in the plane of the array, then moved the module to the same orientation but approximately 12 feet behind and in the shade of the SE array, and again measured ISC. Sun conditions were light wispy clouds, guesstimated 800 W/M2 (pretty darned good for Arlington WA this time o' year), 10:30 local time. We measured 5.9A ISC in front of the array, and 610 milliamps when in the shade the array, leading us to say that just over 10% of the available sun will make it to your orchids. It should be noted that there is a opaque backing behind each SE cell, so the only light that makes it through is through the intercell gaps. I've used Sanyo doubles before, and in those modules the cells are slightly translucent, so
[RE-wrenches] Low-power consuming LEDs
Wrenches, Who is a good supplier of low-power consuming individual LEDs. Thank you very much for your recommendations. Best regards, Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] 6-volt, 10-watt solar module?
Hello Wrenches, I need a 6-volt approximate 10-watt solar module and a 6-volt charge controller and timer similar to the Morningstar 12-volt SL-10L-12V. Thanks in advance for your recommendations. Best regards, Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Home Depot solar?
Solar Electrical Systems (SES) in Westlake Village California was a Home Depot installer for BP Solar systems for a few years. SES does excellent work. SES no longer installs BP Solar or Home Depot systems but occasionally replaces BP modules that fail on the systems that they installed. Joel Davidson - Original Message - From: Jesse Dahl dahlso...@gmail.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Thursday, September 29, 2011 7:39 AM Subject: [RE-wrenches] Home Depot solar? Anyone out there have any experience with Home Depot's solar installers? Jesse Sent from my iPhone ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Suniva
Hello Keith, I have not bought Suniva cells or modules, but I know that Dr. Ajeet Rohatgi, founder and CTO, is one of the world's top PV scientists and US and Asian cell customers are lined up waiting to buy their cells. Joel Davidson - Original Message - From: Keith Cronin To: RE-Wrenches Sent: Monday, September 12, 2011 3:08 PM Subject: [RE-wrenches] Suniva Folks- any of you purchased any of these? http://suniva.com/index.php Aloha, Keith -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] unique battery bank design question
On T-105 battery banks, I've used taps with alligator clips so the tap could be moved every few days to power 1 amp or less loads. The taps worked because I equalized the battery bank every month. I've used voltage-dropping resistors (simple and cheap), Vanner equalizers (ambulance grade hardware), off-the-shelf DC-to-DC converters (some only lasted 2 years) and custom DC-to-DC converters with MPPT. All work well when they are designed for the peak load and continuous load, have good heat dissipation and their parasitic load is included in the system's energy production. Joel Davidson - Original Message - From: Rob Shappell r...@nwes.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Friday, September 02, 2011 6:53 AM Subject: Re: [RE-wrenches] unique battery bank design question As far as I know, The DC/DC and the Equalizers do basically the same thing (step up or down). I recollect that the Equalizers are adjustable and can be used as a load dump. Enermaxer comes to mind. It's been a long time... but a refresher will be gladly accepted from those in the know. Rob Shappell -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jason Szumlanski Sent: Friday, September 02, 2011 9:42 AM To: RE-wrenches Subject: Re: [RE-wrenches] unique battery bank design question Yeah, Rob, you and I have talked about this before regarding 12V required for generator start/control with a 48V battery bank. In that case we did the inefficient thing by charging the generator starting battery with a 12V charger off the AC output of the inverter. A separate PV panel was the more expensive option. I appreciate your input on this. What can you tell us about battery equalizers as an alternative to DC-DC converters?? Jason Szumlanski Fafco Solar -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Rob Shappell Sent: Friday, September 02, 2011 8:24 AM To: 'RE-wrenches' Subject: Re: [RE-wrenches] unique battery bank design question I never, never recommend taps of any sort, but sometimes we have to satisfy the needs of the customer. If any taps are done in any manner I would recommend AT LEAST an annual reconfig of the taps. To reduce and/or eliminate the imbalance of the 12 volt and 24 volt taps, you could install a 12 volt charging source to the 12 volt tap, a 24 volt charging source to the 24 volt tap and the 48 volt loads get a 48 volt charging source. The array is still calculated the same, just distributed different through different controllers. Is this bullet proof or perfect? Nope, but neither are DC/DC converters and the system is much more efficient too. Rob Shappell ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Warranty repair costs [was Evergreen goes down]
How much does a $29 part cost your business when you have to pay a technician to travel to a jobsite, troubleshoot, submit an RMA or order a replacement, and return and replace the bad unit? I advise contractors not to subsidize bad equipment suppliers by doing repairs and replacements at their own expense. I also advise suppliers to factor in realistic service costs and support their installing contractors. Joel Davidson - Original Message - From: Jason Szumlanski To: RE-wrenches Sent: Friday, August 19, 2011 3:47 AM Subject: Re: [RE-wrenches] Evergreen goes down Sounds like you are making a good argument for microinverters. We've already had that warranty discussion, but if module mismatch is an expensive and difficult to manage module warranty issue, microinverters allow you to, a) not replace a bad module, or b) replace it with a different module if physical size permits. All I am saying is that warranty becomes less of an issue as equipment prices drop. When my DVD player cost $500 I wanted a warranty. When it cost $29, not so much. Jason Szumlanski Fafco Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Joel Davidson Sent: Thursday, August 18, 2011 5:48 PM To: RE-wrenches Subject: Re: [RE-wrenches] Evergreen goes down Hello Jason, Warranty coverage could be a non-issue if you buy from a company with a warranty escrow account. Still, call-back costs and finding same-size, same-spec replacement modules costs do matter. Factor in travel time, labor, troubleshooting, finding replacement modules, paperwork, phone calls, etc. to replace 200-watt modules that cost less than $400? Not to mention how selling bad products and buying from unreliable suppliers affect your reputation. How many spare modules and inverters can a contractor afford to stock? The risk is always there because even reputable manufacturers make bad modules. The pile of bad modules made by reputable companies keeps growing. Europeans have recently recycled 600 tonnes of solar modules plus thousands of dead inverters. See http://www.waste-management-world.com/index/display/article-display/2373267650/articles/waste-management-world/opinion/2011/08/Solar_PV_Recycling_-_One_Step_Ahead_.html 600 tonnes at 40 lbs/module = approx 33,000 modules at 150 watts = approx 5 MW. 5 MW sounds like a lot but is only 0.03% of the 16 GW installed PV in Europe. Are wrenches seeing less than 0.03% of the modules they install ending up in the trash or sent back to the manufacturer? Yes, Astropower made a good module. Some good people use to work there. Joel Davidson - Original Message - From: Jason Szumlanski To: RE-wrenches Sent: Thursday, August 18, 2011 12:10 PM Subject: Re: [RE-wrenches] Evergreen goes down Pretty soon I believe warranty coverage will become a virtual non-issue. At well under $2/watt, does it matter much anymore? Is there really that much risk of product or performance failure with most reputable manufacturers? Yes, I paid $10+/w for Astropower modules over a decade ago, and warranty definitely mattered at that time. Anyway. sad to see them go. We were a big fan for a while. Jason Szumlanski Fafco Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of boB Gudgel Sent: Thursday, August 18, 2011 2:23 PM To: RE-wrenches Subject: Re: [RE-wrenches] Evergreen goes down On 8/18/2011 11:10 AM, Marco Mangelsdorf wrote: Evergreen Solar, one of the last remaining independent U.S. module manufacturers, announced their plan to file for bankruptcy protection this week. Done in by plummeting module pricing no doubt. I'm sure you all are getting the same kind of solicitation emails that I get from mod manufacturers and wholesalers from across the globe peddling mods at low, low prices, including Evergreen. Anyone have any idea what's going to happen to the warranty coverage for Evergreen mods? Will they become unwanted, unwarrantied orphans, a la Astropower? Sad, sad.. marco I'd beware of newer companies offering say, 50 year warranties ! Hopefully NOT the new business model ! boB ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm
Re: [RE-wrenches] Evergreen goes down
Hello Jason, Warranty coverage could be a non-issue if you buy from a company with a warranty escrow account. Still, call-back costs and finding same-size, same-spec replacement modules costs do matter. Factor in travel time, labor, troubleshooting, finding replacement modules, paperwork, phone calls, etc. to replace 200-watt modules that cost less than $400? Not to mention how selling bad products and buying from unreliable suppliers affect your reputation. How many spare modules and inverters can a contractor afford to stock? The risk is always there because even reputable manufacturers make bad modules. The pile of bad modules made by reputable companies keeps growing. Europeans have recently recycled 600 tonnes of solar modules plus thousands of dead inverters. See http://www.waste-management-world.com/index/display/article-display/2373267650/articles/waste-management-world/opinion/2011/08/Solar_PV_Recycling_-_One_Step_Ahead_.html 600 tonnes at 40 lbs/module = approx 33,000 modules at 150 watts = approx 5 MW. 5 MW sounds like a lot but is only 0.03% of the 16 GW installed PV in Europe. Are wrenches seeing less than 0.03% of the modules they install ending up in the trash or sent back to the manufacturer? Yes, Astropower made a good module. Some good people use to work there. Joel Davidson - Original Message - From: Jason Szumlanski To: RE-wrenches Sent: Thursday, August 18, 2011 12:10 PM Subject: Re: [RE-wrenches] Evergreen goes down Pretty soon I believe warranty coverage will become a virtual non-issue. At well under $2/watt, does it matter much anymore? Is there really that much risk of product or performance failure with most reputable manufacturers? Yes, I paid $10+/w for Astropower modules over a decade ago, and warranty definitely mattered at that time. Anyway. sad to see them go. We were a big fan for a while. Jason Szumlanski Fafco Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of boB Gudgel Sent: Thursday, August 18, 2011 2:23 PM To: RE-wrenches Subject: Re: [RE-wrenches] Evergreen goes down On 8/18/2011 11:10 AM, Marco Mangelsdorf wrote: Evergreen Solar, one of the last remaining independent U.S. module manufacturers, announced their plan to file for bankruptcy protection this week. Done in by plummeting module pricing no doubt. I'm sure you all are getting the same kind of solicitation emails that I get from mod manufacturers and wholesalers from across the globe peddling mods at low, low prices, including Evergreen. Anyone have any idea what's going to happen to the warranty coverage for Evergreen mods? Will they become unwanted, unwarrantied orphans, a la Astropower? Sad, sad.. marco I'd beware of newer companies offering say, 50 year warranties ! Hopefully NOT the new business model ! boB -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] mechanical vs. electronic kwh meter
Electronic meters always work in favor of the utility company. Mechanical meters can be ratcheted 1-way or unratcheted bi-directional. Bi-directional meters can be calibrated accurately. Meters are the utility's cash registers. Businesses get very angry if you touch or even look closely at their cash registers. The recession has resulted in more business closings and home foreclosures which means fewer utility meters and less revenue so utility companies are watching their meters very closely. Utility workers are also concerned about bi-directional electricity flow safety. LADWP's revised solar program says if the PV system meter shows 10 hours or more PV production before the net-meter is placed, then the customer forfeits the rebate and the contractor can be taken off the approved installers list. It often takes Southern California Edison 6 to 8 weeks place a meter on a PV system. LADWP is even slower. Yet new non-PV services get meters/cash registers placed usually within 3 days. Expect strong pushback if you try to fight your electric utility's meter policy. You're better off making friends so that they place meters on your jobs quickly. Joel Davidson - Original Message - From: Kirk Herander To: RE-wrenches Sent: Friday, August 12, 2011 6:45 AM Subject: [RE-wrenches] mechanical vs. electronic kwh meter Hello, I am now in a debate with the metering dept. of a local utility. They don't want a PV system to be energized and tested until a bidirectional electronic meter is installed. They insist that an old plain Jane mechanical meter can be damaged and is a safety concern if power is pushed through it (its running backwards) to the grid. I have never heard of, witnessed, or been told this by any utility or AHJ inspector until now. Have any of you ever? I don't know the reason for their paranoia. I assume that many utility districts don't to this day install bidirectional electronic meters. And rely on the original mechanical meter to count backwards reliably and safely. Kirk Herander VT Solar, LLC dba Vermont Solar Engineering NABCEPTM Certified installer Charter Member NYSERDA-eligible Installer VT RE Incentive Program Partner -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Power Factor (was Efficient step up, down transformers)
Power factor less than 1.0 can shorten the life of and damage equipment and reduce PV production. We installed a 200 kW PV system on a facility with a lot of 3-phase motors and monitored the PV and the grid. We measured around 0.7 PF being delivered by the Los Angeles Dept of Water Power. The data was used as evidence by the PV client to negotiate compensation for lost power and get better quality power at that site and other facilities. Now I always monitor utility power on commercial systems for trouble-shooting. Joel Davidson - Original Message - From: Exeltech exelt...@yahoo.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Tuesday, July 26, 2011 12:13 PM Subject: Re: [RE-wrenches] Efficient step up, down transformers Hello Ray, Wow. I could do an another thesis on the topic of power factor alone... There's no good way to fully explain this in depth here .. so all we can do is scratch the surface. First, a quick review. Power factor less than 1.0 causes current flow in a load that's out of phase with the applied voltage. The actual power delivered to the load (and thus consumed by the source, disregarding efficiency for now), would be: Vac * Iac * COS(theta) .. where theta is the phase angle differential between the voltage and current (with the values for V and I in rms). Though the real power consumed in a reactive circuit is going to be less than the real power consumed in an equivalent resistive circuit (by virtue of the phase angle), the amperage in the reactive circuit is still whatever is flowing. Now, to answer your question... All inverters will operate at a lower efficiency when connected to a load with lousy power factor than if connected to a purely resistive load under similar operating conditions (VA vs. watts). The actual efficiency reduction will depend also on whether the low power factor is due to reactive components (e.g. inductors or capacitors), or due to a non-linear load, such as a switching power supply in a computer, microwave oven, etc. Nonlinear loads present their own issues that I'll skip for now. Let's presume reactive... That said... The majority of the losses in inverters under these conditions would be resistive. Here's why: Inverters made with power transformers have large amounts of copper wire, and consequently, wire resistance. When connected to a load with a poor power factor, transformer-based inverters will not perform as efficiently as they do when connected to a purely resistive load. With a very low power-factor load, you could theoretically be providing the max current from an inverter at much lower real power output than it's rated. This additional loss, when taken into account at an AC power with low real wattage output, will make the inverter's efficiency worse than with a resistive load. Expect the efficiency hit to be on the order of 2-5% for transformer-based inverters (again, depending on inverter's max wattage rating as well, as this will impact the wire size used in its construction, and thus the total wire resistance). Transformerless inverters don't have this large mass of wire (thus much lower internal resistance). Subsequently, they aren't nearly as affected by low-power-factor loads - but even here, I'd expect around 0.5-1% efficiency reduction, all other conditions being equal. Power factor is deceptively simple .. but is one of the more complex aspects of power systems and power equipment design. Hope this helps. Dan Lepinski Sr. Engineer Exeltech P.S. Thanks for being a long-time Exeltech customer. Much appreciated. --- On Mon, 7/25/11, R Ray Walters r...@solarray.com wrote: From: R Ray Walters r...@solarray.com Subject: Re: [RE-wrenches] Efficient step up, down transformers To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Monday, July 25, 2011, 4:10 PM Hi Dan; I agree that a 2000 VA inverter isn't equal to a 2000 watt unit. The focus on VA here though was not about looking at the rating of the inverter, but instead noting that a load with a high reactive component might draw more energy than a purely resistive load in a battery based inverter system. AC watts might be equal, but my understanding (perhaps false?) is that the inverter efficiency decreases with PF. SInce you're in the inverter manufacturing biz, perhaps you could better explain this to the rest of us. My fundamental question is: how does power factor effect the efficiency of an inverter? A better understanding of this issue would not only help us with the current issue of transformers vs. big wire, but also help us better size battery based systems to all types of AC loads. Thanks in advance for your time, R. Walters r...@solarray.com Solar Engineer (and long time Exeltech user) On Jul 25, 2011, at 1:41 PM, Exeltech wrote: Focusing on VA ratings would not be advisable. Here's why. Watts are real power. This would be actual DC volts times actual DC amps. Measuring DC volts and DC amps
Re: [RE-wrenches] Power Factor (was Efficient step up, down transformers)
Hi Bob, The inverter PF was 1.0. The grid was always less than 1.0 and often down to 0.7. LADWP would not say what they did to fix the problem. Joel Davidson - Original Message - From: boB Gudgel b...@midnitesolar.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Cc: Joel Davidson joel.david...@sbcglobal.net Sent: Tuesday, July 26, 2011 7:30 PM Subject: Re: [RE-wrenches] Power Factor (was Efficient step up, down transformers) On 7/26/2011 4:42 PM, Joel Davidson wrote: Power factor less than 1.0 can shorten the life of and damage equipment and reduce PV production. We installed a 200 kW PV system on a facility with a lot of 3-phase motors and monitored the PV and the grid. We measured around 0.7 PF being delivered by the Los Angeles Dept of Water Power. The data was used as evidence by the PV client to negotiate compensation for lost power and get better quality power at that site and other facilities. Now I always monitor utility power on commercial systems for trouble-shooting. Joel Davidson That's very interesting... I would expect a current-source type grid tie inverter would be very close to PF of 1.0 (if that one WAS a CS type which I would think it would be) Might be because the grid voltage at that facility is really distorted because of the loads you mentioned. Did you measure the PF of the line from the GT inverter itself ? What kind of inverter system was this ?? A big one of course. Some GT inverters that are more of a voltage source will supply lower power factor and tend to clean up the dirty voltage waveform. boB - Original Message - From: Exeltech exelt...@yahoo.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Tuesday, July 26, 2011 12:13 PM Subject: Re: [RE-wrenches] Efficient step up, down transformers Hello Ray, Wow. I could do an another thesis on the topic of power factor alone... There's no good way to fully explain this in depth here .. so all we can do is scratch the surface. First, a quick review. Power factor less than 1.0 causes current flow in a load that's out of phase with the applied voltage. The actual power delivered to the load (and thus consumed by the source, disregarding efficiency for now), would be: Vac * Iac * COS(theta) .. where theta is the phase angle differential between the voltage and current (with the values for V and I in rms). Though the real power consumed in a reactive circuit is going to be less than the real power consumed in an equivalent resistive circuit (by virtue of the phase angle), the amperage in the reactive circuit is still whatever is flowing. Now, to answer your question... All inverters will operate at a lower efficiency when connected to a load with lousy power factor than if connected to a purely resistive load under similar operating conditions (VA vs. watts). The actual efficiency reduction will depend also on whether the low power factor is due to reactive components (e.g. inductors or capacitors), or due to a non-linear load, such as a switching power supply in a computer, microwave oven, etc. Nonlinear loads present their own issues that I'll skip for now. Let's presume reactive... That said... The majority of the losses in inverters under these conditions would be resistive. Here's why: Inverters made with power transformers have large amounts of copper wire, and consequently, wire resistance. When connected to a load with a poor power factor, transformer-based inverters will not perform as efficiently as they do when connected to a purely resistive load. With a very low power-factor load, you could theoretically be providing the max current from an inverter at much lower real power output than it's rated. This additional loss, when taken into account at an AC power with low real wattage output, will make the inverter's efficiency worse than with a resistive load. Expect the efficiency hit to be on the order of 2-5% for transformer-based inverters (again, depending on inverter's max wattage rating as well, as this will impact the wire size used in its construction, and thus the total wire resistance). Transformerless inverters don't have this large mass of wire (thus much lower internal resistance). Subsequently, they aren't nearly as affected by low-power-factor loads - but even here, I'd expect around 0.5-1% efficiency reduction, all other conditions being equal. Power factor is deceptively simple .. but is one of the more complex aspects of power systems and power equipment design. Hope this helps. Dan Lepinski Sr. Engineer Exeltech P.S. Thanks for being a long-time Exeltech customer. Much appreciated. --- On Mon, 7/25/11, R Ray Walters r...@solarray.com wrote: From: R Ray Walters r...@solarray.com Subject: Re: [RE-wrenches] Efficient step up, down transformers To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Monday, July 25, 2011, 4:10 PM Hi Dan; I agree that a 2000 VA inverter isn't equal to a 2000 watt
Re: [RE-wrenches] Fwd: Car charging station without grid
Hi Allan, Off-grid batteryless EV charging? Perhaps if the EV battery was tapped to keep the off-grid inverter awake, but that would void the vehicle warranty. I'm sure you considered PV into Sunny Islands (or similar) with a small sealed battery into Sunny Boys. I question if a person in SF who wants an off-grid PV system without batteries to charge a battery vehicle is really a customer. Good luck, Joel Davidson - Original Message - From: Allan Sindelar To: RE-wrenches Sent: Thursday, July 14, 2011 1:43 PM Subject: [RE-wrenches] Fwd: Car charging station without grid Wrenches, I'm stumped as to the best approach for a customer who wants a non-grid-tied, batteryless PV-powered EV charging station. See below, from one of our salespeople. Any ideas? Thank you, Allan Original Message Allan: Monday I sit down with an interesting fellow who sounds like a potential good customer (has money and right enviro goals) - in SF. He brought up the idea of discussing a car charging station for future electric car that: 1.. stands alone, no grid connection 2.. no batteries - he pictures his car is home most days - he parks it and when the sun shines it gets charged directly Why that approach? 1.. He is thinking this must be the most efficient conversion, i.e. directly without batteries or line loss of electrons to and from utility 2.. Wants the car to function independent of dirty fuel/dirty electrons 3.. He assumes less equipment; maybe less cost but the cost is not important other than as example for others Issues I see: 1.. All inverters that can produce the high voltage needed need grid power or if off grid need batteries - know of anything stand alone available? 2.. Power or voltage fluctuation as panels see more or less sun; ie hours of day or clouds, etc - what will be the output from inverter? 3.. Without tieing into grid investment in PVs (both his financial and the embodied for manuf.) gets wasted when car fully charged or car not home and sunny. 4.. Is total amps output in peak sun even going to meet the charging requirements? ie takes 10 days to recharge instead of 4 hours - or overly massive system to match rate of charge? Your thoughts? Karlis Allan Sindelar al...@positiveenergysolar.com NABCEP Certified Photovoltaic Installer NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Positive Energy, Inc. 3201 Calle Marie Santa Fe, New Mexico 87507 505 424-1112 www.positiveenergysolar.com -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Fwd: Car charging station without grid
Allan, We also did what Dana suggests (as did many PV and or EV wrenches). For us, the idea morphed into www.solarelectricalvehicles.com Whether PV is on the vehicle or somewhere else, tapping into the vehicle battery bank voids the vehicle warranty. Joel Davidson - Original Message - From: Dana To: al...@positiveenergysolar.com ; 'RE-wrenches' Sent: Thursday, July 14, 2011 3:32 PM Subject: Re: [RE-wrenches] Fwd: Car charging station without grid Hey Allan, We did freestanding golf cart charger direct dc array to charger controller with a direct coupler to the golf cart's battery. Works just like an off grid system. Could you do the same for a car? Bypassing or paralleling the internal controls. Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever believe anything, but seriously trust through action. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Allan Sindelar Sent: Thursday, July 14, 2011 2:43 PM To: RE-wrenches Subject: [RE-wrenches] Fwd: Car charging station without grid Wrenches, I'm stumped as to the best approach for a customer who wants a non-grid-tied, batteryless PV-powered EV charging station. See below, from one of our salespeople. Any ideas? Thank you, Allan -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Dangerous installs/installers..
Wrenches, We've seen solar shutters displayed recently at two trade shows in the Los Angeles area. See http://plugnsaveenergyproducts.com/shutters/ The solar shutters use zip cord and the people at the shows were telling people to just plug the inverter into a wall outlet. I told them that they were violating the NEC and endangering people. They replied that ETL is testing their product and said it will get listed and be put on the CEC eligible module list. We asked how much power a solar shutter produces when mounted inside a window and getting light through the window and frame and if one shutter slat shades cells on the slat below it. They replied that their solar shutter works and seem to sincerely believe in their product. Joel Davidson - Original Message - From: R Ray Walters To: RE-wrenches Sent: Saturday, May 07, 2011 12:34 PM Subject: Re: [RE-wrenches] Dangerous installs/installers.. Even a bad solar installer isn't going to use cut up extension cords; that install was DIY or a knowledgable inebriated neighbor. I lived in the backwoods for many years, and saw even my own work get turned into horror systems. As far as your competitor doing bad work, we had the same problem for years with a guy who was finally run out of Taos by the inspector and a growing list of angry customers. He's now in California doing Wholesale Solar. Your best bet is to turn him in to the AHJ for illegal contracting, along with pics of the work., but make dang sure he really did it. Enough complaints and eventually they'll get him. Luckily much of the system can survive without OCP; the array is current limited and won't pop an OCP anyway, and the house wiring can't actually fry at 2500 watts continuous, so a battery wiring issue will be the most dangerous situation. (batteries on NEC systems are not really protected from the most likely dangers like a wrench being dropped across the terminals) I've rewire dozens of such monsters, and you don't even want to have your fingerprints on it without having approval to completely rewire it. Also, for budget cabin systems like that, we would often just supply parts and a wiring diagram, and let them keep the liability. It can get cost prohibitive and unnecessary to bring the whole system up to NEC 2011, my own beautiful house has 103 yr old Knob tube wiring that is going great. I only added AFCI breakers and replaced all the lights with low current CFs. You have to suspend some of the code junky in you, and proceed with common sense, or don't proceed at all. Definitely not for the faint of heart, Good luck, R. Walters r...@solarray.com Solar Engineer On May 7, 2011, at 11:21 AM, Jesse Dahl wrote: Good point, and I guess I could see work like this from a homeowner, but this is from a energy solutions company in my area. I can fix the problems with the solar, some new parts, some conduit, pull some wire.. I just don't know what to do about this energy solutions guy. Show him why it's wrong, confront him Thanks, Jesse Sent from my iPhone On May 7, 2011, at 11:37 AM, Jason Szumlanski ja...@fafcosolar.com wrote: Yeah – it can be scary. Retrofits/fix-its are the worst, but can be fun and profitable at times. Starting from scratch is usually the answer, reusing components if practical. Word of caution… be careful not to harshly criticize work in front of the customer. Sometimes they claim that “another idiot PV installer” did the system, when in fact it was a DIY installation. You can be matter of fact about the safety hazards and code violations, but I’ve seen the look on a person’s face who obviously did it himself as I tore the system apart. Jason Szumlanski Fafco Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of d...@foxfire-energy.com Sent: Saturday, May 07, 2011 7:58 AM To: RE-wrenches Subject: Re: [RE-wrenches] Dangerous installs/installers.. Welcome to the Rodeo partner.. Dan Brown Foxfire Energy Corp. Renewable Energy Systems (802)-483-2564 www.Foxfire-Energy.com NABCEP #092907-44 Original Message Subject: [RE-wrenches] Dangerous installs/installers.. From: Jesse Dahl dahlso...@gmail.com Date: Sat, May 07, 2011 2:45 am To: RE-wrenches re-wrenches@lists.re-wrenches.org Wrenches, The other day on my travels, I came across a very scary small stand-alone hunting shack install. All the wiring is cut extension cords and some UF, the cable from the charge controller to the batteries is an extension cord with the 14s paralleled. mice chewed wire, splices taped and laid on the ground, mis matched modules (least of the problems). not a disco or OCPD to be seen. Also a 500W wind
Re: [RE-wrenches] commercial system monitoring
Daron Stein Locus Energy LLC 646 395 9913(desk) 646 660 5223 (cell) www.locusenergy.com - Original Message - From: Marco Mangelsdorf To: 'RE-wrenches' Sent: Thursday, June 09, 2011 11:52 AM Subject: [RE-wrenches] commercial system monitoring I'm looking for a bare-bones, cheap (hah!) web-based monitoring system for three-phase systems using either Satcon or PV Powered inverters. I'm having a hard time finding any package (it doesn't have to be bloomin' revenue-grade) under $3,000. Anyone know of anything reputable and lower cost out there? Thanks, marco -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Dangerous installs/installers..
Except for the renewable energy equipment, I saw poor wiring throughout India, soon to be the most populated country in the world. As my Arkansas Ozark mountain neighbor with poor wiring use to say about poverty of the mind, Poor folks have poor ways. I hope you left a wiring diagram of a properly designed system. Joel Davidson - Original Message - From: Jesse Dahl To: RE-wrenches Sent: Friday, May 06, 2011 11:45 PM Subject: [RE-wrenches] Dangerous installs/installers.. Wrenches, The other day on my travels, I came across a very scary small stand-alone hunting shack install. All the wiring is cut extension cords and some UF, the cable from the charge controller to the batteries is an extension cord with the 14s paralleled. mice chewed wire, splices taped and laid on the ground, mis matched modules (least of the problems). not a disco or OCPD to be seen. Also a 500W wind generator 100 yards from the battery bank, feed with #10s and then spliced to #12s (most of it just laying on the ground. Now I think the owner should have some responsibility to stop work when the see things this awful, but what can/should we as an industry do about this? What do we say to people that install stuff like this? Take them to court? A small 2500w with surge of 5000w inverter was used here with 6 paralleled 12V deep cycle batteries. Powering a few lights and a vacuum at first, a well pump was added later. I could see the lights and vacuum, but a pump? How do you go about wiring the output of an inverter like this? From a receptacle on the inverter to what? This guy cut an extension cord off and splice it to some NM and ran it inside to the loads. No breaker, I just can't get over the fact this guy sleeps at night... You should see the photos of this mess... Thank you for your thoughts, Jesse Sent from my iPhone -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Side-by-side microinverter, maximizer, and conventional inverter comparisons
Wrenches, A few years ago, we compared conventional and MPPT charge controllers and found power production improvement in only in unique conditions and rarely over 15%. Now Microinverter and DC maximizer companies are claiming as much as 25% increased electricity production and a booming market. See http://www.interpv.net/market/market_view.asp?idx=401code=401part_code=01 I've been comparing grid-connected microinverters since 1994 when Henk came out with his OK4U and am not impressed in full-sun (no shade) comparisons. In 2005, I compared a side-by-side 200 kW system with two 100 kW Xantrex inverters with a 200 kW system with 74 SMA inverters and saw no difference in kW or kWh. Have any wrenches made side-by-side comparisons? Are the claimed improvements hype or real? Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Battery SG testing (was Battery watering)
Hello Dana, Sounds like you've solved the sore back problem without over- or under-watering cells. I water and check electrolyte level every 2 to 6 months depending on the battery bank's age and use (grid-tie float only, off-grid daily charge/discharge, etc.). I encourage spot-checking specific gravity of about 10% of the cells before each scheduled watering and changing the sampling cells each time. That's only 5 cells of a 48 cell battery. But is that an adequate sampling or am I just rationalizing to avoid a sore back? Joel Davidson - Original Message - From: Dana To: 'RE-wrenches' Sent: Saturday, April 02, 2011 1:06 PM Subject: Re: [RE-wrenches] Battery watering Hey Joel, We have a couple of auto water systems in use that we connect manually and it takes less than 5 minutes to water a triple HUP 1690 amp hour-24vdc bank. Pretty sweet but doing the SG is a bit of a hassle as you have to unscrew each cap. I hear that there are auto water caps that have a port for the extraction of electrolyte for testing, but I have not used or seen this cap. Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever believe anything, but seriously trust through action. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Joel Davidson Sent: Saturday, April 02, 2011 9:59 AM To: RE-wrenches Subject: Re: [RE-wrenches] Battery watering Dana, One of my battery suppliers gave me the same or similar float. He said something like, Here's a sample from one of the watering systems that we sell. It's pretty good, but sometimes the float sticks open and sometimes it sticks closed so I wouldn't turn on the water supply unless I was there to monitor it. He said that his forklift customers schedule 30 minutes for watering - turns the water on before going to lunch and checks to see if the cells are full when he comes back from lunch. Joel Davidson - Original Message - From: Dana To: 'RE-wrenches' Sent: Friday, April 01, 2011 2:37 PM Subject: [RE-wrenches] Battery watering I found Battery Watering Systems ; http://www.batterywatering.com/ Kits and lots of options on parts for battery service. I am getting a new pressure sprayer and ordered a gun that stops when the battery fluid is at a preset level $80, includes a flow meter visual, 20PSI pressure reducer, sprayer handle and auto stop tip. No more sore back from leaning over the battery bank, Yes! Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever believe anything, but seriously trust through action. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery watering
Dana, One of my battery suppliers gave me the same or similar float. He said something like, Here's a sample from one of the watering systems that we sell. It's pretty good, but sometimes the float sticks open and sometimes it sticks closed so I wouldn't turn on the water supply unless I was there to monitor it. He said that his forklift customers schedule 30 minutes for watering - turns the water on before going to lunch and checks to see if the cells are full when he comes back from lunch. Joel Davidson - Original Message - From: Dana To: 'RE-wrenches' Sent: Friday, April 01, 2011 2:37 PM Subject: [RE-wrenches] Battery watering I found Battery Watering Systems ; http://www.batterywatering.com/ Kits and lots of options on parts for battery service. I am getting a new pressure sprayer and ordered a gun that stops when the battery fluid is at a preset level $80, includes a flow meter visual, 20PSI pressure reducer, sprayer handle and auto stop tip. No more sore back from leaning over the battery bank, Yes! Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever believe anything, but seriously trust through action. -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery watering equipment
Forklift battery suppliers and Wrenches told me that automatic watering systems either stick closed (dry cells) or stick opened (flooded battery box). Warehouse operators told me that they operate their so-called automatic watering systems manually. I use an RL Flo-Master 1.5-Gallon Polyethylene-Tank Sprayer from Home Depot for $11. It works great. Model # 1415D. Internet # 100637818. Store SKU # 367767 Joel Davidson - Original Message - From: d...@foxfire-energy.com To: RE-wrenches Sent: Thursday, March 31, 2011 6:22 PM Subject: Re: [RE-wrenches] Battery watering equipment I like using a plant sprayer (a new one), with the end of the wand removed, and a piece of tape for a depth gauge.. and a good head light.. db Dan Brown Foxfire Energy Corp. Renewable Energy Systems (802)-483-2564 www.Foxfire-Energy.com NABCEP #092907-44 Original Message Subject: Re: [RE-wrenches] Battery watering equipment From: jay peltz j...@asis.com Date: Thu, March 31, 2011 7:14 pm To: RE-wrenches re-wrenches@lists.re-wrenches.org Are you talking semi-automatic or manual? jay peltz power On Mar 31, 2011, at 6:01 AM, Dana wrote: I am currently looking for recommendations on battery watering equipment. We have a regular route of clients that want us to perform regular battery checks for SG and VPC and water afterwards, generator oil check and operation, control settings [older Trace and Xantrex equip. w/o non-volatile memories] etc. What has worked for you, who supplies it, would you buy it again? What would you do differently? Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Nabcep Stamp
Greg, I think some states require designers to have a professional engineering license. I know some clients require a licensed engineer with professional liability insurance. You can be rightly proud of your NABCEP certification. It is good that NABCEP supports the practitioner concept and encourages life-long learning, but Bill Brooks is right. What out for slippery slopes. Joel Davidson - Original Message - From: Greg Egan To: re-wrenches@lists.re-wrenches.org Sent: Thursday, March 31, 2011 9:36 AM Subject: [RE-wrenches] Nabcep Stamp Bill Peter, Okay, if I have a PE Stamp that means I went to school and worked under a mentor for an amount of time to qualify for the PE exam. Passed the exam and I got my stamp. If I have NABCEP certification that means I worked installing solar electric systems (in my case) for an amount of time and /or went to school to qualify for the NABCEP exam and passed the test. I'm having a hard time seeing the difference here. If NABCEP provided a stamp to it's members that they could use to stamp drawings all it would show is that someone who passed the NABCEP exam reviewed the design and hung his or her name on the job. I don't see where NABCEP would be responsible for the design anymore than the PE board or whoever is in charge of giving out PE stamps would be culpable in a case of a bad design by a PE. I think NABCEP should provide a stamp with the certificated member's # on it. All it would do is identify them as a NABCEP member. My understanding is that NABCEP was formed to help the general public distinguish between fly by nights and real RE professionals. A stamp would help do that. If the city of xyz decides that they've seen a lot of good work from NABCEP members and that NABCEP certification is good enough for them, what's wrong with that? Greg Egan Remote Power Inc. NABCEP PV Installer -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Value of PV system to a home
Consider not moving or selling your PV powered home. Making your PV powered home your retirement home is a better investment than a savings CD and definitely a hedge against increased grid electricity prices for retired people on a fixed income. Plant some roots and lead your neighborhood by example. Joel Davidson - Original Message - From: Kirpal Khalsa To: RE-wrenches Sent: Tuesday, March 22, 2011 9:33 PM Subject: Re: [RE-wrenches] Value of PV system to a home What I have been putting forth to our customers and potential customers, is that a PV system when looked at like an appliance is simply equal to the value of the energy it produces over a given periodfor straight grid tied systems I have used what I think is a conservative number of 20 years and then I multiply that by today's energy costs...so if a system is installed in Oregon and electricity is $.09/kWh and the system is expected to produce 4500kWh per year then that system would add 4500kWh x $.09 x 20 years = $8100 in value to their property.in Oregon.. Certainly you could add average utility price increases over time to the value of the energy produced, as well as reductions in system output overtime as equipment degrades.additionally if a party is buying a house equipped with a PV system they may not want to calculate a full 20 years into that formula if the system was installed years earlier...I prefer to use conservative numbers in my formula inputs, however the argument could be made stating that the 20 year time span is too short and if the lifetime is potentially double that the value of the system also doubles. In my mind an off grid system can be more directly tied to the cost of the equipment as the grid is not an alternative to the power that is supplied. Finally, we have never had a customer disagree with this basic approach, however it still falls flat on its face if the customer is not planning on moving or selling their property! -- Sunny Regards, Kirpal Khalsa NABCEP Certified Solar PV Installer Renewable Energy Systems www.oregonsolarworks.com 541-218-0201 m 541-592-3958 o On Tue, Mar 22, 2011 at 7:44 PM, Exeltech exelt...@yahoo.com wrote: I spoke last October with the Appraisal Journal, and specifically with Rick Nevin, author of the referenced articles. Mr. Nevin stated a recent review conducted by the Appraisal Journal confirmed the information in the reports is as applicable today as it was when the study was conducted, and even more so given the increased cost of energy that's occurred since the study was published. Dan --- On Tue, 3/22/11, Jamie Johnson jjohn...@spefl.com wrote: From: Jamie Johnson jjohn...@spefl.com Subject: Re: [RE-wrenches] Value of PV system to a home To: Keith Cronin electrich...@yahoo.com, RE-wrenches re-wrenches@lists.re-wrenches.org, Joel Davidson joel.david...@sbcglobal.net Date: Tuesday, March 22, 2011, 5:01 PM Keith Joel, The old metric was $20 in value for each $1 saved in energy, however the Appraisal Institute has not supported that valuation metric for some time now and neither has Fannie, Freddie or FHA. Using the gross sales price that the customer paid for PV as a valuation number was also shot down. And unfortunately most regional MLS databases don't provide a category for solar electric, solar hot water or solar pool heaters, so that makes it difficult for an appraiser to use the sales comparison approach. A year ago I began developing a valuation model for PV for the Appraisal Institutes Educational Committee and they are now incorporating parts of it into their training programs on valuation of sustainable buildings for appraisers. Earlier this year DOE awarded a grant to Sandia Natl Lab to essentially do the same thing for the Solar America Cities program (soon to be the Solar America Communities program) and they have since picked up my work on the valuation model. A proof of concept spreadsheet (which takes all of the fun out of it) and pdf explanation of the valuation model should be released this summer. I will provide the download link to the list when it is available. It's important to note that any valuation model for PV needs to be accepted by Fannie, Freddie and FHA before it is relied on and quoted by the PV industry. There are currently ongoing discussions between FFF, AI and DOE on PV valuations and hopefully they will resolve the PV valuation issues for loan transactions soon. Jamie Johnson NABCEP Certified PV Technical Sales Professional PVTS012911-44 NABCEP Certified Solar PV Installer 031310-118 General Manager SOLAR POWER ELECTRIC
Re: [RE-wrenches] Value of PV system to a home
FHA and some other federally funded housing orgs have hardening of the arteries. Although EnergyStar has some problems too, they do have mortgages that recognize the value of energy efficiency. See http://www.energystar.gov/index.cfm?c=mortgages.energy_efficient_mortgages If anyone doubts the immediate and future value of PV on a home, they can talk to the homeowners and realtors in my neighborhood who live with PV (as compared to PV wannabes with pv envy). Joel Davidson - Original Message - From: North Texas Renewable Energy Inc To: RE-wrenches Sent: Wednesday, March 23, 2011 6:40 AM Subject: [RE-wrenches] Value of PV system to a home While the Appraisal Institute model is about the only widespread reference point available, it too lacks strong credibility due to the perception that it's out dated information and nothing else confirms its conclusion. Many in the anti-RE realm point to the fact that F/FFHA don't support the premise that energy saving has real value and use FF as a valid reason, along with the ...no credible evidence argument, not to. FF are private mortgage investment corporations that are supported with taxpayer money, money that kept them from collapsing under the weight of their own bad mortgage investments. Their dislike of any pro-renewable program [PACE comes instantly to mind] is grounded in their perception that the low risk design that makes PACE so desirable to cities and homeowners is a financial risk to the private investors returns. The logic is: homeowner with PV defaults, taxing authority bonds are exempt from risk, investment banks are left holding the bag, investors lose pennies. Those investors lobbyists pushed back up the chain of authority to, among other things, seriously wound California's own voter approved and taxpayer friendly version of PACE. As usual the taxpayers lost much of the the momentum that had brought them so close to creating another national standard for renewable energy financing without taxpayers having to foot the bill before the investment cartel pulled the rug out from under us. The FHA, being nothing more than a hand-puppet for the mortgage industry, nodded in agreement and brandished their rubber stamp of approval. The factual and irrefutable data proving beyond any doubt that homes businesses with PV are worth more should be an immediate goal for the RE industry. While that proof, if it even exists, might not open the investment floodgates, it would however open more doors for investors which moves our industry a step closer to reaching critical mass. my 2¢ Jim Duncan PV installer financial know-it-all From: Jamie Johnson jjohn...@spefl.com Keith Joel, The old metric was $20 in value for each $1 saved in energy, however the Appraisal Institute has not supported that valuation metric for some time now and neither has Fannie, Freddie or FHA. Using the gross sales price that the customer paid for PV as a valuation number was also shot down. And unfortunately most regional MLS databases don't provide a category for solar electric, solar hot water or solar pool heaters, so that makes it difficult for an appraiser to use the sales comparison approach. A year ago I began developing a valuation model for PV for the Appraisal Institutes Educational Committee and they are now incorporating parts of it into their training programs on valuation of sustainable buildings for appraisers. Earlier this year DOE awarded a grant to Sandia Natl Lab to essentially do the same thing for the Solar America Cities program (soon to be the Solar America Communities program) and they have since picked up my work on the valuation model. A proof of concept spreadsheet (which takes all of the fun out of it) and pdf explanation of the valuation model should be released this summer. I will provide the download link to the list when it is available. It's important to note that any valuation model for PV needs to be accepted by Fannie, Freddie and FHA before it is relied on and quoted by the PV industry. There are currently ongoing discussions between FFF, AI and DOE on PV valuations and hopefully they will resolve the PV valuation issues for loan transactions soon. Jamie Johnson NABCEP Certified PV Technical Sales Professional PVTS012911-44 NABCEP Certified Solar PV Installer 031310-118 General Manager SOLAR POWER ELECTRIC Original Message Subject: [RE-wrenches] Value of PV system to a home From: Keith Cronin electrich...@yahoo.com Date: Tue, March 22, 2011 2:57 am To: RE-Wrenches re-wrenches@lists.re-wrenches.org Hi Was wondering if anyone has any new data points on the additional value
Re: [RE-wrenches] Value of PV system to a home
In general, for every $1/year energy savings add $20 to the home's value. See http://www1.resnet.us/ratings/overview/resources/appraisal/default.htm - Original Message - From: Keith Cronin To: RE-Wrenches Sent: Monday, March 21, 2011 11:57 PM Subject: [RE-wrenches] Value of PV system to a home Hi Was wondering if anyone has any new data points on the additional value a PV system adds to the home? If someone spends $X for a system and saves $Y a month/year, how is this being calculated? Do we have actuaries with enough empirical data to suggest what the numbers would look like? Realizing alot has to do with location, current cost per kWh of electricity etc. Could have swore there were some studies done to imput the value of two homes on the same street, one with solar and one without- for some granular details on the delta in values. Thanks Keith -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Electromagnetic Pulse (EMP)
The subject of EMP comes up from time to time, usually when real catastrophes occur or imagined catastrophes are expected to occur. In the 1960s, the US military thought that an EMP would affect semiconductors so all the electronics at the nuclear missile base where I was stationed had tubes instead of transistors. Meanwhile, the civilian world was going solid-state. Sure, you can harden your equipment, but no one has ever reported a problem with a PV system as the result of an EMP. I'm reminded of a phone call I got in 1984 from a PV customer living in southern Utah who called himself a survivalist. He asked how his solar module would be affected by an EMP from a nuclear blast. I asked him if he planned to watch the end of civilization on his solar powered TV and told him to get a life. Joel Davidson - Original Message - From: Drake To: RE-wrenches Sent: Saturday, March 19, 2011 7:53 AM Subject: [RE-wrenches] Electromagnetic Pulse (EMP) Hello Wrenches, I had an inquiry concerning the effect of EMP on photovoltaic systems. We are heading for a period of solar activity that likely will produce this effect. According to a local AEP (American Electric Power) representative, the utility is spending a lot of money to counter this anticipated problem. Additionally, nuclear related issues are moving back to the front burner. It is clear that the pulse would damage an inverter, but possibly it could be put in a Faraday cage. But a number of questions arise. a.. Would the pulse damage the modules? b.. Could the large currents and voltages induced by EMP damage the conductors in the cells? c.. Even if the inverters were surrounded by a Faraday cage, would induced currents voltages from the modules harm the inverters? a.. Would series fuses and surge protectors be adequate protection. Has any research been done in this area? Does anyone know answers to any of these questions? Thanks, Drake Drake Chamberlin Athens Electric OH License 44810 CO license 3773 NABCEP Certified PV -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Smart Utility meters
Smart meters for whom? Smart meters (toll booths) are just another way for electric utility companies to increase their revenue and stop customer-owned solar power distributed generation. - Original Message - From: Carl Adams To: RE-wrenches Sent: Sunday, March 06, 2011 6:55 PM Subject: Re: [RE-wrenches] Smart Utility meters William, We have run into issues with smart meters. We had a customer in one of the pilot neighborhoods. What we saw was the meter registered his production as consumption. Effectively doubling his consumption per the meter. After some research it was determined that while the new smart meters were indeed net metering capable the software back at the reporting station was not net metering capable. Solution was to install an old dumb meter which was bi_directionally accurate. I hope this helps. Cheers Carl Sunrock Solar LLC On Mar 5, 2011 6:47 PM, William Miller will...@millersolar.com wrote: Friends: Our local utility (PGE) is installing smart meters. These will not apply to interconnected customers because the meter apparently is not capable of two way metering. There has been a lot of controversy about smart meters regarding safety, accuracy and many other issues. Do any of you have any evidence that smart meters are a problem in any regard? Thanks, William Please note new e-mail address and domain: William Miller Miller Solar Voice :805-438-5600 email: will...@millersolar.com http://millersolar.com License No. C-10-773985 -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Smart Utility meters
If on-site generator powers all or part of the load and does not send (wheel) power backwards to the grid, the utility company cannot detect the on-site generator. The kWh consumption reduction will look like you are conserving energy or are on vacation and should not attract their attention. --- On Mon, 3/7/11, William Miller will...@millersolar.com wrote: From: William Miller will...@millersolar.com Subject: Re: [RE-wrenches] Smart Utility meters To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Monday, March 7, 2011, 10:10 AM Joel: It is my understanding that Smart meters will prevent unauthorized (guerilla) grid-tie installations from reducing energy costs. You can still defray your costs as long as you don't try to run the meter backwards. If you do, the amount you sell is accounted for as consumption. Is that your understanding as well? If this is true, Smart meters are not detrimental to approved intertie installations. William Miller At 07:22 AM 3/7/2011, you wrote: Smart meters for whom? Smart meters (toll booths) are just another way for electric utility companies to increase their revenue and stop customer-owned solar power distributed generation. -Inline Attachment Follows- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] NEC 690.11 - Arc Fault Protection ProvisionQuestions ?
A building like a garage or a dwelling for human occupancy? - Original Message - From: Bill Brooks billbroo...@yahoo.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Wednesday, March 02, 2011 11:48 PM Subject: Re: [RE-wrenches] NEC 690.11 - Arc Fault Protection ProvisionQuestions ? Ryan, 690.11 refers to any system that is building mounted--usually roof mounted, but an awning would apply. It is not intended to deal with ground-mounted systems unless the dc conductors penetrated a building. The intension is that any PV system associated with a building where people are located would have this extra safety. Bill. -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Ryan J LeBlanc Sent: Wednesday, March 02, 2011 11:10 PM To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] NEC 690.11 - Arc Fault Protection Provision Questions ? Wrenches, NEC 2011, 690.11 says, PV Systems with DC source Circuits, DC output Circuits, or both, on or penetrating a building...at over 80V... Shall be protected by a listed (DC) arc fault circuit interrupter, PV type, or other system components listed to provide equivalent protection. and then it goes on to say what the arc fault should do. My questions are: 1) What does on mean? On the roof? attached to the wall? Say the array is in a field, with combiner boxes having PV output circuits run underground and stubbed up into the bottom of a DC disconnect mounted to the side of a house. The conduit is strapped to the side of the house on it way up to the bottom of the disconnect switch. Is this on the building? 2) What is a building? Is it a dwelling, small and large commercial buildings? How about an enclosed MW in a box solution in the middle of a MW power plant, is that a building? I like for example that in the 600V max limitation that it specifies 1 or 2 family dwellings, leaving small large commercial buildings opportunity to have 1000V systems. Any clarification from Bill Brooks, Matt Lafferty, David Brearly, or the host of other awesome PV Guru's on the list is extremely appreciated. ~Ryan L ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] module / panel
Cells? Modules? Bell Labs use to call them solar batteries. Call them what you will, but please buy and use them. Nomenclature from micro to macro: Cell Module Panel Sub-array Array Power Field. From Solar Photovoltaic Applications Seminar: Design, Installation and Operation of Small, Stand-Alone Photovoltaic Systems, July 1980, DOE/CS/32522-T1 (with thanks to Jim Fortenberry for his copy when the DOE shut down the PV Division of the Jet Propulsion Laboratory in 1984): A PV array is composed of many subarrays, panels, modules, and cells in various series, parallel, star, and delta combinations. Individual cells are wired together and mounted to produce a module. From UL 1703: 2. Glossary 2.13 Module (Flat-Plate) - The smallest environmentally protected, essentially planar assembly of solar cells and ancillary parts, such as interconnects and terminals, intended to generate dc power under unconcentrated sunlight. The structural (load-carrying) member of a module can either be the top layer (superstrate), or the back layer (substrate), in which: a) The superstrate is the transparent material forming the to (light-facing) outer surface of the module. If load-carrying, this constitutes a structural superstrate. b) The substrate is the material forming the back out surface of a module. If load-carrying, this constitutes a structural substrate. 2.15 Panel (Flat-Plate) - A collection of modules mechanically fastened together, wired, and designed to provide a field-installable unit. Cell/Module/Panel factoids: There are such things as non-solar PV cells and modules. In 1983, a UCLA researcher used a silicon solar cell to measure the contractions (beats) of a heart cell. The heart cell was viewed on a television screen that was connected to a microscope. The solar cell was taped to the TV screen. When the cell contracted, the photons emitted by the TV screen changed causing the solar cell to generate current that was then recorded. In 1993, while at Solec International, I had a customer who used a small custom solar module mounted near the combustion chamber of a natural gas heater. The solar module used the photons emitted by the combusted gas to power the gas flow regulator. In 1994, while at Solar Integrated Technologies, I got the first UL listing for a photovoltaic panel (not module). Joel Davidson - Original Message - From: benn kilburn To: Wrenches Sent: Tuesday, February 08, 2011 2:49 PM Subject: [RE-wrenches] module / panel Wrenchers, Which term do you to describe a single framed unit with either a j-box or two wire leads on the back, module or panel? Which term do you believe to be correct and why? My interpretation is that a single framed unit is a module. Any number of modules attached to a single detached 'rack' is a panel, and a group of panels with the same orientation or mounting location/type is an array. If you agree with my interpretation, what are your thoughts on the widespread use of the term 'panel' to describe a module. thanks, benn DayStar Renewable Energy Inc. b...@daystarsolar.ca 780-906-7807 HAVE A SUNNY DAY -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] PV encapsulation qualities
Conrad, Your concern about encapsulation is justified but not just for Chinese products. EVA and Tedlar are relatively standard throughout the world. My concern is less about the source or the materials and more about process time and temperature which are critical in the encapsulation process. In an effort to be better-faster-cheaper or to differentiate themselves from the pack, some manufacturers are using other encapsulants. This is not bad. While it is true that not all change is for the better, nothing gets better without change. Your choices are clear: buy tried-and-true technology from well-established companies and hope that they continue to practice good quality control and/or take the risk and buy innovative technology. I do both with open eyes and an open mind and have rarely been burned. Joel Davidson - Original Message - From: Conrad Geyser conr...@cape.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Friday, February 04, 2011 8:33 AM Subject: [RE-wrenches] PV encapsulation qualities Esteemed wrenches, As the Chinese invasion continues, I imagine that most of us will end up using products made in China at some point. Most of my experience and knowledge has indicated the Chinese modules are by and large going to be of comparable quality to any other crystalline silicon module. The one aspect that I haven't seen much information on is the encapsulation. Anyone up on their Tedlar Tedlar substitutes? All the Tedlar that I've known from 80's exterior pipe insulation has truly been amazingly durable stuff even in direct sunlight. The stuff typically is still holding up 30 years later. But now I've been stymied by trying to get backing and encapsulation information out of manufacturers no matter where they are. I am very nervous that less expensive substitution will lead to premature failure of backing or other encapsulation points. I've seen too many plastics undergo breakdown with age to not be nervous. My concern for a early February day... Conrad Cotuit Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Multi-MW PV Maintenance
Hello Wrenches, I have experience performing periodic inspection, maintenance, and cleaning of roof-mounted arrays up to 500 kW and smaller ground-mounted arrays, but no experience maintaining and cleaning multi-MW ground-mounted arrays. Any experiences you can share would be appreciated. Does someone have a written procedure? I would think that first, a review of past performance and any troubles and repairs would be in order. Then walking or using a slow-moving vehicle like an open golf cart going up and down the rows would be a good way to make a preliminary inspection. Stopping and spot-checking fasteners, wiring, and connections would be required. Opening up and inspecting cabinets and equipment enclosures would be needed. Then using a mobile sprayer to clean the subarrays while keeping radio contact with someone monitoring the array for current and voltage fluctuations (sort of megging for faults). What do you think? Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Roofers installing solar = creative, new installation methods
Guys, You're missing a business opportunity. Instead of complaining about roofers' bad work and competition, show the company owners photos of their screw-ups and your quality work. Tell him that he is a risk. Then offer to do their design and electrical installation (let them do the sales, roofing, and grunt work). Joel Davidson - Original Message - From: Warren Lauzon To: RE-wrenches Sent: Friday, January 28, 2011 3:35 AM Subject: Re: [RE-wrenches] Roofers installing solar = creative,new installation methods We have seen a lot of the roofing companies nibbling around the edges of solar installs lately. I have only seen a couple of installs personally, and they were far from what I would call professional or reliable. Not quite as bad as your example, but in one case they had used Romex to run the wiring down to the inverter, and not in conduit. From: Nick Soleil Sent: Thursday, January 27, 2011 8:11 PM To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] Roofers installing solar = creative,new installation methods Hi wrenches: Have you noticed that roofing companies have recently been trying to sell solar? One company thought of something that I had never considered. Listen to this neat story. I was servicing a job today, where a roofing company recently removed and re-installed a PV array on a 12 degree sloped roof. The funny thing is that the roofer didn't want to penetrate his new roof, so he and the customer decided to leave the panels sitting on the composition roof without any attachments to the structure. They didn't think it was necessary! Shortly afterward, the array slid down the roof, and a MultiContact connector came unplugged. The customer noticed that his system was not operating, and called us to the site. Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax: 707-769-9037 -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org Northern Arizona Wind Sun - Electricity from the sun since 1979 Online Solar Store Free Solar Discussion Forum -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Roofers installing solar = creative, new installation methods
Andrew, Carter era contractors did not kneecap alternative energy industry in the 1970s, but that's not a wrenches subject. Sure, everyone has stories about bad customers, GCs, subs, equipment, etc. Some of us are honest enough to admit that we have made a mistake or two. You don't have to work for or with people you don't like or buy equipment you don't like. But I don't know anyone in the building or energy industry who does not work with others. Few contractors nowadays do all the trades in-house. Do you sub out structural engineering, surveying, roofing, arborist, concrete cutting, crane, etc.? Then what's wrong with you being a sub if you like the other guy's work and can control design and electrical installation or whatever you need to control? There are plenty of decent contractors in your service area who would like to have a good go-to PV company just as you like to have good go-to roofer. You know your design and electrical costs and what margin you need for that portion of your work. So what's the hassle? Joel Davidson - Original Message - From: Solar Energy Solutions To: RE-wrenches Sent: Friday, January 28, 2011 8:41 AM Subject: Re: [RE-wrenches] Roofers installing solar = creative,new installation methods Joel, Our company cannot survive without selling an entire system. When we help the unqualified and untrained we legitimize unsubstantiated pv businesses. We get a dozen phone calls a month from folks wanting us to install their systems. It is a rat hole and we have learned that not only are such ventures unprofitable, they are fraught with poor designs and a plethora of other hassles. This whole thing reminds me of the Carter solar Gold Rush where, sure, a bunch of systems were installed, but look at the damage it did to the industry. Respectfully, Andrew Koyaanisqatsi President Solar Energy Solutions, Inc. Since 1987, Moving Portland and Beyond to an Environmentally Sustainable Future. 503-238-4502 www.solarenergyoregon.com Better one's House too little one day than too big all the Year after. --- On Fri, 1/28/11, Joel Davidson joel.david...@sbcglobal.net wrote: From: Joel Davidson joel.david...@sbcglobal.net Subject: Re: [RE-wrenches] Roofers installing solar = creative, new installation methods To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Friday, January 28, 2011, 7:06 AM Guys, You're missing a business opportunity. Instead of complaining about roofers' bad work and competition, show the company owners photos of their screw-ups and your quality work. Tell him that he is a risk. Then offer to do their design and electrical installation (let them do the sales, roofing, and grunt work). Joel Davidson - Original Message - From: Warren Lauzon To: RE-wrenches Sent: Friday, January 28, 2011 3:35 AM Subject: Re: [RE-wrenches] Roofers installing solar = creative,new installation methods We have seen a lot of the roofing companies nibbling around the edges of solar installs lately. I have only seen a couple of installs personally, and they were far from what I would call professional or reliable. Not quite as bad as your example, but in one case they had used Romex to run the wiring down to the inverter, and not in conduit. From: Nick Soleil Sent: Thursday, January 27, 2011 8:11 PM To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] Roofers installing solar = creative,new installation methods Hi wrenches: Have you noticed that roofing companies have recently been trying to sell solar? One company thought of something that I had never considered. Listen to this neat story. I was servicing a job today, where a roofing company recently removed and re-installed a PV array on a 12 degree sloped roof. The funny thing is that the roofer didn't want to penetrate his new roof, so he and the customer decided to leave the panels sitting on the composition roof without any attachments to the structure. They didn't think it was necessary! Shortly afterward, the array slid down the roof, and a MultiContact connector came unplugged. The customer noticed that his system was not operating, and called us to the site. Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax: 707-769-9037 ___ List sponsored
Re: [RE-wrenches] Low grid voltage fix
Dan, Thank you for the quick reply. I have been using the 108 VAC default setting since 1998. I'll try 95 VAC. It is interesting to hear other wrenches comment on utility low and high voltage. Power factor control is another challenge for some utility companies. On the other hand, they hold the RE industry to very tight power quality standards. I have tried to get Los Angeles Department of Water Power (LADWP) and Southern California Edison (SCE) to keep their voltage within spec and improve their power factor. Their responses are similar to asking City Hall to fix potholes in the road. Sometimes they do. Sometimes they don't get a round tuit for a while. SCE power is generally ok except in old neighborhoods with wires and transformers over 40 years old. Forget about LADWP. They are off on another planet. The smaller municipal utilities in southern California are pretty good at managing power quality. Fortunately, today's inverters can be adjusted manually. Perhaps some day inverters and loads will self-compensate for less than stellar grid power quality. Happy Holidays! Joel Davidson - Original Message - From: d...@foxfire-energy.com To: RE-wrenches Sent: Sunday, December 19, 2010 2:54 PM Subject: Re: [RE-wrenches] Low grid voltage fix Try menu 11.. Ac input. Dan Brown Foxfire Energy Corp. Renewable Energy Systems (802)-483-2564 www.Foxfire-Energy.com NABCEP #092907-44 Original Message Subject: [RE-wrenches] Low grid voltage fix From: Joel Davidson joel.david...@sbcglobal.net Date: Sun, December 19, 2010 12:24 pm To: RE-wrenches re-wrenches@lists.re-wrenches.org Wrenches, It's Christmas time again in Southern California Edison (SCE) territory which means low insolation and high regional electric consumption. Every night SCE voltage drops to around 105 VAC or lower. Our grid-tie SW4048 inverter sees SCE's low voltage as a brownout and switches to autonomous mode which is normal. However, we have only 4 kWh of battery storage so the combination of nightly brownouts and a series of cloudy days eventually depletes our battery bank causing the inverter to do a low-voltage shut down which is normal. Power goes off in our home and we have to switch over to SCE power, reset the inverter, and wait until the battery bank is recharged. How do we set the SW4048 to accept as low as 100 VAC from the grid before switching to autonomous mode? Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
Here's a true story about another foolish but lucky guy. My Arkansas Ozark Mountain neighbor had a big 115 VDC windcharger and a battery bank of large 2-volt cells inside a shed at the base of his 85 feet tower. One day he opened the door with a smoke in his mouth. The H2 (not the batteries) exploded, rocketing him out the door, and knocking him on his ass. He was a big, strong guy and didn't get hurt, but he swore he would never smoke around batteries again. (Preventive action - ventilate battery room before entering.) - Original Message - From: Luke Christy To: re-wrenches@lists.re-wrenches.org Sent: Thursday, December 16, 2010 7:52 AM Subject: Re: [RE-wrenches] Battery based hydrogen incidents These descriptions of battery explosions certainly drive home the point that one should always always wear protective gear when working on batteries. I have a story that may take the prize for the most foolish behavior yet described (thankfully I wasn't involved until the cleanup stage). In 2008 a neighbor of mine was filling a bank of 12 L-16s installed in a remote home here in So. Colorado. Apparently it didn't occur to him that it probably wasn't a good idea to smoke while adding water to gassing batteries. Two or three batteries into the job, sure enough, a spark fell off his lit cigarette, probably landed in or near the open cap of the cell he was filling, and the resulting explosion blew the top off of the L-16, also spraying electrolyte everywhere in the battery room. My neighbor (who shall remain nameless) was not wearing protective gear of any kind, and of course he had acid in his eyes and all over his face. He was alone at this house, 40+ miles from the nearest town, and close to ten miles from the closest neighbor. He managed to wash his eyes and face in a creek, and was somehow able to drive the ten miles to the neighbor's house, who then took him to a hospital. Amazingly, he came out of it without permanent eye damage or scarring, but that must be due to having had more than his share of luck that day. I had the job of cleaning up the mess and replacing the blown-up battery. One thing that stood out was the fact that the top of the battery disintegrated into dozens of very sharp shards of plastic. These were obviously thrown out with the explosion and could have easily caused serious injury themselves. The entire wall of the battery room was covered with tiny bits of plastic, plate particles, and electrolyte, almost making a cartoon-like outline of my neighbor, as he had been standing in front of the wall when the battery blew. Always wear your eye protection. (and it seems that smoking plus hydrogen equals bad things). Luke Christy NABCEP Certified PV Installer™: Certification #031409-25 (Luke Christy) CoSEIA Certified PV Installer (Luke Christy) Solar Gain Services, LLC Monte Vista, CO. sgsrenewab...@gmail.com -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
I have sold thousands of off-grid PV systems and hundreds of on-grid PV systems with batteries. In 1984, one customer located 30 miles north of New Orleans with an off-grid PV system and T-105 batteries reported that a battery exploded. The cause was a clogged cell cap vent that trapped H2 that was ignited by transient current from a nearby lightning strike (that also destroyed his charge controller). About 6 months later another nearby lightning strike fried another controller. The PV array was a few hundred feet from the home. The owner wired the PV array and home equipment ground rods together and made sure that cap vent holes were kept clean. Subsequent lightning storms caused no problems. The only exploded battery that I actually saw was also in the 1980s at a Sears service station. An automobile battery had exploded and tore a hole in the car engine hood. Joel Davidson - Original Message - From: Dana To: 'RE-wrenches' Sent: Wednesday, December 15, 2010 8:10 AM Subject: [RE-wrenches] Battery based hydrogen incidents Ken - To meet the flow have run 2 and 3 fans to meet the flow. 2 output from the fan into a 4 header with a matching 2.5 inlet as far away on the lowest portion of the battery box. In 22+ years in off grid installations I have yet to see or even hear of one hydrogen explosion. I get repeatedly asked why we have to go to the efforts we go to for box and venting. I am not able to provide even one incident that I have heard rumor of. Q - How many battery based hydrogen incidents have happened in our collective experience? Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever belive anything, but seriously trust through action. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Tuesday, December 14, 2010 12:07 PM To: Wrenches Subject: [RE-wrenches] Battery Venting Fellow Wrenches, The discussion about battery venting reminds me of a useful and inexpensive program, BattMV, for determining ventilation requirements per EN-50272. EN-50272 is a European standard used to determine how much air flow is needed for a room, I don't know of a equivalent standard used in the U.S. It takes a surprising amount of ventilation. For a 400-AH 48-volt L16 bank charged at 57.6 volts and 24 amps, it's about 7 CFM just to keep the %H2 down to 4%. A 12-volt Zephyr vent is good for about 5 CFM! If you think you are venting enough, take some time and study this issue. Kent Osterberg Blue Mountain Solar -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] To insulate a battery bank -- sort of
First of all, there is no one solution to battery selection, installation, operation, and maintenance. One size does not fit all. Allan and other wrenches with lots of battery experience have a good understanding about batteries in their regions for their customers. Second, insulation is used to control temperature change. Insulation slows both heat loss and gain. Large battery banks tend to change temperature slowly due to their mass and may not need insulation in your region or in a specific installation. The goal is to keep the battery bank at its optimum temperature. Cold batteries have reduced capacity. 40 F (4.4 C) is too cold for almost all RE system batteries. Hot batteries have shorter lives. Heat affects both battery chemistry and materials. For example, the plastic around Absolyte terminals cracks if their temperature is repeatedly 90 F (32.2 C) which can happen in an uninsulated battery area in the southwest U.S. So too hot or too cold is not good. Third, batteries need ventilation to safely remove hydrogen. Surprisingly, what most people consider a small amount of battery ventilation will suffice unless the battery bank is being charged excessively. For example, a PV system with eight 100 watt modules (rated 17.1 V, 5.88 A) and sixteen 6-volt batteries is wired for 24 volts DC. The required venting is 0.0135 x (5.88 x 4) x 12 = 3.81 CFM or 228.6 cubic feet per hour. Many, if not most, rooms are 8 feet in height with 2 air changes per hour. A room 8’ x 6’ x 6’ has 288 cubic feet volume and naturally vents 576 cubic feet per hour, almost 2.5 times the required 288.6 cubic feet per hour. In general, a battery area, room, box, etc. should be kept at 70 F (21.1 C), have good ventilation, no open flames (heater, gas water heater nearby?), no electrical sparks (automatic igniters, etc.?), easy to maintain and inspect, tidy, out of reach of non-authorized personnel, and have an up-to-date fire extinguisher handy. Batteries operate by electro-chemical process almost like living things. If they are too hot or too cold, they perform poorly and can die. If they are not fed properly (charged correctly), they will die. Interestingly, we use expressions like die and end of life to describe these non-living things. Most wrenches know people who party all weekend, don't eat well, forget to dress properly for the weather, and get sick. Likewise, if a battery bank is deeply discharged, not properly recharged, and too hot or too cold, it will perform poorly and die prematurely. You get the picture. Lastly, we have learned a lot about batteries in the 200 year since physicist, Allessandro Volta, developed the first cells. Unfortunately, a lot of battery myths exist. Explode myths (but not batteries) by asking the 5 whys. See http://en.wikipedia.org/wiki/5_Whys Joel Davidson - Original Message - From: d...@foxfire-energy.com To: RE-wrenches Sent: Saturday, December 11, 2010 5:32 PM Subject: Re: [RE-wrenches] To insulate a battery bank -- sort of Ok, I'm a little reluctant to kick this critter much.. because I feel like I must be missing something here... but let me float this notion.. If we stuff flammable gas producing batteries in an enclosure (and proceed to button them up tighter than a bull's ass in fly season -- fan or no fan), Haven't we just created a Class I Division 1 location? (NEC 500.5). then say we do rely on a $4. fan (OK -- $15.) to declassify as allowed in 500.5(A)fpn, Wouldn't we still have a Class I Division 2 location? NEC 500.5(B)(2)(2)/(3). So my point is -- are fully enclosed battery boxes really worth the hassle? are they even A good idea? I can't seem to find where NFPA 70 Requires a battery enclosure.. 690 VIII says you need to protect electrical connections (in dwellings) and kicks you back to 480, but makes no mention of requiring a battery enclosure.. 480.8 says basically that if you use racks or trays, they've got to hold up. 480.9 outlines ventilation and working space, but again doesn't require enclosures. (480.6 deals with Insulation of batteries.. But I'm thinking they're talking about electrical insulation)... But nowhere in the NEC have I found any mention of battery boxes or Enclosures being Required.. On the contrary, Seems to me they're suggesting that if by design you can provide for proper work space, adequate ventilation (both out and in) and protect the electrical connections, you're good as far as NEC is concerned.. In NFPA 70E, (Workplace Safety) 320.4 says batteries should be under lock and key (or require a tool for access), and that they be protected both physically and electrically. also in NFPA 70E, 320.6 kicks around enclosure requirements some, but seems to focus more on protecting terminals and related equipment.. Now in OSHA 1926 (Subpart K), .441 seems to be where required enclosures originates, but again, it seems to be referring to commercial workplace safety
Re: [RE-wrenches] To insulate a battery bank DEPENDS on a lot offactors.
Insuating batteries does not have to be complicated. Several years ago, a Minnesota man (can't recall his name) who worked for the Jacobs brothers at their Wind Electric Company in the 1930's told me how he insulated his glass case Edison cells. He kept his battery bank outdoors on boards and covered with a tarp. Before the first snow, he would heap a big pile of loose hay on the tarp and then cover the whole hay pile and batteries with another tarp. Between winter storms he would lift the tarps and hay to check his batteries and add water if needed. He said he stored his potatoes and other root crops that didn't fit in his root cellar the same way. He and other old-timer in Massachusetts who also had Edison cells told me that they would dump out the electrolyte every 5 years and clean the jars and plates with plain water and add fresh electrolyte. The gentleman in Massachusetts bought his batteries from Mr. Edison in 1935 and was still using them in the early 1980s when he bought Arco ASI 16-2000 modules. Sensible people. Simpler times. Joel Davidson - Original Message - From: Dana To: 'RE-wrenches' Sent: Sunday, December 12, 2010 3:13 PM Subject: [RE-wrenches] To insulate a battery bank DEPENDS on a lot offactors. Great discussion and Thanks to all of you for the input. I thought of attempting a wrap up of the various presentations but there are and always will be many variables in battery storage and insulation requirements. Here are my thoughts and a distillation from you all with respect to my high elevation climate in W. CO. - 6 months of winter and cool nights in summer [typically]. Type of battery - Wet VS. Sealed batteries. : depends on size and usage of system and client choice. Climates – 4 season with 5-6 months of winter like conditions VS. a mild year round costal climate. : A long winter climate can seriously chill a poorly insulated bank and therefore reduce capacity when the bank get cold. I get more calls each Nov. from new to off grid folks with an under sized array and cold battery bank about reduced capacity. Does it cool off at night in the summer? VS. It is hot 24/7 for 4 months? Size of bank – Small VS. Large. : Smaller reacts more quickly to a cooling or heating trend VS. Larger react slowly. Ambient building temperature. – heated building VS. walled in shed/free standing battery box in a snowy scenario. : If I can put the bank on a temperature controlled radiant concrete slab I do so. Ability to sink the battery bank into the ground VS. not being able to do so. : installation cost can be a challenge here. Powered venting VS. convective venting ; Powered with a back draft damper seems to be a better option in winter climates. I have used the Zephyr Industries powered vent with backdraft damper for many years with great success. As mentioned batteries are an electrochemical unit that requires, like us, a narrow window for temperature to exist and operate efficiently. When working hardest, typically during winter, the recharge requirements are high and the hours of sunlight are low, therefore the temperature window is best on the warmer end of the range. The time of year when power requirement can be lowest in summer, the usage is lower due to long days and lack of heating systems drawing them down over night, unless you are irrigating and perhaps a PV direct design would then be best. Thanks all. Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever belive anything, but seriously trust through action. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Joel Davidson Sent: Sunday, December 12, 2010 11:59 AM To: RE-wrenches Subject: Re: [RE-wrenches] To insulate a battery bank -- sort of First of all, there is no one solution to battery selection, installation, operation, and maintenance. One size does not fit all. Allan and other wrenches with lots of battery experience have a good understanding about batteries in their regions for their customers. Second, insulation is used to control temperature change. Insulation slows both heat loss and gain. Large battery banks tend to change temperature slowly due to their mass and may not need insulation in your region or in a specific installation. The goal is to keep the battery bank at its optimum temperature. Cold batteries have reduced capacity. 40 F (4.4 C) is too cold for almost all RE system batteries. Hot batteries have shorter lives. Heat affects both battery chemistry and materials. For example, the plastic around Absolyte terminals cracks if their temperature is repeatedly 90 F (32.2 C) which
[RE-wrenches] Internet-based monitoring
Hello Wrenches, The subject of PV system monitoring has been discussed before, but I want to get your latest recommendations. I have over 50 commercial PV systems in several states that I want to monitor on computers both at the site and at one central location. Some sites have more than one PV system. What internet-based PV monitoring system for multiple commercial PV systems have you found to be reliable, provides useful information for identifying problems and trouble-shooting, and is reasonably priced? What other attributes should I be looking for? And what should I avoid? Thanks in advance for your practical and sage advice. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Megger for array testing
Perhaps someone has an electronic copy of Field Wet Resistance Test revised 7/18/94 that was developed by the PVUSA Project, PGE, and Bechtel that they could share with the group. Joel Davidson - Original Message - From: Matt Lafferty To: 'RE-wrenches' Sent: Wednesday, November 17, 2010 6:29 PM Subject: Re: [RE-wrenches] Megger for array testing Hi Drake, Disclaimer #1: i do not recommend megger-testing an array (or module or string) unless you have an approved procedure from the module manufacturer for the installed configuration. Disclaimer #2: i am not the foremost authority on the list for this topic... Mr. Brooks? (Note: Bill's post just came in, but i want to share this anyway) i have, however, conducted these tests, as part of the commissioning requirements, on about a dozen systems which were installed under RD grants. Back in the day, pretty much all systems bigger than 4 or 5 kilowatts were required to be megger tested, if they were on the radar in any way. This was a function of the fact that public dollars were being spent in the HOPE that PV could some day become a mainstream technology. And the fact that PV modules were so expensive. The combination of these factors meant that, in any meaningful sense, only projects that received subsidies were built, and grant requirements were in play. One of the conditions was that these tests be performed. This is a logical requirement in many ways. Each system, that i've done this on, was different from the others. In each case, the procedure and analysis methodology was different. Sufficiently different, that i learned early on to NOT MAKE UP MY OWN PROCEDURE. Manufacturer procedures varied in lead placement, array sections to be tested, surface wetting techniques, test voltages, temperature compensation, and Pass/Fail values. i've made up lots of procedures over the years, but i'm not touching this one. I don't understand it well enough. The basic theme and theory was the same, pretty much across the board. But the actual methods... The steps... They were different. The very limited information i was able to extract from manufacturers' engineers varied. Some warned about reverse-biasing diodes and others didn't think it was a concern. Some insisted that test-lead arrangement was super-critical and others didn't. Some wanted to test at voltages lower than the system voltage and others said 1kV was fine on a 500V circuit. Some wanted to connect one pole to ground. Most didn't. Applying test voltages to, and measuring the resistance of, an installed, illuminated source circuit or array, is very different than applying test voltages to, and measuring resistance of, a single, unilluminated and shorted module. Myriad additonal factors and considerations must be accounted for. My observation is that at least half of the manufacturers' engineers were only guessing, and crossing their fingers that everything would be fine after performing megger testing on a source circuit or array. Another observation is that at least half of these engineers had never contemplated megger-testing an array as a completed system... Only as a single module within the hi-pot test regime for manufacturing and listing purposes. As a group, they all were resistant to provide a documented procedure and acceptable test values. None, as in Z-E-R-O, were able to predict actual test results with any reasonable degree of accuracy. As in, off by megohms in many cases. Even though the subjects under test were designed, and largely manufactured, by their companies. Even though these guys were responsible for the actual system design, in most cases. Even though my experience leads me to believe these guys are at least half full of crap, i do believe this test is valid and has merit. i believe that all arrays should be tested for their dielectric resistance during the commissioning process, in fact. If we are going to megger our field-installed conductors... And we absolutely should be... It's a simple step. In order to do this, as an industry, we just need a better understanding of the characteristics and test procedures. My requests that manufacturers publish a procedure for each module they make, with acceptable test results in common circuit configurations, have resulted in squat. Going forward, i hope somebody forces them to do it, 'cause they ain't likely to bother otherwise. Under controlled conditions, such as those found during module manufacturing, predicting a test result within a reasonable degree of accuracy has a much higher chance for success than a prediction under uncontrolled conditions in a multi-subject combination. I get that. Nevertheless, we are deploying these products into an installed configuration. There is shipping to the distributor. Shipping to the installer. Shipping to the jobsite. Unpacking and handling. Getting it to the roof. Bolting it down. Wiring
Re: [RE-wrenches] Forklift battery life
William, What is the size of your forklift battery and what is the 24-hour self-discharge rate? - Original Message - From: William Korthof wkort...@gmail.com To: re-wrenches@lists.re-wrenches.org Sent: Saturday, October 30, 2010 7:52 PM Subject: Re: [RE-wrenches] RE-wrenches Digest, Vol 3, Issue 600 The batteries in my forklift are from the early 90's and continue to perform, despite regular abuse and irregular care. I'll second the comment about the economy of golf cart batteries... They are great for situations where they can be made to fit. They've worked well for me in all sorts of applications, and even when they actually fail due to abuse or application misfit, the remedy is not much of a hardship. But you do need to remember that they are commodity traction batteries, not heavy duty solar float or cycling batteries... /wk On Oct 30, 2010, at 10:35 AM, re-wrenches-requ...@lists.re-wrenches.org wrote: Send RE-wrenches mailing list submissions to re-wrenches@lists.re-wrenches.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org or, via email, send a message with subject or body 'help' to re-wrenches-requ...@lists.re-wrenches.org You can reach the person managing the list at re-wrenches-ow...@lists.re-wrenches.org When replying, please edit your Subject line so it is more specific than Re: Contents of RE-wrenches digest... When responding to posts within the Digest, be sure to restore the Subject: line to the original, and please edit out any extraneous lines from the quoted message. Today's Topics: 1. Re: Are Thick Plate Batteries Worth the Price? (Dave Palumbo) -- Message: 1 Date: Fri, 29 Oct 2010 22:57:43 -0400 From: Dave Palumbo d...@independentpowerllc.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] Are Thick Plate Batteries Worth the Price? Message-ID: 051901cb77de$42a97d00$c7fc77...@com Content-Type: text/plain; charset=us-ascii All, I've worked with most battery types in 23 years in the trade. There are no easy answers here. We see the unusual T-105 battery bank go 12 years. Conversely we have seen people blow through L-16's in 3 years. I personally have some gigantic (Hoppecke LA's 330lbs each cell) 2v cells in my shop system that are 16 years old and show no signs of decline. They are German made and brought in special to make good on a failed fibered NICAD battery we sold for Hoppecke in the early 90's (that was not a pleasant experience, I would not do it again, even for a free 20 year+ battery bank as a make-up gift). Also, I wouldn't want to actually buy these large 2v cells. If you can trust the life cycle, depth of discharge, charts from the manufacturer and calculate a simple best value for the dollar, than you've done your job. Then it's up to a good system sizing design, good metering and great user care. Our number one rule is fully charge every ten days (at least). If you do this, you avoid sulfation, the number one culprit in early battery demise. For a small system the T-105's typically are the best value. In larger system's there are more choices. A string, or two, of 2v cells can be an excellent choice depending on the price/value ratio. Medium size systems will normally call for Surrette/Rolls 6v, or Trojan L-16 batteries. All for off grid applications. Sealed batteries for battery backup grid tied. Dave Palumbo Independent Power LLC Offices in Lamoille and Champlain Valley, Vermont www.independentpowerllc.com NABCEP Certified PV Installer Vermont Solar Partner 802.888.7194 From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of jay peltz Sent: Friday, October 29, 2010 8:52 PM To: RE-wrenches Subject: Re: [RE-wrenches] Are Thick Plate Batteries Worth the Price? HI Nick, I gotta ask have you ever seen a battery last 25 years that wasn't in float and had to do some work, or even 15 years? jay peltz power On Oct 29, 2010, at 5:17 PM, Nick Soleil wrote: You generally pay for what you get. The industrial 2V cells generally cost more, but will last a lot longer (up to 25 yrs.) I think it depends on the customer's budget, and the long term plans for the property. Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax: 707-769-9037 -- next part -- An HTML attachment was scrubbed... URL: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20101029/ac82880a/attachment.html -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings:
Re: [RE-wrenches] The perfect solar ready roof
Roof construction knowledge and roofing experience is essential if you are a solar designer and installer. You or people you work with must with have roof experience. If you do not have an experienced roofer in your organization, then you must work closely with an experienced roofing subcontractor (unless you like getting angry phone calls when it is raining). Framing and roofing a standing seam metal roof is not difficult. There is no need to guess or to ask inexperienced people what they think should be done. Good suppliers will provide specifications, instructions, and drawings and put you in touch with experts who can answer your questions. In 1996, I did the Unisolar standing seam roof at the University of California Irvine campus. See http://www.hamcontact.com/unisolar/roofapps.html All we had was to start with was a 2nd floor deck and a contract with Southern California Edison (SCE) and the DOE UPVG (Utility Photovoltaic Group now called SEPA) who cost-shared the 5 kW new roof BIPV system. Unisolar provided standing seam metal roofing installation instructions but knew very little about roofing. I talked with McElroy, the manufacturer of the roofing Unisolar used for their SSR product. I also visited metal roofing jobsites during construction to see if anything new had been developed since I last did a metal roof a few years before. Then I designed the framing, building attachments, and the PV system and got SCE and Campus approval. I was concerned about my attachments to the roof deck knee-wall so I asked for the building structural drawings and really lucked out. The engineer who had designed the building still worked at his nearby office part-time even though he was 85 years old. (This old-timer still came to his office in a suit and tie to share his over 50 years of knowledge, experience, and wisdom. I love working in the construction industry.) He and I spent 15 minutes reviewing my design and he gave it his blessing. When I designed the solar roof, the University's Combustion Engineering Lab Director said that he might want to someday enclose the roof deck so we put in metal diagonal straps under the roof panels to brace the roof. The engineer said this was a good idea because it strengthened the roof in case of earthquakes. The construction went smoothly. We fastened the ledger and post attachments with lag bolts and attached the posts, beams and purlins. The SSR panels were laminated at the Unisolar factory and shipped from Troy, Michigan (a waste of time and money). When we started fastening the standing seam panels, I had to ask the University lab engineers to turn off the experimental natural gas fuel cell they were testing on the deck because the rising heat was cooking us on the roof like grilled hotdogs. We fastened clips 6 inches from panel ends and also every 12 inches using self-taping stainless steel screws (over-kill but it went fast). The slowest work was lapping the 12-feet panels over the 18-feet panels because each panel's standing seam had to be notched with a sidecutter and fit into place. The electrical work was conventional. The homerun in conduit went into the building to a Trace SWODE SW5548 that back-feeds to a 120 VAC breaker in a subpanel. A few years ago, I was on campus so I dropped by to inspect the system. The deck was enclosed and the space turned into offices and the Trace inverter was still working like new. Joel Davidson - Original Message - From: North Texas Renewable Energy Inc To: RE-wrenches Sent: Friday, October 22, 2010 7:47 AM Subject: Re: [RE-wrenches] The perfect solar ready roof Phil hits the nail on the head, it sounds like we've both been down this road. Problem is it's not always as simple as asking the roofers to do their job your way when you are not signing their paycheck. I contracted a metal roof PV installation a few years back but only got the job on the condition, by the very fastidious homeowner, that I could verify that the installation won't cause leaks or void the warranty on the 2 year old roof. He gave me the roofers name and the roofing product and mfgr. I researched the manufacturers installation requirements for our inland climate. Then I called the roofer and asked if the 16 wide panels were installed per the mfgrs specs. He proceeded to go ballistic, telling me that if I put one module on 'his' roof he would void the warranty. Even after sending him links to the S5 engineering test results he refused to even talk to me. Finally the customer had to have a long talk with the guy before he was convinced his roof had been installed correctly. Bottom line you cannot ever be certain about the quality of the installation by someone else. Besides, the homeowners insurance company will have the last word on whether a PV mounted roof, found across the street after a windstorm, was installed right or not. CYA Jim Duncan -Original
[RE-wrenches] Need 12 each 200-watt PV laminates
Wrenches, I need 12 each 200-watt or higher output PV laminates (no frames). Please contact me off-list if you know a source. Thanks in advance. Best regards, Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] AC voltage in North America
Hello Darryl, I tip my hat in honor to your many years working with electricity. 110 volts was Edison's choice for direct current. Then Tesla/Westinghouse chose higher voltage alternating current stepped down to 120 volts. See http://en.wikipedia.org/wiki/War_of_Currents 115-volt AC/DC universal motors in drills and other tools were fairly common until low-cost induction motors became widespread. Best regards, Joel Davidson - Original Message - From: Darryl Thayer To: RE-wrenches Sent: Monday, October 18, 2010 7:18 PM Subject: Re: [RE-wrenches] AC voltage in North America When I was an electrical apprentus back in the late 40's we called it 110/220 then in the fifties the voltage was reised to 115/230 and some time in the 1960 it was raised to 120 240 Darryl --- On Mon, 10/18/10, Marco Mangelsdorf ma...@pvthawaii.com wrote: From: Marco Mangelsdorf ma...@pvthawaii.com Subject: [RE-wrenches] AC voltage in North America To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Date: Monday, October 18, 2010, 8:27 PM I just don’t understand it. Lots of people—from reporters to homeowners—consistently refer to the AC voltage in their homes as “110/220.” Where does this come from? If North American utilities were putting out power at that voltage range, they would be in serious trouble. Anyone able to educate me on this matter? marco -Inline Attachment Follows- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Enphase v. string inverter
Hello Drake, I have observed hundreds of PV systems in the early morning and can say without doubt that string inverters are not inherently slow to wake up. For example, today my 12 year old SW4048 with a single crystal PV array facing south at 12 and 18 degrees tilt and my SB2100 with a single crystal PV array facing south at 18 degrees both were putting out power at 7:45 am when the sun was 9 degrees above the horizon at azimuth 105 degrees. Today the sky is clear and the sun rose in Los Angeles at 6:57 am. I have seen systems with 100 kW Xantrex inverters and flat Unisolar arrays wake up before the morning sun rose above the horizon. Granted the systems were putting out less than 5 kW, but the inverters were on. See you all at the solar conference. Best regards, Joel Davidson - Original Message - From: Drake To: RE-wrenches Sent: Monday, October 11, 2010 6:39 AM Subject: Re: [RE-wrenches] Enphase v. string inverter I'm now monitoring a 5.376 kW system we recently installed. The sun is barely up, with light clouds, and a portion of the array is still in shade. The system is putting out 700 watts. A string inverter would probably be waiting to start. My main problem with the Enphase is the 199 watt limit to its output. The inverters are rated for up to 235 watt modules. This 224 watt module array spends a fair amount of time at full inverter capacity during cool sunny days. Maybe these inverters should not be used with over 210 watt modules. Drake At 12:50 AM 10/11/2010, you wrote: The main advantage of Enphase is the module level monitoring. However, the increased output due to partial shading can be significant. I was at a 6 year old PV site this week, and a tree had grown up near the base of the roof. Branches were casting a few minor shadows on the array, but was wiping out 75% of the production. I can assure you, those 9 modules would have been producing '50+% greater output' Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax: 707-769-9037 From: Jamie Johnson jjohn...@spefl.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Sun, October 10, 2010 5:38:55 AM Subject: Re: [RE-wrenches] Enphase v. string inverter Marco, The last I heard the NREL was testing enphase vs. a string inverter, they were also suppose to test enphase vs. A competitors module level mpp tracking. Not sure if that performance test is complete yet. I have seen 1 independent unshaded test ( potentially biased ) which IIRC showed enphase ~1% less than a string inverter, this seems to match the inverters CEC rating. What we see around here is an over estimate of kWh production by the selling contractor using enphase, sometimes by 50+% greater than unshaded kWh estimates. Performance guarantees with monetary compensation back to the customer if estimates are not met can be a good thing and improve the industry IMHO. Jamie Johnson General Manager SOLAR POWER ELECTRIC TM NABCEP Certified Solar PV Installer #031310-118 (941) 380 - 0098 www.SPEFL.com Commercial Residential FL State Certified # EC13001765 Sent from my iPhone On Oct 9, 2010, at 7:07 PM, Marco Mangelsdorf ma...@pvthawaii.com wrote: Does anyone know of any reports out there from a neutral, 3rd party which compares an Enphase array with an array using a string inverter with both arrays on the same unshaded surface? Some Enphase peddlers here are saying that the energy harvest from an Enphase system is going to be better since they supposedly come on sooner and stay on later in the day. One guy is actually saying that the Enphase inverters come on before the sun comes over the horizon. Maybe from the same family that claimed that a-Si modules produced power from the moonlight. Thanks, marco ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios
Re: [RE-wrenches] UL and Grid-tied Battery Back Up Systems
Peter, California utilities use to require operating steps (list not UL listing) for all grid-tied systems in the interconnection application. A copy of the operating steps from the equipment manual sufficed. Joel Davidson - Original Message - From: Peter Parrish peter.parr...@calsolareng.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Tuesday, October 05, 2010 4:05 AM Subject: [RE-wrenches] UL and Grid-tied Battery Back Up Systems Are there UL testing procedures for Grid-tied Battery Backup Systems, such as the Xantrex XW systems and the Outback GVFX systems? The reason for my inquiry is that the Los Angeles Department of Water and Power intends to require that ...applicants installing Battery Backups on their solar systems to submit an Operational Listing detailing a precise list of steps of what were to happen if the LADWP grid were to lose power. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] UL and Grid-tied Battery Back Up Systems
Hello Peter, It was good to see you at the LADWP Commissioners Meeting even though we didn't have time to talk. I told Mr. Benyamin, LADWP AGM, at the meeting that there were no safety issues regarding grid-tie PV system with batteries because the inverters were IEEE 929 compliant. He said he was concerned about batteries being added to a PV system after the initial utility inspection. I told him that batteries can not be added to a non-battery inverter. He said it is being done so the conversation ended. How many people are adding battery inverters later? I've done hundreds of grid-tied systems and never added a battery inverter and battery bank after the initial installation. Wrenches, are you adding batteries to non-battery grid-tied PV systems after the initial installation? If yes, what inverter and how do you deal with the inspector? Joel Davidson - Original Message - From: Joel Davidson joel.david...@sbcglobal.net To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Tuesday, October 05, 2010 7:43 AM Subject: Re: [RE-wrenches] UL and Grid-tied Battery Back Up Systems Peter, California utilities use to require operating steps (list not UL listing) for all grid-tied systems in the interconnection application. A copy of the operating steps from the equipment manual sufficed. Joel Davidson - Original Message - From: Peter Parrish peter.parr...@calsolareng.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Tuesday, October 05, 2010 4:05 AM Subject: [RE-wrenches] UL and Grid-tied Battery Back Up Systems Are there UL testing procedures for Grid-tied Battery Backup Systems, such as the Xantrex XW systems and the Outback GVFX systems? The reason for my inquiry is that the Los Angeles Department of Water and Power intends to require that ...applicants installing Battery Backups on their solar systems to submit an Operational Listing detailing a precise list of steps of what were to happen if the LADWP grid were to lose power. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] PV and Roof Flammability
Wrenches, Building fires are serious stuff. The Northbrook UL labs fire tests are awesome. Imagine a gale-force wind driving a wide, roaring natural gas flame at the roof eave to see how far the fire will spread as it consumes the roofing material and anything else combustible. Tremco has a photo of the spread-of-flame test at http://www.tremcoroofing.com/qa/fire_test.asp Some roofing material is self-extinguishing. Some roofing material burns to ashes. PV module glass does not feed the fire from the top but module backsheets combust. Non-glass modules combust readily but can be rated Class A in low-pitch applications. For a photo of the burning brand test see http://www.extension.org/pages/Fire_Ratings_for_Roofing_Material Glass solar modules on stand-off mounts have saved homes from flying burning brands. I think that most wrenches warn their customers about fire hazards. Stay safe. Joel Davidson - Original Message - From: Matt Lafferty gilliga...@gmail.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Thursday, September 23, 2010 6:22 PM Subject: Re: [RE-wrenches] PV and Roof Flammability Wrenches, I'm coming from a perspective of comparing beneath array areas to not beneath array areas of the same roof. Regarding flammability, I don't really care what the source of ignition is in this conversation. I prefer to think that the PV isn't the cause, frankly. Would rather think in terms of flying embers from a fire in the area (wild fire, neighbor's house on fire, chimney, etc.), but I don't think we can discount any cause out of hand. I think it is very important to understand that the UL tests are designed to emulate pre and early-stage combustion, as opposed to emulating a fully-involved fire situation. This is important because it marks the difference between fire resistant and fire proof materials. Only fire proof materials would survive to pass a full-on fire test. These tests essentially test the fire resistance of roofing materials. Another element to understand is that these tests only test from the top. They don't emulate an attic-fire burning thru the sheathing and engulfing the roofing materials from the back. Based on observation and farm boy commons, it seems to me that the biggest problem area is low-profile, flush mounted arrays over petroleum-based roofing materials. These are parallel to and close to the roof surface. Most commonly with horizontal rails below the surface of the modules, thereby reducing the effective clearance to the roof by the height of the rail. Which dramatically reduces convection. This mounting configuration concentrates heat onto the roof surface and traps roof gasses beneath the array from otherwise normal ventilation. Gassing is normal and occurs throughout the life of most roofing materials. Petroleum based roofing products tend to gas at a declining rate throughout their life cycle. This gassing is not generally combustible in these concentrations. Combustible gasses are created when a roofing material begins to burn. Early-stage combustion. If these combustible gasses are not allowed to evacuate quickly, the fire is exacerbated Gaining heat and intensity quickly. Flame spread. Once the roofing material is fully involved, meaning self-sustained burning, it's probably not gonna matter much whether there is an array above it or not unless someone is there to fight the fire. The chimney effect behind a tilted array would have three primary effects on this cycle. The first effect is that normal gassing would occur similarly to adjacent roof sections not covered by the array. The second is that, during pre and early-stage combustion, the combustible gasses will not concentrate between the module and the roof, effectively reducing the fuel and heat concentration by some amount. Possibly to a level that is equal to adjacent roof sections not covered by the array. Possibly even extinguishing an ember or small flame in a manner similar to blowing on a lit match. The third effect would occur once the roofing material is fully involved. In this part of the cycle, the chimney effect could certainly draw more air into the fire, possibly increasing its intensity, much like blowing into the base of a campfire. From a pure flammability perspective, I like the tilted array better than the flush array. My reasoning is primarily that normal aging will be more likely and, if an ember were to reach the roof beneath the module, it is more likely to self-extinguish or at least act like the adjacent roof. These characteristics reduce the overall liklihood of actually catching fire in the first place. Which I like. In the event that the roof beneath a tilted array were to become involved and induce an adverse chimney effect, the fire would be WAY more accessible to a water hose than with a flush mounted array. Another negative that a flush mounted array has in the fully involved scenario, is that it's
Re: [RE-wrenches] PV and Roof Flammability
On the plus side, roofs under PV arrays receive less ultraviolet radiation. On the negative side, some roofing shaded by PV arrays experience mold growth. - Original Message - From: Darryl Thayer daryl_so...@yahoo.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Thursday, September 23, 2010 6:39 PM Subject: Re: [RE-wrenches] PV and Roof Flammability Hi all Of course there were some fires with thermal collectors where the wood and shingles cought fire with inadaquite venting. No venting was the case. But I have measured the temperature under PV when it was vented and the roof was cooler under the array than elsewhere. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] PV and Roof Flammability
Hello Bill, Thanks for the feedback. I need to learn more about this issue. I plan to attend the October 15th SolarABC meeting after the LA conference. Is 2012 IBC draft available? How can PV systems be classified, let alone fire-rated, when there is a seemingly infinite combination of module, mount, wiring, inverter, and safety devices possible? Will system classification require system certification like Florida? Is the air gap considered a problem only for tilted PV arrays? The reasons I ask are (1) because stand-off arrays parallel to low-pitched roof are mounted like HVAC equipment and (2) HVAC and other roof-mounted equipment do not change the building's occupancy group, construction type and minimum roof class. Best regards, Joel Davidson - Original Message - From: Bill Brooks billbroo...@yahoo.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Thursday, September 23, 2010 8:29 AM Subject: Re: [RE-wrenches] PV and Roof Flammability Joel, The problem is not with the rating of the modules. It is with the way we install them. The air gap is a problem. If HVAC systems were installed like PV modules, they would have the same problem. There will be changes of some sort coming in the next year or so. The IBC in 2012 will require PV systems to have a fire rating. Module fire rating may become irrelevant. Time will tell. This is in a very preliminary stage. All we know is that changes are likely with this new IBC language. There is a group working on this issue that includes several representatives from the PV manufacturing and PV installing industries. If this is something you want to put a lot of personal effort into, there are ways to accommodate good input. The SolarABCs will be helping coordinate ongoing efforts. Bill. -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Joel Davidson Sent: Wednesday, September 22, 2010 7:12 PM To: RE-wrenches Subject: [RE-wrenches] PV and Roof Flammability Wrenches, See http://www.solarabcs.org/flammability/ and the report at http://www.solarabcs.org/flammability/Flammability_Interimreport.pdf Is there any flammability difference between PV equipment on a roof and HVAC or air handling equipment on a roof? My concern is whether PV is being singled out as a flammability concern while other more established industries with more powerful lobbyists are not. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] PV and Roof Flammability
Wrenches, See http://www.solarabcs.org/flammability/ and the report at http://www.solarabcs.org/flammability/Flammability_Interimreport.pdf Is there any flammability difference between PV equipment on a roof and HVAC or air handling equipment on a roof? My concern is whether PV is being singled out as a flammability concern while other more established industries with more powerful lobbyists are not. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Delta LAs
Wrenches, Allan Sindelar's 2003 RE-Wrenches lightning discussion compilation was a keeper. Email me off-list for a copy. (Thank you Allan). Joel Davidson - Original Message - From: August Goers To: RE-wrenches Sent: Tuesday, September 14, 2010 6:00 PM Subject: Re: [RE-wrenches] Delta LAs Jay - I can see that point, but does that really effect insurance payout? It seems like one could argue that a properly installed system with proper grounding inspected by a building official has a lot more clout than and little grey cylinder next to the inverter or disconnect. Please all wrenches, correct me if I'm wrong but I can't remember a single time when there was a post about an actual lightning strike and a lightning arrestor actually doing its job - meaning that an arrestor took a hit and protected the array and or inverter. I've heard plenty of stories about blown lightning arrestors and good equipment but no one seems to know what caused the situation. It might be that lightning is hard to track and I agree with that. And lightning might have been the cause. It would be great to track lightning-fried installations to see what happened and what could be fixed. If lightning arrestors are the solution then by all means we should install them. Most of the time I think that proper grounding is the solution although I wish that field experience would prove the point. What do you think? -A On Tue, Sep 14, 2010 at 5:28 PM, jay peltz j...@asis.com wrote: I also live in a area without much lightning, however I install one in most systems for the simple reason of insurance. If there is lightning damage, the insurance company can't use that as a way to not pay any claims. ie cheap insurance. jay peltz power On Sep 14, 2010, at 8:39 AM, August Goers wrote: All - I guess my thought is a little off topic, but are lightning arrestors even worth using at all? My logic has always been that if lightning does indeed strike that it's likely going to blow the arrestor and and inverter. We don't have much of a lightning issue issue in the Bay Area so I don't have any direct experience. Best, August ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- August Goers VP, Engineering Luminalt Energy Corporation 1320 Potrero Avenue San Francisco, CA 94110 O: 415.641.4000 M: 415.559.1525 aug...@luminalt.com -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Delta LAs
CE is a self-certification that requires no 3rd party testing. In other words, if you think your product meets a standard and take the time to write a letter stating such, then you are CE certified. There are companies who you can pay to give you the letter, but it is easy to go on-line, learn the CE mark requirements and DIY. From: Mick Abraham m...@abrahamsolar.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Tue, September 14, 2010 12:17:34 PM Subject: Re: [RE-wrenches] Delta LAs Citel products do have a listing mark but this is European style CE, not American style UL/ETL. Citel is reputedly working on American certification but one would be advised to not hold one's breath. The Citel products which mount to a DIN rail have an LED indicator which goes dark once the surge elements have been sacrificed. Also some of their units have an auxiliary switch which can remotely indicate a blown condition. This is in the form of dry contacts..a normally open and a normally closed one, so various indicator circuits can be designed around that. The contacts have a low amp AC rating and also a (lower amp) DC rating but I do not remember the numbers at present. Jolliness, Mick Abraham, Proprietor www.abrahamsolar.com Voice: 970-731-4675 On Tue, Sep 14, 2010 at 12:43 PM, R Ray Walters r...@solarray.com wrote: You could buy several ground rods for the cost of one Delta. Ground Impedance is the real issue. Both the Delta and the Polyphasor need a good ground to work. While I haven't seen much of a correlation between Deltas and reduced lightning damage, (lots of system damage with and without) I have found that well grounded systems (tied to a steel cased well) have never had a problem, even with direct strikes to a wind turbine (did lose the $40 turbine rectifier, but nothing else) I now own a clamp-on ground impedance tester, and the results were miserable. Some electrodes were over 800 ohms to ground! (code requires under 25 ohms) I'd spend more time and money reducing ground impedance, and then if it makes you feel good inside, throw the little lightning faeries in, if the AHJ isn't looking... If its really lightning country, and a really expensive off grid system, I use Polyphasor, but they have their own issues. (very expensive, no UL listing, loose internal connections, nuisance tripping, need a large J-box to mount them inside, etc.) I haven't tried the Citel stuff, but it looks to be listed, and mounts on a DIN rail. After installing a couple hundred Deltas, I'd try something else at this point. R. Walters r...@solarray.com Solar Engineer On Sep 14, 2010, at 10:22 AM, Kristopher Schmid wrote: My thought here is that nothing will protect the equipment from a direct strike, but a near strike that may induce a significant surge may be absorbed by the LA and protect the equipment. I like the feedback so far. It would not break my heart to stop using them altogether.:-} Kris Legacy Solar 864 Clam Falls Trail Frederic, WI 54837 715-653-4295 sol...@legacysolar.com www.legacysolar.com -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of August Goers Sent: Tuesday, September 14, 2010 10:39 AM To: RE-wrenches Subject: Re: [RE-wrenches] Delta LAs All - I guess my thought is a little off topic, but are lightning arrestors even worth using at all? My logic has always been that if lightning does indeed strike that it's likely going to blow the arrestor and and inverter. We don't have much of a lightning issue issue in the Bay Area so I don't have any direct experience. Best, August On Tue, Sep 14, 2010 at 6:29 AM, Kristopher Schmid sol...@legacysolar.com wrote: It is quite ironic that just a week after I posted a question to the group on testing the integrity of lightning arrestors, I had one apparently faulty out of the box. The manifest of this was interesting: when the AC LA (LA302R) was connected in parallel on the AC input to a SB3000 inverter, there was 125vac neutral to L1, 125vac neutral to L2, and 1Vac L1 to L2. SMA tech support suggested the LA as the issue and sure enough, it was. Attempting to test good and faulty arrestors with an ohmmeter gave the same result - off scale open. Any thoughts or comments from the group? Kris Schmid Legacy Solar 864 Clam Falls Trail Frederic, WI 54837 715-653-4295 sol...@legacysolar.com www.legacysolar.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- August Goers VP,
[RE-wrenches] Module Ground (was The Demise of Reason)
Bill, You and John Wiles have shown leadership on the module grounding issue. It would be good to know who at UL is preventing a universal solution so that this issue can be resolved at the highest level once and for all. What do you suggest for the course of action? Joel Davidson From: Bill Brooks billbroo...@yahoo.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Cc: Christopher Flueckiger christopher.fluecki...@us.ul.com; Tim Zgonena timothy.p.zgon...@us.ul.com Sent: Mon, September 13, 2010 8:44:39 AM Subject: Re: [RE-wrenches] The Demise of Reason Peter, No tone was intended. The theme of your post was good, but the subject was misleading. The fact that you were shocked twice by my questioning your subject means that you misunderstood the tone of my questioning of your subject title. I misunderstood your post and reacted to a very negative subject heading that gave the impression that the WEEB product was generally experiencing its demise. I have heard of a few companies that have withdrawn information about the WEEB in their literature, but I was unaware that SunPower was one of them. Grounding of module frames has been a big issue for over a decade and module manufacturers have not done a lot to help the installer in this area. When UL cracked down on the haphazard way that grounding was being approached in the field, it became a major issue. Manufacturers had to retest many of their products and provide details on the methods allowed in their manuals. Since adding grounding options to a module required additional testing which was expensive, many manufacturers went the easiest route to get approved. This was not good for products like the WEEB since it now required testing with every module type. In addition, my understanding is that UL has not allowed the WEEB on UL-listed products since the product was not evaluated by UL and they do not have the test data that supports how it was evaluated. That may be the source of the issue with SunPower--you would have to ask them directly. We need a more generic approach to grounding and that is what is currently underway. Grounding and bonding is extremely important and jurisdictions are focused on it for obvious safety reasons. We need solutions that are clearly reliable and straightforward so that installers and jurisdictional authorities don't have to constantly be revisiting the issue. Bill. -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Peter Parrish Sent: Monday, September 13, 2010 7:18 AM To: 'RE-wrenches' Cc: 'Christopher Flueckiger'; 'Tim Zgonena' Subject: Re: [RE-wrenches] The Demise of Reason Bill (and Chris and Tim), Be a little bit more careful in your choice of subjects...? I am shocked, shocked that you would use that tone with me. If you would re-read my post, I talked about three things: (1) SunPower's no longer supporting the WEEB clip technology and regressing to the ILSCO GBL-4DBT. You are right about the insertion of the star washer between the lug and module frame. I wonder what SP's response to that might be... (2) As for SP's comment that they pulled the WEEB clip, due to UL testing changes. Does anyone close enough to the situation know what this means? (3) I never mentioned the SP IFF clip. I mentioned the Tyco SolKlip. SP mentions the IFF in their literature but do not offer it to their dealers (as far as I know), and I haven't been able to find it yet in their product literature, except for a small low-resolution image. I assumed that the Tyco SolKlip was a different component -- however it may be similar or may be rebranded by SP as the IFF -- I don't know. Bonding PV arrays and their supporting structures is complicated subject and in my experience is one of the more frequently examined aspects of PV installations by inspectors (along with bonding and grounding the other components). So it would seem to be an apt subject for discussion by those of us actively installing PV systems subject to inspection by the AHJ. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Bill Brooks Sent: Sunday, September 12, 2010 8:50 PM To: 'RE-wrenches' Cc: 'Christopher Flueckiger'; Tim Zgonena Subject: Re: [RE-wrenches] The Demise of Reason Peter, Be a little more careful in your choice of subjects. You are talking about the SunPower IFF clip. I have not heard this story, but I don't doubt it. There have been significant changes at UL and ETL, the two largest listers of PV modules, in the area
Re: [RE-wrenches] Micro-Inverter Challenge Winners Declared.Interesting details to follow.
Hello Ryan, I wonder if SMA still thinks their 569 Sunny Boy system at the Mont-Cenis Academy is a good design? See http://www.google.com/imgres?imgurl=http://www.sma.de/uploads/tx_templavoila/SB04_04.jpgimgrefurl=http://www.sma.de/en/products/references/solar-inverters.htmlusg=__z_925mXuLKvJFrs9XG6_snB1bHE=h=156w=222sz=58hl=enstart=3zoom=1itbs=1tbnid=dZezHYAqkkXV5M:tbnh=75tbnw=107prev=/images%3Fq%3Dphotovoltaic%2BAcademy%2BMont-Cenis%26hl%3Den%26gbv%3D2%26tbs%3Disch:1 Joel Davidson - Original Message - From: Ryan J LeBlanc r...@naturalenergyworks.com To: re-wrenches@lists.re-wrenches.org Sent: Sunday, September 05, 2010 6:33 AM Subject: [RE-wrenches] Micro-Inverter Challenge Winners Declared.Interesting details to follow. Hello all, Jay Ruzicka of Occidental Power (CA) was the first to submit a design that I could not find a reasonable solution that would work as smartly with available string inverters as they would with a micro-inverter design. Allan Sindelar of Positive Energy (NM), gets a runner up win, for a value equaling a case of good stout. Having been in the large commercial space for a while, it was nice of these guys to submit designs and have the discussions. My guess would've been that folks were going to be submitting a typical 3kW residential system design with multiple planes, or shading issues, and arguments of MPPT, or reliability, or that putting a bunch of inverters behind the modules would be fine because they said it was ok, but what I found was definite lack of efficient, cec listed, small power inverters for these sub 2kw, and sub 1kw systems, and designers just have a lack of options in this smaller territory. Good lesson to String Inverter Manufacturers to continue to develop higher efficiency single string inverters to compete, meanwhile some seem to be bailing from this space, regarding smaller listed inverters and lower input voltages. There are literally no sub-1000's or 1100's listed with competitive efficiencies. Kaco has the 1500 at 95.5% the same as Enphase's best number. After that, there's a few other 1500's and 2000's that post 95%, 94.5% and worse. For projects in this system size territory, that is sub-2kw, where one could reason that only a few inverters behind the modules may be ok, there is a lack of alternatives. So, some of the things that would be good for string inverter manufacturers to work on to combat the micro-inverter craze, seems to be continuing in the race to bring up the efficiency of smaller units, perhaps working on multiple MPPT units, perhaps with power stages like the larger fronius units but at lower or wider voltage ranges and smaller power ratings, perhaps offering units with lower input voltage windows to accommodate shorter strings, integrating better/cheaper monitoring, or letting more people know about their existing monitoring solutions, keeping cost down, and getting them listed and approved soon. In a podcast recently @ http://www.renewableenergyworld.com/rea/news/podcast/2010/02/micro-inverters -vs-central-inverters-is-there-a-clear-winner, Raghu said that a couple hundred thousand units have been sold since 08, for the sake of discussion let's say they're 200W each and $1/Watt. That's 200,000 (x) 200 (x) $1 = $40 Million in sales... Guess I should listen to the podcast again to make sure he said that many, but if so, that's quite a chunk of change these other guys should be working for. If micro-inverter efficiency were to hold up, and installation speed could be dramatically increased, a string inverter that would compete will have to be able to accommodate shorter strings, at better efficiencies. Obviously, not ground breaking work, we've all already known that sub 2kw systems were viable candidates for micro-, but I was very disappointed to see such a lack of competition on the CEC list for those of us looking to keep our inverters out from underneath the array. Ryan ** ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Inverter for fire protection pump
Hi Ray, Thank you for your input. The pump is part of a fire protection system that sucks water out of the swimming pool and pumps it to roof sprinklers with fire retardant added to the water. I'll forward your email to my colleague who has the details. Best regards, Joel Davidson - Original Message - From: R Ray Walters r...@solarray.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Friday, August 27, 2010 7:23 PM Subject: Re: [RE-wrenches] Inverter for fire protection pump Forgot to mention the usual info: look at the pump to see if a smaller or no surge Grundfos SQE might be able to handle the flow rate and pressure needed. Pumps are cheap, when you're considering multiple inverters.. Given what you mentioned (110 amp surge at 240 vac), I don't think even a quad stack of Outbacks could do it. ( please ignore my earlier post) A quad stack could run that, just not start it. Franklin makes a soft start controller, that might work with that pump. What is the Horse power rating? R. Walters r...@solarray.com Solar Engineer On Aug 27, 2010, at 3:52 PM, R Ray Walters wrote: Little beyond a pair of Outbacks, possibly a pair of Magnasine inverters, or a quad stack of Outbacks. R. Walters r...@solarray.com Solar Engineer On Aug 26, 2010, at 2:41 PM, Joel Davidson wrote: Wrenches, Our customer has a fire protection pumping system that operates at 240VAC and 22 amps with a 110 amps starting surge. The pump will only be used for up to 4 hours in an emergency (but hopefully never). The customer wants an inverter and battery (no generator or PV) in case grid power is destroyed by fire. What inverter(s) do you recommend? Thank you very much for sharing your off-grid knowledge. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Inverter for fire protection pump
Wrenches, This group's experience, collective wisdom, and willingness to share practical knowledge and interesting ideas are how I envision higher education in the future. Thank you all for your helpful information. I'll report back what the customer decides to do. Joel Davidson - Original Message - From: Darryl Thayer daryl_so...@yahoo.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Saturday, August 28, 2010 8:24 AM Subject: Re: [RE-wrenches] Inverter for fire protection pump Sorry this could be more helpful if I had a better memory, I don't mean to ramble, but some wrenches may find value. I am working on a standalone system now and I am in testing. Normally I use OUtback, (and I am very happy) and this time I decided to use Magnum 4024 AE. The job has both a large motor and is AC coupled to DGI inverter. The large motor draws over 120 amp (120 volt) surge when connected to a grid source. I have started this motor in test repeatedly My Greenlee amp clamp says it is surging at 90 amps! The VOM says the min voltage is 97 volts. This is on ONE 4024 AE, Magnum is getting close to release of the paralled version The test battery set is Trojan T105 single string, and the surge DC measured by Ideal DC clamp on is 280 amps. Voltage and minimum battery voltage is 21 volts Ideal VOM. I would think that the parrellel version could handle your motor. Old system I did a fire pump install in a large residence, I think back in 2004? the specs were similar except the starting surge was higher and the running was almost the same (maximum of 20 amps and less depending upon flow). I used an Odd number of OUtback inverters (5) but not all were to this task. First the starting surge measured by my greenlee clamp-on amp meter was higher on the grid than it is on the inverters. I did a lot of field tests, however I do not know where I put the data. I noticed that if I had fully charged batteries the starting was 100% reliable but on batteries at near 50% SoC the system started to fault on low AC during start-up The batteries were L-16 Surrette 48 volt string. If the system was started every five minutes it would fault, but if a longer waiting period I remember during the course of the job I started the pump over 100 times in test mode with out a failure. (this system gets annual tests and no problems so far) Pumps: We found that the pump current draw depended upon the flow rate we allowed.. If we had one head open, the current draw was less than all heads open. The maximum curent draw was at some flow rate in the middle flow range! The starting surge was independent of whether the valve was open or closed. If it would be possible to use a SQflex this would be a good choise. Finally this system is grid tied and has a relay to Outback if the Grid should fail and it has a generator inlet box if a generator is avaiable to take the load. --- On Fri, 8/27/10, Joel Davidson joel.david...@sbcglobal.net wrote: From: Joel Davidson joel.david...@sbcglobal.net Subject: Re: [RE-wrenches] Inverter for fire protection pump To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Friday, August 27, 2010, 9:50 PM Hi Ray, Thank you for your input. The pump is part of a fire protection system that sucks water out of the swimming pool and pumps it to roof sprinklers with fire retardant added to the water. I'll forward your email to my colleague who has the details. Best regards, Joel Davidson - Original Message - From: R Ray Walters r...@solarray.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Friday, August 27, 2010 7:23 PM Subject: Re: [RE-wrenches] Inverter for fire protection pump Forgot to mention the usual info: look at the pump to see if a smaller or no surge Grundfos SQE might be able to handle the flow rate and pressure needed. Pumps are cheap, when you're considering multiple inverters.. Given what you mentioned (110 amp surge at 240 vac), I don't think even a quad stack of Outbacks could do it. ( please ignore my earlier post) A quad stack could run that, just not start it. Franklin makes a soft start controller, that might work with that pump. What is the Horse power rating? R. Walters r...@solarray.com Solar Engineer On Aug 27, 2010, at 3:52 PM, R Ray Walters wrote: Little beyond a pair of Outbacks, possibly a pair of Magnasine inverters, or a quad stack of Outbacks. R. Walters r...@solarray.com Solar Engineer On Aug 26, 2010, at 2:41 PM, Joel Davidson wrote: Wrenches, Our customer has a fire protection pumping system that operates at 240VAC and 22 amps with a 110 amps starting surge. The pump will only be used for up to 4 hours in an emergency (but hopefully never). The customer wants an inverter and battery (no generator or PV) in case grid power is destroyed by fire. What inverter(s) do you recommend? Thank you very much for sharing your off-grid knowledge. Joel Davidson
[RE-wrenches] Inverter for fire protection pump
Wrenches, Our customer has a fire protection pumping system that operates at 240VAC and 22 amps with a 110 amps starting surge. The pump will only be used for up to 4 hours in an emergency (but hopefully never). The customer wants an inverter and battery (no generator or PV) in case grid power is destroyed by fire. What inverter(s) do you recommend? Thank you very much for sharing your off-grid knowledge. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Tight roof layout questions: edge walkway requirements small gap hardware options
This May 2010 UL/NFPA report Fire Fighter Safety and Emergency Response for Solar Power Systems shows eave-to-ridge solar arrays and has a lot of good information for designers. See http://www.nfpa.org/assets/files/PDF/Research/FFTacticsSolarPower.pdf - Original Message - From: Mick Abraham To: RE-wrenches Sent: Thursday, August 26, 2010 5:53 PM Subject: Re: [RE-wrenches] Tight roof layout questions: edge walkway requirements small gap hardware options The Wrench List participants have again responded with aplomb. Thanks to all for the dozen or so replies. My takeaway from this is that I need to send my roof layouts to the nearby fire department...it's another authority having jurisdiction situation. I received the below mail off list from a fire captain in San Jose. He cannot post to the List so he asked me to post on his behalf. Moderator Michael approved, so Matt Paiss' remarks are copied below. Jolliness, Mick Abraham, Proprietor www.abrahamsolar.com Voice: 970-731-4675 Mick, I wanted to reply to your post. As a firefighter, and an instructor of PV safety for the fire service like Dan Fink, I would like to take a moment to expand on what Dan was eluding to. Firefighters will not always look at an edge-to-edge array and decide to Let it burn just based on the array size. We will take into account the size of the fire, the involvement of the actual structural members, and the potential life risk within the structure before any tactical strategy is implemented. I have written off buildings just based on wind, or available water supply. What a setback (the term being used for walkways) allows is primarily for access to a roof, or rapid egress off a roof when the fire gets out of control, not necessarily for cutting a hole. I teach firefighters to vent on the other side of the ridge from the array. There is no time to remove modules, and while micro-inverters definitely address the safety issues of a 600vdc string, they do not address access or egress. I am not going to recommend that ANY firefighter tear off a module to vent a roof because he thinks a micro-inverter is present. I realize that these new codes are more restrictive, but even wind load zones recommend against edge-to-edge installs. There will be some latitude in the fire codes for setbacks, so I recommend building a good relationship with your local AHJ's. One way of doing this is by demonstrating safe, high quality installs. I have seen too many wire-ties holding up PV wire that will be rubbing against comp shingles for a decade. How confident are you that that will not be a problem? Regards, Matt Paiss Matthew Paiss, Fire Captain San Jose Fire Department 170 W. San Carlos St. San Jose, CA 95113 (831) 566-3057 cell On Thu, Aug 26, 2010 at 12:45 AM, Philip Boutelle philboute...@gmail.com wrote: Just to clarify what is and isn't law in California: the final draft guidelines developed and adopted by Cal Fire are guidelines, not law, unless the local fire/AHJ has adopted them or parts of them into local ordinances. I have heard that in Southern Cal, those guidelines have been adopted all over the place already, but not so in the rest of the state yet. I think the guideline was officially incorporated into the next NEC/NFPA cycle, so it will be law pretty soon. Bill Brooks could probably confirm here on future adoption. Not that any of this helps your Atlanta install -Phil Boutelle Real Goods Solar On Wed, Aug 25, 2010 at 12:38 PM, Max Balchowsky m...@seesolar.com wrote: Mick, here in California the fire department in the various agencies has the final say on clearances. There is a very clear cut standard in place for the state, but we have been successful a few times in getting allowances to vary due to various site conditions. A call to the local AHJ is the place to start. In the early days of our installations (mid 1990's) we used power strut and bolted panels directly to the rails. A lot slower but no gaps between panels. We went from there to designing our own T clamps. There wasn't as many choices then for mounting hardware. Max Balchowsky Design Engineer SEE Systems 1048 Irvine Ave Suite 217 Newport Beach, Ca. 92660 760-403-6810 -- From: Brian Teitelbaum bteitelb...@aeesolar.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Wed, August 25, 2010 11:40:04 AM Subject: Re: [RE-wrenches] Tight roof layout questions: edge walkway requirements small gap hardware options Hi Mick, To answer part of your post, the DPW Power Rail mid-clamps give you a 3/8” gap between modules, and the SnapNrack mids give you a 1/2 gap. I doubt if that will give you much of a walkway though….
[RE-wrenches] Solar License Database
The Interstate Renewable Energy Council (IREC) created a Solar Licensing Database as a resource for policy makers, practitioners, consumers, and anyone else looking for solar licensing information in the U.S. The state-by-state information offers a handy comparison for reviewing the different approaches across state lines, and identifies various practices for regulating the solar installation industry. In the database, licensing requirements for installing photovoltaic and solar thermal systems are documented for each state. Today, only 14 states have established specific solar license classifications, usually sub-classifications of electrical or plumbing licenses, and often specifically defined to limit the scope of work to direct solar installations and maintenance tasks. See http://irecusa.org/2010/08/solar-licensing-information/ ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Power Loss from Dust on PV Modules
Wrenches, A recent news story about Self-cleaning technology from Mars can keep terrestrial solar panels dust free at http://www.ecnmag.com/News/2010/08/Self-cleaning-technology-from-Mars-can-keep-terrestrial-solar-panels-dust-free/ said A dust layer of one-seventh of an ounce per square yard decreases solar power conversion by 40 percent, Mazumder explains. In Arizona, dust is deposited each month at about 4 times that amount. Deposition rates are even higher in the Middle East, Australia, and India. I have measured up to 15% power from a few months Los Angeles summer time dust and dirt and much higher loss at a very dirty location in Long Beach. I dry wipe small arrays clean and water hose (no wiping) up to 10 kW residential arrays. Is anyone experiencing 40% power loss from dust? How are you removing dust and dirt? Thank you for your feedback. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] The Genie Lens
Wrenches, Rick Lewandowski (founder of SunWize) and his team have been making PV modules with an optical film. See http://www.prismsolar.com/ Prism Solar's primary advantage is less PV cell material lowers cost. How Prism Solar differs from SolOptics: - film is laminated with the cell so it does not get wet, - holographic material is UV stable and is used in extraterrestrial applications, - tests have shown PS holograms degrade less than 0.04% per year compared to silicon cells at 0.5-1% per year, - angular and spectral multiplexed holograms result in cooler running cells and useful light down to 0.25 suns. Rick has worked several years to get Prism Solar ready for primetime. See their video and live test results and tell me what you think. Best regards, Joel Davidson - Original Message - From: Mark Dickson m...@oasismontana.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Thursday, August 12, 2010 9:43 AM Subject: Re: [RE-wrenches] The Genie Lens They claim that their film should last the 20 year lifespan of the modules. With most warranties at 25 years and modules lasting much longer than that, that claim does not do them much justice. I can't imagine modules will work very well with a tarnished or degrading film on them. Imagine how pissed a customer would be trying to peel that crap off after a few years getting baked in the sun. I am sure the module manus would love to disqualify any warranty claims that came back with this stuff on it. Also, they claim a 4-12.5% increase. Best regards, Mark Dickson, NABCEP Certified Solar PV Installer T Oasis Montana Inc. -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Peter Parrish Sent: Thursday, August 12, 2010 10:17 AM To: 'RE-wrenches' Subject: [RE-wrenches] The Genie Lens Anybody know anything about these claims? SolOptics, the solar division of Genie Lens, has created a new lens design that improves solar PV performance by 12.5 percent. The new thin-film design can be applied to any PV module, just like a sticker. The new design is created by the company's ray tracing software that embosses microstructures onto thin polymer film. That film can then be applied to solar panels much like tinting film can be applied to a window. In testing, the microstructures in the lens improved PV efficiency by 10 to 12.5 percent. I think the claim of a lens is complete hogwash. As for being an anti-reflective coating, that might work, but reliability would be my concern (UV, heat, moisture). Think how many tinted car windows you have seen with blisters all over them? I am posting this for a client who is a really dedicated solar enthusiast and occasionally emails me with questions about solar technology. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] NECPLUS Article
Interesting news item, but the link does not connect to the fire fighter report. Does someone have the correct report link? In May 2010 the Fire Protection Research Foundation (FPRF) completed a one-year research project addressing photovoltaic (PV) power systems. The report, titled Fire Fighter and Emergency Response for Solar Power Systems, is of direct interest to the NEC® community and is available for download on the FPRF website (at www.nfpa.org/foundation). - Original Message - From: hol...@sbcglobal.net To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Thursday, August 05, 2010 2:17 PM Subject: [RE-wrenches] NECPLUS Article This may be of interest...from the NEC newsletter http://www.necplus.org/Features/Pages/ThePoweroftheSunResearchinSupportofSafePhotovoltaicPower.aspx?sso=0 Holt E. Kelly Holtek Fireplace Solar Products 500 Jewell Dr. Waco TX. 76712 254-751-9111 www.holteksolar.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] low cost DAS systems - Follow-up
Hello Wrenches, After a busy 1.5 months, I'm finally getting back to setting up the software for PowerSave Envi (aka Current Cost)monitoring system on our home/office PV systems. What software do you recommend? As always, thank you for sharing what you have learned. Best regards, Joel Davidson - Original Message - From: Joel Davidson To: ch...@solarandwindfx.com ; RE-wrenches Sent: Friday, May 28, 2010 5:55 PM Subject: Re: [RE-wrenches] low cost DAS systems - Feedback Wrenches, Chris' email motivated me to buy a low-cost, easy-to-install monitoring system for residential and small commercial PV systems. I sent RFQs to vendors asking for a monitoring system for my PV systems, a SunnyBoy 240VAC PV system, and an oldie-but-goodie Trace 120VAC PV system. See http://www.solarsolar.com/oursys.html and http://www.solarsolar.com/solardwgs.html sa...@fatspaniel.com and distribu...@theenergydetective.com did not reply to my RFQ email. Draker Labs sent an automated reply but did not contact me. Daron at locusenergy.com replied quickly. He was very supportive, quickly answered questions, and gave us a training webinar. Price for one system is reasonable: $509 for 5 years of generation monitoring, data hosting, and performance hardware, plus $40 for California rebate program automated reporting, plus $130 to monitor electric consumption. Daron did a good job explaining Locus, but I needed 2 systems and didn't want to spend over $1,000. Charlie at egauge.net also replied quickly. Their residential eGauge system to monitor the Grid, PV system #1 and #2 costs $760, It includes the eGauge main unit, homeplug communication adapter and 5 CT's (2 CTs for the main utility feeds - one on each leg), 1 CT for the SunnyBoy system and 2 CTs for the Trace system. Better price, but still higher than I wanted to spend. Robin at powersave.us (Envi) answered my phone and email questions quickly. Their price was much lower so I bought their hardware. $237 for 1 Envi monitor with 1 transmitter and 2 CTs for PV system #1, plus $79 for 1 transmitter with 2 CTs for PV system #2, plus $12 for the USB cable, plus $17 for shipping. Powersave shipped the equipment promptly, but it took me a few days to get around to installing the hardware. The Envi monitor is in our office next to my computer. Installing the transmitter and CT on the Trace/battery PV system was easy. The Trace inverter is in the garage next to our office but not away from our electric service panel. You only need one CT to monitor a 120VAC PV system's output. The SunnyBoy inverter is next to the electric service panel. Grid power wiring into the service panel is behind the clamped and sealed utility meter. I did not want to break the utility seal to open that section of the panel so I am not monitoring the grid. Besides, monitoring the grid with a net metered PV system only tells what the utility kWh meter measures. Inside our 200A service panel, there is just barely enough space for the transmitter. The CTs are big, but I was able to squeeze them into the panel, replace the breaker cover, and close the panel door. Loading the USB cable driver was easy, but I had trouble getting the computer to see the 3rd party monitoring software. So I used the C2 Terminal free software to make sure my computer was seeing the Envi meter. I still could not get any of the monitoring software to work because the instructions were not intuitive or simple enough for me to understand. Tony at http://makehistori.net/ emailed instructions a few days ago. Today I had some time to muddle my way through downloading, logging in, registering, etc. and am up and running. I am still learning how to use his software. Chris at currentcost.com is has been emailing to help me use their software. I'll give it a try. Robin at powersave.us recommends Techtoniq. I'll give it a try too. When I first talked to Robin at powersave.us, I asked him why his device was not listed on the California Solar Initiative (CSI) Eligible System Performance Meters List. See http://www.gosolarcalifornia.org/equipment/meter.php He did not know about the list but understood immediately how important it was to get listed. Today, he emailed that their meter will be on the CSI list June 1st. Joel Davidson - Original Message - From: Chris Schaefer To: re-wrenches@lists.re-wrenches.org Sent: Monday, April 12, 2010 10:07 AM Subject: [RE-wrenches] low cost DAS systems Good Day Wrenches, I'm looking for suggestions for a low cost DAS system for home/small commercial use. It just seems to be such a useful basic tool to verify performance other than just the Kwh meter. I'd like to add this to all of our clients quotes and projects. Looking for the basics like module temperature and irradiance and it would be nice if it would tie into the existing inverters DAS like an Enphase
[RE-wrenches] Need 100kW 220V 50Hz inverter
Hello Wrenches, What brand and model inverter do you recommend for a 100kW, 220V, 50Hz, 3-phase, grid-tie PV project that I am working on in the Middle East? Medium and large commercial inverters are in short supply so I will consider multiple smaller inverters, transformers, and frequency converters if not too costly. Thanks in advance for your help. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] maximum efficiency module inquiry
Hello Kirk, See champion cell efficiencies in slide 11 at http://www.nrel.gov/docs/fy09osti/44201.pdf When price is no object, some solar vehicles have used space program gallium arsenide cells. See http://photovoltaics.sandia.gov/docs/PVFSCGallium_Arsenide_Solar_Cells.htm Joel Davidson - Original Message - From: Kirk Herander, VSE To: 'RE-wrenches' Sent: Monday, July 19, 2010 6:34 AM Subject: Re: [RE-wrenches] maximum efficiency module inquiry Peter, Keith, What I / they are interested in is max kwh/day in their climate. I don't know what they are willing to pay or receive for being a beta site, the first step is to see what's out there and what it takes to get it installed if appropriate. This customer is an outside-the-box thinker that doesn't often take no for an answer, and maximum energy harvest will trump the cost. The site is in the Mid-Atlantic U.S. - it is common for temps to be in the upper 90's with high humidity in summer. Delivery would occur in mid 2011. Kirk Herander Vermont Solar Engineering 802.863.1202 NABCEP(tm) Certified Solar Installer NYSERDA-eligible Installer VT Solar Incentive Program Partner -- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Peter Parrish Sent: Sunday, July 18, 2010 1:08 PM To: 'RE-wrenches' Subject: Re: [RE-wrenches] maximum efficiency module inquiry Hi Keith, A few que[#] stions: (Q1) How much is your client willing to pay for the most efficient module (module not cell)? (Q2) If they are willing to be a beta site, what would they be willing to do (or agree to let happen) of value in return? (Q3) What is the average high temperature at the site in question for June, July, August and September? (Q4) When would they/you want to take delivery? The real question behind Q3 is why are they/you focussed on efficiency, and not kWh/kWdc/year or $/kWdc/year or IRR? Based on where your client is coming from, I may be of help. Regards, - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 -- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kirk Herander, VSE Sent: Saturday, July 17, 2010 11:57 AM To: 'RE-wrenches' Subject: [RE-wrenches] maximum efficiency module inquiry Hello, I have been charged with the task by a corporate client to do diligence in finding the most efficient PV out there which is commercially available, or may be available in the next five years. They are not satisfied with the roughly 20% efficiency of Sanyo / Sunpower, for instance. They want the greatest power density available and may be willing to serve as a beta test site for something of highest efficiency, and money may not be an object. The roof footprint can accommodate roughly 85KW of Sanyo 210's as it looks today. Any info you folks can provide would be greatly appreciated. I basically need to write a white paper describing everything out there and the pros and cons of each. It is possible I could hire a consultant (recommended by or from our wrench list) to do this research for me if it feels right. I imagine this type of analysis has been done before. Thanks in advance. Kirk Herander Vermont Solar Engineering 802.863.1202 NABCEP(tm) Certified Solar Installer NYSERDA-eligible Installer VT Solar Incentive Program Partner -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery Boxes?
Hi August, That's it. http://www.nulime.com/titan-packer-45-polyethylene-storage-chest/p261914 also sells it for less. Is $213.08 with shipping included a good price for a store-bought enclosure for 4 each L16s? Joel Davidson - Original Message - From: August Goers To: RE-wrenches Sent: Friday, July 16, 2010 8:16 AM Subject: Re: [RE-wrenches] Battery Boxes? Joel - I think this is the tool box you mentioned: http://www.toolboxes4less.com/titan-packer-storage-chest-31.html Looks almost ideal. I'll let you know how it works. Best, August On Thu, Jul 15, 2010 at 10:40 PM, Ken Schaal k...@commonwealthsolar.com wrote: We build our own boxes using a cement board like 4x8 sheets of Hardi Board--fireproof, strong enough , with appropriate bracing, to take the inevitable ' stuff ' that gets piled on top of boxes in garages,etc. If you need acid resistance, coat the inside with an epoxy paint, like garage floor paint. But for GTWB, it's mostly AGM's. Ken Schaal CommonWealth Solar - Original Message - From: August Goers To: RE-wrenches Sent: Wednesday, July 14, 2010 2:37 PM Subject: Re: [RE-wrenches] Battery Boxes? Hi Wrenches - We're seeing more and more interest in grid tied battery backup systems in the Bay Area. Anyway, I'm finding that off the shelf battery boxes are quite expensive - the products from MidNite Solar, DPW, etc are all really nice but super pricey. Any recommendations on battery boxes? We've been using L16 AGM batteries but we might be going to a different size and shape. Any recommendations on favorite batteries is also appreciated. I hope you're all enjoying solar high season! Best, August August Goers Luminalt Energy Corporation 1320 Potrero Avenue San Francisco, CA 94110 m: 415.559.1525 o: 415.641.4000 aug...@luminalt.com -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.830 / Virus Database: 271.1.1/3004 - Release Date: 07/14/10 02:36:00 ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org -- August Goers VP, Engineering Luminalt Energy Corporation 1320 Potrero Avenue San Francisco, CA 94110 O: 415.641.4000 M: 415.559.1525 aug...@luminalt.com -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery Boxes?
Hello August, See The New Solar Electric Home, 3rd edition, page 225, for a photo of polyethylene tool boxes used to enclose L16 batteries (also John Wiles' Home Power #98 article). I suggest asking John Wiles where to get the boxes. Best regards, Joel Davidson On 7/14/2010 12:37 PM, August Goers wrote: Hi Wrenches - We're seeing more and more interest in grid tied battery backup systems in the Bay Area. Anyway, I'm finding that off the shelf battery boxes are quite expensive - the products from MidNite Solar, DPW, etc are all really nice but super pricey. Any recommendations on battery boxes? We've been using L16 AGM batteries but we might be going to a different size and shape. Any recommendations on favorite batteries is also appreciated. I hope you're all enjoying solar high season! Best, August August Goers Luminalt Energy Corporation 1320 Potrero Avenue San Francisco, CA 94110 m: 415.559.1525 o: 415.641.4000 aug...@luminalt.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Need SP140 modules
Wrenches, I need 10 each Siemens SP140 or SP150 modules (72-cell, 24V) to replace broken modules. Please contact me off-list. Thank you very much. Joel Davidson ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Demand savings from PV FYI
Hello Daryyl, California electric utilities base their monthly demand charge on the highest 15 consecutive minutes kW demand for each month. PV clients can have excellent mid-day demand reduction until 15 minutes and 1 second of clouds occurs. Then that high demand sets the monthly rate. However, demand management with or without PV can significantly reduce the monthly demand charge. For more information see http://www.sce.com/NR/rdonlyres/DE3375D0-8402-43CC-ABE1-38C65682B6CF/0/527V10707TOUPAB.pdf and http://communities.nrri.org/c/document_library/get_file?p_l_id=49730folderId=49865name=DLFE-2208.pdf Joel Davidson - Original Message - From: Peter Parrish peter.parr...@calsolareng.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Saturday, June 26, 2010 1:25 PM Subject: Re: [RE-wrenches] Demand savings from PV FYI Darryl, I'm sure what you say is generally true, but unless your utility has an enlightened tariff, I still think we have a problem. Since the demand charges are based on the highest demand recorded on a trailing 12 month basis, what happens on that one sunny hot day when a cloud passes in front of the sun for 15 minutes and the recorded demand for that time period is recorded and the demand then snaps back to historical values. In SCE territory, I believe, the demand charge gets pegged at that value for the next 12 months, regardless. Please explain to me anything I'm missing. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 peter.parr...@calsolareng.com Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Darryl Thayer Sent: Saturday, June 26, 2010 7:21 AM To: RE-wrenches Subject: Re: [RE-wrenches] Demand savings from PV FYI Hi all A while back we had a thread going on demand savings from PV. I reciently viewed a 1 year data set. The PV Savings were $36/ month on energy and almost $100 a month on Demand. The company is a small business with lots of computers and of course air conditioning We are blessed with a diurnal temp swing. so morning are cool, and economizers are effective. The builoding does not have building automation system. The summer demand is by far the highest, Every monthly peak occured in the afternoon, The highest peaks were on sunny days in the afternoon, the solar reduced all the highest demand peaks. The Demand fee structure is both a monthly charge and a ratchet that follows the highest peak for 11 months. The system is 12 Outback inverters. BTW the smud program with Silent Power should reduce both utility and customer demand charges. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
[RE-wrenches] Universal tool for PV connectors
10.06.2010: The Multitool - the new universal closing tool from Wieland Electric - replaces the multitude of special tools which, up to now, were necessary for the on-site assembly of photovoltaic plug connectors. Technicians can now cut and strip cables and crimp the silver plated contacts of PST40i1 photovoltaic plug connectors on site using a single tool. The universal tool replaces wire cutters, wire strippers and crimping tools, and facilitates the installation of photovoltaic panels with plug connectors, especially on roofs and in areas that are difficult to reach. The Multitool can be used on cables of 4 and 6mm². . Source: Wieland Electric http://www.wieland-electric.com The complete press release can be viewed in PHOTON's archive using the following link: http://www.photon-international.com/newsletter/document/26254.doc ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Real world PV production
PVWatts is a good general estimator when you fine-tune the derate factor. For single crystal and multicrystalline arrays, I generally use 0.65 for battery-based PV and inverter systems and 0.82 for batteryless inverter systems. PVWatts annual results are l5% low for Unisolar arrays because PVWatts uses the crystalline silicon temperature coefficient. Even though PVWatts2 may seem more accurate, it does not factor in unique local climate conditions like California coastal morning and afternoon fog or inland persistent winter Tule fog. However, NREL's climate data does include LA's June gloom see http://en.wikipedia.org/wiki/June_Gloom For flat roofs in snowy climates like the Unisolar project in Rochester NY, I deduct 30% from PVWatt's November through March estimates for a fairly accurate annual estimate. Powerlight (now SunPower) also uses an additional 30% monthly derating for flat roofs in snowy locations. PVWatts does not account for really dusty and dirty air locations. Bill Brooks worked at PVUSA and is very knowledgeable about power loss from soiling from agricultural dust in central California. Bill also measured 35% power loss at the Long Beach CA harbor waste-to-energy powerplant PV systems. That location and most LA county freeways experience particulate pollution that not only reduces PV production but causes permanent respiratory damage to children and shorten the lives of elderly people, sort of like the canary in the mine. Joel Davidson - Original Message - From: Kelly Keilwitz, Whidbey Sun Wind To: RE-wrenches Sent: Thursday, June 10, 2010 7:57 AM Subject: Re: [RE-wrenches] Real world PV production Thanks, Don, Performance predictions such as from PV Watts VASTLY underestimate PV production in our area. For example, PV Watts estimates 940 kWh/kW for a 4:12 pitch at 180˚, whereas such systems are actually producing up to 1300 kWh/kW (as measured by a renenue-grade production meter). We have to set the derating factor to nearly 100% in order for the predictions to match. I assume that is partly due to coarse irradiance data (not accounting for higher irradiance for our location in the rain shadow of the Olympic Mountains), but also due to our clear, cool, windy summers, good natural washing, and (perhaps) dispersed distribution of irradiance. I want to know if the opposite is true: Do performance predictions OVERESTIMATE PV production in areas with historically high irradiance, but significant soiling and temperature issues. Thanks, -Kelly Kelly Keilwitz, P.E. Whidbey Sun Wind Renewable Energy Systems ke...@whidbeysunwind.com 360-678-7131 On Jun 9, 2010, at 8:59 AM, i2p wrote: On Jun 9, 2010, at 8:22:12 AM, Kelly Keilwitz, Whidbey Sun Wind ke...@whidbeysunwind.com wrote: Thanks, Joel How about PV systems away from the coast, in a hotter, dustier location, like Bakersfield, Fresno, Sacramento, Palm Springs, etc? In central CA we do a little better. I casually monitor several systems in this area and expect around 1500-1600 kwh/kw. per year. Don Loweburg -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Astopower 120 failure
Hello Jim, Astropower's evolution is characteristic of some of the changes that happen to PV manufacturers, but Astropower's legal problems are not typical. Some very talented people worked at Astropower. They made good solar cells and modules. The company had it heyday. See http://www.allbusiness.com/banking-finance/financial-markets-investing-securities/6113472-1.html followed by http://guntherportfolio.blogspot.com/2007/05/astropower-saga-continues-fraud-claims.html and possibly ending with http://www.sec.gov/litigation/litreleases/2009/lr20938.htm For a chronology, see http://guntherportfolio.blogspot.com/2006/08/astropower-decline-of-solar.html Regarding your comment about revolving doors, it may seem that way because good ideas and good people hang in there. I think that one of the fundamental problems with PV is that is so darn attractive to both idealists and opportunists. At the wrench level, many of us techno-environmentalists were attracted to this wonderful electric generator that almost magically consumes and emits nothing. Our involvement with PV borders on obsession. The same attraction (sometimes not so idealistically) occurs at the manufacturing level where scientists, engineers, marketing sales people, and managers are constantly stirring the pot resulting in change that often drives wrenches crazy. Arco Solar popularized the PV change game. Some of you may recall when Arco Solar announced that it was committed for 10 years to making 1 ft by 4 ft modules only to change to 13-inch wide modules the very next year. That was that start of the industry's constant model churning that has resulted in umpteen different shapes, sizes, and colors that change as often as fashion clothes. Arco management loved PV enough to invest $150 million over 10 years into Arco Solar - which benefited Siemens - which then went to Shell - which is now SolarWorld. Astropower's launch and crash took less time than Arco Solar, but was driven by the same fundamental motivation - a desire to make big bucks in technology followed by the realization that PV is not a billionaire maker. Nevertheless, there are few better ways for techno-twits to earn money while waiting patiently for foul your nest and move west to be replaced by sustainability. Joel Davidson - Original Message - From: James A. Hartley gr...@inil.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Tuesday, June 08, 2010 10:11 AM Subject: Re: [RE-wrenches] Astopower 120 failure Has anyone been chronicling the curious morphological progressions of PV module manufacturers over the years? I'd be curious to know how that has flowed, and maybe why precisely. From my current distant remove from all this action what I see is endless revolving doors or brand new doors looking for a convenient passing hole. Is that how all the bucks get recycled for a spell and then the buckeroos go on to the next best opportunity elsewhere? I think there's a fitting name for that inclination but I conveniently forget it. - Original Message - From: Bill Brooks billbroo...@yahoo.com To: 'RE-wrenches' re-wrenches@lists.re-wrenches.org Sent: Tuesday, June 08, 2010 10:46 AM Subject: Re: [RE-wrenches] Astopower 120 failure Carl and David, Of course this means nothing related to the AstroPower warranty. The lawyers at GE Energy were very careful to wait until AstroPower was officially dead before they bought the Equipment to make modules from them. There is no warranty--even though they are materially identical to the early GE product. In the U.S. we call that business. Bill. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Real world PV production
1433 kWh/kW/year 20 each Siemens SP75 single crystal silicon solar modules Array mounted 6 inches above comp shingle roof Array azimuth 205 degrees; tilt 18 degrees 1 each SMA SWR2100U inverter Culver City, 5 miles north of LAX and 5 miles east of Pacific Ocean Low to medium air quality but mostly better than the rest of the Los Angeles basin Average maximum summer temp. 81 degrees F. Average minimum winter temp. 46 degrees F. - Original Message - From: Kelly Keilwitz, Whidbey Sun Wind ke...@whidbeysunwind.com To: RE Wrenches listserve re-wrenches@lists.re-wrenches.org Sent: Tuesday, June 08, 2010 10:34 AM Subject: [RE-wrenches] Real world PV production CA Wrenches, What does a PV system in a hot, smoggy or dusty area of California actually produce, in kWh/kWp/year? Not an ideal system that is washed every month, but real-world, average system figures, verified by a production meter. Thanks, -Kelly Kelly Keilwitz, P.E. Whidbey Sun Wind Renewable Energy Systems 987 Wanamaker Rd. Coupeville, WA 98239 ke...@whidbeysunwind.com PH FAX: 360.678.7131 NABCEP Certified PV Installer WA Electrical Administrator ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] FSEC Approval Required for Permit?
Hello Jason, I got the first FSEC BIPV certification. The paperwork was time-consuming, but the FSEC people were reasonable. Getting FSEC certification is like getting UL, IEC, CSI, etc. certification. It's the price of admission to get you and your product in the game. Superior Solar, Solartek, etc. already have certified Enphase in combination with various solar modules. Sun Electronics has paid its dues and has multiple system certifications. Also Enphase has worked with FSEC. See http://www1.eere.energy.gov/solar/pdfs/segis_winners_2008.pdf I encourage you to get Enphase to support your effort to expand the use of their product. Joel Davidson - Original Message - From: Jason Szumlanski ja...@fafcosolar.com To: re-wrenches@lists.re-wrenches.org Sent: Thursday, June 03, 2010 6:57 AM Subject: [RE-wrenches] FSEC Approval Required for Permit? Hi Wrenches, Has anyone dealt with a jurisdiction that requires FSEC or similar system approval as a prerequisite for obtaining a PV permit? Although we have installed many systems in a particular jurisdiction in our area, they just rejected a permit application because we do not have an FSEC system certification on this system (24 Enphase microinverters). We are having a hard time getting them to explain from where the requirement came. It seems like a nonsense roadblock to me. I can't imagine what purpose an FSEC certification would serve in the case of microinverters. As long as you are using a module on Enphase's compatibility list and the module itself has FSEC certification, can you think of any logical reason to jump through this hoop? On that note, I contacted FSEC to see what it would require to certify Enphase microinverter systems. They are telling me that we would have to apply for one system, and then apply for similar systems if the number of inverters changes. That doesn't make any sense to me. Are we supposed to submit applications for 1, 2, 3...50...150 module systems? I doubt they have time to deal with the paperwork for hundreds of similar system applications. Imagine dropping 200 similar system applications in their inbox to cover all quantities of microinverters. Jason Szumlanski Fafco Solar Cape Coral, FL ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] low cost DAS systems - Feedback
Wrenches, Chris' email motivated me to buy a low-cost, easy-to-install monitoring system for residential and small commercial PV systems. I sent RFQs to vendors asking for a monitoring system for my PV systems, a SunnyBoy 240VAC PV system, and an oldie-but-goodie Trace 120VAC PV system. See http://www.solarsolar.com/oursys.html and http://www.solarsolar.com/solardwgs.html sa...@fatspaniel.com and distribu...@theenergydetective.com did not reply to my RFQ email. Draker Labs sent an automated reply but did not contact me. Daron at locusenergy.com replied quickly. He was very supportive, quickly answered questions, and gave us a training webinar. Price for one system is reasonable: $509 for 5 years of generation monitoring, data hosting, and performance hardware, plus $40 for California rebate program automated reporting, plus $130 to monitor electric consumption. Daron did a good job explaining Locus, but I needed 2 systems and didn't want to spend over $1,000. Charlie at egauge.net also replied quickly. Their residential eGauge system to monitor the Grid, PV system #1 and #2 costs $760, It includes the eGauge main unit, homeplug communication adapter and 5 CT's (2 CTs for the main utility feeds - one on each leg), 1 CT for the SunnyBoy system and 2 CTs for the Trace system. Better price, but still higher than I wanted to spend. Robin at powersave.us (Envi) answered my phone and email questions quickly. Their price was much lower so I bought their hardware. $237 for 1 Envi monitor with 1 transmitter and 2 CTs for PV system #1, plus $79 for 1 transmitter with 2 CTs for PV system #2, plus $12 for the USB cable, plus $17 for shipping. Powersave shipped the equipment promptly, but it took me a few days to get around to installing the hardware. The Envi monitor is in our office next to my computer. Installing the transmitter and CT on the Trace/battery PV system was easy. The Trace inverter is in the garage next to our office but not away from our electric service panel. You only need one CT to monitor a 120VAC PV system's output. The SunnyBoy inverter is next to the electric service panel. Grid power wiring into the service panel is behind the clamped and sealed utility meter. I did not want to break the utility seal to open that section of the panel so I am not monitoring the grid. Besides, monitoring the grid with a net metered PV system only tells what the utility kWh meter measures. Inside our 200A service panel, there is just barely enough space for the transmitter. The CTs are big, but I was able to squeeze them into the panel, replace the breaker cover, and close the panel door. Loading the USB cable driver was easy, but I had trouble getting the computer to see the 3rd party monitoring software. So I used the C2 Terminal free software to make sure my computer was seeing the Envi meter. I still could not get any of the monitoring software to work because the instructions were not intuitive or simple enough for me to understand. Tony at http://makehistori.net/ emailed instructions a few days ago. Today I had some time to muddle my way through downloading, logging in, registering, etc. and am up and running. I am still learning how to use his software. Chris at currentcost.com is has been emailing to help me use their software. I'll give it a try. Robin at powersave.us recommends Techtoniq. I'll give it a try too. When I first talked to Robin at powersave.us, I asked him why his device was not listed on the California Solar Initiative (CSI) Eligible System Performance Meters List. See http://www.gosolarcalifornia.org/equipment/meter.php He did not know about the list but understood immediately how important it was to get listed. Today, he emailed that their meter will be on the CSI list June 1st. Joel Davidson - Original Message - From: Chris Schaefer To: re-wrenches@lists.re-wrenches.org Sent: Monday, April 12, 2010 10:07 AM Subject: [RE-wrenches] low cost DAS systems Good Day Wrenches, I'm looking for suggestions for a low cost DAS system for home/small commercial use. It just seems to be such a useful basic tool to verify performance other than just the Kwh meter. I'd like to add this to all of our clients quotes and projects. Looking for the basics like module temperature and irradiance and it would be nice if it would tie into the existing inverters DAS like an Enphase, Fronius or SMA to name a few since they already have inverter and PV in/output information. Or is Fat Spaniel and Helitronics my only options otherwise? Thanks for the help ahead of time. Christopher Chris Schaefer's WHERE KNOWLEDGE EQUALS POWER INDEPENDENCE Specializing in Off-Grid Electricity for Remote Homes Grid-Tied Power for Residential and Commercial Sites Tel 585-229-2083 ~ Cell 585-748-1870 5115 South Hill Road Canandaigua New
Re: [RE-wrenches] recover broken modules
Jeff, You can put another glass front on top of the module to protect the cells and wiring to get a few more years use from the module. My customer got 3 years of use from a broken module in extreme Alaska weather. Other customers had similar luck. 1. Clean with low pressure dry air to remove loose glass and dirt. Be careful with flying glass and avoid damaging cells, interconnects, and bus wires. 2. Inspect and repair backsheet tears. 3. Test to ensure Voc and Isc are within specifications. 4. Wipe front edge of frame with clean, dry cotton cloth. 5. Apply non-acid silicone RTV on front edge of frame. 6. Apply glass cover module and let silicone seal cure for at least 24 hours. Good luck. Joel Davidson - Original Message - From: Jeff Yago To: RE-wrenches Sent: Wednesday, May 26, 2010 8:19 PM Subject: Re: [RE-wrenches] recover broken modules Over the past few years we have had our share of modules damaged in shipment or in handling on our end that were never installed but had broken glazing. As you know, when these things go they usually look like a car windshield, with the vinyl backing holding all the broken small glass pieces together. Seems like a shame to trash, is there anyone out there with a way to re-glaze a new module with broken glazing. Any chance you could just place a new glass glazing over the broken glass and seal? Or some way to remove the glass pieces without damaging the module cells and inter-connect foil connections being held in place by the backing. Seems like a business opportunity, Jeff Yago -- Netscape. Just the Net You Need. -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Rip in panel backing
MessageBrian is correct. 739 is a reliable sealant. Some people put acid-free, clear, insulating tape on the tear after cleaning (clean, dry or lightly damp cotton cloth) and drying (heat gun on low setting or hair dryer) the area and before applying the silicone. The tape is optional. Joel Davidson - Original Message - From: Brian Teitelbaum To: RE-wrenches Sent: Tuesday, May 25, 2010 4:51 PM Subject: Re: [RE-wrenches] Rip in panel backing I like Blair's idea, but I've always used a silicone sealant that doesn't use acetic acid as the curing agent. Dow #739 is one type, but any silicone sealant that is rated as food-grade, or for aquariums, should work fine. The 739 is a moisture-cure, 100% silicone, which uses moisture present in the air as the curing agent. I was told many years ago that this is the stuff that is used by module manufacturers to attach and seal module junction boxes and the exit point in the laminate where the tabs come out. It would be great if a module rep could confirm this with us. Brian Teitelbaum AEE Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Blair May Sent: Tuesday, May 25, 2010 3:09 AM To: 'RE-wrenches' Subject: Re: [RE-wrenches] Rip in panel backing I use a heat gun to remove moisture smooth out the rip then I've used some bitchathane w/ foil tape over that. I am not sure about the possible corrosive effects of the silicone during curing. -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of bob Sent: Tuesday, May 25, 2010 5:49 AM To: 'RE-wrenches' Subject: [RE-wrenches] Rip in panel backing I have a customer who just put a rip in the (tedlar?) on the back of a Solar World 175 watt panel. For some reason he thought that he needed to move the leg to a different hole on his RGM mount instead of just collapsing it. What's the best way to seal it back up? There is no other internal damage that is noticeable its about 1.5 long and ½ at the widest end. My first thought is to use silicone caulk, but I thought I would pick the collective brain, so to speak. Thanks, Bob Ellison -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Rip in panel backing
MessageYou can also use GE Silicone RTV-108 sold by Grainger. - Original Message - From: Joel Davidson To: RE-wrenches Sent: Tuesday, May 25, 2010 6:07 PM Subject: Re: [RE-wrenches] Rip in panel backing Brian is correct. 739 is a reliable sealant. Some people put acid-free, clear, insulating tape on the tear after cleaning (clean, dry or lightly damp cotton cloth) and drying (heat gun on low setting or hair dryer) the area and before applying the silicone. The tape is optional. Joel Davidson - Original Message - From: Brian Teitelbaum To: RE-wrenches Sent: Tuesday, May 25, 2010 4:51 PM Subject: Re: [RE-wrenches] Rip in panel backing I like Blair's idea, but I've always used a silicone sealant that doesn't use acetic acid as the curing agent. Dow #739 is one type, but any silicone sealant that is rated as food-grade, or for aquariums, should work fine. The 739 is a moisture-cure, 100% silicone, which uses moisture present in the air as the curing agent. I was told many years ago that this is the stuff that is used by module manufacturers to attach and seal module junction boxes and the exit point in the laminate where the tabs come out. It would be great if a module rep could confirm this with us. Brian Teitelbaum AEE Solar From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Blair May Sent: Tuesday, May 25, 2010 3:09 AM To: 'RE-wrenches' Subject: Re: [RE-wrenches] Rip in panel backing I use a heat gun to remove moisture smooth out the rip then I've used some bitchathane w/ foil tape over that. I am not sure about the possible corrosive effects of the silicone during curing. -Original Message- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of bob Sent: Tuesday, May 25, 2010 5:49 AM To: 'RE-wrenches' Subject: [RE-wrenches] Rip in panel backing I have a customer who just put a rip in the (tedlar?) on the back of a Solar World 175 watt panel. For some reason he thought that he needed to move the leg to a different hole on his RGM mount instead of just collapsing it. What's the best way to seal it back up? There is no other internal damage that is noticeable its about 1.5 long and ½ at the widest end. My first thought is to use silicone caulk, but I thought I would pick the collective brain, so to speak. Thanks, Bob Ellison ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] 30-year old PV module
Hello Drake, (silicon not silicone) Good question about thickness. I recently inspected a circa 1996 solar array with 300 micron thick, 6-inch round cells encapsulated behind 3 mm thick glass and found a few cracked cells and impact fractures. Today, some cells are 260 to 200 microns and even down to 180 to 160 microns thick. I think if the cells are handled properly, and the glass is 4 mm thick, and the module frame is strong enough to minimize twisting, and the modules are handled and installed with care, then cell breakage can be kept to a minimum. It's not how thin the cells are. It is how the cells and modules are encapsulated and handled. Joel Davidson - Original Message - From: Drake Chamberlin To: RE-wrenches Sent: Saturday, May 22, 2010 1:39 PM Subject: Re: [RE-wrenches] 30-year old PV module Thanks for the excellent article. I have two of these old Arcos, and they still put out like new, even though one was (apparently) used in a concentrator, due to the fact that it came bronzed. Do you think the newer modules, with thinner silicone, will last as long? At 10:53 AM 5/21/2010, you wrote: If your prospect asks how long do PV modules last, refer them to this article http://www.greenbuildingadvisor.com/blogs/dept/musings/testing-thirty-year-old-photovoltaic-module Drake Chamberlin Athens Electric OH License 44810 CO License 3773 NABCEP TM Certified PV Installer Office - 740-448-7328 Mobile - 740-856-9648 -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
