The heat transfer performance of energy storage was improved.• Hybrid nano-PCM was the most efficient enhancer.• An optimal 1.6% volume fraction balanced performance and economics. • 1.6% hybrid nano-PCM reduced overall melting time by 16.8%.Latent thermal energy storage systems are widely utilized to match the inequality between heat supply and demand. Despite these systems' wide range of uses in various applications, their high potential is limited by the slow charging rate. The target of this study is to augment the thermal performance of paraffin-based on triplex tube heat storage by dispersion of two different types of conductive mono nanoparticles (Al2O3, CuO) and hybrid Nano additives of various volume fractions (0.4, 0.8, 1.6, 3.2%) into paraffin wax. The experimental work involves measurements and preparation of the considered Nano-PCM. The enthalpy porosity model and finite volume method simulated the melting process. The study also investigated the temperature and liquid fraction variations in the axial, radial, and angular directions throughout melting to aid in predicting heat transfer in the storage throughout the phase transition process of PCM. Results revealed that including 1.6% of hybrid nanoparticles in PCM can increase the stored energy by 5.97%. The results also indicated that the hybrid nano-PCM exhibits the best phase transition rate and energy recovery for all volume fractions compared to mononano-PCM. At 1.6% volume fraction, the storage efficiency can be improved up to 76.8%, 75.5%, and 73.63% for hybrid nano-PCM, Al2O3-PCM, and CuO-PCM, respectively.