Influence of the size of facets on point focus solar concentrators

• Published in: Renewable energy Vol. 36; no. 3; pp. 966 - 970
• Main Authors: Riveros-Rosas, David, Sánchez-González, Marcelino, Arancibia-Bulnes, Camilo A., Estrada, Claudio A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-03-2011; Elsevier
• Subjects: Applied sciences; Brightness distribution; Concentrators; Construction costs; Design engineering; Economics; Energy; Error analysis; Exact sciences and technology; Faceted concentrator; Natural energy; Optical design; Optical error; Optimization; Radiative flux distribution; Ray tracing; Renewable energy; Solar collectors; Solar concentrator; Solar energy; Solar thermal conversion; Sun; Faceted concentrator; Ray tracing; Optical error; Radiative flux distribution; Optical design; Solar concentrator; Solar energy concentrator; Focal length; Theoretical study; Irradiance; Optimization; Convolution; Spherical mirror; Simulation; Width; Parabolic concentrator; Facet
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2010.08.038

It is a common practice in the development of point focus solar concentrators to use multiple identical reflecting facets, as a practical and economic alternative for the design and construction of large systems. This kind of systems behaves in a different manner than continuous paraboloidal concentrators. A theoretical study is carried out to understand the effect of the size of facets and of their optical errors in multiple facet point focus solar concentrating systems. For this purpose, a ray tracing program was developed based on the convolution technique, in which the brightness distribution of the sun and the optical errors of the reflecting surfaces are considered. The study shows that both the peak of concentration and the optimal focal distance of the system strongly depend on the size of the facets, and on their optical errors. These results are useful to help concentrator developers to have a better understanding of the relationship between manufacturing design restrictions and final optical behavior.