The invention provides an energy storage apparatus comprising a crucible having a cavity and a channel, a phase change material stored in the cavity of the crucible and a heat exchanger having an inlet and an outlet, wherein at least a portion of the heat exchanger is disposed along the channel. Also provided are methods of reversibly storing and/or extracting energy, and an energy storage array comprising a plurality of energy storage apparatus as described above.

A thermal energy storage system includes one or more containment vessel comprising an internal cavity containing a bed of phase change material (PCM) operable to store thermal energy, an array of heaters embedded in the molten phase change material, and a tube bundle. The heaters are electrically coupled to an electric power source and operable to heat and melt the PCM to a molten state. The tube bundle comprises heat exchanger tubes embedded in the molten PCM and configured to convey a working fluid (e.g., water or other) through a tube-side of the tubes. The tubes may be arranged in plural individual tube cartridge each insertable and removable from the vessel. In operation, the working fluid is heated by absorbing stored thermal energy from the molten phase change material. The PCM may be heated by power extracted from the power grid during off-peak demand periods.

The invention relates to a system and a method for storing electrical energy which are based on a closed thermodynamic cycle. They make it possible to store electrical energy in a very efficient, cost-effective, and safe manner. No environmentally hazardous or expensive materials are required. The system comprises a compressor, a turbine, and two packed-bed storage units which are operated at different temperature levels.

In order to load the packed-bed storage units, the cycle is operated as a counterclockwise heat pump process. In this process, the heat generated at the outlet of the compressor is expanded at a high temperature level into a first packed-bed storage unit and stored therein. The “cold” produced during the subsequent expansion of the gaseous working medium in a turbine is stored in a second packed-bed storage unit. This requires mechanical energy which is provided by an electrical machine. In order to discharge the energy storage system, the cycle is operated in reverse (i.e., as a clockwise cycle). Before entering the compressor, the working medium is cooled with the cold stored in the second packed-bed storage unit and, after compression, absorbs the heat from the high-temperature packed-bed storage system. The hot working medium at high pressure is expanded by means of the turbine and thus energy is generated.

A heating system including a heat pump; a thermal battery loop including a thermal battery and a pump configured to circulate a working fluid through the thermal battery; a fluid conductor for receiving the first fluid at an inlet at a first temperature and delivering the first fluid at a second temperature; a first heat exchanger configured to thermally couple the heat pump and the fluid conductor at a first location of the fluid conductor; a second heat exchanger configured to thermally couple the thermal battery loop and the heat pump; and a third heat exchanger configured to thermally couple the thermal battery and the fluid conductor at a second location of the fluid conductor, wherein the second location of the fluid conductor is a location downstream from the first location of the fluid conductor between the inlet and the outlet of the fluid conductor.

An element for an easily scalable thermal energy storage, distinctive in that the element includes an outer shell being a combined casting form and reinforcement, a solid thermal storage medium in the form of hardened concrete, which concrete has been cast and hardened into said outer shell. A method for building and use of the element is also disclosed.

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.

The invention provides a method for storing heat and continuously generating electricity, the method comprising a phase change material; first fluid conduit in thermal communication with the phase change material wherein the first conduit is adapted to receive a first fluid; a second fluid conduit in thermal communication with the phase change material, wherein the second conduit is adapted to receive a second fluid; and a turbine in thermal communication with the second fluid. Also provided is a method for continuously charging the energy power block portion of a combined thermal energy storage and heat exchanger unit with heated fluid generated by concentrated solar power, the method comprising intermittently storing heat in a phase change material; and continually directing the heat from the phase change material to a turbine such that the phase change material buffers the turbine against inconsistent solar heat inputs.

The invention is directed to energy storage and supply system (100) comprising a combination of a heat pump (HP) (2) and a thermochemical storage (TCS) (1) unit, adapted for storing and supplying energy. In a further aspect, the invention is directed to a method for operating the energy storage and supply system (100), wherein said method comprises charging and discharging phases which both comprise providing a HP warm stream by the HP and leading said HP warm stream to the TCS unit to respectively thermally charge and discharge said TCS unit.

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 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.