The purpose of this study is to determine past and future energy efficiency of fossil power generation in EU-27. It is found that the average efficiency for gas-fired power generation increased sharply from 34% in 1990 to 50% in 2005 and is expected to increase to 54% by 2015 (based on lower heating value), For coal-fired power generation the efficiency increased from 34% in 1990 to 38% in 2005 and is expected to increase to 40% by 2015 (LHV). The improvements are largely determined by the introduction of new generating capacity. The amount of natural gas-based generating capacity has strongly increased in the last 15 years. The share of gas-fired power generation in total fossil power generation in the EU increased from 11% in 1990 to 34% in 2005 and is expected to increase to 46% by 2015. The average CO2-intensity for fossil-fired power generation in the EU decreased from 920 g CO2/kWh in 1990 to 720 g/kWh in 2005, mainly due to a shift from coal to natural gas. For the period 2005-2015 another decrease is expected from 720 to 630 g/kWh. Total greenhouse gas emissions from fossil power generation are however expected to increase by 10% in 2020. (C) 2009 Elsevier Ltd. All rights reserved.