Numerical perspective of copper nanoparticle morphology on energy conversion in a novel photovoltaic-thermal system

Abstract

The photovoltaic modules’ (PV-M) temperature increase significantly reduces their efficiency and accelerates their degradation, highlighting the need to design more efficient and durable photovoltaic-thermal hybrid systems (PVT-Ss). A new PVT-S, evaluated through three-dimensional numerical modeling in COMSOL Multiphysics, is recommended, which analyzes several criteria varying inlet velocity and solar radiation, including energy-exergy efficiency, durability, annual production, exergy destruction, and entropy generation phenomena. Two working fluids were compared: clear water and a nanofluid based on copper nanoparticles (Cu NPs) dispersed in water. Different forms of these nanoparticles were tested to identify the optimal configuration. The results show that blade-shaped nanoparticles offer the best performance, with a 3.21 % improvement in thermal efficiency compared to octahedron-shaped nanoparticles and a 3.56 % improvement compared to cooling using water alone. The maximum exergy efficiency of 15.35 % is obtained for PVT-S using Cu/water nanofluid, compared to a 15.13 % value achieved for PVT-S using pure water at low velocity. The total annual energy-exergy productions for PVT-S using Cu/water are 2672.09 kWh and 515.76 kWh, respectively. These values are higher than those obtained for PVT-S using pure water and for the conventional PV-M. The sustainability of the system improves as solar irradiance increases, reaching a value of 1.1689 for the PVT-S based on the Cu/water nanofluid. The findings of this work reveal that the use of Cu NP-based nanofluids, combined with geometry optimization, maximizes the energy and exergy efficiencies of the PVT-S while enhancing its overall sustainability.

Keywords: Copper nanoparticles, Energy and exergy efficiency, Nanofluids, Photovoltaic-thermal systems, Three-dimensional numerical simulatio.