Support to renewables could encourage innovation and diffusion of emissions-reducing technologies, beyond the incentives provided by the EU ETS. However, OECD analysis shows that when a carbon price exists, applying other policy tools, including renewable or biofuel subsidies and targets, can lead to overlap and undermine cost-effectiveness (OECD, 2009c). Despite simplification of administrative and permitting procedures, these are still seen as the main obstacle to development of the renewable energy sector (IEA, 2009a).