An energy storage plant includes a casing for the storage of a working fluid different from atmospheric air, in gaseous phase and in pressure equilibrium with the atmosphere; and a tank for the storage of said working fluid in liquid or super-critical phase with a temperature close to the critical temperature. The critical temperature is close to the ambient temperature. The plant is configured to perform a closed cyclic thermodynamic transformation, first in one direction in a charge configuration and then in an opposite direction in a discharge configuration, between said casing and said tank. In the charge configuration the plant stores heat and pressure and in the discharge configuration generates mechanical energy to drive a driven machine.

A fluid storage tank can be configured to store a cooling fluid in a liquid state and a gas state. A first heat exchanger can be configured to release heat into the fluid storage tank. A second heat exchanger can be disposed fluidly downstream of the fluid storage tank and configured to exchange heat between the cooling fluid and a heat load. A pressure control device can be disposed fluidly downstream of the second heat exchanger. The first heat exchanger can be fluidly downstream of the second heat exchanger such that cooling fluid, after being heated in the second heat exchanger, passes through the first heat exchanger and thereby heats upstream cooling fluid resident in the fluid storage tank.

A fluid storage tank can be configured to store a cooling fluid in a liquid state and a gas state. A first heat exchanger can be configured to release heat into the fluid storage tank. A second heat exchanger can be disposed fluidly downstream of the fluid storage tank and configured to exchange heat between the cooling fluid and a heat load. A pressure control device can be disposed fluidly downstream of the second heat exchanger. The first heat exchanger can be fluidly downstream of the second heat exchanger such that cooling fluid, after being heated in the second heat exchanger, passes through the first heat exchanger and thereby heats upstream cooling fluid resident in the fluid storage tank.

A fluid storage tank can be configured to store a cooling fluid in a liquid state and a gas state. A first heat exchanger can be configured to release heat into the fluid storage tank. A second heat exchanger can be disposed fluidly downstream of the fluid storage tank and configured to exchange heat between the cooling fluid and a heat load. A pressure control device can be disposed fluidly downstream of the second heat exchanger. One of the first cooling fluid that has been heated by the second heat exchanger or a second cooling fluid different than the first cooling fluid can pass through the first heat exchanger and thereby heat upstream first cooling fluid resident in the fluid storage tank.

A fluid storage tank can be configured to store a cooling fluid in a liquid state and a gas state. A first heat exchanger can be configured to release heat into the fluid storage tank. A second heat exchanger can be disposed fluidly downstream of the fluid storage tank and configured to exchange heat between the cooling fluid and a heat load. A pressure control device can be disposed fluidly downstream of the second heat exchanger. One of the first cooling fluid that has been heated by the second heat exchanger or a second cooling fluid different than the first cooling fluid can pass through the first heat exchanger and thereby heat upstream first cooling fluid resident in the fluid storage tank.

An energy system having a) one or more catalyst sources which store a catalyst; b) one or more water sources which store water; c) one or more heat sources which store a heat storage medium; d) one or more reaction chambers into which the water, the catalyst, and the heat storage medium are introduced, which are configured for an exothermic reaction between the catalyst and the water to take place while in the presence of the heat storage medium, and in which steam is generated from the exothermic reaction; and f) one or more turbines downstream of the one or more reaction chambers which are adapted to be driven by the steam generated within the one or more reaction chambers.

An energy system having a) one or more catalyst sources which store a catalyst; b) one or more water sources which store water; c) one or more heat sources which store a heat storage medium; d) one or more reaction chambers into which the water, the catalyst, and the heat storage medium are introduced, which are configured for an exothermic reaction between the catalyst and the water to take place while in the presence of the heat storage medium, and in which steam is generated from the exothermic reaction; and f) one or more turbines downstream of the one or more reaction chambers which are adapted to be driven by the steam generated within the one or more reaction chambers.

The present invention provides a thermal energy storage apparatus comprising a housing which defines a hollow interior chamber, the chamber arranged in use to house graphite solids material in an inert gas atmosphere therewithin; and at least one conduit arranged to extend through the hollow interior chamber via inlet and outlet openings in the housing, the conduit being sealingly fitted to the housing at the inlet and outlet openings, and an exterior surface of the or each conduit being arranged in a close facing relationship with the graphite solids material located within the hollow interior chamber, wherein, in use, the or each conduit is arranged for conveying a flow of a fluid therethough such that in a first configuration, said flow transfers thermal energy to the graphite solid material, and in a second configuration, the graphite solid material transfers thermal energy to said flow.

A fluid storage tank can be configured to store a cooling fluid in a liquid state and a gas state. A first heat exchanger can be configured to release heat into the fluid storage tank. A second heat exchanger can be disposed fluidly downstream of the fluid storage tank and configured to exchange heat between the cooling fluid and a heat load. A pressure control device can be disposed fluidly downstream of the second heat exchanger. The first heat exchanger can be fluidly downstream of the second heat exchanger such that cooling fluid, after being heated in the second heat exchanger, passes through the first heat exchanger and thereby heats upstream cooling fluid resident in the fluid storage tank.

A cryogenic energy storage system comprising a liquefaction apparatus for liquefying a gas to form a cryogen, wherein the liquefaction apparatus is controllable to draw power from an external power source to liquefy the gas, a cryogenic storage tank in fluid communication with the liquefaction apparatus for storing cryogen produced by the liquefaction apparatus, a power recovery apparatus in fluid communication with the cryogenic storage tank for recovering power from cryogen from the cryogenic storage tank by heating the cryogen to form a gas and expanding said gas, a hot thermal store for storing hot thermal energy, wherein the hot thermal store and the power recovery apparatus are arranged so that hot thermal energy from the hot thermal store can be transferred to the gas before and/or during expansion in the power recovery apparatus, and a charging apparatus which is controllable to draw power from the external power source when the power drawn by the liquefaction apparatus is below a threshold value, and supply the cryogenic energy storage system with thermal energy.