This publication is a response to the Group of Eight (G8) leaders at their Gleneagles Summit in July 2005, and to the International Energy Agency's Energy Ministers who met two months earlier. Both groups called for the IEA to develop and advise on alternative scenarios and stragegies aimed at a clean, clever and competitive energy future ... "Energy Technology Perspectives" presents the status and prospects for key energy technologies and assesses their potential to make a difference by 2050. It also outlines the barriers to implementing these technologies and the measures that can overcome such barriers.