Low-Cost, Long Duration Electrical Energy Storage Using a CO2-based Pumped Thermal Energy Storage (PTES) System
The Echogen Power Systems team will develop an energy storage system that uses a carbon dioxide (CO2) heat pump cycle to convert electrical energy into thermal energy by heating a “reservoir” of low-cost materials such as sand or concrete. During the charging cycle, the reservoir will store the heat that will be converted into electricity on demand in the discharge or generating cycle. To generate power, liquid CO2 will be pumped to a supercritical pressure and brought to a higher temperature using the stored heat from the reservoir. Finally, the supercritical CO2 will be used to expand through a turbine to generate electricity during the discharge cycle.
If successful, DAYS projects will provide new forms of long-duration stationary electricity storage systems that enhance grid resiliency, provide low-cost energy capacity, support grid infrastructure, and enable a greater share of intermittent renewable resources in the generation mix.
Long-duration storage can help prevent blackouts and smooth overall grid operation, improving resilience and enhancing grid security.
New, extended storage options could enable greater integration of intermittent renewable energy sources, greatly reducing emissions from the power sector.
Energy storage technologies could help improve grid efficiency and promote the growth of domestic renewable energy sources.