Solar thermal

A solar heating central is an industrial i nstallation in which, from heating a fluid by solar radiation and its use in a conventional thermodynamic cycle, the power required to move an alternator for power generation is produced as a thermal classic.


It is necessary to concentrate the solar radiation in order to reach high temperatures, from 300 ° C to 1000 ° C, and thus obtain a yield acceptable in the thermodynamic cycle, which could not be got with lower temperatures. The uptake and concentration of the sun's rays are made through mirrors with automatic guidance pointing to a central tower which heats the fluid. The whole of the reflecting surface and its guidance device is called heliostat.
  • Mirror Heliostats
Heliostatos

A heliostat is a set of mirrors that moves on two axes, which allows, with appropriate movements, maintain a reflection of the sun's at a point or small surface undoing in the reflected ray the daytime ground movement.

A tower central -- also known as the central receiver system -- is composed of a hub system or a field of heliostats, which captures and focuses the component of the direct solar radiation on a receiver where the conversion of radiant energy into thermal energy is produced. The working fluid can be, among others, air, water steam, molten sodium or molten salts, depending on the technology chosen. The water steam moves a turbine directly. In the other cases, the fluid transports heat to a water steam generator, which makes a turbine that drives the electric generator working.

  • Parabolic trough cylinders
Cilindros parabólicos

The difference with the previous one is on the way to collect the sun's energy. Instead of heliostats, mirrors on a parabolic cylinder are used. By the focus of the parable, where the fluid is heated, goes a pipe which receives the concentrated rays of the Sun. Once the fluid is warm, the process is the same as that of the tower central.