This paper analyzes the roles of policies and preferences in national adoption of solar and wind energy technologies. We use cross-sectional and panel regressions for both the European Union and a broader international sample. We find that countries that price carbon emissions have gone on to adopt more solar and wind energy. The aggregate level of policy support, measured in euros per megawatt hour, appears to have been important for solar energy adoption. We also find that solar energy adoption has been larger in countries with higher proportions of people concerned about climate change. In addition, we assess the effects of other key explanators including financial system size and income levels.