Effect of Zirconium Oxide Nanofluid on the Behaviour of Photovoltaic–thermal System: an Experimental Study

Recently, photovoltaic technology applications have occupied a wide range in electric generation. The temperature rising higher than the operating temperature permissible is the weak point facing this technology, which significantly influences the performance of the photovoltaic cells. Using nanofluids as the coolant of photovoltaic (PV) modules is an effective method, circulating nanofluids in the heat exchanger attached to the backside of the PV module to absorb excess heat and enhance the performance of the PV module. The current work investigates using zirconium oxide (ZrO 2) nanofluid as a coolant at different volume concentrations (0.015 vol%, 0.025 vol%, 0.0275 vol%) in deionized (DI) water to reduce the temperature of the photovoltaic PV cells and then analyses the performance from the energy/exergy viewpoints. The results indicate that the PV module temperature was reduced by 10.2 °C when cooled by ZrO 2 nanofluid at 0.0275% volume concentration in DI water compared to the reference PV module, resulting in remarkable system energy and exergy enhancement. Besides, the cooling by DI water has decreased the PV module temperature by 5.1 °C. The overall efficiencies gradually increment with an increase in volume concentration by 8.9%, 18.8 % and 24.4%, respectively, compared with PV modules cooled by DI water. Using ZrO 2 nanofluids with 0.0275 vol% could enhance the exergy efficiency by 66.8% and reduce the exergy losses and entropy generation by 7% and 26%, respectively.