It is a semiconductor that converts sunlight to electric current. This electricity can then be used either directly for powering devices or can be stored in batteries for use whenever necessary. These systems can be designed as a stand-alone system, i.e. as an independent source of energy to cater to a particular limited requirement. These can also be used as grid interactive systems, in which the solar generated electricity would become part of an elctricity pool suitable for wider and multi purpose use. These systems can also be made in hybrid with Grid Wind, Diesel Generaor or any other type of power generation systems.

The thermal energy from the sun is absorbed in a collector and transferred to a fluid which is stored in an insulated tank. For smaller capacities thermosyphon mode of heat transfer is used and for larger systems forced flow circulation method is adopted. The fluid normally used is water for transferring the heat absorbed by the Solar Collector. The time taken to heat the water from an ambient temperature of 20^O C to 75^O C is normally about 4- 5 hours. However this also varies from place to place depending on the ambient temperature and the weather conditions.