In present scenario, the new and renewal energy sources acquired a significant of eco friendly nature & freely available. 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 consrve our environment by utilizing the new and renewable energy sources scientifically and managerially. An integrated approach should be appraised in this context for economic and overall development of the nationa. 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 subjecys such as solar energy, solar thermal energy, solar photovoltaic technology, wind energy, biogas technology, geothermal & ocean energy. All the information constituted in this book has been discusse with suitable updated recent information and easy to understand illustration, figures, tables, flow charts etc. which made the subject very cleare and useful. Adjacently, this book covers the basic terminology 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 source for competative examination such as GATE, NET, ICAR etc.