I haven’t blogged about a mashup in awhile, but I was catching up on some news and saw a link to RoofRay, a Google Maps app that calculates the solar energy potential of a building’s roof. First, you digitize a polygon representing your roof area, then a ray for the direction of the roof’s slope and enter its angle. Then the app will calculate the Peak Power, Power per sq. ft. and other stats. It was a little glitchy when i tried it out, but I think it is a cool idea.