Energy storage and recovery.

摘要

During off-peak hours, mechanical energy is stored by pumping liquid from a first cavern into a second cavern containing a gas. In this way the gas in the second cavern is compressed. The stored energy is recovered by allowing the gas in the second cavern to expand, which causes liquid to flow-back from the second to the first cavern. The liquid flowing back from the second to the first cavern is used for driving a turbine.