Comparison of V-trough and asymmetric CPC linear dielectric concentrating PV covers for building integration

Linear dielectric concentrating PV covers based on an asymmetric CPC geometry and optimised for building façade integration can achieve optical efficiencies above 90% for a wide range of incidence angles and have demonstrated up to a 2.01 power ratio over non-concentrating panels for the same PV area. However the employed CPC geometry requires complex mould manufacturing techniques and PV conversion efficiency can suffer from highly uneven energy flux distribution. This paper investigates dielectric V-trough concentrators as an alternative to the CPC for building integrated PV. Employing planar surfaces, do not require complex fabrication techniques. Angular acceptance and optical efficiency have been analysed with three dimensional ray trace. Appropriately designed for façade building integration V-trough concentrators can collect similar amounts of beam and diffuse solar radiation compared to asymmetric dielectric CPC. A 79% increase in annual solar radiation collection per m2 of absorber area compared to a flat glass PV cover was calculated. Predicted energy flux distribution on the PV surface is fairly homogeneous allowing for higher PV conversion efficiencies.