How many of the nation’s houses have solar panels? The 2017 American Housing Survey has the answer. Overall, 3.1 million occupied housing units in the United States had solar panels in 2017 – or 2.6% of the total. This is the percentage of homes with solar panels by census division...

4.0% in New England
2.2% in Middle Atlantic
0.7% in East North Central
0.6% in West North Central
1.5% in South Atlantic
0.6% in East South Central
1.5% in West South Central
3.8% in Mountain
7.4% in Pacific

The 2017 American Housing Survey also asked about solar panels on houses in selected metropolitan areas. Here are the findings: in Riverside-San Bernardino, 9.7% of homes had solar panels; San Francisco 6.9%; Phoenix 6.5%; Los Angeles 5.0%; Atlanta 1.0%; and Seattle 0.8%.