The green economy policy discourse has devoted a lot of attention to the design of public policy addressing low-carbon technologies. In this paper the researchers examine the impacts of public R&D support and feed-in tariff schemes on innovation in the wind energy sector. The analysis is conducted using patent application data for four western European countries over the period 1977–2009. Different model specifications are tested, and the analysis highlights important policy interaction effects. The results indicate that both public R&D support and feed-in tariffs have positively affected patent application counts in the wind power sector. The (marginal) impact on patent applications of increases in feed-tariffs has also become more profound as the wind power technology has matured. There is also some evidence of policy interaction effects in that the impact of public R&D support to wind power is greater at the margin if it is accompanied by the use of feed-in tariff schemes. These results support the notion that technological innovation requires both R&D and learning-by-doing, and for this reason public R&D programs should typically not be designed in isolation from practical applications. The paper ends by outlining some important avenues for future research.