Residential solar photovoltaic seeding effects and their unequal impact on diffusion across racial and ethnic groups in the U.S.

This study investigates the impact of early adopters (“initial seeds”) on the diffusion of residential solar photovoltaic (PV) systems across racial and ethnic communities in the U.S. Using an event study model with comprehensive controls, we evaluate and quantify the impact over time of adoption patterns. Results indicate that the seed impact—the incremental effect on subsequent solar PV installations triggered by initial adopters—remains significantly positive across all racial and ethnic groups. However, we observe notable differences in the strength and persistence of these seed impacts: Black-majority block groups experience a robust immediate seed impact that diminishes over time, while Hispanic- and Asian-majority block groups exhibit smaller initial seed impacts that intensify in subsequent periods. Our findings highlight that equitable solar PV adoption requires hybrid policy strategies tailored to community-specific adoption dynamics and barriers. Short-term incentives should lower initial hurdles and stimulate early visible adoption, while long-term efforts must prioritize culturally informed outreach, trust-building, and educational programs to sustain diffusion. Policymakers should explicitly incorporate peer-driven network externalities into cost-benefit analyses, recognizing initial installations as strategic investments that activate broader community engagement, thereby enhancing both the scale and inclusivity of clean energy transitions.