The solar concentrator is a device that concentrates a beam of solar rays on a heat carrier that gives you the opportunity to increase efficiency. The coolant can be either water or oil, which absorb the heat energy.
The concentrator have a different design and shape. The outer side of these structures is covered with mirrors. From the hub which form is used depends on how concentrated the sun’s beam, at one point or linearly.
There are several of the most common designs:
– the heliocentric (in the form of a tower) concentrator have several complex design. It consists of a tower and receiver, which is located at the top of her, and of a system of heliostats. A system of heliostats follows the sun light, thus ensuring that focus the flow of solar rays to the receiver. The receiver absorbed the heat energy acts on the turbine and drives the generator. In concentrators of this type as the heat transfer fluid can be a vapor or gas, provided that they can withstand temperatures up to 1000º. It may also be a liquid metal or a liquid that can withstand temperatures up to 800º. These centralizers coolant performs two functions: it drives the generator and directly involved in the production of electricity. The use of such concentrators are very efficient, but at the same time, such a system is costly, for it needs a large area more than 50 Hectares.
– parabolic (plate) resemble satellite dishes. This design consists of a large number of mirrors of parabolic shape. Focus solar beam is on each mirror separately, that enables the coolant to heat up to 1000º. As this forms a large amount of steam should be used for maximum efficiency Stirling engines. Because of this effect, the concentrators of this type are very promising. Today energy giants actively develop this direction at the time of such concentrators are very effective in domestic use, provided that the property is located in the solar zone.
– the cylindrical parabola concentrator is made in the shape of a parabola. Sizes in diameter reach up to 50m. The surface of the concentrator covered with mirrors, a concave shape. Throughout the mirror structure includes a coolant, and each mirror directs the accumulated energy at a certain point of the coolant. Thus, there is a transfer of thermal energy. The heat carrier is enclosed in a tube and covered with a special glass casing. This helps to reduce heat loss. For such a system concentrator, an important tracking system for solar radiation. Install a solar system with a mandatory orientation on the South side of the world. Tracking is due to the fact that the coolant is heated to 400º and allocated the steam acts on a turbine generator, thereby resulting in the movement system. It has been empirically demonstrated that this type of concentrator is less effective than previous types.
The above described advantages of solar concentrators give the possibility of their wide use, both industrially and in the home for hot water and space heating. But is it worth all this to consider one disadvantage of the concentrator common to all types. These devices can efficiently work only in sunny weather, so their use is limited. Their use is justified in those parts of the world where most of the year sunny. Today, electricity production of industrial volume concentrators use in the deserts (the Sahara desert).