Google’s Project Sunroof Data: 79% of US rooftops analyzed are viable for solar – is yours?

Solar viability at Google’s Googleplex HQ

Today Google updated its Project Sunroof with some pretty striking data on approximately 60 million buildings and the viability for Solar Panels to power them. According to the search giant, almost 4 in 5 US homes are viable for solar panels with over 90% of homes in sunny states like Florida and California being viable. But even for houses in “not so sunny states” like Maine and Minnesota, over 60% of the homes surveyed were eligible to benefit from solar panels.

That’s a huge, untapped market for solar companies like Tesla’s SolarCity subsidiary… 

Standout numbers from Google’s data:

• Seventy-nine percent of all rooftops analyzed are technically viable for solar, meaning those rooftops have enough unshaded area for solar panels.
• Over 90 percent of homes in Hawaii, Arizona, Nevada and New Mexico are technically viable, while states like Pennsylvania, Maine and Minnesota reach just above 60 percent viability.
• Houston, TX has the most solar potential of any U.S. city in the Project Sunroof data, with an estimated 18,940 gigawatt-hours (GWh) of rooftop solar generation potential per year. Los Angeles, Phoenix, San Antonio, and New York follow Houston for the top 5 solar potential cities

The findings aren’t entirely new. In December of last year, the National Renewable Energy Laboratory came out with some equally startling statistics (PDF embedded below) on the percentage of suitable “small building” per zip codes and the percentage of the electricity needs they could generate per state:

NREL’s study, as we said in December, is based on a module efficiency of 16%, but module efficiency keeps increasing, and several higher solar modules from SunPower, LG, Panasonic and Tesla are currently at 20% and going up — so the total will go up accordingly. Last year at this time, NREL estimated that 40% of US energy needs could be generated from rooftop solar. That’s not including utility scale solar installations.

Deployment is still the main issue. SolarCity used the data collected by NREL to illustrate the current deployment of residential solar versus what it could be based on NREL’s study. Each little square represents enough residential solar to power ~80,000 homes:

As you can see, we’re just at the cusp of solar deployment. Customers in US States like Florida with governments that are hostile to solar and other green energy development will be able to circumvent utilities with lower cost solar/battery combinations.

That’s where Google’s Project Sunroof’s data explorer tool steps in, allowing anyone to explore rooftop solar potential across U.S. zip codes, cities, counties and states.

If your home is or to see if your home is viable for solar, click this link and fill out a short form. A solar installer in your area will reach out to discuss solar at no obligation to you.

Here’s the December NREL study in full:

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