The standard assumed irradiance for math purposes has always been 1000W/m2. I’ve seen days where base-line was 1200 on my Daystar meter, and elevation was barely above sea level, say 500ft, max 1000ft. I imagine Edge of cloud effect on a day like that could send the current as high as 1.56 David
On Mon, May 18, 2026 at 6:24 AM Dana Orzel via RE-wrenches < [email protected]> wrote: > VERY High elevation 10,000’+ , with high wind & very low temps. Not normal > installation definitely a “Special” situation. I agree in 95% of > installations 1.56 is an excessive. > > > > _________________________________________________________ > > Dana Orzel GREAT SOLAR WORKS! > > C – 208.721.7003 E – [email protected] > > W - www. greatsolarworks.com www.solarwork.com > > *“Responsible Technologies for Responsible People since 1988!”* > > > > > > ---------- Forwarded message ---------- > From: Drake Chamberlin via RE-wrenches <[email protected]> > To: RE-wrenches <[email protected]> > Cc: "[email protected]" < > [email protected]> > Bcc: > Date: Mon, 18 May 2026 13:09:27 +0000 > Subject: [RE-wrenches] 1.56 Rule > > The logic of this rule for calculating PV amperage seems a little off to > me. - It is a calculation that is set in stone as a bedrock truth of the > solar industry. (1.25 X 1.25 = 1.56). > > The multiplier of 1.25 for a continuous load is relevant for sure. To > multiply again by another 1.25 seems excessive. > > Although it is certainly true that modules put out considerably more power > when it is cold out, in my experience that is almost all due to the > increase in voltage. The amperage goes up a little, but no where near 25%. > > Just because I haven't seen it doesn't mean it can't happen. Are there > circumstances where the amperage of a PV module can go up by 25%? > > Thanks, > > Drake > > > *Drake Chamberlin* > > *Athens Electric LLC* > > *Ohio Electrical Contractor’s License 44810* > > *NABCEP Certified PV Installation Professional* > -- > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: [email protected] > > 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/[email protected]/ > 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 > >
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