Experimental investigation for a hybrid aluminum oxide nanofluid-phase change material photovoltaic thermal system based on outdoor test conditions

This study presents a novel hybrid technique for optimizing energy harvesting from solar radiation using com-bined cooling and heat storage mechanisms. The proposed system is introducing a combination of Nanofluids as a working fluid and a PCM (Phase Change Material) as a heat storage element in a compact device. It investigates experimentally the effect of using Nanofluid (Al2O3-water) and adding PCM (paraffin wax RT35) as a coolant on the performance of PV cells. Firstly, the cooling systems are tested for pure water and, pure water by adding PCM at different flow rates of pure water (0.8, 1.2, and 1.6 l/min). After that, the impact of using Nanofluid (Al2O3- water) is investigated at weight fractions (0.05, 0.1, 0.2, 0.3, and 0.4)% and the effect of adding PCM with a cooling Nanofluid circulation system at different weight fractions on the performance of the PV module. Results show that the cooling system works optimally when PCM (paraffin wax RT35) is added with a cooling Nanofluid (Al2O3-water) at a concentration of 0.4% weight fraction and flow rate of 1.6 l/min. It leads to a decrease in the PV cell temperature 8.39 and 12.11 C average and maximum value across the day respectively, compared to the reference PV module and the generated electricity of PV cell increased by 25.33% and 37.81% average and maximum value across the day respectively, compared to the reference PV module. In addition, the total effi-ciency which is the sum of electrical and thermal efficiencies reached 82.7%.