Liquid air energy storage

In liquid air energy storage systems, also known as cryogenic energy storage, electricity is used to compress and cool air to cryogenic temperatures (-196°C), recharging the storage system. The liquid air is then stored in an insulated tank at low pressure. When power is required, liquid air is drawn from the tank, pumped to high pressure, reheated (by exposure to ambient air, or with waste heat from industrial processes or the previous compression stage) and expanded. This produces gaseous air, which can be used to drive a piston engine or a turbine to generate electricity. Co-locating next to a source of unused cold (to reduce the power consumption in the liquefaction process) or unused heat (for the evaporation process) increases the overall efficiency of the storage system.