An experimental analysis of photovoltaic thermal collector with trapezoidal and plain plates: an energy, exergy, and life cycle assessment

The present study explored the benefits of using the trapezoidal plate as a heat exchanger over the plain plate in a PVT unit (conventional unit). The study compares the performance based on annual energy and exergy generation, key energy matrices, CO₂ mitigation, and corresponding carbon credits. Initially, the airflow rate was optimized from the range of values 0.0039–0.0117 kg/s, identifying 0.0094 kg/s as optimal for the annual performance assessment. Experiments were carried out on the rooftop of the Department of Mechanical Engineering, NIT Silchar, India, from December 2022 to November 2023. Results indicate that the trapezoidal plate-based unit maintains a 2.8 °C lower PV module temperature and a 1.9 °C higher outlet temperature compared to the conventional unit. The exergy destruction rate of the trapezoidal plate unit is 1.89 % and 2.73 % lower than the conventional unit on a typical winter and summer day. Additionally, it generated 8.7 %, 8.4 %, and 1.62 % higher annual overall energy, overall exergy, and net electrical energy than the conventional unit. The energy payback time achieved by the trapezoidal plate unit is 9.5 % (overall energy) and 5.4 % (overall exergy) less than the conventional unit. Additionally, the trapezoidal plate unit mitigates 8.6 % and 8.8 % more CO₂ mitigation annually on an overall energy and exergy basis, respectively.