Numerical Evaluation of Overall Efficiency for Solar Photovoltaic and Thermal Hybrid System

Abstract

Climate change and the exhaustion of conventional energy sources with the growing demand for energy have caused concern among researchers all over the world. Renewable energy sources are a long-term alternative to our reliance on fossil fuels and reduce carbon emissions. Solar energy is radiant light and heat from the Sun that is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy, and solar architecture. Photovoltaic thermal (PVT) is a hybrid system, which includes both thermal and electrical energy generations. A 3D solar photovoltaic and thermal hybrid system is considered in this study where the encloser of the heat exchanger is fabricated from corrosion resistive stainless-steel sheet, and uncovered surfaces to the air of the heat exchanger are insulated using the glass wool. The fins manual air circulation and the channels are made of aluminium. The top side of the fins is bended and tightly attached to the lower back floor of the solar PV panel, wherein heat switch from the PV panel to the fins happens via the conduction technique. The equations of the heat transfer for PV layers such as for glass, cell, fins, heat exchangers, and laminar flow equation for the fluid domain are solved numerically applying the finite element method (FEM). Temperatures of air at the inlet-outlet and solar cell of the PVT system, are obtained for the variation of solar irradiance from 200 to 400 W/m2 using the weather situation of Bangladesh. Finally, the overall efficiency is calculated under different weather conditions in Bangladesh. The numerical results depict that the new layout of the heat exchanger efficiently transfers heat to the circulating air and the overall efficiency of the PVT is greater at the lowest solar irradiance of 200 $\mathrm{W}/\mathrm{m}^{2}$.