Although it sounds very "sciencey" to the uninitiated, CPV solar technology – or "concentrated solar power" – is really a very simple concept, as well as an ancient one. In fact, if you've ever had to start a campfire with a magnifying glass and a mirror, you pretty much understand the basics. When the sun's rays are concentrated and amplified, then directed toward solar panels or some type of pipe or duct containing a heat conductor, the generation of solar power becomes much more efficient.
The roots of CPV technology date back over two millennia. Chinese during the Han Dynasty experimented with elements of this energy generation method, and according to legend, the ancient Greeks used mirrors and concentrated solar power to repel a Roman invasion by setting their ships on fire (this was actually replicated by a Greek scientist in the early 1970s).
An early cpv solar generator was built in the late 1860s using a parabolic trough, but it took another century before this was combined with the magnifying glass to create the first workable CPV solar generator. This plant was able to heat water to more than 1,000 degrees, creating superheated steam that could generate a thousand kilowatts of usable electrical energy. Today, the largest such facility is located in the Southern California desert; SEGS (Solar Energy Generating System) puts out a whopping 354 megawatts.
There are a variety of CPV solar systems, not all of which use parabolic troughs. Dish systems employ direct solar heat, while the Stirling Engine – a 21st Century twist on the 19th Century steam engine – uses the energy of fluids and gases as they expand with the application of heat. The most efficient way to use this technology however is to direct the sun's rays onto a concentrated photovoltaic panel – eliminating the loss of heat energy that inevitably occurs during a transfer process. These panels must be mounted on a tracking system that keeps the components facing in the optimal direction as the sun moves across the sky over the course of the day.
With the development of new alloys and materials, the day is quickly approaching when the efficiency rate of these facilities will be as high as 50% of those of fossil fuels, and eventually, they will render fossil-fueled power plants obsolete.
