Beyond technical and financial feasibility: The role of collaborative governance in renewable energy adoption at municipal wastewater treatment plants in the United States

Municipality-owned wastewater treatment plants (WWTPs) are increasingly diversifying energy sources to reduce costs and contribute to sustainability goals, yet renewables adoption varies dramatically even among facilities with similar physical characteristics and resources. Through semi-structured interviews with 30 WWTP operators and managers representing 21 facilities in California and across the United States, this study investigates how organizational dynamics and collaborative governance contribute to solar adoption and renewable energy transitions more broadly. We find that collaborative decision-making between WWTP managers and local governments is closely associated with higher levels of renewable energy adoption compared to non-collaborative approaches. Collaborative approaches facilitated solar and broader renewable adoption by mobilizing technical expertise, unlocking access to grants and partnerships, and integrating projects into municipal sustainability strategies and planning frameworks. Notably, collaborative facilities that did not adopt solar still developed alternative renewable portfolios, suggesting collaboration mediated comprehensive energy planning rather than single-technology adoption. Policy incentives alone appear insufficient to drive renewable adoption without organizational learning, leadership engagement, and interdepartmental collaboration. These findings indicate that renewable energy transitions in public infrastructure depend as much on organizational and institutional dynamics as on technical or financial feasibility, and that strengthening collaboration between utilities and municipal leadership can align sustainability goals and objectives with operational realities. This may accelerate renewable energy adoption including solar adoption across municipal infrastructure including WWTPs, drinking water systems, and other public infrastructure.