RoofRay is a site that let’s you calculate your home’s solar power potential using the power of GoogleMaps.
It’s very interesting as the site will caculate the solar power potential based on the roof area and the slope of the roof.
It’s probably pretty accurate as most data is using direct satellite images off GoogleMaps.
The greatest part about this site is that you can find out how much energy you will be able to make with new solar power cells. Then you calculate how much it is to install new solar panels on your roof to see how long it will take you to payoff the panels itself.
The RoofRay site allows you to specify location, size and slope of your roof via Google Maps. It then uses this info to estimate how much energy can be generated from your available exposure.