This document summarizes information about solar energy. It discusses how solar energy is generated from nuclear fusion in the sun and emitted as heat and light. It then describes some applications of solar energy technologies, like solar cells, water heaters, and cookers, and notes they are pollution-free and can operate in remote areas. However, it also outlines some disadvantages of solar energy systems, such as high initial costs, dependence on weather, and expensive energy storage. It provides details on how solar cells work and the development of solar power in India and the state of Tamil Nadu.