Solar Thermal Electricity generating system
A Solar Thermal Electricity generating system also known as Solar Thermal Power plant is an emerging renewable energy technology, where we generate the thermal energy by concentrating and converting the direct solar radiation at medium/high temperature (300ºC – 800ºC). All solar thermal systems capture the energy of the sun by absorbing light as heat. Solar thermal power systems focus sunlight, usually with mirrors, to heat a fluid to high temperatures and drive an engine. With their high efficiency and the lowest power production costs of all solar technologies, the technologically mature parabolic trough power plants in particular have
outstanding prospects for the future. The uninhabited deserts of North Africa alone could generate many times the European power requirements. It will also
contribute directly to the CO2 reduction strategy. According to a Greenpeace study, the use of CSP(concentrated solar power) can prevent 154 million tons of
CO2 emissions worldwide by 2020. This approach stands in contrast to photovoltaic solar power systems, in which light interacts with special materials directly to separate charges and generate electricity. Photovoltaic power enjoys many advantages, such as unattended operation and small-scale feasibility, but remains significantly more expensive as a source of large-scale power than solar thermal technologies.
The modern era of large scale solar power generation was born in California’s Mojave Desert in the 1980s, when Luz Industries built a total of 354 MW of Solar Electric Generating System, or SEGS, power plants. The SEGS plants use long parabolic mirrors with pipes at the focus point, where circulating oil is heated to
700 F (350 C). The oil is pumped through heat exchangers which boil water to make high-pressure steam, which drives turbine generators to make electric power.
The ability to store energy as heat makes solar thermal electric power particularly valuable, because energy can be stored when the sun is shining and released for electricity generation when the power is needed most. Often peak electricity demand extends well into the evening on hot summer days; solar thermal electric power is uniquely able to deliver zero-carbon electric power to meet these demands. Solar plants can be built to be “dispatchable”, gathering energy during daylight hours and releasing it during times of peak demand. Solar technologies have the potential to be major contributors to the global energy supply.