If it modules not diodes which will give you different issues, no voc change but a combination with less power at 25c best to use a iv curve tool like the solmetric product very cool and printable On Jun 4, 2014 10:36 AM, "Nathan Charles" < [email protected]> wrote:
> So I read this paper, Smith, R. M., Jordan, D. C., & Kurtz, S. R. (2012). > Outdoor PV Module Degradation of Current-Voltage Parameters, which seems to > seems to suggest that Voc doesn't degrade like Isc degrades. Based on that > and other data I've seen it seems like panels that degrade at 0.5%/year are > outliers on the low side. > > Thoughts from other wrenches? > > > > > On Tue, Jun 3, 2014 at 11:59 PM, Bill Hoffer <[email protected]> wrote: > >> Dana >> >> Bill Brooks, passed on past data, ( correct me Bill if I am out of date >> here) recommends 1% Power loss per year with approximately 0.5% current and >> 0.5%voltage. That is also what Solar Energy International Best Practices >> curriculum recommends. Based on some newer data from larger projects >> requiring testing to actually determine those values for the Bankability >> requirements ( PVsyst PAN files), I believe we are seeing lower numbers >> than that now. In general, quality of modules are higher than the older >> modules. We of course are usually not privy to those results and may not >> even be getting the same level of binning for small residential projects as >> the MW projects do. 0.5% V loss per year seems like a like a good >> conservative number to me, especially if you add a little buffer (1-2%) in >> there. >> >> Bill >> >> >> On Tue, Jun 3, 2014 at 3:41 PM, Dana Brandt <[email protected]> >> wrote: >> >>> Hi Wrenches, >>> >>> Does anyone know what percentage of module degradation over time is >>> voltage and what is current? I'm wanting to make sure we give ourselves >>> plenty of breathing room on the minimum Vmp of the inverters over the long >>> term so need to try to anticipate how much voltage we'll lose on the array >>> over 30 years. >>> >>> Thanks, >>> >>> Dana >>> >>> Dana Brandt >>> Ecotech Energy Systems, LLC >>> www.ecotechenergy.com >>> [email protected] >>> 360.318.7646 >>> >>> _______________________________________________ >>> List sponsored by Redwood Alliance >>> >>> List Address: [email protected] >>> >>> Change listserver email address & settings: >>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>> >>> List-Archive: >>> http://www.mail-archive.com/[email protected]/maillist.html >>> >>> List rules & etiquette: >>> www.re-wrenches.org/etiquette.htm >>> >>> Check out or update participant bios: >>> www.members.re-wrenches.org >>> >>> >>> >> >> >> -- >> William Hoffer >> 161 SE Fourth Ave >> P.O. Box 1823 >> White Salmon, WA 98672-1823 >> [email protected] <[email protected]> >> >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> >> > > > -- > Nathan Charles > Engineer > NABCEP Certified PV Installation Professional #042013-20 > Paradise Energy Solutions > (717) 283-2021 direct > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/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: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/[email protected]/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
