Techno-economic and environmental investigation between a low-concentrating photovoltaic thermal collector and a regular photovoltaic flat plate thermal collector

Photovoltaic/thermal (PV/T) systems are highly efficient due to their simultaneous generation of heat and power. To achieve better efficiency of these systems, optimization in design and performance is required. In this research, a thermal flat collector coated with nanoparticles and equipped with concentrators was employed. Flat mirrors were used to reflect more solar radiation and a black graphene nanoparticle coating on the absorber was employed. The primary aim of using this coating is to increase the efficiency of thermal energy production enhancing heat transfer to the harp channels. The harp water channels, welded on the rear side of the absorber, were designed to efficiently pass water flow and absorb heat. To illustrate the performance of this system, it was compared to a regular PV system. A comparison indicated that the low-concentrating PV/T (LCPV/T) system had 41.01% percent more total efficiency than a regular PV/T system. In addition, a 71.90% improvement in the Nusselt number was observed. In this study, both systems were optimized via the Taguchi method in the Minitab software. Moreover, the LCPV/T system showed a 39.15% reduction in emissions and a 2.72-year shorter energy payback time (EPBT) due to the use of effective approaches. The present research involved an experimental performance and optimization comparison between PV/T and LCPV/T systems under constant flow rate conditions at various times of the day.