A 3 MW community solar project in Morris, Illinois. Summit Ridge Energy
By the end of 2023, more than four million households in the United States had switched to rooftop solar energy. However, certain communities still face significant barriers to rooftop solar adoption, particularly households living in multifamily properties, renters, and low-income households. Community solar – where multiple customers purchase solar energy through a shared system – has emerged as a potential model to expand solar energy access to these underserved communities. Unlike rooftop solar, community solar does not pose specific barriers to residents or tenants of multifamily properties and can be more economically accessible to low-income households.
In a new paper recently published in Nature energyResearchers from the Berkeley Lab and the National Renewable Energy Lab (NREL) are evaluating the extent to which community solar has expanded access to solar energy. For the first time, the researchers combine household-level data from Berkeley Lab’s ‘Tracking the Sun’ rooftop solar data set with data collected as part of NREL’s ‘Sharing the Sun’ community solar survey, as well as additional data from community users adopting solar energy for the study. The researchers statistically analyze the demographic characteristics of the two adoption groups to evaluate how well community solar has performed in reaching communities underserved by the rooftop solar market. The analysis provides early evidence of the impact of community solar on solar access based on historical data.
The researchers come to two main conclusions.
First, the researchers conclude that community solar has effectively expanded access to solar energy for multifamily residents, renters, and low-income households. The data shows that in 2023, community solar users were approximately 6.1 times more likely to live in multifamily buildings than rooftop solar users, 4.4 times more likely to rent and Earn 23% less annual income. These results suggest that community solar has expanded solar adoption to communities that would otherwise have struggled to adopt rooftop solar.
Second, the researchers show that these access benefits are determined more or less evenly by differences in business models and differences in policies. The community solar business model has enabled households to adopt solar energy without owning a home or having exclusive access to a roof, two conditions that would pose significant barriers to rooftop solar adoption. As a result, community solar can expand access to solar energy without specific policies to support such access, especially among residents and tenants of multifamily buildings. Nevertheless, the researchers find that the policy has increased these access benefits, particularly those that provide targeted support to help low-income households adopt community solar. Statistical analysis shows that this type of policy support explains about two-thirds of the differences in income levels between community and rooftop solar users, about 40% of the differences in tenant rates, and about 20% of the differences in terms of multifamily housing.
Funding support was provided by the U.S. Department of Energy’s Solar Energy Technologies Office as part of the Solar Energy Innovation Network Initiative.
News item from Berkeley Labs