Process for storage and recovery of energy using a combined plant that comprises a gas treatment unit and an energy generation unit, wherein - in a first operating mode, a low-temperature gas liquefaction product is generated from compressed feed gas that is cooled in a heat-exchange system of the gas treatment unit, and using the gas liquefaction product, a stored liquid is provided, - in a second operating mode, using the stored liquid, a low-temperature process liquid is provided that is warmed in the heat-exchange system, obtaining a pressurized fluid that is work-producingly expanded in the energy generation unit, - the compressed feed gas is cooled in a first heat-exchange unit of the heat-exchange system in the first operating mode in counterflow to a heat-transfer fluid, and the process liquid is warmed in the first heat-exchange unit in the second operating mode in counterflow to the heat-transfer fluid, - the heat-transfer fluid is cooled in the first operating mode at least in part by means of at least two further heat-exchange units (16, 18) of the heat-exchange system that are operated at different temperature levels, and also each having at least one organic coolant, and said heat-transfer fluid is warmed in the second operating mode, - the directions in which the heat-transfer fluid and the feed gas are conducted through the first heat-exchange unit in the first operating mode are opposite to the directions in which the heat-transfer fluid and the process liquid are conducted therethrough in the second operating mode, and - the heat-transfer fluid and the compressed feed gas are conducted, in the first operating mode, in each case at first pressure levels, and the heat-transfer fluid and the process liquid, in the second operating mode, are conducted in each case at second pressure levels through the first heat-exchange unit, wherein the first pressure levels are at least 5 bar above the second pressure levels. - in a first operating mode, a low-temperature gas liquefaction product is generated from compressed feed gas that is cooled in a heat-exchange system of the gas treatment unit, and using the gas liquefaction product, a stored liquid is provided, - in a second operating mode, using the stored liquid, a low-temperature process liquid is provided that is warmed in the heat-exchange system, obtaining a pressurized fluid that is work-producingly expanded in the energy generation unit, - the compressed feed gas is cooled in a first heat-exchange unit of the heat-exchange system in the first operating mode in counterflow to a heat-transfer fluid, and the process liquid is warmed in the first heat-exchange unit in the second operating mode in counterflow to the heat-transfer fluid, - the heat-transfer fluid is cooled in the first operating mode at least in part by means of at least two further heat-exchange units (16, 18) of the heat-exchange system that are operated at different temperature levels, and also each having at least one organic coolant, and said heat-transfer fluid is warmed in the second operating mode, - the directions in which the heat-transfer fluid and the feed gas are conducted through the first heat-exchange unit in the first operating mode are opposite to the directions in which the heat-transfer fluid and the process liquid are conducted therethrough in the second operating mode, and - the heat-transfer fluid and the compressed feed gas are conducted, in the first operating mode, in each case at first pressure levels, and the heat-transfer fluid and the process liquid, in the second operating mode, are conducted in each case at second pressure levels through the first heat-exchange unit, wherein the first pressure levels are at least 5 bar above the second pressure levels.