climateadaptation:

“The city of Cambridge, Mass has teamed up with MIT to produce a Solar Tool that allows people to type an address into a website and get a detailed account of that roof’s solar electric potential. This is probably the most detailed service now existing and every building in Cambridge is covered. You can learn how much of your roof sees enough sun for a PV installation, how large that PV installation can be, how much it will cost, how high your Federal and state tax rebate will be, how much electricity it will produce in a year, and how much carbon it will displace.”

Solar Tool v.2. Via

Massachusetts has substantial subsidies for property owners who want to add green/renewable power features to their properties.  So what would be really interesting is to add a dollar figure on the top of each building representing how much the property owner could get back from the state for investing in the (pricey) solar panels and hookups.