Exergy and sustainability index of photovoltaic thermal (PVT) air collector: A theoretical and experimental study

This paper presents a review of the exergy and sustainability index of solar thermal systems. The review includes exergy analyses of solar collectors, solar drying systems and photovoltaic thermal (PVT) systems. Solar collectors, the most essential components of solar thermal systems, receive solar energy and convert it into thermal energy. The PVT collector is a popular means of harvesting solar energy. A PVT collector can generate electrical and thermal energies simultaneously. Experimental and theoretical approaches for a PVT air collector with a ∇-corrugated absorber are investigated in this study. A steady-state energy analysis of the PVT air collector is performed to predict photovoltaic (PV) and air outlet temperatures. Experimental results are in close agreement with the results of the theoretical study. The percentage errors of PV and air outlet temperatures between experimental and theoretical values are 5.49% and 3.75%, respectively. The PVT exergy efficiency of the PVT air collector with a ∇-corrugated absorber is 13.36% and 12.89% for the theoretical and experimental study, respectively. Furthermore, a sustainability index is proposed. The sustainability index of the PVT air collector is 1.168 and 1.148 for the theoretical and experimental study, respectively.