What Is Concentrated Thermal Solar Power?

When we think of solar power the most common image that comes to mind is that of blue or black rectangular panels perched on a house roof, silently supplying electricity to the home below without charge or pollution. However there are many more ways of using the sun's energy to create electricity and one of the major ones is Concentrated Thermal solar power. This technology has been used to build power stations that can work on a scale approaching that of fossil fuel powered plants. What is this technology and how does it work?

Whereas domestic solar panels convert sunlight directly into electricity, Concentrated Thermal solar works with the heat of the sun's rays. As children most of us will have used a magnifying glass to burn bits of wood, cardboard and the odd unfortunate ant. When we concentrate of the sun's rays through the magnifying glass lens it is acting as a heliostat. Concentrated Thermal works in a similar way but it reflects the heat from mirrors rather than condensing it through a lens.

By making a mirror in an arc shape called a parabola, it is possible to reflect all the light that hits it onto one point. The amount of heat focused on that point is then a factor of the size of the mirror. A large surface area of mirror can produce incredibly high temperatures. This fact is utilized in dish shaped solar camping cookers that can be used to boil water.

For commercial electricity production, a tube of synthetic oil is run through the focal point of such a mirror. The oil in the tube is heated into the many hundreds of degrees. The oil is pumped through the tube to the power generating turbine where it is used to boil water. The steam from this drives the turbine to make electricity in the same way that a coal fired power station woks.

The bigger the total mirror surface, the more heat is harvested and therefore more electricity can be generated. Power stations employing this technology consist of seemingly endless rows of curved trough mirrors, all moving with the sun throughout the day to maximize electricity production. Concentrated Thermal power stations can also produce electricity at night. Throughout the day excess energy is stored in vats of molten salt. At night the heat given off by these salts cooling is used to continue steam and therefore electricity production.

This method of generating electricity works only where there is enough sunlight. It is cheap, reliable and safe and on a large enough scale it is capable of providing base load domestic electricity. The only pollution associated with such a power station is from the initial building. Aside from that it provides endless clean energy at a minimal cost. - 39468