The present application pertains in some embodiments to a thermal storage system. The system may include, for example, a warm thermal storage region; a cold thermal storage region; and a physical divider. The warm thermal storage region may include at least two liquid phases. The cold thermal storage region may include at least one liquid phase. The physical divider substantially separates the warm thermal storage region from the cold thermal storage region.

A thermal energy storage system for comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a plurality of vessels to store the working fluid. Each 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 vessels 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 vessels. The vessels are arranged in parallel.

A thermal energy storage system is provided, comprising an outer shell defining an outer shell volume, an energy transfer module, comprising an input port for providing energy to the energy storage system, an output port for retrieving energy from energy storage system, wherein the outer shell is provided with a fluid distribution network.

The invention relates to a sensible heat storage apparatus that comprises a core material that can be heated to a high temperature while it has been placed in a heat transfer fluid that absorbs essentially all the heat that is lost by any heat leakages from the core material. Accordingly, there is a very low, or almost absent overall heat loss, even though the sensible heat storage apparatus can store heat at a very high temperature. The gist of the invention is further that the high amount of heat can gradually be transferred to the HTF, which heat can in turn be put to use for domestic applications (e.g. domestic hot water and/or space heating) or for steam generation.

A store (1) for thermal energy, the store comprising: a housing (5) defining an internal chamber having an inlet and an outlet; and a plurality of receptacles (7) provided within the internal chamber and spaced from one another so that heat transfer fluid can flow over and around the receptacles (7) as the fluid moves from the inlet to the outlet; wherein each said receptacle (7) defines an internal cavity (9) for the storage of phase change material (PCM) so that thermal energy can transfer between the stored PCM material and the heat transfer fluid as the fluid passes over and between the receptacles.

Systems and methods are provided for charging a pumped thermal energy storage (“PTES”) system. A system may include a compressor or pump configured to circulate a working fluid within a fluid circuit, wherein the working fluid enters the pump at a first pressure and exits at a second pressure; a first heat exchanger through which the working fluid circulates in use; a second heat exchanger through which the working fluid circulates in use; a third heat exchanger through which the working fluid circulates in use, a turbine positioned between the first heat exchanger and the second heat exchanger, configured to expand the working fluid to the first pressure; a high temperature reservoir connected to the first heat exchanger; a low temperature reservoir connected to the second heat exchanger, and a waste heat reservoir connected to the third heat exchanger.

Heat energy storage systems described in this disclosure can be used for long-term storage of large amounts of thermal energy. In some cases, such systems receive electrical energy from renewable energy sources such as solar panels or wind turbines. Using novel techniques, the heat energy storage systems covert the electrical energy to thermal energy that is stored in hot materials such as molten silicon, molten salts, or any other material that can store large amounts of heat. The heat energy storage systems incorporate extremely good thermal insulation of the thermal energy storage tank that contains the hot materials. The systems are also configured to release thermal energy in an efficient manner to an electricity-producing steam turbine using novel heat exchanger systems and techniques that are described. The energy storage systems described herein have a higher overall real-world efficiency than energy storage systems currently available.

A thermal energy storage system including an enclosure having an internal volume. An incompressible phase change material (PCM) is provided within the internal volume of the enclosure, where the PCM contracts into a solid state when its temperature falls below a certain temperature and expands into a liquid state when its temperature goes above the certain temperature. An elastic bladder is positioned adjacent to the PCM within the internal volume of the enclosure and is filled with a compressible material, where the PCM pushes against the bladder when it is expanded to the liquid state and causes the compressible material to be compressed within the bladder and the enclosure.

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.

A floating piston configured to be disposed in a vessel of a thermal energy storage system to separate a hot working fluid from a cold working fluid. The floating piston includes a piston body having a first end, a second end, and a central region. There is a compressible member which is disposed in the central region of the piston and which is configured to engage with an inner surface of the vessel when the piston is disposed in the vessel.