Experimental study on an air-based photovoltaic-thermal (PV-T) system with a converging thermal collector geometry: A comparative performance analysis

Abstract

An air-based photovoltaic-thermal (PV-T) system with a converging collector (i.e. a channel with a decreasing hydraulic diameter), to the best of authors' knowledge for the first time, has been experimentally studied against a PV-T counterpart with the conventional thermal collector geometry (i.e. with fixed hydraulic diameter) as well as a PV module with no thermal management system. An iterative method for the calculation of the convective heat transfer coefficient (h(d)) introduced in the study revealed that h(d) for a conventional thermal collector can be easily increased up to 38 % using the idea of the converging collector with no need for any extra energy or cost. According to the measurements, this enhancement results in an increase in the net overall efficiency of the PV-T system by 12 % on average compared to a PV-T system with a conventional thermal collector. Meanwhile, the converging thermal collector results in an almost uniform temperature distribution for the PV, confirming the idea of the uniform cooling in air-based PV-T systems is possible, which has not been previously reported.