Heat transfer behavior of nanoparticle enhanced PCM solidification through an enclosure with V shaped fins

•Simulation of NEPCM solidification is presented.•To model this unsteady phenomenon, FEM has been used.•Solidification rate decrease with rise of β but it increases with rise of L.•Nanoparticle and V shaped fins are employed to enhance heat transfer. Thermal storage unit can be utilized to satisfy the balance of energy supply and demand. Copper oxide nanoparticles and V shaped fins are involved in storage unit in current research to expedite the solidification. To show the variation of energy storage efficiency, Finite element method has been employed. Important selected parameters are nanofluid concentration, angle of V shaped fin, copper oxide particle size and length of fins. Contours and profiles in various time steps are depicted. Outputs display that discharging rate augments with rise of angle of V shaped fin. Using copper oxide helps solidification. Length of fin has inverse relationship with discharging rate.