Solar energy harnesses the light and thermal energy of the sun to generate electricity and/or heat energy. This can come in a number of forms:
Solar voltaics directly convert sunlight into a direct current through an electrochemical reaction. This is the most widely used form of solar, with over 250 GW installed globally by the end of 2015.
CSP involves using mirrors to re-direct sunlight to a central boiler, typically mounted on a central tower or as part of a parabolic trough arrangement. This focuses solar energy from a large area on a small space, to produce steam in a boiler which is used to power a turbine. Installed capacity globally was c. 4.5 GW in 2014.
solar thermal technologies harness the thermal energy of the sun to heat a medium, such as heat or water. These are typically low temperature applications used for space heating, or process heating such as separation of salt and water through evaporation. Similar technologies can be used in cooling applications, through absorption chilling.
