This book presents a comprehensive review of renewable energy sources, the environment and sustainable development. This includes all the renewable energy technologies, materials and their development, energy efficiency systems, energy conservation scenarios, energy savings and other mitigation measures necessary to reduce climate change. Also explored in this volume is ocean energy, its benefits and barriers and solar radiation as a primary daytime source of energy. Various scenarios are extrapolated in order to assess the potential environmental impact of increasing world population and consumption throughout the 21st century and a general overview of the world-wide trend in fossil fuels.