Fossil fuels are a finite resource, and their continued use as the world's dominant energy supply is damaging the environment. Future use of alternative methods of energy supply is inescapable, and this book explores the historical origins, technical features, marketability, and environmental impacts of the complete range of sustainable energy technologies: solar, biomass, wind, hydropower, geothermal power, ocean-energy sources, solar-derived hydrogen fuel, and energy storage. The aim is to inform policy analysts and decision makers of the options available for sustainable energy production. The book is therefore written so as to be accessible to an audience from a broad range of backgrounds and scientific training. It will also be a valuable supplementary text for advanced courses in environmental studies, energy economics and policy, and engineering.