Abstract: A thermal energy storage system includes one or more components from a Rankine Cycle power plant such as steam turbine and other equipment. The system can include a thermal storage material, a heat source that is heated by running electricity through a heating element for heating the thermal storage material, and a heat exchange for generating steam using the thermal energy stored in the thermal storage material. The system can be configured to store energy during periods of low electricity demand or abundant supply. The system can be configured to generate electricity using the stored thermal energy to generate steam and run one or more turbines.