The purpose of this report was to assist European Commission Member State governments in preparing for the implementation of the Renewable Energy Directive (2009/28/EC) and to guide a European policy for Renewable Energy Standards (RES) in the mid- to long-term. Included within this report are analyses of the effectiveness and efficiency of current and future RES support schemes. Current best practices are identified, and future costs of RES and the corresponding support necessary to initiate stable growth are assessed.