Monday, January 24, 2011

Solar Gain

A common misconception about solar electric panels is that it has to be warm for them to work. Nope, that applies to solar thermal panels, like the ones used to heat hot water. The one's used to make electricity actually work better when it's cold. Efficiency in hot weather goes down due to something called electron scattering. Basically, the heat energy makes the electrons go places where they don't do any work for you.

Today was a great solar gain day. The air was the sort of clear you only get on subzero days. The bright sun reflected off the snow pack, acting like a big focusing mirror. Some years my best solar gains happen from the end of January to the beginning of March.

Another bonus is the leaves are all out of the trees, letting the light shine through. Now I supposed I could cut back all my trees and gain some morning sun in the summer. However, right now their shade makes it so I don't need AC. Electrically cooling the house would take more energy than I'd gain from the sun.

I'm really enjoying the solar electric gain right now as December was such a dark and dreary month. Even when it's cold out, sunshine picks up spirits up.



  1. Sunshine has been a rare commodity this winter. The cold fronts suck moisture off the Gulf, keeping us cloudy, then turn around and cloud us up again as they approach. One nice day (two if we're lucky) then the whole process repeats. I sure do miss my sunshine...

  2. Yea Sixbears, but it isn't easy keeping the snow off them. Don't suppose they work too well with a foot or two of snow on top of them. Oh, I forgot, you are way up north and you have to slant them to the south so the snow slides off, right?

  3. Hey Dizzy: In the winter they are set at about 60 degrees. Once the sun hits them they clear pretty quick. If in a hurry, I bundle up and kick the support pole for the rack a few times.