The evidence is clear: energy efficiency has played, and continues to play, a large and valuable role in the sustainable development of the global economy. The energy demand that is avoided as a result of steady improvements in the efficiency of energy-using stock such as buildings, cars and appliances is larger than the total final consumption from coal, oil or gas in IEA member countries. The market for energy efficiency investments is very large estimated between USD 310 billion and USD 360 billion in 2011 and this market is producing results: total final consumption in IEA countries is estimated to be 60% lower today because of energy efficiency improvements over the last four decades. Since 2001, investments in energy efficiency in 18 IEA countries have helped to avoid over 1 700 million tons of oil-equivalent from being consumed. This years report includes an in-depth look at energy efficiency developments in the transport sector and in finance.