System and method for storing and recovering energy using compressed-gas with recovery liquid

A compressed-gas energy storage and recovery method comprising:

• a) compressing at least twice successively gas in a compression line including two compression stages with each compression stage performing at least one compression of the gas;
• b) recovering heat from the compressed gas in at least one heat storage and recovery system after each compression of the gas;
• and
• c) storing the cooled compressed gas in at least one compressed gas storage, the compressed gas leaving the at least one compressed gas storage in an expansion line, the expansion line comprises at least two successive expansion stages wherein in each expansion stage the compressed gas is heated by circulation in the at least one heat storage and recovery system by using heat stored during the compression and thereafter the heated compressed gas is expanded in an expansion device and the heat is stored by using solid heat storage material which remains in the system and before each expansion step the liquid is fed into the compressed gas prior to heating the gas with heat exchange occurring by direct exchange between the gas and the solid heat storage material.

A compressed-gas energy storage and recovery method performed in a compressed-gas energy storage and recovery system comprising the steps of:

• in an energy storage phase:
• a) successively compressing at least twice a gas in a compression line comprising at least two compression stages with each compression stage comprising at least one compression means;
• b) after each compression step, recovering the heat of the compressed gas in at least one heat storage and recovery means including solid heat storage material which remains in the system with heat exchange occurring by direct exchange between the gas and a solid heat storage material;
• c) storing the cooled compressed gas in at least one compressed gas storage means;
• and
• in an energy recovery phase:
• d) circulating the compressed gas leaving the at least one compressed gas storage and means in an expansion line comprising at least two successive expansion stages, and in each expansion stage, heating the compressed gas by circulating the gas in one of the heat storage and recovery means using heat stored during the compression step and then expanding the heated compressed gas in an expansion means, and wherein;
• the heat is stored in the solid heat storage material which remains in the system, and before each expansion step, a liquid is fed into the compressed gas prior to the step of heating the gas.