One Web site can help you evaluate whether solar is feasible for your roof and help you compare costs.
Roofray.com cleverly uses satellite images to help users see for themselves how useful solar arrays might be. The easy solar modeling service even lets you compare utility costs over time.
Users simply type in their street address and nearly instantly a rooftop picture of their home appears. Then a few point-and-clicks later you quickly get an estimated percentage of potential for solar, power per square foot, the area of the solar arrays you drew and a total peak power estimate.
Have your utility bills for the year in hand and you can get an estimate of current costs versus solar costs.
Launched in August 2008, the Web site is up and running but some aspects are still being upgraded or even under construction. At this writing there is no useful help section, but check the blog link for updates on what features will be added.