Modeling and performance optimization of photovoltaic and thermal collector hybrid system

In this paper, the hybrid photovoltaic/thermal collector (PV/T) system's electrical and thermal efficiency was examined by stating a mathematical model and developing a prototype of the system. To enhance the electrical efficiency, the cell temperature of the PV module was decreased with cooling and the heated fluid could be used for low heating applications. For this purpose, a PV/T system was modeled and constructed using a thermal collector placed beneath the photovoltaic panel where the excess heat and solar radiation through the transparent PV module was the input of the thermal collector. A transparent solar module was used in order to improve the total efficiency of the hybrid PV/T system by means of increasing the radiant solar energy reaching the absorber plate of the collector. The absorber plate was coated with titanium dioxide as the absorption level of the coating was higher than 95%, which increases the thermal output by 10%. We note that using TINOX coating for the absorber plate and transparent solar module had the advantage of increasing the thermal yield of the hybrid system. The influences of the dynamic parameters on the system performance, wind speed and water flow rate, were examined on a daily basis and it was observed that the wind speed had a minor effect on the performance and that forced circulation improved the thermal efficiency. The PV/T hybrid system was compared with the separate PV module and thermal collector efficiencies and the results are presented. With these improvements, the efficiency of the single cover, water type PV/T hybrid system is increased to the maximum reported value in literature.