Citation
Buljan, Marina and Benitez Gimenez, Pablo and Mohedano del Pozo, Raúl and Miñano Dominguez, Juan Carlos and Sun, Y. and Falicoff, E. and Vilaplana, J. and Chaves, Julio and Biot Marí, Guillermo and López, J.
(2011).
Freeform Fresnel RXI-RR Köhler design with spectrum-splitting for photovoltaics.
In: "Optical Design and Engineering IV", 05/09/2011 - 08/09/2011, Marsella, Francia. pp. 1-9.
Abstract
The development of a novel optical design for the high concentration photovoltaics (HPCV) nonimaging concentrator (>500x) that utilizes a built-in spectrum splitting concept is presented. The primary optical element (POE) is a flat Fresnel lens and the secondary optical element (SOE) is a free-form RXI-type concentrator with a band-pass filter embedded in it. The POE and SOE perform Köhler integration to produce light homogenization on the receiver. The system uses a combination of a commercial concentration GaInP/GaInAs/Ge 3J cell and a concentration Back-PointContact (BPC) silicon cell for efficient spectral utilization, and an external confinement technique for recovering the 3J cell’s reflection. A design target of an “equivalent” cell efficiency ~46% is predicted using commercial 39% 3J and 26% Si cells. A projected CPV module efficiency of greater than 38% is achievable at a concentration level greater than 500X with a wide acceptance angle of ±1º. A first proof-of concept receiver prototype has been manufactured using a simpler optical architecture (with a lower concentration, ~100x and lower simulated added efficiency), and experimental measurements have shown up to 39.8% 4J receiver efficiency using a 3J cell with a peak efficiency of 36.9%
