In this book, the author primarily concerned with the collection and storage of solar energy for thermal applications by a salinity gradient solar pond system. The purpose of writing this book is to study construction, establishment and maintenance and thermal performance evaluation of salinity gradient solar ponds (SGSPs). And provide a suitable text for the thermal storage, temperature and density profiles, heat transfer, energy balance, reflection, transmission, absorption of solar radiation, and energy collection efficiencies in SGSPs to engineering and science postgraduate and researchers, as well as a guide reference book for practicing professionals.