Energy, exergy and economics study of a solar/thermal panel cooled by nanofluid

Abstract This paper simulates a simple solar panel and the solar panel with a cooling system. The present paper aims to perform an economic and exergy study of PV and PVT 250 W and to compare the return on investment for the operating conditions in China. PVT working fluid is MgO/water nanofluid. PVT cooling system includes a special arrangement of copper tubes placed at its bottom, which cools the panel and produces hot water. COMSOL Multiphysics software and finite element method are employed for numerical analysis and simulation of solar panels. An in-house code is MATLAB code and meteorological data from China are used for economic analysis. The variables include the volume percentage of nanoparticles that is between 0 and 1% and the volume flow rate from 0.5 to 4 lit/min. The results of this study show that enhancing the nanofluid flow in the cooling system makes the panel cooler and reduces the amount of exergy output. The addition of nanoparticles, especially at low nanofluid flow rates, enhances the exergy output. The trend of changes in exergy efficiency with the variations of volume percentage of nanoparticles and volume flow rate is similar to that of the exergy output. The results demonstrate that an increment in the flow rate from 0.5 to 4 lit/min reduces the efficiency by 2.03%. Adding 1% nanoparticles increases the exergy efficiency by 0.45% at a volume flow rate of 0.5 lit/min. The economic analysis of the solar panel shows that the investment recovery is 6 years for PV and 4 years for PVT.