A plant for storing and discharging thermal energy comprises a first heat exchanger coupled to a heat source, a second heat exchanger coupled to a heat user, a fluid configured to store thermal energy, a storage device for the fluid, a circuit configured to couple the first heat exchanger, the second heat exchanger and the storage device. The storage device comprises N+B storage sections fluidly connected to each other, where N is equal to or greater than two and B is less than N; each of the N+B storage sections has a same containment volume. The fluid occupies a volume substantially equal to N times the containment volume. A separation gas is inserted in the storage device, is in contact with the fluid and is configured to always keep separate a hot portion of the fluid from a cold portion of the same fluid.

A thermal energy storage system comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a vessel to store the working fluid. The vessel has an interior region and a floating separator piston in the interior region to separate a hot portion from a cold portion of the working fluid. There is a first manifold thermally coupled to an output of the heat source and to an input of the thermal load and fluidly coupled to the interior region of the vessel and a second manifold thermally coupled to an input of the heat source and an output of the thermal load and fluidly coupled to the interior region of the vessel. There is a controller configured to maintain the working fluid in a liquid state.

A system including: (i) a pumped-heat energy storage system (“PHES system”), wherein the PHES system is operable in a charge mode to convert electricity into stored thermal energy in a hot thermal storage (“HTS”) medium; (ii) an electric heater in thermal contact with the hot HTS medium, wherein the electric heater is operable to heat the hot HTS medium above a temperature achievable by transferring heat from a working fluid to a warm HTS medium in a thermodynamic cycle.

A system or method for thermal storage includes a recess or containment unit having a first storage layer and a second storage layer comprising a permeable filler material. An intermediate layer is disposed between the storage layers. A primary well traverses the layer in the recess. The primary well is in thermal communication with the first permeable filler material and the second permeable filler material. A heat source is provided for heating an inlet fluid. An input pump is in fluid communication with the primary well and the heat source. The primary well receives heated inlet fluid from the inlet pump and injects the fluid into the second layers. The heated inlet fluid transfers heat to the respective permeable filler material radially from the primary well toward an outer periphery of the thermocline recess.

High temperature thermal energy storage, distinctive in that the storage comprises: a thermally insulated foundation, at least one self-supported cassette arranged on said foundation, which cassette is a self-supporting frame or structure containing a number of concrete thermal energy storage elements, some or all of said elements comprising embedded heat exchangers, a pipe system, the pipe system comprising an inlet and an outlet for thermal input to and output from the storage, respectively, and connections to said heat exchangers for circulating fluid through said heat exchangers for thermal energy input to or output from said thermal energy storage elements, and thermal insulation around and on top of the at least one self-supported cassette with concrete thermal storage elements. The invention also provides a method of building and methods of operating the storage.

An energy transportation and grid support system utilizes at least one transportable containment module capable of storing thermal or chemical energy typically produced from renewable or geothermal sources and providing connectivity with energy conversion equipment typically located in a land or sea-based operating facility. The system includes circuitry to hookup to an adjacent electricity grid for the provision of grid support and/or piping to move thermal energy typically used to drive steam turbines generating electricity. The operating facility also includes a communication arrangement to link with and exchange operations control data with a grid or heating operator and the energy transportation operator. The invention is directed to both apparatus and method for the energy transportation and grid support system.

There is provided a system for energy storage comprising: a fluidized bed apparatus with an energy storage material, wherein the energy storage material is provided in volumes coated with an outer layer of solid particles of a different material, wherein the volumes have a largest size in the interval 1-1000 μm and wherein the solid particles (5) have a largest size in the interval 1-500 nm. Advantages of the system include that structural changes in the energy storage material over time are minimized so that the energy storage material can be used over many cycles without any noticeable impairment. The heat transfer to and from the energy storage material is improved. The system can further be used for CO.sub.2 capture.

Thermal energy battery, comprising: an evaporator-condenser thermal energy storage (ec-TES), with an end for vapor and an end for liquid, comprising one-phase stationary material storing at least 70% of the thermal energy stored within the ec-TES, a storage tank for vapor and liquid (ST), with a vapor part at a higher elevation and a liquid part at a lower elevation, a vapor line, arranged to the vapor end of the ec-TES, for inlet and outlet of vapor, a liquid line arranged between the liquid end of the ec-TES and the liquid part of the ST, a tank vapor line arranged from the vapor part of the ST to the vapor line or the vapor end of the ec-TES, and an evaporation control valve (CV6) in the tank vapor line.

An energy storage system converts variable renewable electricity (VRE) to continuous heat at over 1000° C. Intermittent electrical energy heats a solid medium. Heat from the solid medium is delivered continuously on demand. An array of bricks incorporating internal radiation cavities is directly heated by thermal radiation. The cavities facilitate rapid, uniform heating via reradiation. Heat delivery via flowing gas establishes a thermocline which maintains high outlet temperature throughout discharge. Gas flows through structured pathways within the array, delivering heat which may be used for processes including calcination, hydrogen electrolysis, steam generation, and thermal power generation and cogeneration. Groups of thermal storage arrays may be controlled and operated at high temperatures without thermal runaway via deep-discharge sequencing. Forecast-based control enables continuous, year-round heat supply using current and advance information of weather and VRE availability. High-voltage DC power conversion and distribution circuitry improves the efficiency of VRE power transfer into the system.

The invention relates to a modular assembly (E) for storing heat by phase-change material including a plurality of heat-storage modules (M1) attached to one another, the heat-storage assembly comprising a vessel (2). At least two adjacent modules are disposed so that a porous external wall (6b) of one of the modules (M1) is arranged facing a porous external wall (6b) of the other of the modules (M1), and so that a solid external wall (6a) of one of the modules (M1), forming one of the parts of the vessel, is attached to a solid external wall (6a) of the other of the modules (M1), forming another part of the vessel.