AbstractA new geometry of photovoltaic/thermal (PVT) system is introduced in this study, and the application of Al2O3/water nanofluid as the coolant on the electrical and thermal behavior of a solar system is experimentally evaluated. To intensify the thermal ability of the solar collector, a serpentine half‐pipe cooling system is designed and fabricated behind the solar panel for better cooling. The cells of the panel are assembly on a 3‐mm‐thick aluminum plate, and the Tedlar removes from the system to maximize the heat transfer in the cooling section. A special layer arrangement for the composite panel is used to minimize thermal resistance of the system. Different concentrations of nanofluid samples (0.05–0.5 wt.%) prepared. To increase the stability of prepared nanofluids, suitable surfactants are also used. Based on the obtained results, adding the nanoparticles to the pure water can remarkably raise the efficiency of the PVT apparatus. The best behavior of the solar collector is observed for 0.5 wt.% of nanofluid samples. 126.71% and 7.38% enhancement in terms of thermal and electrical efficiency can be gained by the application of nanofluid in the system compared with pure water, respectively. The best obtained value of the overall efficiency is around 93.73% for the studied system. The maximum temperature rise for water and nanofluid is around 5.5 and 9.1°C, respectively, which confirms the better cooling ability of PVT system by nanofluid compared with water.