Re: [RE-wrenches] Fwd: Charge control question 2

[Allan Sindelar]

Dan, Starting around 1999 with the successful introduction of the RV Power Products (long since renamed Blue Sky Energy) Solar Boost 50, we did lots of controller upgrades, as that 15-20% winter boost was a cheap and effective upgrade. For a few years we referred to the C40 as "our best-selling used charge controller". I'll be waiting for the tech info on this from Tigo. It may be good for shaded sites, which (being in the high desert) don't come up as often as in other regions. I'd like to know when to use them, and in which (series and/or parallel) configurations. Thank you, Allan Allan Sindelar al...@positiveenergysolar.com NABCEP Certified Photovoltaic Installer NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Founder and Chief Technology Officer Positive Energy, Inc. 3209 Richards Lane (note new address) Santa Fe, New Mexico 87507 505 424-1112 www.positiveenergysolar.com On 10/15/2012 5:21 PM, d...@foxfire-energy.com wrote: Hey Alan, I checked in with Tigo tech support to reconfirm. they assure me yes, this generation of optimizer (Basically a module level MPPT DC to DC converter) does work with MPPT controllers for battery charging. I pressed them for a cut sheet or statement outlining their performance in battery charging systems and was told they're working on a formal statement that can be shared with the group. I also asked for an updated on their efforts in AFCI. Again, they tell me they'd have something to share PDQ.. I agree, module level optimizers seem a bit like bleeding edge technology (Snake Oil), but I have a new techno weenie customer who swears by them. He tells me he's used them on several projects (mostly for system performance monitoring) and wants me to use them on his install, so I'm trying to do my homework as well. if anyone out there has insight, I sure would appreciate it. I'm still in wonder of the summer of 2003 I think it was.. seems we only installed C40 and C60s up to that point. Then all most over night MPPT controllers became the new industry benchmark.. Seems module level DC to DC converters have the potential to address several issues. I love my job. 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] Fwd: Charge control question From: Allan Sindelar <al...@positiveenergysolar.com> Date: Mon, October 15, 2012 3:46 pm To: RE-wrenches <re-wrenches@lists.re-wrenches.org> Dan, I checked out the Tigo website, and found nothing there to suggest that these were intended for off grid battery charging applications. A round-the-world sailboat is off grid. Are you suggesting that these will work in battery charging applications? If so,this is news. Do you have any more info you can share with us about this? Thanks, Allan Allan Sindelar al...@positiveenergysolar.com NABCEP Certified Photovoltaic Installer NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Founder and Chief Technology Officer Positive Energy, Inc. 3209 Richards Lane (note new address) Santa Fe, New Mexico 87507 505 424-1112 www.positiveenergysolar.com On 10/11/2012 2:58 PM, d...@foxfire-energy.com wrote: Check out Tigo Optimizers: http://www.tigoenergy.com/ db Dan Brown Foxfire Energy Corp. Renewable Energy Systems (802)-483-2564 www.Foxfire-Energy.com NABCEP #092907-44 From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Allan Sindelar Sent: Thursday, October 11, 2012 1:04 PM To: RE-wrenches Subject: [RE-wrenches] Fwd: Charge control question   Wrenches, I'm posting this for Carl Bickford, prof emeritus of the renewable energy training program at San Juan College in Farmington, New Mexico. I'll forward your responses to him. I have a very interesting and talented friend who is rebuilding a blue-water sailboat for a round-the-world trip. He is well versed in solar and is trying to use a relatively large array to charge a big battery bank that will be used for propulsion as well as general electrical. The propulsion system will be backed up with a propane generator he is building himself out of a Toyota truck engine. As you can imagine, there is no place on a sailboat where shading isn’t a problem. He and I were wondering if there were products out there that could MPPT either individual modules, or small groups of them for 12 V battery charging. I have seen such things for the inputs of grid-tied inverters, but nothing yet for off-grid. The other choice is to go with many small MPPT charge controllers like the ones from Solar Converters. Any advice you can offer? Take care, Carl Carl Bickford Professor of Engineering and Renewable Energy San Juan College 4601 College Blvd. Farmington, NM 87402 505-566-3503 bickfo...@sanjuancollege.edu   I offered the suggestion below. Certainly open to other and better ideas. Allan I have not encountered this situation, so I have no advice from experience. At 12V, it's hardly an issue as it is with high voltage parallel strings, where a few shaded cells can cause a whole string to drop out of the inverter's MPPT. At most, a shaded cell weakens the output of that module. And since it's charging batteries, there's a greater amount of head room. I would suggest looking into Blue Sky Energy's "i" series - smaller MPPT controllers that can be networked. We seldom use them, as our residential applications are different. But you could put a controller on a group of modules and network several together. One advantage, I think (you'd want to check this) is that Blue Sky's MPPT algorithm is analog, unlike Outback and others: on the old Solar Boost series, the MPPT boost was set with a trim pot to a particular voltage above battery voltage; the target is to set it to where the boost was greatest. You could set this boost slightly lower than peak, and output just a little below MPP. That way the overall output would be minimally reduced, and a modest amount of shading would not cause the shaded module to drop below collective MPP as readily. Allan Sindelar al...@positiveenergysolar.com NABCEP Certified Photovoltaic Installer NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Founder and Chief Technology Officer Positive Energy, Inc. 3209 Richards Lane (note new address) Santa Fe, New Mexico 87507 505 424-1112 www.positiveenergysolar.com     -- This message has been scanned for viruses and dangerous content by Hudson Valley Computer Services, and is believed to be clean. _______________________________________________ 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

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