The Clingendael policy seminar on EU renewable energy policies on the 22nd and 23rd of October 2009 successfully facilitated a high level debate about the transition to an economy in which renewable energy becomes a crucial source in the future energy mix. In an open and fierce discussion under Chatham House Rules, senior government officials from several European countries and the European Commission, together with experts from industry and research institutes, discussed the challenge of how to realise this transition.