The largest pilot concrete thermal energy storage system constructed to date has been successfully tested at Alabama Power's Ernest C. Gaston Electric Generating plant.

The thermal energy storage technology developed by Storworks was demonstrated in collaboration with the Electric Power Research Institute and Southern Company. The 10 MWh electric energy storage solution was charged using heat from supercritical steam generated by the power plant. More than 80 energy charge and discharge cycles were effectively performed over 700 hours of total operation

The energy-dense components are composed of a high-temperature concrete mixture utilizing fly ash and fitted with air and steam tubes. High-pressure steam from the power plant flows through the tubes and heats the concrete, which stores the thermal energy until it is returned to the power plant by converting feedwater into steam to generate electricity in response to grid demand.

The long-duration energy storage option can be applied to existing or new fossil fuel, nuclear or concentrating solar power plants. The system can be used to shift generation to meet demand, decrease emissions and water use, reduce operating costs, and increase max capacity.