Cryogenic energy storage systems, and particularly methods for capturing cold energy and re-using that captured cold energy, are disclosed. The systems allow cold thermal energy from the power recovery process of a cryogenic energy storage system to be captured effectively, to be stored, and to be effectively utilised. The captured cold energy could be reused in any co-located process, for example to enhance the efficiency of production of the cryogen, to enhance the efficiency of production of liquid natural gas, and/or to provide refrigeration. The systems are such that the cold energy can be stored at very low pressures, cold energy can be recovered from various components of the system, and/or cold energy can be stored in more than one thermal store.

Apparatus, systems, and methods use cryogenic liquids such as, for example, liquefied natural gas and liquefied air or liquefied air components to store thermal energy. The cryogenic liquids may be produced using electrically powered liquefaction methods, for example, using excess electric power during periods of over-generation on the electric grid.

A plant for energy storage, comprises: a basin (2) for a work fluid having a critical temperature (T.sub.c) lower than 0?; a tank (3) configured to store the work fluid in at least partly liquid or super-critical phase with a storage temperature (T.sub.s) close to the critical temperature (T.sub.c); an expander (4); a compressor (5); an operating/drive machine (6) operatively connected to the expander (4) and to the compressor (5); a thermal store (8) operatively interposed between the compressor (5) and the tank (3) and between the tank (3) and the expander (4). The plant (1) is configured for actuating a Cyclic Thermodynamic Transformation (TTC) with the work fluid, first in a storage configuration and then in a discharge configuration. The thermal store (8), in the storage configuration, is configured for absorbing sensible heat and subsequently latent heat from the work fluid and, in the discharge configuration, it is configured for transferring latent heat and subsequently sensible heat to the work fluid.

Apparatus, systems, and methods store energy by liquefying a gas such as air, for example, and then recover the energy by regasifying the cryogenic liquid and combusting or otherwise reacting the gas with a fuel to drive a heat engine. Carbon may be captured from the heat engine exhaust by using the cryogenic liquid to freeze carbon dioxide out of the exhaust. The process of liquefying the gas may be powered with electric power from the grid, for example, and the heat engine may be used to generate electricity. Hence, in effect these apparatus, systems, and methods may provide for storing electric power from the grid and then subsequently delivering it back to the grid.

A method for energy storage with co-production of peaking power and liquefied natural gas (LNG) which integrates the processes of liquid air energy storage and reduction in pressure of natural gas through expander at the co-located city gate station and includes consumption of excessive power from the grid, mechanical power of the natural gas expander and cold thermal energy of expanded natural gas for charging the storage with a liquid air during off-peak hours and production of peaking (on-demand) power by the expanders of natural gas and highly-pressurized re-gasified air with recovering the cold thermal energy of expanded natural gas and regasified liquid air for liquefying a part of delivered natural gas at the city gate station and energy storage facility.

A method for electrical energy storage with co-production of liquefied methaneous gas which comprises in combination the processes of charging the storage with liquid air through its production using an externally powered compressor train and open air auto-refrigeration cycle, storing the produced liquid air and discharging the storage through pumping, regasifying, superheating and expanding the stored air with production of on-demand power, and additionally includes a process of recovering the cold thermal energy released by regasified liquid air for controlled liquefying the methaneous gas delivered into energy storage facility at a rate and pressure consistent with those of liquid air.

Cryogenic energy storage systems, and particularly methods for capturing cold energy and re-using that captured cold energy, are disclosed. The systems allow cold thermal energy from the power recovery process of a cryogenic energy storage system to be captured effectively, to be stored, and to be effectively utilized. The captured cold energy could be reused in any co-located process, for example to enhance the efficiency of production of the cryogen, to enhance the efficiency of production of liquid natural gas, and/or to provide refrigeration. The systems are such that the cold energy can be stored at very low pressures, cold energy can be recovered from various components of the system, and/or cold energy can be stored in more than one thermal store.

Methods and devices for continuously producing liquid air. One embodiment includes bringing a first container confining an unpressurized first volume coupled to outer air in contact with a first cryogenic medium, and maintaining a temperature of the first cryogenic medium substantially higher than the boiling temperature of the first cryogenic medium for affecting continuous production of liquid air.

The invention relates to an installation for producing liquefied gas comprising a circuit for supplying feed gas, a set of heat exchangers, a refrigerator for cooling some or all of the set of heat exchangers, the supply circuit comprising, between the set of heat exchangers and the downstream end thereof, a final expansion turbine for expanding the feed gas in liquid state, the supply circuit comprising a bypass line of the final expansion turbine fitted with a first expansion valve, a second expansion valve disposed in series upstream or downstream of the first expansion valve and of the final expansion turbine, an additional heat exchange line designed to exchange heat with a heat exchanger of the set of heat exchangers when the feed gas is expanded by the first expansion valve via the bypass line, the additional heat exchange line carrying out this heat exchange with said heat exchanger between the expansion carried out by the first expansion valve and the expansion carried out by the second expansion valve, the additional heat exchange line being located upstream or respectively downstream of the expansion carried out by the first expansion valve.

A gas turbine plant includes a gas turbine, a liquefaction facility capable of liquefying air, and a liquefaction controller. A compressor has an intake amount adjuster capable of adjusting an intake amount into a compressor casing. The liquefaction facility includes: a bleed line capable of bleeding compressed air from the compressor; a liquefaction system capable of liquefying the compressed air, a bleed amount adjustment valve; a return air line capable of guiding return air into a flow passage through which compressed air flows in the gas turbine; and a return amount adjusting valve. The liquefaction controller opens the bleed amount adjustment valve if an opening degree of the intake amount adjuster is a first opening degree, and opens the return amount adjusting valve if the opening degree of the intake amount adjuster is a second opening degree, which is an opening degree greater than the first opening degree.