A comprehensive review on the impact of nanofluid in solar photovoltaic/thermal system

Abstract
Solar energy is a major renewable energy resource used in power production, heating processes, and other applications such as domestic and industrial utilization. It is an abundant form of green energy. Different techniques have been made for energy conversion and one among them is solar photovoltaic/thermal (PV/T) system. Unfortunately, the greatest cause of concern is the rise in temperature of solar PV cells, which will have a negative effect on electrical performance. Thereby, eliminating excess heat on PV cells with heat transfer fluids to lower the temperature of the cells can improve electrical efficiency. A nanofluid is a promising heat transfer fluid to effectively enhance the system efficacy compared with conventional fluids. As the nanoparticle size is very small, the surface area of the nanoparticle is large so it enhances the heat transfer rate. Thereby, recently it has taken on a new dimension for research studies to enhance its thermal behavior for engineering application. This review paper discusses about the importance of nanofluid in solar PV/T system and advantages of employing nanofluid in PV/T system which has high thermo-physical properties. Nanoparticle and nanofluid preparation methods were presented. The thermo-physical properties like thermal conductivity, viscosity, density, and specific heat capacity were also discussed.