SustainX has completed construction and begun startup of a megawatt-scale isothermal compressed air energy storage (ICAES) system. The 1.5 MW ICAES system is located at SustainX headquarters in Seabrook, NH.
It takes electricity from the grid and uses it to drive a motor that compresses air and stores it isothermally, or at near-constant temperature. To do so, it captures the heat produced during compression, traps it in water, and stores the warmed air-water mixture in pipes. When electricity is needed back on the grid, the process reverses and the air expands, driving a generator. No fossil fuel is needed to reheat the air and no emissions are produced.
The system can be scaled in both power (megawatts) and energy (megawatt-hours) depending on the application and can be located where needed because it uses standard pipeline storage. The system has a 20-year operating life, and unlike chemical battery systems, ICAES performance does not degrade over its lifetime or need frequent replacement, according to SustainX.
The company says its ICAES technology is an improvement over conventional compressed air energy storage (CAES) systems – which have existed since the 1970s – because those CAES systems burn fossil fuel and are limited by the need for specific geological locations (i.e. caverns) for air storage.
SustainX says its ICAES is the first megawatt-scale compressed air energy storage system built anywhere since 1991, and represents an opportunity to expand the availability and use of this bulk energy storage method.