Performance enhancement of a photovoltaic-thermal thermoelectric collector using night radiative cooling

The electrical production using the PVT-TE (photovoltaic-thermal and thermoelectric) technique is well known, however on the one hand the efficiency is not so large and on the other hand, the electrical production remains limited to the daytime. Some other techniques were developed to exploit radiative cooling by thermoelectric technology to produce electricity by night-time. This study deals with a novel technology that combines a PVT-TE (Photovoltaic-Thermal Thermoelectric) and radiative cooling (RC) mechanism, that is the PVT-TE-RC collector. This technology could generate electrical energy for 24 h a day. The PVT-TE-RC collector is mathematically modeled based on the energy balance of its components. The numerical resolution of this modeling allows access to the thermal behavior conducted to assess the collectors' electrical energy. The main obtained results of this study show that the proposed technology allowed continuous production of electrical energy during daytime and night-time by exploiting solar energy and radiative cooling, respectively. Thus, it will be shown that during the daytime, the efficiency is increased from 15% to 18% compared to a PVT collector. During night-time, the collector continues to produce electrical energy. The monthly results show that the electrical gain produced during the night is between 2.78 and 5.68 kWh/m2, which corresponds to a relative increase of 7.9 and 30% in electrical energy production compared with the conventional PVT-TE collector. Thus, the annual electricity production of the PVT-TE-RC collector is enhanced by 15.6%, making it more electrically efficient than conventional PVT-TE and PVT systems.