Performance of contact and non-contact type hybrid photovoltaic-thermal (PV-T) collectors

The conceptualized non-contact Photovoltaic-Thermal (PV-T) collector consists of a PV panel separated by a conventional sheet and tube solar thermal collector. Simulation of both non-contact type and contact type collectors is carried out and correlations are proposed for both thermal and electrical efficiencies in terms of irradiation, inlet water temperature, ambient temperature and PV transmissivity. At high values of transmissivity (τ > 0.75), the thermal efficiency of the non-contact type system exceeds that of the contact type collector at higher values of inlet temperatures. The PV-T system yields thermal and electrical efficiencies in the order of 30-35% and 8-9% respectively. Experiments are carried out to validate the simulation results and to study the influence of performance parameters. It is found that non-contact type collectors can perform better than the contact type collectors at high water inlet temperatures and high PV panel transmissivity values.