16 October 2012 Experimental characterization of Fresnel-Köhler concentrators
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J. of Photonics for Energy, 2(1), 021806 (2012). doi:10.1117/1.JPE.2.021806
Most cost-effective concentrated photovoltaics (CPV) systems are based on an optical train comprising two stages, the first being a Fresnel lens. Among them, the Fresnel-Köhler (FK) concentrator stands out owing to both performance and practical reasons. We describe the experimental measurements procedure for FK concentrator modules. This procedure includes three main types of measurements: electrical efficiency, acceptance angle, and irradiance uniformity at the solar cell plane. We have collected here the performance features of two different FK prototypes (ranging different f -numbers, concentration ratios, and cell sizes). The electrical efficiencies measured in both prototypes are high and fit well with the models, achieving values up to 32.7% (temperature corrected, and with no antireflective coating on SOE or POE surfaces) in the best case. The measured angular transmission curves show large acceptance angles, again perfectly matching the expected values [measured concentration acceptance product (CAP) values over 0.56]. The irradiance pattern on the cell (obtained with a digital camera) shows an almost perfectly uniform distribution, as predicted by raytrace simulations. All these excellent on-sun results confirm the FK concentrator as a potentially cost-effective solution for the CPV market.
© 2012 Society of Photo-Optical Instrumentation Engineers (SPIE)
Pablo Zamora, Pablo Benítez, Rubén Mohedano Arroyo, Aleksandra Cvetkovic, Juan F. Vilaplana, Yang Li, Maikel Hernández, Julio C. Chaves, Juan C. Miñano, "Experimental characterization of Fresnel-Köhler concentrators," Journal of Photonics for Energy 2(1), 021806 (16 October 2012). https://doi.org/10.1117/1.JPE.2.021806

Solar concentrators


Electrical efficiency

Solar cells

Solar energy


Fresnel lenses

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