At their 2007 Summit in Heiligendamm, G8 leaders called on countries to “adopt instruments and measures to significantly increase the share of combined heat and power (CHP) in the generation of electricity.” As a result, energy, economic, environmental and utility regulators are looking for tools and information to understand the potential of CHP and to identify appropriate policies for their national circumstances. This report forms the first part of the response. It includes answers to policy makers’ questions about the potential economic, energy and environmental benefits of an increased policy commitment to CHP. It also includes for the first time integrated IEA data on global CHP installations, and analyses the benefits of increased CHP investment in the G8+5 countries. A companion report will be produced later in 2008 to document best practiceb policy approaches that have been used to expand the use of CHP in a variety of countries. (view IEA 2008 ufficial document)