I've built a 2 cell panel made for filling with oil and testing the output. I'm gonna put it through extremes and see what happens. If someone has a spring(water) with enough head, they could cool the panels with a constant flow allowing you to get more power out with mirrors.
One thing I'm wanting to find, is how much power each cell can produce with extra light before it dies or maxes out, not from temp, but because that's all the electricity it can take.