Despite their broad appeal and widespread adoption, new technologies don’t always reach every community. Solar power is no exception. According to a new study by the Lawrence Livermore National Laboratory, more than 4 million households had adopted rooftop solar in the United States by the end of 2023. On the other hand, some communities were still not enjoying its benefits.

The study, “Evaluating Community Solar as a Measure to Promote Equitable Clean Energy Access,” was published in the June issue of the journal Nature Energy.

The study hypothesized that rooftop solar may not be as accessible to residents of multifamily buildings and renters because they do not have control over the installation of solar systems, and to low-income households because of the high upfront costs. The Lab defines community solar as arrangements where multiple customers buy solar from a shared system.

The researchers sampled community solar programs in 11 states. They compared rooftop solar adopter data with community solar data.

The findings were significant, showing a higher concentration of multifamily, renter and low-income households among community solar users. Specifically, the study found that community solar adopters in 2023 were about 6.1 times more likely to live in multifamily buildings than rooftop solar adopters, 4.4 times more likely to rent, and earn 23% less annual income.

The paper concludes that these results suggest that “community solar has extended solar adoption to communities that would have otherwise struggled to adopt rooftop solar.”

The study also found that the access benefits of rooftop solar have been evenly distributed regardless of differences in business models and differences in policy, suggesting that community solar can expand solar access without specific policies to support such access. However, the paper did find that some specific policies, especially those targeting low-income households, have “augmented the access benefits” of community solar.