The effect of using phase change materials in solar panel cooling to provide green and sustainable energy of a building

Abstract

The present study numerically investigates the use of solar energy for heating in a building using EnergyPlus and COMSOL. A solar panel with a size of 0.5 × 1 m was simulated. A rectangular chamber containing CaCl26H2O as a phase change material (PCM) was positioned below the solar panel. A pipe with an Al2O3-water nanofluid flow and fins was placed in the middle of the PCM chamber. The hot water outflow of the solar panel was employed to supply the hot water demand of a small residential building. Also, the amount of carbon dioxide production for this house in different months of the year for the house with and without solar thermal panel was compared. Furthermore, the panel temperature and melted PCM fraction below the panel were studied at different nanofluid flow velocities. It was found that a higher flow velocity (20 mm/s) led to a lower panel temperature than a lower velocity (5 mm/s). Thus, a higher nanofluid flow velocity would increase the fraction of energy demand supplied through the solar system during the day (up to 19.1%); however, a rise in the velocity at night diminished the energy fraction. In July, using a solar heating panel to supply hot water to the house reduced carbon dioxide emissions by 43%.