Google today announced the geographical expansion of its Project Sunroof project for checking how much power your home could collect using a solar array.

Starting this week, people in metro areas in Arizona, California, Colorado, Connecticut, Massachusetts, Nevada, New Jersey, New York, and North Carolina will be able to use the service, which is online at google.com/sunroof.

“Having this information will give you information on how to increase energy efficiency while cutting your monthly electric bill,” Project Sunroof engineering lead Carl Elkin wrote in a blog post.

Perhaps that’s the biggest thing here — using aerial images from Google Earth, Google is trying to give people an easy way to see how much money they can save by switching to solar.

Google does walk the walk. It has several solar arrays to support its data centers. Now Google wants to see solar show up in many more places around the U.S.

Google first launched Project Sunroof back in August.