Experimental and mathematical analysis of the effects of collective cooling application and nanofluid use on PV panel efficiency in a monocrystalline PV/T system

The importance of renewable energy sources has been increased that they are more economic and highly efficient to meet the increasing energy needs and low emission to reduce environmental pollution. The most important renewable energy sources are solar energy, which take the energy from an unlimited natural source. Photovoltaic cells are structures that absorb some of the solar radiation and convert them into electrical energy. In this study; the experimental and mathematical analysis were performed on the PV panel efficiency in a heat fin passive cooling and a collective cooling consisting of heat fin in an enclosed fluid cooling by use of nanofluids in a PV/T system using a monocrystalline PV panel. Initially, the temperature drop and panel efficiency increase in case of cooling only with fins were investigated in a PV panel. Then, the temperature decreases and corresponding performance increase of Al2O3-water, TiO2-water and CuO-water ceramic nanofluid cooling, which were prepared in 3 different ratios in mass (0.2%, 0.4% and 0.6%) and water-cooled at a constant fluid flow rate were investigated. According to the test results; it has been observed that when the temperatures of the finned panels are compared with the standard panels, the finned (cylindrical-finned and plate-finned) panels provide more effective cooling. Compared to the standard panel, there were efficiency increases of approximately 2.62%, 1.52% and power increases of 4.87% and 2.36%, respectively in cylindrical and plate-finned panels. In addition, there was an efficiency increase of 1.08% and a power increase of 2.45% in the cylindrical-finned panel compared to the plate-finned panel. As for the collective cooling applications, it has been observed that all types of water-cooled and nanofluid-cooled panels had more effective cooling. In general, there was an electrical efficiency increase of approximately 3.57% in the water-cooled-finned panel compared to the finless-uncooled panel. The highest temperature drops among the nanofluid cooled panels, were respectively for TiO2-water, Al2O3-water, CuO-water nanofluid prepared at 0.2% and 0.4% in mass. The highest power average increase rates were for 0.2% nanofluids during a day. It was observed that the highest power increase rates were 4.344%, 4.058%, 3.420% and 2.693% for Al2O3-water, TiO2-water, CuO-water and water-cooled panels, respectively. As a result, the highest power increase rate of 0.2% by weight was observed in the Al2O3-water nanofluid cooled panel. As a result, in all cooling types with Al2O3-water, TiO2-water and CuO-water nanofluids prepared at 0.2%, 0.4% and 0.6% by mas; the greater power increase, thermal efficiency, total efficiency and heat convection coefficient were obtained in comparison to the water-cooled and non-cooled panels.