Numerical Investigation of Thermal Efficiency of a Solar Cell

Solar air and water heaters are beneficial in many countries across the globe where solar radiation is massive in the daytime. As the surface temperature of the photovoltaic cell increases, the efficiency of the cell scales down. We carried out the cooling of solar panels in order to maximize their efficiency. In the present work, we examined the dependence of the inlet boundary condition on the area average temperature at the outlet of the tube. The tube comprises a square cross-section and carries three folds in order to maximize the area in contact with a solar panel. We investigated the dependency of thermal efficiency of solar panels on inlet boundary conditions and observed that with the increase in Reynolds number, i.e., velocity at the inlet, the thermal efficiency initially increases up to Re = 700 and then remains constant at 94%. We also found that when 40% of the heat input was carried away by cooling water, 20% electrical efficiency was achieved.