Concentrated Solar Thermal
Concentrator solar thermal systems focus sunlight onto a tube or surface to heat a fluid to high temperature (200 to 500 ºC), the heat energy stored in the fluid is converted into electricity using conventional steam turbine or heat engine generators. Linear concentrators focus sunlight onto linear absorbers such as tubes using parabolic mirrors or linear Fresnel lenses; field concentrators focus sunlight onto absorbing surfaces using dishes or heliostats. One advantage of thermal systems is that solar energy can be stored as heat for several hours facilitating the generation of electricity overnight when sunlight is not available. Concentrator solar thermal systems also offer a 10:1 energy payback ratio.