Investigating the performance characteristics of low concentrated photovoltaic systems utilizing a beam splitting device under variable cutoff wavelengths

A numerical model combining thermal and electrical models was established and validated against previous literature to investigate the thermal and electrical performance characteristics of a concentrated PV/thermal unit integrated with a beam splitting system. The effect of the cutoff wavelength on the temperature distribution and the maximum allowable concentration ratio (MACR) for uncooled systems was discussed. The maximum efficiency was found to be at about a 900 nm cutoff wavelength, whereas the total output power achieved its maximum value at a cutoff wavelength of 600 nm under MACR conditions. The effect of the splitting system on actively cooled systems was also discussed. Cooling the system allowed for higher concentration ratios beyond MACR but consumed more power. The required cooling water inlet Reynolds numbers under several concentration ratios were estimated. It was discovered that using a splitting system dramatically decreased the required flow rate, hence less cooling power. The overall efficiencies when using a splitting system were higher than those normal systems in all cases. The results of this study could be considered as a guide for designing a hybrid splitting system at optimum conditions with and without cooling and pave the way for more improvements in this field. • A linked thermal/electrical model for low CPV/beam splitting systems is proposed. • Effect of several design and operating parameters on performance is investigated. • Maximum allowable concentration ratio (MACR) is estimated at different conditions. • Maximum output power was reached at a cutoff wavelength of 600 nm under MACR. • Maximum efficiency was reached at a cutoff wavelength of 900 nm under MACR.