This thesis investigates the feasibility of packed bed thermal energy storage charged by a heat pump, a high temperature electric heater, or a combination of the previous two. Two independent models are developed: one simulating the performance of charging and discharging unit, the other regarding the thermal storage. The system model is quasi-steady state and describes the different thermodynamic cycles occurring in the system. The storage model is a dynamic one-dimension two-phase heat transfer model with variable properties for the solid and the fluid phases. The simulation tool is exploited to evaluate the effect of different design parameters which affect the system operation. Segmentation of the storage and cycling effect are analysed. Finally, five possible configurations of the system with different settings and charging strategies are proposed and discussed.