On 12 February 2011 07:19, alan smith wrote: > I have a client who wants to use small (2" square roughly) to power a pro= duct. =A0He provided a sample and I can measure 2.5V roughly and depending = on the load of course how much current. =A0But of course it goes without sa= ying, that its totally dependent on how much sunlight is hitting it. > > The question he is asking...is there some method to calculate how much en= ergy you can get out of a panel that's 2" square, vs 3" square given the sa= me amount of sunlight that hits it. =A0My thoughts are its going to vary fr= om manufacturer, coating, efficiency of the cell, etc. =A0But even with thi= s,if you use the same vendor, is there a industry standard formula? I can tell you more than you want to know about such things including longevity, modes of aging and much more. But leaving for China in under 48 hours so rushing. I'll have internet access so ask on list or off but may take a few days. Rough: In bright summer sun, no clouds, no msog, noon. About 1000 W / m^2 x Z Convert m^2 to inches square yourself (about 1600 OTTOMH) Z =3D efficincy. Finished module top material crystalline silicon may be 13%. More possible but unlikely in cheap panel. Say 10% - 12% crystalline silicon. Epoxy or PET (plastic) outer. Epoxy life 6 months - 2 years in full weather 24/7 PET panel 2 years - 5 years. Longer with extreme care. .. Amorphous silicon about 5% -7% (grey continuous surface with thin lines between cells.) Glass upper surface. Output drops in first few months (Stabler Wronski ggoil knows) and then stabilise OKish. Life may be ?10 years? IF well built. Other new thin film CdTe, CIGS, other. Output between 2 above. Lifetime VERY variable with manufacturer and experience. Flexible plastic film often. As Olin notes [all things being equal (which he didn't say explicitly)] output is ~ proportional to area. Some 2nd order effects. Other aspects as above ... . if you want dependability and lifetime you MUST have provenance. More- ask ... Russell > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .