Solar furnaces are optical systems that concentrate solar radiation in a small area where very high temperatures and heat fluxes are reached These systems are ideal for the study of the optical, chemical, electrical or thermodynamic properties of materials at high temperature, such as phase and vaporization studies, molten, purification and stabilization of ceramic and refractory materials, crystal growth, specific heat or thermal conductance.
Solar furnaces can be considered as natural sources of concentrated solar radiation, which because of their size, are mainly used in the testing of materials at high temperature and solar chemistry experiments on a laboratory scale, using receivers associated to reactors, or to carry out preliminary tests on a small scale as a basis for further industrial scale testing.
These systems reach the highest levels of concentration attainable in solar concentrating systems (of the order of tens of thousands of suns) well above those achieved in any other solar concentrating system.
They are generally small facilities with great ease of access, enabling simple modifications in the testing area for the exchange of experiments. All this coupled with minimal laboratory equipment, make them a very versatile tool where a great variety of essays can be performed.
The solar furnace is the facility with the highest concentration of the Plataforma Solar de Almeria, with peak concentrations range from 3000 to 7000 kW/m2. This is due to the geometric properties of the parabola, by which all the rays incident parallel to its optical axis are concentrated on the focal point.
The main components of the solar furnace are: flat heliostat; parabolic concentrator; slat attenuator and test table. Its operation is very simple, a flat collecting mirror -heliostat-, reflects the parallel horizontal solar rays towards the parabolic dish -concentrator- which in turn concentrates the incoming rays into the focus of the parabola (testing area). The amount of incident light is regulated by the attenuator located between the concentrator and the heliostat. In the focal area there is the test table which place the specimen in focus.
Currently, the PSA solar furnace houses three facilities: horizontal axis solar furnaces SF60 and SF40 and the vertical axis solar furnace SF5.