Solar energy is a renewable form of energy which is produced by conversion of solar irradiance. The heat and light energy of the sun can be converted into electrical and thermal energy. Solar technologies are categorized into passive and active systems. Passive systems don't use any external devices, but use heat and light directly from the sun. An active system employs an external device to convert solar energy into electricity. Some of the common techniques used to harness solar energy are photovoltaics, solar heating and cooling, and concentrating solar power. Some of the major applications of solar power are cooking, heating, lighting and transportation. This book includes some of the vital pieces of work being conducted across the world, on various topics related to solar energy. Also included herein is a detailed explanation of the various concepts and applications of solar energy. As this field is emerging at a rapid pace, the contents of this book will help the readers understand the emerging technologies in this field.