The energy collected from renewable resources such as sunlight, tides, waves and wind is called renewable energy. These energy sources are carbon neutral in nature and are replenished naturally on a human timescale. Some areas of major importance under this discipline are heating and cooling systems, electricity generation, and transportation. A few of commonly used technologies for utilizing renewable energy sources are hydropower systems, wind turbines, bioenergy systems, solar panels and geothermal energy solutions. Renewable energy systems are expected to reduce air pollution and lower the dependency on conventional sources of fuel. This book is compiled in such a manner, that it will provide in-depth knowledge about the theory and practice of renewable energy. It picks up individual branches and explains their need and contribution in the context of a growing economy. As this field is emerging at a rapid pace, the contents of this book will help the readers understand the modern concepts and applications of the subject.