Renewable energy is a numerate and quantitative text-covering subject of proven technical and economic importance worldwide. Energy supplies from renewables (such as solar, thermal, photovoltaic, wind, hydro, biofuels, wave, tidal, ocean, and geothermal sources) are essential components of every nation's energy strategy, not least because of concerns for the environment and for sustainability. Renewable energy resources support multi-disciplinary master degrees in science and engineering and specialist modules in first degrees. Practicing scientists and engineers who have not had comprehensive training in renewable energy will find this book a useful introductory text and a reference book. Due to world energy resource shortage, the development of renewable energy sources is critical. The relevant topics such as energy-saving and power supply quality are also paid much attention. Renewable energy assumes great significance for the future of the world, given the environmental issues that are related to the ways we generate most of our energy and the central place that energy occupies in our society.