Google is test-launching a tool that will let home owners determine if their roofs are suitable for solar energy. “If you’re in one of our test regions, simply enter your address and Project Sunroof will crunch the numbers. It first figures out how much sunlight hits your rooftop throughout the year, taking into account factors like roof orientation, shade from trees and nearby buildings, and local weather patterns. You can also enter your typical electric bill amount to customize the results. The tool then combines all this information to estimate the amount you could potentially save with solar panels, and it can help connect you with local solar providers.” Test regions are Boston, Fresno, and the San Francisco Bay area.