Performance analysis of a novel solar concentrator using lunar flux mapping techniques

• Published in: Solar energy 2020-08, Vol.206, p.200-215
• Main Authors: Roosendaal, C., Swanepoel, J.K., Le Roux, W.G.
• Format: Article
• Language: English
• Subjects: Accuracy; Cameras; Concentrators; Design; Fluctuations; Flux; Flux mapping; Incident light; Light effects; Light pollution; Light sources; Lunar; Lunar phases; Mapping; Modular structures; Moon; Multifaceted; Parabolic bodies; Polymer films; Satellite dishes; Solar dish; Solar energy; Vacuum; Vacuum membrane
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2020.05.050

•Individual facets are made from commercially-available television satellite dishes.•Aluminised plastic film is used to form a multifaceted vacuum membrane concentrator.•Two setups with global diameters of 1.6 m and 4.98 m were constructed.•The testing took place during the full moon phase using a Canon EOS 700D camera.•Intercept factors and peak solar concentration ratios were found using flux ratios. One of the most important issues faced today with regards to solar concentrators is the trade-off between cost and optical accuracy. In this paper, a new design aims to reduce costs while maintaining high optical accuracy with the added benefit of optical adjustability. This is accomplished by manufacturing individual facets out of commercially-available television satellite dishes with aluminised plastic film to form a multifaceted vacuum membrane concentrator. The lightweight facets were affixed to a modular support structure in a hexagonal honeycomb arrangement and in the profile of a paraboloid, where each facet could be adjusted individually. Two different concentrator sizes with global diameters of 1.6 m and 4.98 m were constructed and tested. Testing took place during the full moon phase using a Canon EOS 700D camera with no added equipment. Images of the flux were captured and were treated for the effect of city light pollution. With the use of normalised flux maps, the peak solar concentration ratios of the large and small dish setups were calculated to be 1438 and 539 respectively. The design, therefore, proved to be a viable design alternative for point focus solar concentrators to reduce costs and maintain optical accuracy. Furthermore, the lunar flux mapping techniques proved effective and safe, by using the incident light from the moon and standard camera equipment.