In the face of the climate change threat and rising oil prices, some states, such as Oregon, New York and California, have adopted stronger renewable energy instruments than others. This paper analyzes the variation in instrument strength across states using the Tobit method of analysis. Three instruments are analyzed here: tax incentives, renewable portfolio standards and public benefit charges. Three models of policy adoption are estimated: needs/responsiveness, interest group and innovation-and-diffusion model. The paper finds that electric utilities oppose strong measures to stimulate renewable energy. Variables such as state wealth, electric restructuring programs and opinion liberalism also explain instrument strength. [ABSTRACT FROM AUTHOR]