Augwind Energy has announced plans to construct its first commercial-scale AirBattery project in Germany. The facility will be the first commercial-scale installation of the company's AirBattery hydraulic compressed air energy storage (CAES) technology, designed for long-duration, grid-scale applications.
The AirBattery system combines principles from pumped hydro and compressed air storage by circulating water between underground chambers to compress and decompress air. Surplus energy is used to compress air to pressures ranging from 50 bar to over 200 bar, depending on demand and geological conditions, and store it in underground caverns.
This allows renewable energy to be stored for later use, such as during periods with low solar or wind generation. A typical cavern can store enough compressed air to generate between 3 and 8 GWh of electricity. Energy is recovered by releasing the high-pressure air through water-filled chambers, driving a turbine to produce electricity.
At its demonstration site, the system has achieved a 47% round-trip efficiency (AC-to-AC). The upcoming facility in Germany will make use of a mined salt cavern suitable for long-duration storage applications.
