Assessment of environmental impact on thermoelectrical performance of HCPV/T systems in arid climates

Densely packed high-concentration photovoltaic/thermal (DP-HCPV/T) systems operating in desert climates experience severe thermal stresses and dust-induced optical degradation, which are often evaluated separately. This study develops a novel, fully coupled optical-thermal-electrical framework for a water-cooled DP-HCPV/T system designed for Al-Kharsaah, Qatar, at 1500 suns. A dust-aware Monte Carlo ray-tracing model is integrated with a three-dimensional conjugate heat-transfer and computational-fluid-dynamics model to quantify clean and dusty performance over Reynolds numbers (Re) from 1124 to 11236. The results indicate that under clean conditions, the Fresnel lens attains an optical efficiency of 81.46%, producing an average incident flux of 1.02 × 10⁶ W/m². The clean-case optimum occurs at Re ≈ 8989, where the module maintains an average cell temperature of 62.50°C, a coolant outlet temperature of 35.04°C, and a temperature non-uniformity of 21.28°C. At this condition, the module produces 244.11 W of net electrical power and 336.03 W of thermal power, with electrical and thermal efficiencies of 41.61% and 46.59%, respectively. In contrast, under a uniform dust layer, the optical efficiency drops to 32.58%, and the average incident flux decreases to 4.1 × 10⁵ W/m². The dusty-case optimum occurs at Re ≈ 5618, where the lower absorbed flux yields 98.61 W of net electrical power, 140.79 W of thermal power, and efficiencies of 42.00% and 19.52%. Finally, overall exergy efficiency declines from 36.43% in the clean case to 14.62% in the dusty case. These results confirm that dust strongly degrades overall cogeneration performance and shifts the optimum operating condition to a lower Re.