Unlocking hybrid solar efficiency: Experimental integration of aluminum foam fins and nanofluids in PVT collectors

Hybrid photovoltaic-thermal (PVT) systems experience significant performance deterioration under elevated operating temperatures, while conventional enhancement techniques often suffer from limited heat-transfer capability and inadequate thermal stability in hot climates. To address this gap, this study experimentally assesses a dual-enhancement strategy that couples high-porosity aluminum foam fins with thermally improved nanofluid coolants to enhance both electrical and thermal performance. Aluminum foams with porosities between 85 % and 95 % were fabricated using caustic-soda foaming method and mounted on the rear surface of polycrystalline PV modules. Outdoor experiments were conducted in Al Marj, Libya, under solar irradiance ranging from 400 to 1000 W/m 2 , using SiO 2 , TiO 2 , and SiC nanofluids at mass-flow rates between 0.068 and 0.170 kg/s. All measurements were obtained using calibrated sensors, with temperature, irradiance, and electrical uncertainties maintained within ±1.08 °C, ±5 %, and below ±0.1 %, respectively, ensuring high reliability of the recorded data. Among all tested configurations, the SiC-based collector delivered the strongest enhancement, achieving a thermal efficiency of 69 %, an electrical efficiency of 14.16 %, and a combined efficiency of 85 %. Additionally, nanofluid cooling reduced module temperatures by up to 15.11 °C and improved electrical output by >35 % compared with water cooling. The results highlight the effectiveness of integrating aluminum foam fins with nanofluid cooling as a scalable solution for mitigating thermal losses in hybrid solar systems, particularly in high-temperature environments.