Solar power is actually as old as life on earth; the original solar energy generators are any plants that use photosynthesis. We use this energy when we eat these plants. It is also stored in the remains of plants that lived and died over 300 million years ago in the form of fossil fuels.

Solar power plants that use the sun's energy directly aren't exactly new, either. During China's Han Dynasty (roughly contemporaneous with the Roman Empire in the West), people were already experimenting with ways to use solar energy, and legend has it that the ancient Greek scientist Archimedes, by using mirrors, was actually able to turn solar energy into a weapon that incinerated a Roman fleet. (Believe it or not, one of Archimedes' descendants was able to recreate this about forty years year.)

The first primitive solar collectors started coming into use in the 1890s, but it took several more decades before concentrated photovoltaic solar power became practical.

The latest generation of solar power plants use a series of parabolic mirrors – much like Archimedes' legendary weapon – to focus the sun's rays into a small area, creating a great deal more "bang for the buck" when it comes to solar energy. This is what concentrated photovoltaic power generation is; it has the effect of concentrating and amplifying the heat energy of the sun's rays, creating higher temperatures.

One of the serious limitations of solar energy, whether generated from individual cells or concentrated photovoltaic arrays is the fact that until now, solar cells could only use parts of the solar spectrum in order to generate electricity and heat energy. As you may be aware from your high school physics, sunlight contains several different colors that range from deep reds on one end to deep violet and purples on the other (the extremes of this range that cannot be seen by human eyes are known as infrared and ultraviolet). By using a prism that breaks up sunlight into its various components, one can see the different colors (water droplets also do this, which is what creates rainbows).

Until now, solar cells could only capture the central part of the spectrum – orange-red to light purples. However, recent discoveries by scientists in the U.S. and Japan have discovered new alloys that are able to capture the entire spectrum – pointing the way toward the day when concentrated photovoltaic solar power plants will be as practical and far more cost-effective (not to mention more environmentally friendly) than coal, gas and oil-fired plants. Eventually, we may see the day when every home and building has its own concentrated photovoltaic generation facility, taking everyone "off the grid."

Wayne Hemrick writes about--solar power plants http://amonix.com/content/seven-generations.