It's a heated model, so that no ice will accumulate on the radar antenna and ultrasonic transducers. Because of this, the power consumed by the station is much higher in the winter. The station will be mounted a long way from any power source, so I'm going to use solar panels to charge a couple of truck batteries, and a controller to give me a constant 24 volts. Those solar panels will be pointed toward true south (not magnetic south) to maximize the light they'll catch. But what angle from the vertical should they be?
I'd have guessed something like 45 degrees from the vertical. When I calculate it, though, I come up with approximately 30 degrees from vertical (closer to straight up and down than flat). We're at roughly 41.5 degrees latitude here in Paradise. Add the earth's 23.5 degree tilt to that, and mid-winter the sun's elevation at noon is just 90 - (41.5 + 23.5) = 25 degrees. The rest of the winter it's between 25 and 35 degrees. Splitting the difference to work well all winter long, we get about 30 degrees. That's what we get for living so close to the North Pole!!!
Will their be an issue with snow buildup in the winter limiting the panel's ability to produce energy?ReplyDelete
With an angle that steep, I'm not really expecting a problem - any snow accumulation should slide right off. This is about the same angle used on a chalet, and for that exact reason. The only scenario I can think of that's problematic is if we get freezing rain that sticks to the panels (if the panels are below freezing, and the rain is liquid when it hits them). That's certainly possible, and if it happens I'd have to use antifreeze or something to clean them....ReplyDelete