Utility Scale Solar power Generation
Posted July 26, 2008on:
Solar-thermal generated energy is only just emerging from the experimental stage to full-scale electricity production. Solar-thermal power concentrates the sun to heat up fuel such as gas or oil. The heat trapped within is then used to convert water into steam, which powers a conventional steam turbine to generate electricity. Fossil fuels are sometimes used as a back-up to heat the water in the boiler if the sun is not shining. There are three different methods for concentrating
the sun’s rays:
Parabolic Trough — This method uses long, parallel rows of glass mirrors in the shape of a trough to concentrate the sun’s rays toward the “absorber tube” — usually filled with oil — to maximum effect.
Power Tower — Similar in principle to parabolic-trough technology, the mirrors are placed in a circular pattern. At the center of the circle is a tower, at the top of which is a receiver filled with water, air, liquid metal or molten salt that moves to a power block and is used to power a steam turbine.
Parabolic Disk System — In this system, dishes rather than troughs are used to concentrate the power of the sun. An example of this type of solar project is the 500-megawatt Solar Energy Systems plant is operational in the Mojave Desert in California.