Derating 24v Solar Panels?

red31 wrote:
• Nominal operating cell temperature (NOCT): 45±2?

looks like that panel gets 25C warmer with 80% sun.

The coefficients are used with temps different than 25C STC

http://pvcdrom.pveducation.org/MODULE/NOCT.htm

Thanks for the link!

Red,

If Tair = 30C, and NOCT = 45C, and S = 80, it gives a result of 55C. Would this be the cell temp for a fairly well ventilated, average panel, at 30C ambient, then?

If so, 55C - 25C = 30C, so the panels I'm considering would lose about 67.5 watts, at 30C ambient? ( 0.45% x 30 = 13.5% x 500w = 67.5w )

(In that case, the peak amps would likely be in the 26a range :))