I'm new to this forum but I had a question and thought this might fit. I've built a 12 volt panel that supposedly outputs 60-70w max. It outputs 18v with no load but when I apply loads I get unexpected results. I get considerably less power than I'd hoped for. I'm not necessarily surprised given its November her in North Carolina but I'd like to be sure. I expected less sun but I did not consider the intensity of the sun in fall/winter going down.
I've gotten so many weird results I'll limit to a few. I put a 10 ohm load on the panel which if I was getting full power I believe should give an 18v across it but I got 15v across the load. I'm leaning towards this being a sun intensity problem because I tried a single solar cell in same conditions and got similar results. thanks