Bill, I looked into this several years ago, and I was able to get some digitized I-V data. I can't find that now (but I will). The data supports my claim.
Let's take the simplest case (constant cell temperature) and what was a fairly popular PV module: Kyocera's KC200GT. Although it is a little tedious to calculate the MPP, I found the following: 200 W/m^2 Vmp=25 V, Imp=1.514 A (37.9 W), 1,000 W/m^2, Vmp=27V, Imp=7.58A (205W) For more realistic conditions (i.e. operating temperatures) the result will be different and you could be right, but as far as constant cell temperature concerned, there is a shift with irradiance. By the way, the way you can see that there might be a real effect here is to notice that Isc is almost perfectly linear from 200 W/cm^2 to 1000 W/cm^2, whereas Voc is linear with irradiance only from 600 to 1000 W/cm^2. - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [email protected] _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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
