Dana Bill Brooks, passed on past data, ( correct me Bill if I am out of date here) recommends 1% Power loss per year with approximately 0.5% current and 0.5%voltage.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 <d...@ecotechenergy.com> 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 > d...@ecotechenergy.com > 360.318.7646 > > _______________________________________________ > 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 > > > -- William Hoffer 161 SE Fourth Ave P.O. Box 1823 White Salmon, WA 98672-1823 suneng...@gmail.com <bhof...@sunergyengineeringservices.com>
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