Use of solar energy

1992/02/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Energia berriztagarriak

Australian researchers have developed a surface to be used in a collector that transforms 98% of solar energy into heat. The surface is installed in a solar generator.

This solar generator is a solar generator in which the heat obtained from the sun allows to boil water, transfer steam to a turbine and generate electricity. According to researchers, 20% of the energy coming from the sun is transformed into electricity. Therefore, this system of obtaining electricity is, comparatively with conventional systems, of better performance.

This unique surface is called a highly efficient selective surface or SMI and consists of metal, metal ceramic (zermet) and insulating materials. The different layers that make up this surface are sandwiched and are very effective in absorbing the high energy emitted by the sun.

At the same time, layers hinder low-energy infrared radiation. Therefore, the loss of radiation through this pathway is between three and four times lower than the loss in conventional systems. The range supported by TSJPV is very wide, being able to extend from the ambient temperature to 500ºC.

The SMI consists of four layers. The upper is anti-reflective and consists of a transparent insulating material, such as silicone oxide. The next two layers are fenced, with light absorption capacity. Finally, a layer of copper or other metal carries the accumulated heat inward.

In the heart of the collector there are two glass cylinders (inside the baptism), with a gap between both.

It is placed on the outside of the inner cylinder of the SMI. Inside this cylinder there is a steel tube. There the water begins to boil by heat effect.

The size of the device is 2 x 1 m and the price of the energy it can bring is 4 pts/kWh. If you consider that the price of energy from nuclear or thermal power plants is 9 pts/hour/kWh, the savings obtained is evident.