This book provides a synthesis of the energy-related results of the large scale project entitled "Climate Teclmology Strategy within Competitive Energy Markets" partly financed by the European Commission under the Non Nuclear Energy (JOULE III) EU-RTD programme (Contract JOS3-CT95-0008). Research in this project involved several organisations from almost all European Union member states, including: ICCS/NTUA (co-ordinator), CES/KULeuven, GRETA Associati, University of Mannheim/ZEW, ESD Ltd., IEPE/CNRS, IDEI, IPTS/JRC, UCL/CORE, SSE/EFI, KFA/STE, ENSPM-FIICEG, University of Strathclyde, IER/University of Stuttgart, YTT, ETSU, IIASA/ECS, ERASME/CCIP, ECOSIM Cons. Ltd., OME, BPB, CRES. In relation of the "pre-and post-Kyoto" context for Climate Change and also with th respect to the preparation of the y EU-RTD Framework Programme, a large exploitation ofthe results is being made. Huguette Laval of the European Commission, DGXII, was the project scientific officer. With Pierre Yalette, Head of the Unit in DGXII, they have given fruitful I advices for the project. Thanks are given to them.