This Thursday, July 18, 2013 photo shows a house owned by Ketch Ryan with solar panels installed on the roof in Chevy Chase, Md. To help neighbors, Ryan helped found a cooperative, Common Cents Solar. The first thing is to get an assessment of your roof and whether it’s viable for solar. The condition of the roof, the type of roofing material used, and the angle are among the things that need to be looked at. (AP Photo/Manuel Balce Ceneta)