Solar concentrator technology is a complex and growing field. There are three types of concentrators and these include power towers, Parabolic troughs with mirrors and dish type systems.
What is the problem? Existing energy systems use energy, which is not renewable. PV Solar is one alternative however solar cells have a very low power density and so it takes a lot of solar panels to produce enough to do heavy work like powering heavy machinery and melting and heating materials.
Why Concentrating Solar? Concentrating solar uses radiation from the sun just like PV solar. However, instead of directly converting it into electricity it concentrates it to create tremendous heat enough to melt most metals and to power a steam turbine, which can then produce electricity. This is what makes concentrating solar potentially more versatile and feasible as an energy source than PV panels.
What are the potential options? Currently one company SES is developing a system that takes the sun's rays and converts it to electricity via a Stirling engine. One problem with this option is that this Stirling is experimental and that the overall system itself is expensively designed.
Experiments are now being done at the University of Nevada at Los Vegas combining Concentrating Solar with experimental triple junction PV panels to convert 36.9 percent of the sun's energy to electricity. Potentially this could dramatically reduce the cost of generating electricity from solar energy. Fewer solar cells are required to achieve a level of power production that would normally require more cells. The strategy is to replace large areas of semiconductor materials with relatively inexpensive optics (solar concentrators) that provide optical concentration. Higher cost of multijunction cells is offset by the use of fewer cells. Triple junction cells when coupled with solar concentrators have the potential to surpass 40% conversion.
Another option is to use solar concentrators with steam turbines to produce electricity with proven and widely accessible technologies. The advantage of this would be that micro-turbines are now widely available and thus the focus would be on developing inexpensive and durable materials to concentrate the solar onto the heating plate, which would then create steam for use in the steam generator.
Where is the research on these technologies being done? The UNLV is now doing research on these technologies. Another notable player is Stirling Energy Systems, which has several Stirling gen-sets in operations. Bill Gross of Idea Lab has also been developing this technology. And of course Tamera Ecovillage in coordination with Bomin Solar Technologies.
Where is concentrated solar being used?
Solar 1 is a plant in southern California by Barstow that uses parabolic mirrors
The Auroville Ecovillage uses a large concentrating solar dish to cook food for 1000 people every day.
SES has several dish solar systems in operation in California, UNLV and Arizona.