EP-4739972-A1 - ENERGY STORAGE SYSTEMS

EP4739972A1EP 4739972 A1EP4739972 A1EP 4739972A1EP-4739972-A1

Abstract

Heat energy storage systems described herein 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 or wind. Using novel techniques, the heat energy storage systems convert the electrical energy to thermal energy that is stored in hot materials such as molten silicon 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 one or more electricity-producing steam turbines and/or to one or more industrial heating systems of manufacturing plants, using novel heat exchanger systems and techniques described herein. The energy storage systems described herein have higher overall real-world efficiencies than energy storage systems currently available.

Inventors

KIM, YOUNG-HWA
Olmsted, Richard Dale

Assignees

Higher Dimension Materials, Inc.

Dates

Publication Date: 20260513
Application Date: 20240627

Claims (20)

1. An energy storage system comprising: a vacuum chamber; a container located within the vacuum chamber; a thermal energy storage medium located within the container; a heater located within the vacuum chamber; a heat receiver located within the vacuum chamber; a first radiation shield that is movably reconfigurable between: (i) a first position that separates the heater from the container and (ii) a second position in which the heater is exposed to the container; and a second radiation shield that is movably reconfigurable between: (i) a first position that separates the heat receiver from the container and (ii) a second position in which the container is exposed to the heat receiver.
2. The energy storage system of claim 1 , further comprising thermal radiation shielding located between an inner wall of the vacuum chamber and the container.
3. The energy storage system of claim 2, wherein the thermal radiation shielding is also located between the inner wall of the vacuum chamber and the heater.
4. The energy storage system of claim 2, wherein the thermal radiation shielding is also located between the inner wall of the vacuum chamber and the heat receiver.
5. The energy storage system of claim 2, wherein the thermal radiation shielding comprises multiple layers of sheet material that are spaced apart from each other.
6. The energy storage system of claim 1 , further comprising a first thermal radiation reflector, wherein the heater is located between the first thermal radiation reflector and the container.
7. The energy storage system of claim 1 , further comprising a second thermal radiation reflector, wherein the heat receiver is located between the second thermal radiation reflector and the container.
8. The energy storage system of claim 1 , further comprising one or more support members disposed between a bottom of the container and a bottom inner wall of the vacuum chamber, wherein the support members elevate and separate the container from the bottom inner wall of the vacuum chamber.
9. The energy storage system of claim 8, wherein each one of the one or more support members comprises multiple pieces of thermal insulating material in a stacked arrangement.
10. The energy storage system of claim 9, wherein the thermal insulating material comprises zirconia.
11 . The energy storage system of claim 8, further comprising thermal radiation shielding located between an inner bottom wall of the vacuum chamber and the container.
12. The energy storage system of claim 1 , wherein the thermal energy storage medium comprises silicon.
13. The energy storage system of claim 1 , wherein the heater comprises a resistive heating element.
14. The energy storage system of claim 1 , wherein the heater and the heat receiver are each spaced apart from the container.
15. The energy storage system of claim 1 , further comprising a first actuator coupled to the first radiation shield and operative to move the first radiation shield between: (i) the first position that separates the heater from the container and (ii) the second position in which the heater is exposed to the container.
16. The energy storage system of claim 1 , further comprising a second actuator coupled to the second radiation shield and operative to move the second radiation shield between: (i) the first position that separates the heat receiver from the container and (ii) the second position in which the container is exposed to the heat receiver.
17. An energy storage system comprising: a vacuum chamber; a container located within the vacuum chamber; a thermal energy storage medium located within an interior of the container; a heater located within the vacuum chamber and spaced apart from the container; a heat receiver located within the vacuum chamber and spaced apart from the container; and a protrusion extending from an inner wall of the container and in contact with the thermal energy storage medium.
18. The energy storage system of claim 17, wherein the protrusion is a pyramid structure.
19. The energy storage system of claim 17, wherein a volume of the protrusion is at least 10% of a volume of the interior of the container.
20. The energy storage system of claim 17, further comprising multiple layers of thermal radiation shielding surrounding the container and within the vacuum chamber.

Description

ENERGY STORAGE SYSTEMS CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority to U.S. Application No. 18/348,916, filed on July 7, 2023, the entirety of which is herein incorporated by reference. BACKGROUND Technical Field [0002] This disclosure relates to novel energy storage systems for long-term energy storage and include extensive energy loss mitigation means to enhance the efficiency of the long-term energy storage. This disclosure also relates to the integration of such energy storage systems with renewable energy sources (e.g., solar energy and/or wind energy) and working-fluid heating systems (e.g., steam/water heating systems) that can power an electricity-producing steam turbine. Background Information [0003] The Earth receives energy from the Sun that is more than 10,000 times the energy that all humans on the Earth consume. Wind energy is a derivative of the energy from the Sun. Yet, energy-hungry societies depend mostly on energy from burning fossil fuels. There is strong international pressure to reduce the consumption of fossil fuels and to switch to renewable energy sources such as solar or wind power. [0004] The cost of renewable energy is now roughly equal to or lower than the cost of energy generated by fossil fuels. However, a serious challenge of renewable energy is that electricity generated by solar panels and wind turbines cannot be stored economically for long periods of time. This boils down to the need for longterm economic methods of storing large amounts of the energy from the Sun. [0005] It is critically important to have energy storage systems (“ESS”) that can store renewable energy from solar panels and/or wind turbines for many weeks or a few months. Such long term storage of large amounts of renewable energy from solar panels and/or wind turbines is necessary if a society wants to drastically reduce its dependence on energy from fossil fuels. Currently, battery-based ESS are widely used as ESS of renewable energy. However, the performance of battery-based ESS quickly deteriorates, and its service life is less than 10 years. Moreover, batterybased ESS depend on supply-limited materials such as lithium and nickel. The disposal of huge amounts of expired battery-based ESS is environmental disaster. These well-known shortcomings of battery-based ESS is a major reason why ‘clean’ energy from solar panels and/or wind turbines cannot yet substitute or reduce significantly the extensive use of energy from burning fossil fuels. SUMMARY [0006] This disclosure describes novel ESS for long-term storage of large amounts of thermal energy in hot materials. In some cases, such ESS receives electrical energy from renewable energy sources such as solar panels and/or wind turbines. Using novel techniques described below, the ESS converts the electrical energy to thermal energy that is stored in hot materials such as molten silicon. The ESS described herein incorporate extremely good thermal insulation of the thermal energy storage container that contains the hot materials. The ESS includes multiple means for mitigating radiative, conductive, and convective heat losses. Accordingly, the thermal energy storage is highly efficient. The ESS is also configured to release its thermal energy in an efficient manner to a working-fluid (e.g., water/steam) that can power an electricity-producing steam turbine using novel heat exchanger systems and techniques that are described below. Accordingly, when the ESS described below is integrated with an energy source (e.g., a renewable energy source) and a steam turbine electricity generator system, the ESS can provide highly efficient energy receipt, storage, and delivery. This type of ESS can greatly enhance the practical viability of renewable energy sources such as wind and solar. [0007] In some embodiments, the ESS described herein store thermal energy in molten silicon. Such ESS are capable of storing energy received from solar panels or wind turbines as thermal energy in molten silicon and include extensive thermal insulation of the molten silicon with multi layers of thermal radiation shielding sheets of Molybdenum and/or stainless steel in a vacuum chamber. Silicon melts at about 1 ,415 °C. Silicon has a very high heat of fusion. In the ESS described herein, several unique and novel ideas are applied for the rigorous minimization of losses of thermal energy from the molten silicon, and equally rigorous maximization of the thermal efficiency of how the silicon receives energy from solar panels and wind turbines and how the silicon heats working-fluids such as water/steam in its heat exchange tank. A major goal of ESS described herein is the maximum utilization of the exceptionally high heat of fusion of silicon by means of elaborate prevention/mitigation of heat transfer through thermal radiation between key parts of the ESS, and rigorous minimization of the losses of thermal energy of silicon through heat conduction throug