Improvement of energy efficiency is one of the important options for reducing greenhouse gas emissions. According to the Third Assessment Report of the Intergovernmental Panel on Climate Change, hundreds of technologies for improving the end-use energy effiiciency make up more than half of the global potential for greenhouse gas emission reduction in the short and medium term (2010 – 2020). (IPCC, 2001; see also WEA, 2000). An important next question is how these options can actually be deployed. More specifically, one may ask what role governments can play by using policy instruments to promote the deployment of energy efficient technologies.