One of Google’s corporate principals is to allow their employees time to pursue projects they are interested in, even if it is not part of their regular job duties. These 20% projects can generate some unique opportunities for Google users, like the new Project Sunroof. This project, from engineering lead Carl Elkin, aims to help people tap into the power of solar energy as a way to save some money and go green.

Elkin noted that in conversations that he had with many people, there was a lot of misunderstanding about what kind of potential existed for the use of solar power at the residential level. People often thought there was not enough available sunlight or that deploying a solar panel system would be too expensive. Thus, Project Sunroof was born.

The tool uses the same high-resolution aerial mapping utilized by Google Earth to calculate solar energy potential for a selected rooftop. All users will have to do is enter a street address and Project Sunroof handles all the rest. This includes calculations of how much sunlight is typically received per year based on roof orientation, shade from trees or other buildings, and weather patterns. Users will also have a tool available to enter their typical electrical costs so potential savings can be calculated.

Of course, a Google product, even one in a pilot phase, would not be complete with the potential to tap into some ad revenue. In the case of Project Sunroof, once all the number crunching is done, the tool will also point users to local solar providers who can offer services and additional help.

Project Sunroof is currently limited to Boston, San Francisco and Fresno. However, if testing continues to work and Google can scale things up, they hope to expand to cover the entire U.S. and perhaps the rest of the world.