Selecting the best nanofluid type for A photovoltaic thermal (PV/T) system based on reliability, efficiency, energy, economic, and environmental criteria

Abstract The foremost alternative for running a PV unit is chosen among five items using analytical hierarchy process (AHP) decision-making approach. Two items are individual PV usage and pure water based PV/T system, and three other ones are, Al2O3, TiO2, and ZnO nanofluid based PV/T technologies. The experimental data gathered throughout a year for a 250 W multicrystalline module is utilized to obtain the results. Energy yield, electrical and thermal efficiencies, payback period, and CO2 reduction are the decision-making criteria, while reliability is added to them to have a broader insight from the performance. According to the results, with the gained score of 33.1 out of 100, ZnO nanofluid based PV/T system is the best alternative. It has annual energy production and average electrical and thermal efficiencies of 632.5 kWh, 14.65, and 47.63%, respectively. Moreover, it can reduce CO2 emission by 853.8 kg and enjoy the reliability of 0.986388, which is the highest one among the alternatives. Additionally, this alternative offers a payback period of 5.12 years, which is around 10% lower than the main rival, i.e., TiO2 nanofluid based PV/T system. Utilizing pure water PV/T is also found much better than Al2O3 one because of economic issues.