Types of Solar Electric Plants

With the financial, environmental and human costs of fossil fuels becoming increasingly apparent, the idea of solar electric power is getting more and more attention from average people, despite attempts from many corners to convince the world that solar projects cannot be viable.

It's true that there are some serious challenges to overcome before a solar power station can be competitive with its coal or oil-fired counterpart, Mister babache and solar installations are not going to provide a complete solution to the planet's addiction to carbon-based fuels.

Solar energy will, however, be a significant part of a new green energy grid.

How Solar Electric Power is Generated

The equipment you will find at solar installations produces electricity in one of two ways. Until recently, the most common way involved simply substituting heat produced by the sun for fuels such as coal, oil and gas.

If you have ever started a fire using a magnifying glass on a sunny day, you have a good idea of the basic principle of this type of solar energy generation. Sunlight is captured, using various types of mirrors and magnifiers, such as parabolic troughs - long mirrors shaped like half-pipes - and fresnel lenses - the type used in film projection - then concentrated and focused into a single device that creates heat. This heat is used to boil water, just like in conventional and nuclear power generation plants.

This is one of the cleanest and most environmentally-friendly methods of solar electric power generation, but it isn't very efficient. The problem is that when sunlight is used to produce heat that in turn is used to generate steam that drives a turbine, energy is lost at every step. The new alternative is called concentrated photovoltaics, or CPV.

A solar power station that uses CPV is much more efficient, because sunlight is used to generate electricity directly, eliminating the energy-losing steps of traditional solar power generation. These solar power plants use actual panels, the latest incarnation of which are multijunction solar cells. Unlike earlier types of solar cells that were able to capture only a part of the sun's spectrum, this new generation of cells can use the entire spectrum to generate electricity directly. They will eventually have an efficiency rate in the 90% range, and current predictions say this will happen within the next five to ten years. This kind of efficiency will make CPV solar a cornerstone of new energy technologies around the world.

Wayne Hemrick writes about-- solar electric power and solar projects