This textbook is intended for an audience with little or no power engineering or renewable energy background. The book covers electric energy from alternative energy sources, including solar, wind, water, hydropower, geothermal, and ocean energy. Core issues discussed include wind and solar resource estimates and analysis, solar thermal systems, solar collectors, photovoltaics, wind turbines, geothermal energy, energy small hydropower, wave, tide and ocean energy, and characteristics of energy conversion, control, and electrical aspects. This is one of the most comprehensive textbooks for students, engineers, and professionals who study renewable energy. There are several questions and problems, presented with increasing difficulty, most of which focus on practical applications. The materials and problems are drawn from the author's extensive experience in renewable energy analysis, assessment, design, control, and the power electronics of wind and solar energy conversion systems. Each section of the book contains several solved examples, as well as practical and advanced discussions, that instill critical thinking and apply to industrial applications. The book is divided into eight chapters and covers the most important aspects of renewable energy sources and technologies.