Performance, solar energy collectors

Hottel, H. C., Whillier, A., Transactions of Conference on Use of Solar Energy, Scientific Basis, Vol. II, Thermal Processes, Part 1, Section A, Flat-Plate Collectors, Evaluation of Flat-Plate Solar-Collector Performance, Tucson, Ariz., 78 (Oct. 31— Nov. 1, 1955). 

Polymers have many potential applications In solar technologies that can help achieve total system cost-effectiveness. For this potential to be realized, three major parameters must be optimized cost, performance, and durability. Optimization must be achieved despite operational stresses, some of which are unique to solar technologies. This paper Identifies performance of optical elements as critical to solar system performance and summarizes the status of several optical elements flat-plate collector glazings, mirror glazings, dome enclosures, photovoltaic encapsulation, luminescent solar concentrators, and Fresnel lenses. Research and development efforts are needed to realize the full potential of polymers to reduce life-cycle solar energy conversion costs. 

The optimization of photoelectrochemical devices for solar energy conversion depends on the choice of semiconductor, electrolyte, and cell design. The performance of the cell is strongly dependent upon the design, surface area, and placement of the counterelectrode and current collectors. This type of solar cell may be economical under concentrated illumination or in regions where electrical power has high value. 

Simon, F.F., February 1975. Flat-plate solar-coUector performance evaluation with a solar simulator as a basis for collector selection and performance prediction. Solar Energy 18 (5), 451-466. 

Abstract. Usual plate solar collectors, based on a metal absorber (Cu, Al) selectively coated are technologically very sophisticated, expensive to produce and they are great consumer of fossil raw material. Polymeric materials are considered as a promising alternative for many interesting properties easy moldability, corrosion resistance, they also offer a significant cost-reduction for solar thermal collectors, and a mass production may thus benefit to a broader utilization of solar energy. Most drawbacks of polymers are their low thermal properties essentially thermal conductivity coefficient may strongly affect the solar absorber efficiency and deteriorate the collector performance. 

Another concern is keeping the solar collectors clean. Grime and dust deposited on the mirror surface can rapidly reduce the amount of energy reflected. This in turn decreases the output of the plant. The collectors require windshield wipers to perform frequent cleaning cleaning and/or windshield wiper maintenance causes a significant increase in operating cost. 

Solar heating requires concentrating collectors (e.g., parabolic) to produce the likely process temperatures and overall performance needed. It also limits operation to daytime hours and sunny days or requires a way of storing energy at high temperatures. 

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