Thermal energy storage using phase change materials (PCM) has gained considerable attention since it can eliminate the gap between supply and demand of energy. Paraffin wax is a promising PCM for energy storage from low temperature sources. However, its application is limited due to low thermal conductivity which reduces the rate of melting/solidification. Current work investigates the performance of paraffin wax dispersed with Al 2 O 3 nanoparticle during melting in a copper foam. The solid-liquid interface, isotherms, and stream functions are presented using nonequilibrium computational fluid dynamics (CFD) study. The effect of natural convection inside the porous zone is studied for three heating conditions viz. heating from side wall, top wall, and bottom wall. Results showed that the use of nanoparticles and copper foam reduced melting time through improvement in the effective thermal conductivity of the paraffin wax. Also, natural convection played a significant role in the melting process and could not be ignored. Fastest rate of melting was observed for the case of heating from the bottom wall due to natural convection. The results from the study demonstrate the ability of metal foams and nanoparticles in enhancing the heat storage rate by enhancing the effective conductivity of PCMs.