Numerical analysis and comparison of different serpentine-based photovoltaic-thermal collectors

This study investigated the performance of 25 serpentine-based photovoltaic-thermal (PVT) collector configurations using numerical modeling with COMSOL Multiphysics software. The analysis compared single-inlet, double-inlet and triple-inlet configurations, with tubes arranged both horizontally and vertically, while maintaining constant geometric properties. Some of the configurations examined were studied for the first time in the open literature. The analyses were conducted in two stages. First, all configurations were compared under base- case conditions using various energetic and exergetic performance metrics. The results revealed that configurations K1 and M, which are novel, and configuration B demonstrated superior performance. Second, the effects of water inlet temperature, flowrate, and solar irradiance on the temperature distribution and efficiency metrics were evaluated for the top three performing configurations. The findings showed that these configurations exhibited similar trends in response to changes in operating conditions. Specifically, increasing the flowrate significantly enhanced thermal, electrical, and primary energy saving efficiencies, while higher water inlet temperatures led to reductions in all efficiency metrics. Moreover, pressure drop decreased as the number of inlets increased. The research emphasizes the importance of selecting a design to enhance the performance of PVT collector based on the various performance metrics.