The effect of SiO2 nanoparticle on the performance of photovoltaic thermal system: Experimental and Theoretical approach

The low conversion efficiency of solar cells produces large amounts of thermal energy to the cells, and with an increase in the temperature of solar cells, their electrical efficiency decreases. Therefore, a hybrid photovoltaic thermal system improves the overall efficiency of the system by adding thermal equipment to the solar cell and removing excessive heat from these cells. In this paper, we study the effect of SiO2/water nanofluids on thermal and electrical efficiency of domestic photovoltaic thermal systems (DPVT) theoretically and experimentally. In the theoretical part, based on the control-volume finite-difference approach, an explicit dynamic model was developed for a single-glazed flat-plate water-heating photovoltaic thermal collector with closed loop cooling system with withdrawing urban water from the storage tank. The model accuracy was verified in comparison with the measured experimental data. Experimental results show that by increasing concentrations of nanofluid, the thermal and electrical performance has improved and overall efficiency decreased by increasing the diameter of the nanoparticles. The overall efficiency of the DPVT for 0 and 3 weight percent of SiO2/ water nanofluids with a diameter of 11-14 nanometers increased to 5.4% and 7.76% compared to base fluid, respectively.