In present scenario, the new and renewable energy sources acquired a significant position. This is on account of Eco friendly nature & freely availability. Our environment becomes much of polluted because of use of conventional fuel. Now we have to think about the utilization of Eco friendly energy sources. Thus, there is an urgent need to conserve our environment by utilizing the new and renewable energy sources scientifically and managerially. An integrated in approach should be appreised in this context for economic and overall development of the nation. In order to expose youth, this book has been written for a foundation course both at school & College levels. There is an inclusion of major aspects of the sugjects such as solar energy, solar thermal energy, solar photovoltaic technology, wind energy, biogas technology, geothermal & ocean energy. All the information constituted in this book have been discussed eith suitable updated recent information and easy to understand illustrationd, figures, tables, flow charts act. which made the subject very clear and useful. Adjacently, this book covers the basic terminologies as well as question bank. The authors hope that this book will raise a helpful hand for students and serve as a guide and ready sources for competitive examination such as GATE, NET, ICAR etc.