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.

The invention provides a heat-storage medium conveying system for a solar-thermal power plant. The system includes a high-level tank subsystem including a high-level tank used to store the heat-storage medium. The system further includes a heat-storage medium transport subsystem. The high-level tank subsystem is connected with the heat-storage medium transport subsystem. The heat-storage medium transport subsystem includes a low-level tank. A mounting height of the low-level tank is lower than that of the high-level tank. A volume of the low-level tank is smaller than a volume of the high-level tank. The heat-storage medium can enter the low-level tank from the high-level tank partially or completely by its own gravity. The low-level tank is provided with a conveying pump, and the heat-storage medium is pumped out of the low-level tank through the conveying pump. The invention solves the problems such as construction cost, operation and maintenance cost brought about by using the vertical long-shaft submerged molten salt pump, while avoiding the potential safety hazards in the design of large and small tanks or high-level and low-level tanks.

A method including: operating a pumped-heat energy storage (“PHES”) system in a generation mode to generate electricity; and responsive, at least in part, to a determination that a power generation plant will reduce supply of electricity to an electrical grid by a reduction amount of electricity, changing modes of the PHES system from the generation mode to operate in a charge mode. Operating in the charge mode can include receiving a charge amount of electricity, at least equal to the reduction amount of electricity, into the PHES system from the power generation plant and converting at least a portion of the charge amount of electricity to stored thermal energy.

In one aspect, compositions are described herein which include a first phase change material (PCM) component comprising an organic PCM, a second PCM component comprising an inorganic PCM, and a crosslinker linking the first PCM component to the second PCM component. In another aspect, a thermal energy storage system is described herein which comprises a container, a heat exchanger disposed within the container, and a composition described herein disposed within the container. The heat exchanger and the composition of such thermal energy storage systems are in thermal contact with one another.

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 disclosure relates to particle heaters for heating solid particles to store electrical energy as thermal energy. Thermal energy storage directly converts off-peak electricity into heat for thermal energy storage, which may be converted back to electricity, for example during peak-hour power generation. The particle heater is an integral part of an electro-thermal energy storage system, as it enables the conversion of electrical energy into thermal energy. As described herein, particle heater designs are described that provide efficient heating of solid particles in an efficient and compact configuration to achieve high energy density and low cost.

The present invention comprises a duplex thermal transfer pack. The pack includes a large bag containing many smaller sub bags. Each sub bag contains plain water. The volume within the large bag but outside the sub bags contains a second substance. This second substance freezes with a consistency akin to crushed ice or packed snow. The second substance allows the thermal transfer pack to remain malleable even when its contents are frozen.

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.

Electric power is accumulated in another form without using a storage battery so as to more effectively utilize electric power generated by solar power generation. A cold heat source storage system includes a freezer operated by directly utilizing the output power of a solar power generation device, a cold heat source storage chamber cooled by the freezer, a number of water tanks installed in the cold heat source storage chamber, and a heat exchange device installed in the cold heat source storage chamber. The system can be included in heat source storage system, which includes a heater operated by directly utilizing the output power of the solar power generation device, a heat source storage tank which stores water heated by the heater, and a heat exchange device installed in the hot heat source storage tank.

A pumped heat energy storage system is provided. The pumped heat energy storage system may include a charging assembly configured to compress a working fluid and generate thermal energy. The pumped heat energy storage system may also include a thermal storage assembly operably coupled with the charging assembly and configured to store the thermal energy generated from the charging assembly. The pumped heat energy storage system may further include a discharging assembly operably coupled with the thermal storage assembly and configured to extract the thermal energy from the thermal storage assembly and convert the thermal energy to electrical energy.