BFL13 wrote:
The installation instructions for my Sharp panels I had a few years ago said minimum 5 degrees for rain drain. Warned about puddles on the panel making for "hot spots" (ISTR that was the term) and damage to cells.
EDIT Read up some on that. Hot spots caused by shading with uneven heating. "Self-cleaning" by rainfall to clear off dust--most say at least 10 degrees. Panels have drain holes that should be kept clear.
My Canadian Solar brand panel installation guide does not mention tilting for rain like my old Sharp one did.
I have nearly flat panels on the Class C roof, and have seen how rain puddles make for dirty areas after they dry if the panels are dusty before it rains. That might lead to shading related hot spots if not washed. I clean my panels fairly often anyway.
Thanks, BFL, 10 degrees or more makes sense, in order to get good rain run-off and dust wash-off, and eliminate any puddling of water after a rain.
I'm installing five 100 watt panels, so I'm thinking of not angling them all the same direction. Even though installed at say a 10 degree angle, yes, at some times of day, the panels angled the slightly opposite way to the sun will provide a little less production. But at the same time, when the sun is in the opposite side of the sky, the panels angled the opposite way may provide a bit more production, so seems like it would balance out.
