Should you go solar? Just ask Project Sunroof.

As the COP21 conference in Paris comes to an end this week, we’re expanding Project Sunroof, our online tool to help homeowners explore whether they should consider installing solar panels to reduce their energy costs, which we first launched in August. Starting this week, millions of homeowners across select metro areas in the most active solar states in the U.S., including California, Massachusetts, Arizona, New York, New Jersey, Nevada, Connecticut, Colorado and North Carolina, will be able to calculate their roof’s solar energy potential by using the same high-resolution aerial mapping technology used in Google Earth. Having this information will give you information on how to increase energy efficiency while cutting your monthly electric bill.

To provide accurate estimates, Project Sunroof uses a unique set of data that assesses how much sunlight your roof gets, the orientation, shade from trees and nearby buildings, and local weather patterns—essentially creating a solar score for every rooftop that it maps. You can then provide your current average electricity costs and compare them to what you'd pay with solar. So not only can you learn whether your house is a good fit for solar panels, but you can also determine whether paying for installation will pay off in the long run -- in short, see the effect sunlight can have on your wallet.

Map of sunlight hitting roofs in downtown Boston

Solar installations today are growing rapidly (a system is installed every 2.5 minutes in the U.S.), but there remains tremendous untapped potential. In fact, only half a percent of U.S. electricity comes from solar power. According to GTM Research and the Solar Energy Industries Association’s U.S. Solar Market Insight Report, the US is on track for a record-breaking year, thanks to a booming residential photovoltaics market. By end of 2016, cumulative solar installations are poised to nearly double.

Solar may help you cut costs while increasing efficiency. With Project Sunroof, you can more easily assess your home's solar energy potential—and help move us all toward a more renewable future.