Thermal and electrical performance of a trough-type spectral beam splitting concentrating photovoltaic/thermal system

Concentrating photovoltaic/thermal systems can enhance photovoltaic (PV) output, but they also impose higher requirements on spectral utilization and thermal management of PV modules. In this study, a spectral beam splitting concentrating photovoltaic/thermal (SBS-CPV/T) system based on a parabolic trough concentrator is proposed. To accommodate the spot distribution generated by the dual-row prisms, a double-cell shared-substrate PV module with active flow-channel cooling is designed. A coupled optical-electrical-thermal method is adopted to analyze the effects of spectral splitting, active cooling, and key operating parameters on system performance. The results show that, at the PV module scale, the split PV-band radiation is relatively uniform, with a maximum difference in average irradiance of approximately 1.02%, whereas irradiance non-uniformity remains at the individual cell scale. This non-uniformity mainly intensifies local temperature differences. Compared with the equivalent uniform input, the maximum temperature difference of the double-cell unit increases by 13.64%, while the average temperature of the PV cell module increases by only 3.23%. Compared with the non-splitting case under the same active flow-channel cooling condition, spectral splitting reduces the maximum and average cell temperatures by 29.6 °C and 25.0 °C, respectively, and results in a 21.73% relative increase in PV efficiency. The parametric analysis shows that increasing direct normal irradiance significantly enhances the electrical and thermal outputs of the system, while reducing the cooling-water inlet temperature and increasing the inlet velocity help enhance cell cooling and improve PV efficiency. This study provides guidance for PV module structural design and PV-side thermal management in high-concentration SBS-CPV/T systems.