Residential rooftop solar installations have typically been affordable only to wealthier homeowners due to the high upfront costs.

That may be changing.

According to a study released by the Lawrence Berkeley National Laboratory, rooftop solar is expanding to less-affluent households. “Residential Solar-Adopter Income and Demographic Trends: 2022 Update,” published in February 2022, examines address-level data for 2.3 million residential solar adopters across the country. From that data, the report describes trends in solar-adopter households by a variety of factors, such as income level, race and ethnicity. It also examines differences related to system-ownership models, installers, system sizes and other factors.

Of the more significant findings, the study notes that the historical gap between the (higher) incomes of most residential solar-adopters and that of the general population has been slowly narrowing over the past decade. Between 2010 and 2020, U.S. median solar-adopter annual income fell from $138,000 to $115,000.

The drop reflects what the study describes as a “deepening” of solar markets. In other words, as solar penetrates more deeply into the residential market, more homeowners—including those who are not in the higher income brackets—are having the technology installed. This causes the average income of solar adopters to fall.

Other statistics reinforce this finding. For example, the study reports that the average income of solar adopters compared to the median income for the county in which they live also fell from 180% to 158% over the same time frame.

The study notes that while solar adopters come from all income ranges, the average income level of solar adopters still skews high. For example, while the national median household income for solar adopters was $115,000 in 2020, this was almost double the overall U.S. median of $63,000.

Geography also plays into this dynamic. The study notes that roughly half of residential solar adopters in the country are in California. Because it is a relatively high-income state, this skews the national average income figures higher.