There are two systems to produce electricity by solar thermal energy: high concentration and low concentration.
The low concentration system , the most commercially widespread, uses some light collectors installed on the roofs of houses, with which it is possible to cover the basic needs of a home, such as heating water or heating rooms.
These parabolic systems operate at temperatures between 100 and 400ºC . The thermal energy coming from the solar rays reaches the collectors, heating the fluid circulating inside them (water with antifreeze).
This energy in the form of hot water reaches another circuit where it accumulates in a tank until it can be used.
¿ What are the applications ?
Between his applications stand out: the sanitary hot water , the heating by radiant floor, the climatización of swimming pools, refrigeration and hot water for industrial processes, among others.
The sun’s energy, the most abundant on Earth, is renewable, inexhaustible and clean, and contributes to the reduction of CO2 emissions and other greenhouse gases.
According to the Institute for the Diversification and Saving of Energy (IDAE), a single-family house can avoid 1.5 tons of carbon dioxide (CO2) per year using this type of clean energy and replacing the electricity consumption.
Another example: a hotel with capacity for 400 people can avoid up to 128 tons of CO2 per year with these systems.
Solar thermal power plants
When we talk about high concentration systems , we refer to large thermoelectric solar plants. The operation of a thermosolar plant is similar to that of a thermal power plant, but with the difference that instead of using coal or gas, it uses the energy of the sun.
The sun’s rays are concentrated by curved mirrors or parabolic discs in a receiver that reaches temperatures of up to 1,000 ºC. This heat is used to heat a fluid and generate steam, which moves a turbine and produces electricity.
Unlike other countries, Spain has the advantage of receiving a large amount of solar radiation a year, especially in the southern half. This means that our country can become a great exporter of green energy in the future.
According to data from Protermo Solar, in addition to the plants that are already operational, by 2013 it is expected that some 60 plants will be in operation, which together will have around 2,500 MW of installed capacity. Check the map of the Thermoelectric Solar Industry in Spain.