Drawing from research interviews and the academic literature, this article conceptualizes the conditions that promote investor confidence and the social acceptance of wind and solar sources of electricity. It explores the factors influencing the acceptance of commercial wind turbines in Denmark and India and residential solar panels in Germany and the United States. The article begins by justifying its selection of case studies and explaining the methodology behind its research interviews and field visits. It then summarizes some of the key findings in recent surveys of public attitudes and market acceptance concerning renewable energy, with a focus on why some investors and communities reject wind and solar systems whereas others rapidly approve and adopt them. The article proposes that acceptance has multiple dimensions – socio-political, community, and market – that must be met holistically in order for investors and users to embrace renewable energy. The article argues that acceptance hinges upon the prevalence of nine factors; the lack of such factors creates environments where they are rejected. The theory is tested against four case studies that explore the forces driving renewable energy in Denmark, Germany, India, and the United States.