What is Concentrated Solar?
Concentrated solar takes the sun’s energy and collects it through a series of arrays and then concentrates or focuses it on a location that is the center of the arrays. The energy at that central point becomes very hot, hot enough to melt many metals and to produce steam.
Concentrator Designs:
Solar concentrator technologies comes in several forms:
- Power towers - are designed for large scale centralized grid applications. They are only a few prototypes in operation and they use parabolic mirrors to reflect the sun's radiation and then focus it on the power tower which is located in the center of the reflectors and elevated above the ground.
- Dish Solar Concentrators - are a smaller version of a power tower. A mirror array concentrates the sun's energy on the center of the concentrator. In the SES and SAIC systems this is where the gen-set or power generator is located. Their power range varies in relation to the size of the concentrator array but the SES/SAIC system generator about 20-40 kwh about enough to power 4-6 homes.
- Solar Troughs - Usually designed as part of a large scale centralized power system, however they do not rely on a centralized focus point as does the power tower and can be used for smaller scale applications.
- High-Flux Solar Furnace - Involves the concentration of to many times the normal intensity of the sun at the Earth's surface, creating very high temperatures enabling the molding of metals using energy directly from the sun.
What are its advantages and disadvantages of this technology as compared to Solar PV?
Solar PV is expensive and one reason it is expensive compared to other energy sources like oil is that you need a lot of PV panels that take up a lot of area to produce a certain amount of electricity. Concentrated solar though requires a much small footprint because it operates at a higher level of efficiency converting more of the sun per unit of collector into energy. However it is still not known for sure whether the cost of this technology will be competitive with PV solar much less petroleum or natural gas because this technology is still in the experimental stages. At the present time there is no capacity to mass produce the parts needed to make the SES solar concentrators so they are expensive to make. SES of course believes that once they have developed an economy of scale the cost will of constructing these arrays will go down dramatically.
The two major companies developing concentrating solar technology have used External combusion engines as the gen-set. However the versatility of the dish solar system allows for different gen-sets to be installed. The Nevada 1MW Solar Dish Engine Project too place at a UNLV test facility. Two dish solar competitiors SAIC and SES were evaluated against each other. SES seemed to produce more power and performed well overall. However what was interesting was the concentrated solar/PV that was created with the use of triple junction solar cells. This hybrid has the potential to significantly increase cell capacity therefore dramatically improving power yield from cells reducing the number of cells needed to produce electricity. This though is still an experimental technology. Other possibilities involve the use of thermal-electric coupling or steam turbines.
Application Areas:
Large scale solar development for centralized power solutions as SES proposes with its 1000 MW stirling generator facility is one option towards a renewable energy economy.
Focus on decentralized, community based solutions that fits with our Village Economy model.
The Solar Power Village technology does fit this model and it also offers low-cost sterling engine solutions rather than high cost solutions put forward by SES. However SES's system may be more geared to produce electricity for sale to utilities than the Solar Power Village System. In one test performed by UNLV's solar research program SES's concentrator system outperformed SAIC's.
Background
Abstract
Keywords:
Development needs
Next steps
The most appropriate technology approaches are those focused on Distributed Power and/or District Power solutions and this primarily includes Dish and Trough solar Thermal systems. These systems are versatile, in that they can be used both in what are called distributed decentralized power systems and centralized, grid based or stand alone (off grid) applications (like the way most is generated today in large power plants at centralized locations.
Possible alternatives devices
Location
References
See Help:Footnotes for more.
