Solar Illuminace vs Panel Output
How does solar illuminace effect panel output? From yesterdays observation at noonish: 750W, poly, flat, 100F ambient, Vmp=91.7V, Imp=8.18 Logged Varray=75V, Iarray=8.5A, Controller out=605W ...
Forum Discussion
CA Traveler wrote:
OK, heat reduces the output but by how much? At 131F my panel specs say I should get 658W and I got 605W, so perhaps 53W was loss due to flat mounted? But my panels are mounted 6” off of the roof so perhaps the panel cell temp is below 131F which is just a guess anyway.
We all use generalized panel information which is what we’ve got and what I used as a basis for my system. But having a quality controller that logs data under live operating conditions is proving enlightening.
you lost more than you expected..
that is what you want to explain..
it is heat loss, IF you can.. try measuring the temp at the panel surface
PS..what i posted was just an example
if there is loss with a NO load dead short condition
extrapolate from there.. the loss factor when flat mounted, charging and hot as HECK
