Definition of concepts, explanation of technologies, growth in Spain, and explanation of advantages, disadvantages and barriers to overcome in technological, operational, financial, social and environmental terms. Contains chapters on: wind energy, generating power from biomass, bio-ethanol, bio-diesel, thermal solar energy, photo-voltaic solar energy, energy from waste, bio-climatic building and hydrogen. It is a small reference manual containing a great deal of practical information for the non-specialist public, enabling the reader to understand what each renewable energy is, how developed it is in this country, what difficulties impede its development and when are these barriers expected to be overcome. It includes information on costs, prices and public subsidies.