Re: [RE-wrenches] Remote battery disconnects
> Oh, yeah, the charge controller blowing up thing: Does anyone have any > factual data to share on this? Although our controllers are probably smaller than what you would be considering in this discussion, surviving a load dump (suddenly disconnected battery) is an engineering requirement for us, and likely would be for other responsible MFG's on this list (boB?). The charge controller can either handle full input voltage on the output, or there is a comparator that will shut the controller down instantly when the output voltage gets too high. The only time we run into trouble during a load dump is if there is another charger that is less well-behaved, such as an alternator, running at the same time. This most commonly happens on sailboats, when someone turns off the ignominious battery switch with the engine still running. The alternator spikes the battery line from 12V up to 50-100V+ before the alternator regulator can respond, and the charge controller (and other electronics aboard) might not survive. Tangential to this conversation, it seems battery switches cause our marine and RV customers way more problems than they solve. It seems important to have one, but I wish they were a little more towards the break-glass-in-case-of-emergency end of the accessibility spectrum. Thank as always, Wrenches, for the information you share and high level of discourse. Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
Re: [RE-wrenches] 24/7 Water pumping
For high-voltage MPPT charge controllers, you might check out some of the Australian brands (I remember AERL being one). It seems there are some differences in code there that don't result in the de facto 48Vdc limit we have here in the states. Incidentally, we had a product in that space (up to 144Vdc) about a decade back, but it was essentially killed when the government tabled the subsidies. These were replacing gensets at cattle stations where the roads were too muddy to haul diesel down for 6 months of the year. The economics were still phenomenal without subsidies, but of course, everyone just stopped doing the solar installs waiting to see if the subsidies came back. Sigh... Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com On Tue, Mar 15, 2022 at 3:26 PM Ray Walters wrote: > > The Midnite Classic can go higher to 72v stock, and they have models that can > work with 120 vdc batteries. > > Ray > > On 3/15/2022 12:19 PM, larrycrutcher wrote: > > Hi William, > > A charge controller may not be needed if you are running the pump direct. By > designing the PV array so that the Isc is higher than the maximum load > demands, and the Voc is less than the maximum operating voltage, you can run > PV direct without a controller. Use a high voltage relay (like Gigavac) for > switching from the float or pressure switch. > > Charging a high voltage chemical battery direct from PV power is conceivable > but much harder. If you can’t find a controller, I would opt to use the > pumped water as the battery…pump it high, use gravity. > > Larry Crutcher > Starlight Solar Power Systems > > > > On Mar 15, 2022, at 9:10 AM, William Miller wrote: > > Windy: > > Thanks for the info. I have been in contact with Sun Pumps. They can sell me > a pump that will work off of a high voltage battery bank (greater than 90 VDC > and likely much higher). However they cannot provide or recommend a charge > controller to output PV charge at the higher voltage. Do you or any wrench > know of a high voltage charge controller on the market? > > Thanks in advance. > > William > > On Thu, Mar 10, 2022 at 8:29 AM Windy Dankoff wrote: >> >> Dear William, >> >> SunPumps has a new helical rotor submersible series (positive displacement) >> that is typically much more efficient for high lift compared to a normal >> multi-stage centrifugal sub (you'll have to compare the specs). >> >> https://www.sunpumps.com/Products/HR%2010-525%20AC%20DC >> >> I have no inside-knowledge of this item, but it's based on good technology >> similar to Lorentz and Grundfos and SunPumps is on the same level as a world >> leader. >> >> With any DC pump, you need to be sure it's compatible with battery power if >> you need 24/7. >> >> I hope you'll let us know how it goes. >> >> Windy >> >> >> From: William Miller >> Subject: [RE-wrenches] 24/7 wATER pUMPING >> Date: March 8, 2022 at 7:53:37 AM MST >> To: RE-wrenches >> Reply-To: >> >> >> Friends: >> >> >> >> I have a client that wishes to pump water at about 10 GPM from spring >> through autumn equinoxes. Lift is 300 feet. (This is the project that >> will not siphon beyond 33 feet.) >> >> >> >> I can design a solar/battery/inverter system for this purpose but I am >> wondering if there is a direct DC option. I am going to look at the >> Grundfos SQ-Flex tables to see if this is an option. >> >> >> >> Does anyone out there have any advice on best approach to this project? >> >> >> >> Thanks in advance, >> >> >> >> William Miller >> >> >> >> Miller Solar >> 17395 Oak Road, Atascadero, CA 93422 >> 805-438-5600 >> www.millersolar.com >> CA Lic. 773985 >> >> >> >> >> >> >> >> >> From: Jerry Shafer >> Subject: Re: [RE-wrenches] 24/7 wATER pUMPING >> Date: March 8, 2022 at 8:58:16 AM MST >> To: William Miller , RE-wrenches >> >> >> >> William >> Here is the deal it will be simplest to go AC for the pump because of the >> requirement of high voltage DC yes there are small er output DC pumps but >> that is not what you need, first find a AC pump that can do the required 10 >> GPM at 300 feet of head then design a inverter to fit that bill PV to >> recharge that usage and then some. look at the first and last day of the >> desired water demand and go the shorted day as a production base line. When >> looking at pumps grundfus is
Re: [RE-wrenches] X-240 Buzz
One thing you might want to check is for any DC getting into the transformer. This can cause the transformer to saturate on one side of the sinewave, leading to high peak currents and a buzz. You can try checking for this by putting a DMM set to DC across the AC line. Should be well under a volt. Be sure to use a quality DMM, as cheaper ones might not be able to fully reject the AC, and some of it might show up as a DC reading. To make sure the meter isn't playing tricks on you, you can also try reversing the meter polarity and making sure the DC reading inverts too. Admittedly, I haven't encountered this with an inverter before, just at a friend's apartment, where the DC caused an immediate breaker trip when a large 120->240 transformer was connected. I can sort of imagine a situation where an inverter that's not quite working quite right has a little DC offset at light loads, but that this goes away at heavier loads. Let us know what you find, Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com On Mon, Jan 31, 2022 at 7:51 AM Foxfire Energy wrote: > > Not positive, but I’d suspect resonant frequencies.. might be simple as using > flat washers under the mounting screws.. maybe try adding an inductive load > to skew the power factor.. gobs of information online.. good luck. db > > Sent from my iPhone > > > On Jan 31, 2022, at 10:34 AM, drake.chamber...@redwoodalliance.org wrote: > > > > > > An Outback X-240 auto transformer on a VFX3648 buzzes loudly with a load of > > 400 W. The sound diminishes and finally stops with higher loads. > > > > The load was an electric, oil filled space heater. > > > > Has anyone seen this before? > > > > Thank you, > > > > Drake > > > > Drake Chamberlin > > Athens Electric LLC > > Ohio Electrical Contractor’s License 44810 > > CO Master Electrician’s License 4526 > > NABCEP Certified PV Installation Professional > > > > -- > > ___ > > List sponsored by Redwood Alliance > > > > Pay optional member dues here: http://re-wrenches.org > > > > List Address: RE-wrenches@lists.re-wrenches.org > > > > Change listserver email address & settings: > > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > > > There are two list archives for searching. When one doesn't work, try the > > other: > > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > > > List rules & etiquette: > > http://www.re-wrenches.org/etiquette.htm > > > > Check out or update participant bios: > > http://www.members.re-wrenches.org > > > ___ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
Re: [RE-wrenches] Lithium Ion tool batteries
Generally, storage or use at cold temperatures shouldn't be an issue, as long as the battery can still deliver enough power to operate the tool effectively. Charging though...at cold temperatures, ion mobility goes down. If the battery is charged too fast, the lithium ions can't make it into the graphite anode fast enough and they start to plate out as metallic lithium. At best, this results in a permanent reduction in capacity. Next worst from there, the lithium metal can create an internal soft short, immediately or at a later point in time, resulting in high self-discharge or a dead cell. Worst case, it turns into a hard short and a fire. In theory, the BMS or charger should prevent charging too fast or too cold, but who knows if an edge-case like this is actually implemented correctly on any particular battery system.Be careful charging! Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
Re: [RE-wrenches] J Box adhesive failure.
Hi John, I like polyurethanes for this sort of thing. They are substantially stronger than RTV, and if you need to re-do it, you won't be left with that oily texture that nothing else will stick to. "3M Marine Adhesive Sealant Fast Cure 4000 UV" might be a good choice, and Sikaflex also makes some really good options. One downside is that even the "fast cure" polyurethanes cure rather slowly. If you go with RTV, look for a "neutral cure" type. Others typically off-gas acetic acid when they cure, which can corrode wiring. Good luck, Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
Re: [RE-wrenches] Charging multiple battery banks from one array
I've had good luck personally with the Blue Sea ACR. It's automatic and solenoid-based, so while there's some parasitic draw, there's essentially no voltage drop. (The "Sure Power Multi Battery Isolator" seems to be diode based.) They are also bidirectional. If you'd like, it sounds like you could ditch the isolator, connect the solar to the house bank, use one ACR between each start battery and house battery, and have everything be able to charge everything. This also avoids the potential issues of either trying to make a solar charge controller run through diodes to the battery (though some of ours will, I don't think it's the preferred situation for any MFG), or dealing with differing charge voltages due to isolator diode voltage drops. I believe Blue Sea also makes a newer version with an emergency parallel function, which is regrettably absent on mine. I'm a fan of Blue Sea...my one beef is that, since many of their products are rebranded from other manufacturers, there is no consistency to stud sizes or even nut dimensions, necessitating a way bigger pile of sockets and terminals, and more planning than might otherwise be necessary to get a job done. Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com On Fri, Apr 16, 2021 at 1:28 PM Dave Tedeyan wrote: > > Hi All, > I am adding solar to a boat, which is new for me. There are three batteries: > one for each of two engines (both of which can also power DC loads), and a > house battery connected to an inverter for AC loads on the boat. All three > batteries are able to get charged from the two engine alternators through a > Sure Power Multi Battery Isolator. We are going to have 4 320w panels and two > FM60 charge controllers. It is a 12V system. > > I would like to be able to use the solar to charge all three batteries. Is it > reasonable to use something like another one of those Multi Battery Isolators > to allow all the solar to independently charge each battery? Is there another > product out there that people would recommend for this? > > Thanks for the help! > Cheers, > Dave > > -- > Dave Tedeyan, PE > > 1653 Slaterville Road, Ithaca, NY 14850 > Cell: 607-288-2898 > www.sungineersolar.com > ___ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
Re: [RE-wrenches] Charging 48V Battery with One Module
Hi Jason, et al., Applications in our size range don't come up too often on this list, so I've been mostly an appreciative lurker, but I'd like to introduce myself as the contact for Genasun and Blue Sky Energy, (and the engineer behind the GVB-8 controller in question). To address a few of the questions that have been asked, the GVB-8 can be programmed at the factory with any custom charge profile desired if none of the off-the-shelf options are a good match. Efficiency at ~48V nominal is >98% over most of the power range, and the controllers employ true MPPT, so no configuration is necessary for different panels. As mentioned, 10A Imp input is on the high side for the GVB. Most Genasun controllers were designed when PV was expensive and panels were smaller. Although they do have current limits and thermal rollback for self-protection, running continuously at the standard current limit would be hard on the electronics. Panels have grown, and there is more interest in PV-heavy installations. As we redesign and re-qualify our controllers, we have developed a few workarounds. The GVB-8 can be ordered with the LOWCURLIM (low current limit) firmware option, which limits the input current to about the rated 8A, allowing use with oversize panels, such as the 420W panel in question. Separately, thank you all for the expertise you share on this list. I've learned a lot about installation and code issues for small (and large) solar, and it's given me a great appreciation for the challenges you face trying to integrate all the various pieces of equipment to give your customers a good experience. Regards, Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
Re: [RE-wrenches] Reactive Power
Hi Drake, 25W should be the draw from the batteries after accounting for inverter efficiency. Note that the low power factor will reduce the effective inverter efficiency, since the inverter still has 49VA of reactive power causing losses. For a small switching power supply like the laptop's, the poor power factor is most likely caused by high current peaks as the internal capacitors charge for just a small fraction of the total sinewave cycle, rather than a large phase difference like you might see with a motor or other inductive load. Alex MeVay Blue Sky Energy * http://www.blueskyenergyinc.com Genasun * http://www.genasun.com On Tue, Dec 17, 2019 at 10:17 AM wrote: > > Hello Wrenches, > > I checked my laptop with a Kill A Watt meter. It drew 25 W,but 49 VA. Which > number represents the true draw on the batteries? > > Thanks, > > Drake > > > ___ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] trickle charger for 4 12V batteries
Hi Dave, I'm interested in others' experience here, but personally, I'd skip the charger. If they are brought to full charge before storage and are in decent shape otherwise, they shouldn't have any trouble surviving winter storage. I've seen many sealed batteries die an untimely death due to electrolyte loss from trickle chargers. On the other side, I've many times stored stored vehicles for 3-8 months with batteries disconnected and no apparent ill effects (and enough charge remaining to start the car upon my return), save one battery that was already on the way out. The ideal scenario, in my mind, would be to charge the batteries about once a month. Alex MeVay Blue Sky Energy * http://www.blueskyenergyinc.com Genasun * http://www.genasun.com ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Solbian's panels ?
Hi Dana, I know Bruce Schwab at OceanPlanet Energy brings them over: https://oceanplanetenergy.com/solar-power/ I think he might be the master distributor for the US and will likely be able to give you a trade discount. Finally, for full disclosure here, we do business with all the companies I've mentioned in this thread, save Renogy, but we do so because I believe they offer top-notch products and/or service that help our customers have a good experience with their systems overall. Like many of you, we typically get the call when anything goes wrong in the system, even if it has nothing to do with the controller (i.e., panels, wiring, fuses), so we have the same motivation to choose good partners. Alex MeVay Blue Sky Energy * http://www.blueskyenergyinc.com Genasun * http://www.genasun.com On Thu, Sep 19, 2019 at 11:14 AM Dana wrote: > Solbians website is In Italy; do they have a North American dealer? I > checked the web & no contact. > > > > > > > > Dana Orzel Great Solar Works, Inc. > > *C - 208.721.7003 d...@solarwork.com > * > > Idaho Contractor - # 028765 Idaho PV # 028374 > > NABCEP # 051112-136 www.solarwork.com > > *"Responsible Technologies for Responsible People since 1988" * > > *P* Please consider the environment before printing this email. > > > > > > *From:* RE-wrenches *On > Behalf Of *Alex MeVay > *Sent:* Wednesday, September 18, 2019 6:44 PM > *To:* RE-wrenches > *Subject:* Re: [RE-wrenches] Flex panels? > > > > Hi Dana, > > > > For these types of applications, which make up a lot of our business, we > typically point customers to Solbian, who use Sunpower and other cells. I > believe our more budget-minded customers have also been happy with the > Renogy flex panels. > > > > Merlin Solar makes the best interconnect technology I've seen for > semi-flexible panels: thin grids that cover the cells and keep things > working even if the cell is shattered. I believe they do mostly B2B, but I > know at least some of Solbian's panels incorporate their technology. > > > > If your customer does want to consider some framed glass panels, stick to > the smaller sizes (100-160W) to reduce issues with frame flex (both the > vehicle's and the panel's!). > > > > I do share your skepticism about the flex panels... While I might go flex > next time for the weight savings, I have 2x 100W glass panels on my camper > van, installed by the previous owner. After 7 years and 70,000 miles, many > off-road, they are doing great. > > > > Out of curiosity, do you know what brand your customer's panels were and > how long before they gave out? > > > > Best, > > > Alex MeVay > > Blue Sky Energy * http://www.blueskyenergyinc.com > Genasun * http://www.genasun.com > > > > > > On Wed, Sep 18, 2019 at 6:15 PM Tump wrote: > > Contact Joe Marieno @Mia Sole 707-331-4030 > > On Sep 18, 2019, at 12:22 PM, Dana wrote: > > > > Hey there All – > > > > I have a new client that has an over the top [$100K+] 4X4 off road camper > that has glued down flex PV modules that have died, faded PCV front sheets > with no output. > > I suggested a framed module but client in more interested in a flexible > type of glue down module. > > > > Any suggestions on a flexible possibly glue down type of PV module, > supplier suggestions? > > Thanks in advance. > > > > > > > > Dana Orzel Great Solar Works, Inc. > > *C - 208.721.7003 d...@solarwork.com > * > > Idaho Contractor - # 028765 Idaho PV # 028374 > > NABCEP # 051112-136 www.solarwork.com > > *"Responsible Technologies for Responsible People since 1988" * > > *P* Please consider the environment before printing this email. > > > > > > ___ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > > > *t...@swnl.net * *www.SWNL.net > <http://www.SWNL.net>* > > Solarwinds Northernlights > > * Serving Mid Coast Maine & Northern
Re: [RE-wrenches] Flex panels?
Hi Dana, For these types of applications, which make up a lot of our business, we typically point customers to Solbian, who use Sunpower and other cells. I believe our more budget-minded customers have also been happy with the Renogy flex panels. Merlin Solar makes the best interconnect technology I've seen for semi-flexible panels: thin grids that cover the cells and keep things working even if the cell is shattered. I believe they do mostly B2B, but I know at least some of Solbian's panels incorporate their technology. If your customer does want to consider some framed glass panels, stick to the smaller sizes (100-160W) to reduce issues with frame flex (both the vehicle's and the panel's!). I do share your skepticism about the flex panels... While I might go flex next time for the weight savings, I have 2x 100W glass panels on my camper van, installed by the previous owner. After 7 years and 70,000 miles, many off-road, they are doing great. Out of curiosity, do you know what brand your customer's panels were and how long before they gave out? Best, Alex MeVay Blue Sky Energy * http://www.blueskyenergyinc.com Genasun * http://www.genasun.com On Wed, Sep 18, 2019 at 6:15 PM Tump wrote: > Contact Joe Marieno @Mia Sole 707-331-4030 > > On Sep 18, 2019, at 12:22 PM, Dana wrote: > > Hey there All – > > I have a new client that has an over the top [$100K+] 4X4 off road camper > that has glued down flex PV modules that have died, faded PCV front sheets > with no output. > I suggested a framed module but client in more interested in a flexible > type of glue down module. > > Any suggestions on a flexible possibly glue down type of PV module, > supplier suggestions? > Thanks in advance. > > > > Dana Orzel Great Solar Works, Inc. > *C - 208.721.7003 d...@solarwork.com > * > Idaho Contractor - # 028765 Idaho PV # 028374 > NABCEP # 051112-136 www.solarwork.com > *"Responsible Technologies for Responsible People since 1988" * > *P* Please consider the environment before printing this email. > > > ___ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > > *t...@swnl.net* *www.SWNL.net* > Solarwinds Northernlights > * Serving Mid Coast Maine & Northern California* > * 207-832-7574 Cl. > 610-517-8401 * > *Blair "TUMP" May* > > > * MAINE'S CHARTER * * > NABCEP"Certified PV Installer"* > > > * MAINE'S CHARTER ** > Trace Xantrex "Certified" Dealer / Installer"* > > > > ___ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Hydro system
Hi Mac, We worked for a while building controls for one company in Oz doing small hydro, and I can share some observations, and things I learned coming from a solar background: > My first question is can you run a power system from hydro direct in the 10 > -100 kW range? Yes, I believe this is common in that power range to avoid battery and BoS costs. A DC-coupled/battery-backed approach could be used where the water flow is seasonal or insufficient for loads, or where solar is added. > If so, how do you adjust for varying load? For smaller systems with "normal" (i.e., not "low-head") turbines, the water is pretty much either there or it isn't, so the turbine works with constant head. Typically, these are set up to run at full power, and a diversion load is used to regulate RPM (and frequency for AC systems). For AC systems, rotor/field current can be adjusted to regulate voltage, as you mentioned. For the DC systems we supported, we built our control algorithm to the turbine builder/installer's instructions, and rather than trying to MPPT the turbine as we would for solar, the controller was set to clamp the rectified turbine voltage to a fixed, user-adjustable value. At installation, after the nozzles and penstock were adjusted, the installer would manually adjust the turbine clamp voltage to maximize charging current, then leave the voltage there indefinitely, in effect doing MPPT once. Our controller used a diversion load to regulate the turbine voltage/RPM once the batteries were full. As you scale things up, the diversion load approach would seem to get a little silly, so adjusting the flow rate as Darryl suggested would seem to be the better, if more complex approach. Based on the info you gave for your customer's installation, it seems like the automatic transfer switch is a great idea, but it's probably not worth trying to DC-couple it if it's working well when not clogged. For some background and reference, here are some links to AC and DC hydro products from the company we worked with, and an excellent writeup of a personal small AC hydro installation that talks through the transmission and control issues in great detail: https://www.platypuspower.com.au/ https://ludens.cl/paradise/turbine/turbine.html https://ludens.cl/Electron/picelc/picelc.html https://ludens.cl/Electron/AVR/AVR.html Again, thank you Wrenches for all the knowledge you share. Alex MeVay Blue Sky Energy * http://www.blueskyenergyinc.com Genasun * http://www.genasun.com ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] LiFePo4 vs BOS
Hi All, As Larry said, when a lithium BMS disconnects, this causes a "load dump" just like disconnecting a lead-acid battery. Well-designed chargers (solar or otherwise) should be able to handle this without damage, though a failing or poorly-designed lithium battery may cause this to happen many orders of magnitude more frequently than the once-in-a-blue-moon that may occur with Pb systems. I'd like to share some pitfalls we learned back when we made lithium batteries in case they are helpful to Dan in making his decision about the Li bank. 1. Load dump can mean different things to different chargers. Solar MPPTs, (boost MPPTs excluded) won't put out more than the solar Voc. For mobile installations that may include alternator charging, a "dumped" 12 or 24V alternator may put out 100V plus before the alternator has a chance to respond and the field current can decay. Mobile systems should have a mechanism to cut the field current before popping the BMS relay. 2. Most chargers are not power supplies, and are designed to have a battery attached as the proverbial 900lb gorilla to stabilize the output voltage and buffer load transients. BMSs should be configured never to allow chargers and loads to be directly connected without a battery present. With no battery, load dump transients can destroy sensitive loads, and brownouts or bus voltage instability is likely. Best case is if the BMS has separate controls for charge and load relays, but even with one control output, separate relays for chargers and loads can prevent many problems. 3. Related to #2, most modern MPPTs use synchronous rectification in their power stage. This means that, fundamentally, they can pump power into the array from the battery just as well as in the "normal" direction. It's only the controls that keep power flowing the correct direction. Let's say a one-relay 24V Li BMS disconnects, leaving chargers and loads connected. Say things brown out to 10V on the bus, with the MPPT doing its best to keep things powered, and running from 75Vmp on the array. BMS decides it's time to reconnect, relay closes, bus voltage jumps back up to 26V and instantaneously, the MPPT power stage is still set for a 7.5:1 ratio, so power will get pumped back into the array, trying to push it up to 26V*7.5=195V, and if the MPPTs control loop or protection circuits can't respond fast enough, pop go the MOSFETs (depending on input rating of the MPPT). Separate relays for chargers and loads should prevent this, as most MPPTs will either shut down or go to absorption when the battery is disconnected, preventing the high buck ratios and problems on BMS reconnect. 4. As a side note, we get a fair number of tech support calls from Li battery users complaining of over-voltage LED indications, etc. from our MPPTs. Almost invariably, this turns out to be a "don't shoot the messenger" situation, where the lithium battery was never balanced at the factory (etc.), and is disconnecting, and our controllers are notifying the user of the problem. Usually a little customer education (and patience during cell balancing) solves the problem. Thank you as always, Wrenches, for all the knowledge you share on this list. Alex MeVay Blue Sky Energy * http://www.blueskyenergyinc.com Genasun * http://www.genasun.com ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
