The role of energy in the modern world goes beyond mere technology and economics to influence welfare, the environment, the quality of life and, in broad terms, civilization itself. Since the Industrial Revolution, energy conservation technology has been at the forefront of the innovation required to satisfy the needs of mankind and, more than any other, this technology has always depended on the performance of the materials used. In this, the report of the Fifth Liege Conference devoted to a review of the work of the European Materials Collaborative Programmes, the results of the programmes are presented along the following technology-oriented themes: steam-power plant; gas turbines; diesel engines; advanced combustion; and perspectives. The book thus presents an up-to-date reference on materials technologies in energy conversion from fossil fuels and materials for high-efficiency, low-emission systems.