I did lots of experiments about 15 years ago adding heat to panels with various methods. Heat tape, hot air blowers, exhaust, all kinds of ideas were worked on.
I came up with two things that work. First, lots of insulation on the backs. Spray foam worked extra good. It helps to speed up snow/ice sliding/melting off when the sun comes out. Second thing that works is the application of antifreeze. Propylene glycol is environmentally safe for the wildlife. Sprayer at the top works pretty good. We rigged up one tank that was pressurized with air and had solenoid valve that was turned on via telemetry. Takes almost no energy to pump. Did CO2 pressurization too but that will carbonate the antifreeze and it doesn’t spray as well. You can vent the tank and have it drain back if you want. I also tried a deicing product made from beet juice. It didn’t work too well. Plugged up the spray nozzle. From: Steve D Sent: Sunday, September 20, 2015 12:05 AM To: af Subject: [AFMUG] The dreaded annual "how to keep snow and ice off my solarpanels" thread Maybe it's Saturday night exhaustion talking, but piping the exhaust from a standby generator toward the back of solar panels a bad idea? I'd expect it to not put heat on the panels in the summer except it's weekly exercise cycle but that shouldn't be too bad? LP too so shouldn't be any soot. Or would this just create one little hole of open panel and a pile of ice? Bad in general for the panels? If I did this again, I'd put the damn thing directly under the panels... these Onan's get stinking hot. My little "cool running", comparatively speaking, portable yamaha's will melt a two foot radius of snow around them if they run for a good length of time, all this heat going to waste! The Onan would probably clear the whole rack if it was sitting right below it. Grumble grumble... snow... something, something, curse words... Cheers, Steve D
