Interesting comment - we have thousands of M215's in service with an extremely low failure rate (maybe 1 or 2). I have purposefully not started installing M250's because the M215 seems like a low risk and I'm waiting for good pricing on 280W, 60 cell modules. It's not exactly off-topic, as there seems to be evidence that a higher module rating/inverter rating ratio results in more energy harvest, presumably in part due to inverter efficiency increasing as the input power increases. That's why I have been reluctant to put 250-265W modules on the M250.
Jason Szumlanski Fafco Solar On Tue, Aug 26, 2014 at 1:59 AM, Jerry Shafer <jerrysgarag...@gmail.com> wrote: > Why dont you use the m250 anyway as the 250's so far are more reliable > then the 215 have been. A little off topic i know. > On Aug 25, 2014 1:41 PM, "Jason Szumlanski" <ja...@fafcosolar.com> wrote: > >> I had a tough customer recently that grilled me on how we can put a 270W >> solar module on a 215W inverter. Fortunately, Enphase has a wonderful white >> paper on the subject. However, it got me thinking... Enphase has >> demonstrated that higher output panels in many climates (hot SW Florida >> included) can benefit from modules that far exceed the inverter rating, and >> even exceed the inverter's "recommended input" rating. Enphase has shown >> that 270W+ modules can show energy harvest on the M215 where it makes sense >> to "oversize" the module. >> >> I also received a similar query from a rather uninformed plan reviewer in >> an area AHJ along similar lines. Fortunately I was within the "recommended >> input" rating on the spec sheet of 270W with a 265W module, but I wonder >> what would happen if I had paired the M215 with a 280W module on my plans, >> which are becoming readily available now in 60 cell modules with 300W >> modules on the near horizon. I'm pretty sure my plan would have been kicked >> back for exceeding the manufacturer's recommendation. >> >> My question, which applies to string inverters and microinverters, is how >> much is too much, what would happen if you paired an array that far >> exceeded the rating, and how do inverter manufacturers determine the >> recommended and/or maximum rating of the connected module or array? Also, >> why do some manufacturers have a simple recommendation while others have a >> "maximum" rating? >> >> >> Jason Szumlanski >> >> Fafco Solar >> >> >> _______________________________________________ >> 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 > > >
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