The results of a study conducted by researchers at Department of Energy national laboratories suggest that existing community solar projects are expanding solar access in the United States to a more demographically diverse population.
“Specifically, we find that community solar adopters in 11 states are about 6.1 times more likely to live in multifamily buildings, 4.4 times more likely to rent, and earn 23% less than rooftop solar adopters, on average,” wrote the authors of the study, “Evaluating Community Solar as a Measure to Promote Equitable Clean Energy Access.”
Authors of the study are Eric O’Shaughnessy and Galen Barbosea from the Lawrence Berkeley National Laboratory and Sudha Kannanb and Jenny Sumner from the National Renewable Energy Laboratory.
“Community solar has, thus far, been particularly effective at expanding access in terms of housing type and tenure, while a substantial portion of observed income differences can be attributable to the uptake of community solar among multifamily building occupants and renters,” the study notes.
The study said that nearly four million residential electricity customers had adopted rooftop solar photovoltaics in the United States by the end of 2022.
“Rooftop solar adopters tend to be more affluent than the general population, are less likely to rent, and are less likely to self-identify as a racial minority,” the report said. “Rooftop solar adoption inequity reflects various barriers to adoption for low- and moderate-income (LMI) households, such as high upfront costs to purchase solar systems outright (as opposed to leasing), barriers for renters (e.g., split incentives), and barriers for multifamily building occupants (e.g., shared ownership of rooftop spaces),” the report said.
While adoption inequity is common among emerging technologies, rooftop solar adoption inequity could pose unique challenges to clean energy transitions and grid decarbonization, the study said.
Stating that existing rooftop solar products remain largely inaccessible to renters and families living in multifamily housing, the study noted that another alternative class of solar products in the United States is community solar, wherein multiple customers buy output from a single solar system.
Community solar typically entails no or minimal up-front costs. “Unlike rooftop solar, community solar poses no specific barriers to adoption for renters or multifamily building occupants. As a result, community solar is often theorized to promote more equitable solar access, and is increasingly integrated into U.S. solar adoption equity policies. The federal Inflation Reduction Act includes tax credits for projects serving LMI communities or customers, and at least 17 states have incentives or regulations that promote LMI community solar,” the study said.
The study explores whether existing community solar projects have expanded solar access by analyzing the demographic profiles of rooftop and community solar adopters.
Household-level data is analyzed to explore how the two customer groups vary in terms of median income levels, housing tenure (whether adopters own or rent their homes), housing type (single or multifamily), and race.
“We organize our study around two research questions: 1) How do community solar adopters compare demographically to rooftop solar adopters? and 2) How much of any demographic differences are attributable to the inherent features of community solar as a product versus policies that promote community solar participation by LMI households specifically,” the study’s authors noted.
They emphasized that their analysis is retrospective. “Community solar is projected to grow rapidly and state policies effectively guarantee that future community solar projects will differ substantially from the existing projects analyzed in our study. Our results should be interpreted primarily as retrospective, though we cautiously discuss the implications of our results for the future of the community solar market.”
