If you look at the book "Sustainable Energy without the hot air" you will find it chock full of data. Problem is, it's for the UK, not the US. But FWIW, I think the UK is more north than the continental US.

http://www.amazon.com/Sustainable-Energy-Without-Hot-Air/dp/...

Also wanted to add the invaluable http://www.amazon.com/Sustainable-Energy-Without-Hot-Air/dp/...