1. Charge: The system operates by using electrical energy (excess or off-peak) to drive an air liquefier. Similar equipment is widely deployed for the production of bulk liquid LNG, nitrogen, oxygen or argon.
2. Storage: The liquid air is stored in an insulated tank at low pressure, which functions as the energy store. Again, such equipment is widely deployed as bulk liquid LNG, nitrogen, oxygen or argon storage, and millions of tonnes of liquefied gases are commercially stored and transported around the world
2,000 tonne tank = 200MWhs equivalent
100,000tonne tankage, enough for 10GWhs.
3. Regasification / Power Recovery: When power is required, liquid air is drawn from the tank and pumped to high pressure. Ambient (or above ambient waste) heat is applied to the liquid air via heat exchangers resulting in a phase change from liquid air to a high pressure gas which is then used to drive a turbine and generator.
4. Cold Recycling: During the power recovery, very cold gas is exhausted, which is then recycled back into the liquefaction process (stage 1) reducing the energy demands for producing liquid air and thereby increasing the overall round-trip efficiency.