A comparison of performance of flat and bent photovoltaic luminescent solar concentrators

To employ new solar photovoltaic technologies in products and buildings, many systems need to be adapted. Inspired by the cylindrical shape, in this work we have evaluated the performance of luminescent solar concentrator photovoltaic (LSC-PV) elements with narrow PV cell strips that could be integrated in an outdoor lighting pole. Silicon photovoltaic (PV) cells were attached to the back of both flat and cylindrically bent PMMA lightguide sheets containing the dye Lumogen Red 305, and mirrors to non-covered edges of the light guides. The energy performance of these two elements was measured. The flat and bent LSC-PV elements were also simulated using optical modeling and the resulting performance parameters from simulations and experiments were compared. From simulations for a flat LSC-PV, the optical collection efficiency, concentration and electrical conversion efficiencies were found to be 18%, 1.8% and 2.8%, respectively, for a geometric gain of 10. For a bent LSC-PV shape, the respective values are 21%, 1.4% and 3.4% for a geometric gain of 6.7. Due to reduced sensitivity to the angular dependence of incoming irradiance it is expected that these bent LSC-PV elements would perform well on both sunny and cloudy days.