Energy storage system and energy storage method

Abstract

To improve responsiveness to storage and release of electric energy in an energy storage system.SOLUTION: In conversion of electric energy to potential energy, an electric motor 40 is actuated by supply of electric energy, whereby rotating motion of an endless wire 20 between a first position 2 and a second position 4 higher than the first position 2 is caused by the electric motor 40. Then, a plurality of heavy objects 10 at the first position 2 are sequentially attached to the endless wire 20 in the rotating motion, and a heavy object rising from the first position 2 is detached from the endless wire 20 at the second position 4. In reconversion of potential energy to electric energy, the plurality of heavy objects 10 at the second position 4 are sequentially attached to the endless wire 20, whereby rotating motion of the endless wire 20 is caused by the weight of the heavy objects, and a heavy object 10 lowered from the second position 4 is detached from the endless wire 20 at the first position 2. Then, the electric motor 40 is rotationally driven by the endless wire 20 in the rotating motion.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an energy storage system and an energy storage method that can convert electrical energy into potential energy, store the energy, and reconvert the potential energy into electrical energy and extract the energy as needed. [Background technology]

[0002] Patent Document 1 discloses a system in which electrical energy is converted into potential energy of blocks by lifting and stacking blocks with an electric crane, and then stored. In this system, the potential energy of the blocks is converted back into electrical energy by applying regenerative braking with a generator when the crane lowers the blocks.

[0003] In the system described in Patent Document 1, a block is attached to the end of a cable hanging from a crane, and the block is lifted and stacked in a specified location, and then the cable is lowered again to lift the next block. However, a system that can only lift blocks one at a time like this cannot respond quickly to a request to store electrical energy. Similarly, it cannot respond quickly to a request to reconvert the potential energy of the block into electrical energy. It is possible to improve responsiveness to requests by increasing the number of cranes installed, but this requires more space and increases construction costs.

[0004] In addition to Patent Document 1, Patent Documents 2 and 3 can be mentioned as examples of documents showing the state of the art in the technical field related to the present disclosure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2021-532710 A [Patent Document 2] JP 2000-257545 A [Patent Document 3] Patent No. 6937930 Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure has been made in view of the above problems. One object of the present disclosure is to improve responsiveness to a request for storing and releasing electrical energy in a system that converts electrical energy into potential energy, stores the energy, and reconverts the potential energy into electrical energy as needed. [Means for solving the problem]

[0007] The present disclosure provides an energy storage system. The energy storage system of the present disclosure includes an endless wire, a plurality of weights, an electric motor, a first attachment device, a first detachment device, a second attachment device, a second detachment device, and a generator. The endless wire is installed so as to be able to move in an orbital manner between a first position and a second position higher than the first position. The plurality of weights are attachable to and detachable from the endless wire. The electric motor is configured to receive electric energy to cause the endless wire to move in an orbital manner. The first attachment device is configured to continuously attach the plurality of weights at the first position to the endless wire when the electric motor causes the endless wire to move in an orbital manner. The first detachment device is configured to detach the weights of the weights that rise from the first position from the endless wire at the second position. The second attachment device is configured to continuously attach the plurality of weights at the second position to the endless wire, thereby causing the endless wire to move in an orbital manner due to the weights of the weights. The second detachment device is configured to detach the weights of the weights that fall from the second position from the endless wire at the first position. The generator is configured to generate electricity by being rotationally driven by the endless wire when the endless wire moves in an orbit due to the weight of the attached heavy object.

[0008] In the energy storage system of the present disclosure, the orbital movement route of the endless wire may include a vertical route that is set in a vertical direction, or a diagonal route that is set in a diagonal direction, or the orbital movement route of the endless wire may include a horizontal route that is set in a horizontal direction in addition to the vertical route or the diagonal route.

[0009] In the energy storage system of the present disclosure, the first attachment device may be configured to successively attach weights at the first position to the endless wire with a number of attachments and an attachment interval corresponding to a storage schedule of the electric energy, and the second attachment device may be configured to successively attach weights at the second position to the endless wire with a number of attachments and an attachment interval corresponding to a release schedule of the electric energy.

[0010] The present disclosure provides an energy storage method. The energy storage method of the present disclosure includes an energy conversion step of converting electric energy into potential energy, and an energy reconversion step of reconverting the potential energy into electric energy. The energy conversion step includes a first step, a second step, and a third step. The first step is a step of operating an electric motor by supplying electric energy, and causing an endless wire to move in an orbital motion between a first position and a second position higher than the first position by the electric motor. The second step is a step of continuously attaching a plurality of weight objects at the first position to the endless wire that moves in an orbital motion. The third step is a step of detaching the weight objects that have risen from the first position from the endless wire at the second position. The energy reconversion step includes a fourth step, a fifth step, and a sixth step. The fourth step is a step of continuously attaching a plurality of weight objects at the second position to the endless wire, thereby causing the endless wire to move in an orbital motion by the weight of the weight objects. The fifth step is a step of detaching the weight objects that have descended from the second position from the endless wire at the first position. The sixth step is a step of rotating a generator by the orbiting endless wire, thereby obtaining electrical energy by generating electricity using the generator.

[0011] In the energy storage method of the present disclosure, the second step may be a step of successively attaching a plurality of heavy objects at a first position to the endless wire with a number of attachments and an attachment interval corresponding to a storage schedule of electric energy, and the fourth step may be a step of successively attaching a plurality of heavy objects at a second position to the endless wire with a number of attachments and an attachment interval corresponding to a release schedule of electric energy. Effect of the Invention

[0012] According to the present disclosure, when storage of electric energy is required, an endless wire is rotated by an electric motor, and multiple heavy objects are continuously attached to the rotating endless wire and lifted to a high place, thereby continuously converting electric energy into potential energy. Also, according to the present disclosure, when release of electric energy is required, multiple heavy objects at a high place are continuously attached to the endless wire and dropped, thereby continuously rotating the endless wire by the weight of the heavy objects. Then, a generator is driven to rotate by the continuously rotating endless wire, thereby continuously reconverting the potential energy into electric energy. Continuous conversion of electric energy into potential energy improves responsiveness to a request to store electric energy, and continuous reconversion of potential energy into electric energy improves responsiveness to a request to release electric energy. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of an energy storage system according to a first embodiment and an operation in an energy storage mode. [Diagram 2] FIG. 1 is a schematic diagram showing the configuration of an energy storage system according to a first embodiment and its operation in an energy release mode. [Diagram 3] 4 is a time chart showing an example of an operation of the energy storage system according to the first embodiment with respect to an energy storage / release schedule. [Figure 4] FIG. 11 is a schematic diagram showing the configuration of an energy storage system according to a second embodiment and its operation in an energy storage mode. [Diagram 5] FIG. 11 is a schematic diagram showing the configuration of an energy storage system according to a second embodiment and its operation in an energy release mode. [Figure 6] FIG. 11 is a schematic diagram showing the configuration of an energy storage system according to a third embodiment and its operation in an energy storage mode. [Figure 7] FIG. 11 is a schematic diagram showing the configuration of an energy storage system according to a third embodiment and its operation in an energy release mode. [Figure 8] FIG. 13 is a schematic diagram showing the configuration of an energy storage system according to a fourth embodiment and its operation in an energy storage mode. [Figure 9] FIG. 13 is a schematic diagram showing the configuration of an energy storage system according to a fourth embodiment and its operation in an energy release mode. [Figure 10] FIG. 13 is a schematic diagram showing the configuration of a first modified example of the energy storage system according to the fourth embodiment. [Figure 11] FIG. 13 is a schematic diagram showing a configuration of a second modified example of the energy storage system according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an energy storage system according to an embodiment of the present disclosure and an energy storage method implemented by the energy storage system will be described with reference to the drawings.

[0015] 1. First embodiment 1 and 2 show schematic configurations of an energy storage system 101 according to a first embodiment. The energy storage system 101 is a system that converts electric energy into potential energy of a heavy load 10 and stores the converted energy. The energy storage system 101 has two operation modes, that is, an energy storage mode in which electric energy is converted into potential energy of the heavy load 10 and stored, and an energy discharge mode in which the potential energy of the heavy load 10 is reconverted into electric energy and discharged. The energy storage mode corresponds to an energy conversion step of the energy storage method performed by the energy storage system 101. The energy discharge mode corresponds to an energy reconversion step of the energy storage method performed by the energy storage system 101. The operation of the energy storage system 101 in the energy storage mode is shown in FIG. 1, and the operation of the energy storage system 101 in the energy discharge mode is shown in FIG. 2.

[0016] The energy storage system 101 has two heavy load storage facilities 2 and 4 with a difference in height. The first heavy load storage facility 2 is a storage facility for heavy loads 10 provided at a low position (first position), and the second heavy load storage facility 4 is a storage facility for heavy loads 10 provided at a high position (second position higher than the first position). The second heavy load storage facility 4 is located diagonally above the first heavy load storage facility 2. For example, when building the energy storage system 101 using a mountain, the first heavy load storage facility 2 may be provided at the foot of the mountain, and the second heavy load storage facility 4 may be provided at the top of the mountain.

[0017] The weights of the weights 10 used in the energy storage system 101 range from several hundred kilograms to several tons, for example. However, the size and weight of the weights 10 are standardized, and the variations between the weights 10 are kept within the tolerances. The weights 10 can be made of, for example, concrete or metal.

[0018] An endless wire 20 is used to transport the heavy load 10 from the first heavy load storage facility 2 to the second heavy load storage facility 4. The endless wire 20 is hung on a first pulley 22 installed at the first heavy load storage facility 2 and a second pulley 24 installed at the second heavy load storage facility 4, and can make a circular motion between the first heavy load storage facility 2 and the second heavy load storage facility 4. The circular motion route of the endless wire 20 is maintained in shape by a plurality of pulleys including pulleys 22 and 24 (pulleys other than pulleys 22 and 24 are not shown). As illustrated in Figs. 1 and 2, the circular motion route of the endless wire 20 includes a diagonal route that is laid in a diagonal direction. The endless wire 20 is supported by pillars (not shown) at a plurality of points including this diagonal route.

[0019] The endless wire 20 is connected to a generator-motor 40. The generator-motor 40 functions as a generator when power is supplied to it, and functions as a motor when electricity is supplied to it. In the example shown in Figs. 1 and 2, the generator-motor 40 is installed in the first heavy load storage facility 2, and is connected to the endless wire 20 via the first pulley 22. A reducer (not shown) is provided between the generator-motor 40 and the first pulley 22. It is of course possible to install the generator-motor 40 in the second heavy load storage facility 4, and connect it to the endless wire 20 via the second pulley 24.

[0020] In the energy storage mode shown in Fig. 1, the energy storage system 101 causes the generator-motor 40 to function as a motor. Electric power for operating the generator-motor 40 is supplied, for example, from a power grid or a natural energy power plant such as a solar power plant. When the generator-motor 40 functions as a motor, the endless wire 20 is driven by the generator-motor 40 and performs an orbital motion in the direction shown by the arrow in the figure. The energy storage system 101 transports the heavy load 10 in the first heavy load storage facility 2 to the second heavy load storage facility 4 by the orbital motion of the endless wire 20.

[0021] In order to transport the heavy object 10 from the first heavy object storage facility 2 to the second heavy object storage facility 4, a first attachment device 32 is provided at the first heavy object storage facility 2. The first attachment device 32 is a device for attaching the heavy object 10 to the endless wire 20 that moves in an orbit. A fixture 12 is attached to the heavy object 10. The first attachment device 32 attaches the heavy object 10 to the endless wire 20 by fixing the fixture 12 to the endless wire 20. By fixing the fixture 12 to the endless wire 20, the heavy object 10 is suspended from the endless wire 20. The heavy object 10 is carried into the first attachment device 32 by a carrying-in device (not shown). The carrying-in device continuously carries the heavy object 10 stored in the first heavy object storage facility 2 into the first attachment device 32, and the first attachment device 32 continuously attaches the carried-in heavy object 10 to the endless wire 20. Methods for attaching the heavy object 10 to the endless wire 20 include, for example, a method in which the speed of the endless wire 20 is synchronized with the speed at which the heavy object 10 is carried in by the carrying-in device, and a method in which the endless wire 20 is temporarily stopped each time the heavy object 10 is attached.

[0022] The heavy object 10 attached to the endless wire 20 is transported to the second heavy object storage site 4 by the circular motion of the endless wire 20 driven by the generator / motor 40. The second heavy object storage site 4 is provided with a first detachment device 34. The first detachment device 34 is a device that continuously detaches the heavy object 10 that has been raised from the first heavy object storage site 2 from the endless wire 20. The first detachment device 34 detaches the heavy object 10 from the endless wire 20 by releasing the fixation of the fixture 12 to the endless wire 20. The heavy object 10 detached from the endless wire 20 by the first detachment device 34 is carried out from the first detachment device 34 by a carrying-out device (not shown). The carrying-out device moves the heavy object 10 carried out from the first detachment device 34 to a storage location. Methods for detaching the heavy load 10 from the endless wire 20 include, for example, a method of synchronizing the speed of the endless wire 20 with the speed of the load 10 being carried out by the carrying-out device, and a method of temporarily stopping the endless wire 20 each time to detach the heavy load 10. In the latter case, it is preferable to synchronize the timing of detaching the heavy load 10 from the endless wire 20 by the first detaching device 34 with the timing of attaching the heavy load 10 to the endless wire 20 by the first attaching device 32.

[0023] By operating as described above, the energy storage system 101 can continuously convert the electric energy supplied to the generator-motor 40 into potential energy. This continuous conversion can improve the responsiveness to requests for storing electric energy. The electric energy is converted into potential energy determined by the elevation difference between the first heavy object storage site 2 and the second heavy object storage site 4, the weight of the heavy object 10, and the number of heavy objects 10 transported to the second heavy object storage site 4, and is stored in the second heavy object storage site 4.

[0024] In the energy release mode shown in Fig. 2, the energy storage system 101 supplies power to the generator-motor 40 to make the generator-motor 40 function as a generator. To this end, the energy storage system 101 attaches the heavy load 10 stored in the second heavy load storage 4 to the endless wire 20, and causes the weight of the heavy load 10 to act on the endless wire 20 as a force for making the endless wire 20 move in an orbit. After the endless wire 20 starts to move in an orbit, the endless wire 20 continues to move in an orbit in the direction indicated by the arrow in the figure by successively attaching a plurality of heavy loads 10 to the endless wire 20. As the endless wire 20 moves in an orbit, the generator-motor 40 is rotationally driven via the first pulley 22 connected to the endless wire 20 to function as a generator.

[0025] The second heavy object storage facility 4 is provided with a second attachment device 36. The second attachment device 36 is a device that attaches the heavy object 10 to the endless wire 20 that is moving in an orbit. The second attachment device 36 attaches the heavy object 10 to the endless wire 20 by fixing the fixture 12 to the endless wire 20. The heavy object 10 is carried into the second attachment device 36 by a carrying-in device (not shown). The carrying-in device continuously carries the heavy objects 10 stored in the second heavy object storage facility 4 into the second attachment device 36, and the second attachment device 36 continuously attaches the carried-in heavy objects 10 to the endless wire 20.

[0026] The weight of the heavy load 10 attached by the second attachment device 36 causes the endless wire 20 to make a circular motion, and the heavy load 10, attached to the endless wire 20, descends from the second heavy load storage site 4 to the first heavy load storage site 2. However, until the first heavy load 10 attached moves to the diagonal route of the endless wire 2 and its weight acts as a force to make the endless wire 20 make a circular motion, the energy storage system 101 makes the generator-motor 40 function as a motor to forcibly drive the endless wire 20. After the endless wire 20 becomes capable of making a circular motion due to the weight of the heavy load 10, the energy storage system 101 makes the generator-motor 40 function as a generator. The power generated by the generator-motor 40 is supplied to the power grid or directly to consumers.

[0027] The first heavy object storage facility 2 is provided with a second detachment device 38. The second detachment device 38 is a device that continuously detaches the heavy objects 10 that have been lowered from the second heavy object storage facility 4 from the endless wire 20. The second detachment device 38 detaches the heavy objects 10 from the endless wire 20 by releasing the fasteners 12 from the endless wire 20. The heavy objects 10 removed from the endless wire 20 by the second detachment device 38 are carried out from the second detachment device 38 by a carrying-out device (not shown). The carrying-out device moves the heavy objects 10 carried out from the second detachment device 38 to a storage location.

[0028] By operating the energy storage system 101 as described above, it is possible to continuously reconvert the potential energy stored in the second heavy object storage site 4 into electrical energy. This continuous reconversion can improve the responsiveness to a request to release electrical energy.

[0029] The energy storage system 101 operates according to an energy storage / release schedule. Figure 3 is a time chart showing an example of the operation of the energy storage system 101 in accordance with the energy storage / release schedule. The energy storage / release schedule can be represented by a graph with time on the horizontal axis, required storage power on the positive vertical axis, and required release power on the negative vertical axis. The energy storage / release schedule shown in Figure 3 is designed to store inexpensive nighttime power and release the stored power during the daytime when power is tight.

[0030] The graph in the middle shows the upward transport schedule for the heavy loads 10 from the first heavy load storage site 2 to the second heavy load storage site 4. If the required storage power during nighttime power storage is constant, the upward transport schedule for the heavy loads 10 is established so as to transport a number of heavy loads 10 corresponding to the required amount of stored power at constant time intervals. The first attachment device 32 continuously attaches the heavy loads 10 to the endless wire 20 in the number and at intervals according to the upward transport schedule.

[0031] The graph at the bottom shows the schedule for the downward transfer of the heavy loads 10 from the second heavy load storage site 4 to the first heavy load storage site 2. As shown in this graph, the time interval for transferring the heavy loads 10 is variable. The downward transfer schedule for the heavy loads 10 is set up so that the number of heavy loads 10 corresponding to the required amount of discharge power is transferred at shorter time intervals as the required discharge power is greater. The second attachment device 36 continuously attaches the heavy loads 10 to the endless wire 20 in the number and at the attachment intervals according to the downward transfer schedule.

[0032] The energy storage / release schedule can be designed according to the application of the energy storage system 101. For example, the energy storage / release schedule can be designed so that electrical energy obtained by solar power generation is stored on a sunny day, and the stored electrical energy is utilized on a rainy or cloudy day.

[0033] The energy storage system 101 is operated by a system control device (not shown). The system management device is connected by wire or wirelessly to each device installed in the first heavy object storage site 2 and each device installed in the second heavy object storage site 4. The system control device controls each device installed in the first heavy object storage site 2 and each device installed in the second heavy object storage site 4 according to an energy storage / release schedule. Note that the fact that the energy storage system is operated by the system control device and that the energy storage system is operated according to the energy storage / release schedule is also common to other embodiments described later.

[0034] 2. Second embodiment Figures 4 and 5 show schematic configurations of an energy storage system 102 according to a second embodiment. The energy storage system 102 according to the second embodiment also has an energy storage mode and an energy discharge mode. The operation of the energy storage system 102 in the energy storage mode is shown in Figure 4, and the operation of the energy storage system 102 in the energy discharge mode is shown in Figure 5. In Figures 4 and 5, elements common to the energy storage system 101 according to the first embodiment are denoted by the same reference numerals.

[0035] The energy storage system 102 includes a generator-motor 42 capable of reverse rotation. The generator-motor 40 according to the first embodiment rotates in the same direction whether it functions as a generator or as a motor. In contrast, the generator-motor 42 according to the second embodiment rotates in the opposite direction whether it functions as a generator or as a motor. In the example shown in Figs. 4 and 5, the generator-motor 42 is installed in the first heavy goods storage facility 2, and is connected to the endless wire 20 via the first pulley 22. A reducer (not shown) is provided between the generator-motor 40 and the first pulley 22.

[0036] A first mounting / detaching device 52 and a second mounting / detaching device 54 are provided on the same side of the pulleys 22, 24 on the orbital motion route of the endless wire 20. The first mounting / detaching device 52 is provided in the first heavy load storage area 2. The second mounting / detaching device 54 is provided in the second heavy load storage area 4. Each of the mounting / detaching devices 52, 54 has a function as an mounting device that mounts the heavy load 10 to the orbital motion of the endless wire 20, and a function as a device that detaches the heavy load 10 from the orbital motion of the endless wire 20.

[0037] In the energy storage mode shown in Fig. 4, the energy storage system 102 causes the generator-motor 42 to function as a motor. When the generator-motor 42 functions as a motor, the endless wire 20 is driven by the generator-motor 40 and moves in an orbit in the direction shown by the arrow in Fig. 4. The energy storage system 102 transports the heavy object 10 in the first heavy object storage facility 2 to the second heavy object storage facility 4 by the endless wire 20 moving in an orbit.

[0038] In the energy storage mode, the first attachment / detachment device 52 functions as an attachment device (first attachment device). When the first attachment / detachment device 52 functions as an attachment device, heavy objects 10 stored in the first heavy object storage facility 2 are continuously brought into the first attachment / detachment device 52 by a carrying-in device (not shown). The first attachment / detachment device 52 attaches the heavy objects 10 to the endless wire 20 that moves in an orbit by fixing the fasteners 12 of the brought-in heavy objects 10 to the endless wire 20.

[0039] In the energy storage mode, the second mounting / detaching device 54 functions as a detaching device (first detaching device). When the second mounting / detaching device 54 functions as a detaching device, the second mounting / detaching device 54 releases the fastening of the fastener 12 of the heavy object 10 raised from the first heavy object storage site 2 to the endless wire 20, thereby detaching the heavy object 10 from the endless wire 20. The heavy object 10 detached from the endless wire 20 is carried out of the second mounting / detaching device 54 by a carrying-out device (not shown) and transported to a storage location.

[0040] In the energy release mode shown in Fig. 5, the energy storage system 102 moves the endless wire 20 in a circular motion in the direction shown by the arrow in Fig. 5. Therefore, the second mounting / detaching device 54 functions as a mounting device (second mounting device). When the second mounting / detaching device 54 functions as a mounting device, a carry-in device (not shown) continuously carries in the heavy objects 10 stored in the second heavy object storage area 4 to the second mounting / detaching device 54. The second mounting / detaching device 54 continuously attaches the carried-in heavy objects 10 to the endless wire 20.

[0041] The energy storage system 102 makes the generator-motor 42 function as a motor until the first attached weight 10 moves to the diagonal route of the endless wire 2 and its weight acts as a force to make the endless wire 20 move in circles. However, the generator-motor 42 rotates in the opposite direction to the energy storage mode, and forcibly drives the endless wire 20 in the direction shown by the arrow in Fig. 5. After the endless wire 20 is in a state where it can make circles due to the weight of the weight 10, the energy storage system 102 makes the generator-motor 42 function as a generator.

[0042] In the energy release mode, the first attachment / detachment device 52 functions as a detachment device (second detachment device). When the first attachment / detachment device 52 functions as a detachment device, the first attachment / detachment device 52 releases the fastening of the fastener 12 of the heavy object 10 that has been lowered from the second heavy object storage site 4 from the endless wire 20, thereby detaching the heavy object 10 from the endless wire 20. The heavy object 10 detached from the endless wire 20 is carried out of the first attachment / detachment device 52 by a carrying device (not shown) and transported to a storage location.

[0043] By operating the energy storage system 102 as described above, it is possible to continuously reconvert the potential energy stored in the second heavy load storage site 4 into electrical energy. This continuous reconversion can improve the responsiveness to a request to release electrical energy.

[0044] According to the energy storage system 102 configured as above, the attachment device and the detachment device are integrated instead of being provided separately, thereby making it possible to reduce the space required for the heavy load storage facilities 2, 4 and also to reduce the manufacturing cost of the device. Also, although the shape of the orbital motion route of the endless wire 20 is symmetrical with respect to the pulleys 22, 24 in Fig. 4 and Fig. 5, in the energy storage system 102, the route shape can be different between the side where the heavy load 10 is hung and the other side.

[0045] 3. Third embodiment Figures 6 and 7 show schematic configurations of an energy storage system 103 according to a third embodiment. The energy storage system 103 according to the third embodiment also has an energy storage mode and an energy discharge mode. The operation of the energy storage system 103 in the energy storage mode is shown in Figure 6, and the operation of the energy storage system 103 in the energy discharge mode is shown in Figure 7. In Figures 6 and 7, elements common to the energy storage system 101 according to the first embodiment are denoted by the same reference numerals.

[0046] The energy storage system 103 includes a dedicated electric motor 44 and a dedicated generator 46. The electric motor 44 is installed in the second heavy object storage facility 4, and is connected to the endless wire 20 via the second pulley 24. A reducer (not shown) is provided between the electric motor 44 and the second pulley 24. The generator 46 is installed in the first heavy object storage facility 2, and is connected to the endless wire 20 via the first pulley 22. A reducer (not shown) is provided between the generator 46 and the first pulley 22. It is also possible to install the electric motor 44 in the first heavy object storage facility 2, and install the generator 46 in the second heavy object storage facility 4.

[0047] In the energy storage mode shown in Fig. 6, the energy storage system 103 operates the electric motor 44. The electric motor 44 drives the endless wire 20 to make it move in a circular motion in the direction shown by the arrow in Fig. 6. At this time, the generator 46 is turned off so that regenerative braking is not performed. The energy storage system 103 transports the heavy load 10 in the first heavy load storage 2 to the second heavy load storage 4 by the endless wire 20 moving in a circular motion. In the energy storage mode, the heavy load 10 is attached to the endless wire 20 moving in a circular motion by the first attachment device 32, and the heavy load 10 is detached from the endless wire 20 by the first detachment device 34. The configurations and operations of the first attachment device 32 and the first detachment device 34 are the same as those of the first embodiment, so their explanation will be omitted.

[0048] In the energy release mode shown in FIG. 7, the electric motor 44 forcibly drives the endless wire 20 until the first heavy load 10 attached by the second attachment device 36 moves to the diagonal route of the endless wire 2 and its weight acts as a force to make the endless wire 20 move in a circular motion. After the endless wire 20 is in a state where it can move in a circular motion due to the weight of the heavy load 10, the generator 46 starts generating electricity and the power supply to the electric motor 44 is stopped. Also, the circuit of the electric motor 44 is cut off so that regenerative braking does not work. In the energy release mode, the heavy load 10 is attached to the endless wire 20 moving in a circular motion by the second attachment device 36, and the heavy load 10 is detached from the endless wire 20 by the second detachment device 38. The configurations and operations of the second attachment device 36 and the second detachment device 38 are the same as those of the first embodiment, so a description thereof will be omitted.

[0049] According to the energy storage system 103 configured as above, the electric motor 44 and the generator 46 are provided separately and controlled in a coordinated manner, thereby enabling smooth switching between the energy storage mode and the energy release mode. Furthermore, according to the energy storage system 103, the electric power system to which the electric motor 44 is connected and the electric power system to which the generator 46 is connected can be separated, and the generator 46 can be connected only to consumers.

[0050] 4. Fourth embodiment 8 and 9 are schematic diagrams showing the configuration of an energy storage system 104 according to a fourth embodiment. The energy storage system 104 according to the fourth embodiment also has an energy storage mode and an energy release mode. The operation of the energy storage system 104 in the energy storage mode is shown in FIG. 8, and the operation of the energy storage system 104 in the energy release mode is shown in FIG. 9.

[0051] In the energy storage system 104, the second heavy load storage 4 is located approximately directly above the first heavy load storage 2. For example, when building the energy storage system 104 using a cliff, the first heavy load storage 2 may be provided below the cliff, and the second heavy load storage 4 may be provided on the cliff. Also, when building the energy storage system 104 using a high-rise building, the first heavy load storage 2 may be provided on a lower floor, and the second heavy load storage 4 may be provided on a higher floor, including the rooftop.

[0052] An endless wire 60 is used to transport the heavy object 10 from the first heavy object storage site 2 to the second heavy object storage site 4. The endless wire 60 is hung between a first pulley 62 installed at the first heavy object storage site 2 and a second pulley 64 installed at the second heavy object storage site 4, and can make a circular motion between the first heavy object storage site 2 and the second heavy object storage site 4. The circular motion route of the endless wire 60 is vertical in both the outward and return routes, and the endless wire 60 rises vertically from the first pulley 62 to the second pulley 64 and descends vertically from the second pulley 64 to the first pulley 62.

[0053] The specifications of the weight load 14 used in the energy storage system 104 are basically the same as those of the weight load 10 according to the first embodiment. However, in order to avoid interference between the endless wire 60 extending in the vertical direction and the weight load 14, a clearance groove 14a is provided in the weight load 14. The weight load 14 is attached to the endless wire 60 by a fixture 16. The fixture 16 is prevented from coming off the endless wire 60 in the vertical state by, for example, engaging with a hook formed on the endless wire 60. The method of engaging the fixture with the hook formed on the endless wire can also be applied to the energy storage systems according to the first to third embodiments.

[0054] The endless wire 60 is connected to the generator-motor 48. The generator-motor 48 functions as a generator when power is supplied to it, and functions as a motor when power is supplied to it. In the example shown in Figs. 8 and 9, the generator-motor 48 is installed in the second heavy load storage 4 and is connected to the endless wire 60 via the second pulley 64. A reduction gear (not shown) is provided between the generator-motor 48 and the second pulley 64. When the generator-motor 48 functions as a motor, the endless wire 60 is driven by the generator-motor 48 and moves in a circular motion in the direction shown by the arrow in Fig. 8. When the generator-motor 48 functions as a generator, the endless wire 60 moves in a circular motion in the direction shown by the arrow in Fig. 9 due to the weight of the attached heavy load 14. It is of course possible to install the generator-motor 48 in the first heavy load storage 2 and connect it to the endless wire 60 via the first pulley 62.

[0055] In the energy storage mode shown in Fig. 8, the energy storage system 104 causes the generator-motor 48 to function as an electric motor. A first attachment device 72 is provided in the first heavy object storage facility 2 to attach the heavy object 14 to the endless wire 60 that is driven by the generator-motor 48 to perform orbital motion. The first attachment device 72 attaches the heavy object 14 to the endless wire 60 by fixing the fixture 16 of the heavy object 14 to the endless wire 60. The heavy object 14 is carried into the first attachment device 72 by a carrying-in device (not shown). The carrying-in device carries the heavy objects 14 stored in the first heavy object storage facility 2 continuously into the first attachment device 72.

[0056] A first detachment device 74 is provided in the second heavy load storage facility 4 in order to detach the heavy load 14 lifted from the first heavy load storage facility 2 from the endless wire 60. The first detachment device 74 detaches the heavy load 14 from the endless wire 60 by releasing the fixing device 16 from the endless wire 60. The heavy load 14 removed from the endless wire 60 by the first detachment device 74 is carried out of the first detachment device 74 by a carrying-out device (not shown) and transported to a storage location.

[0057] In the energy release mode shown in FIG. 9, the energy storage system 104 makes the generator-motor 48 function as a generator. For this purpose, the second heavy load storage facility 4 is provided with a second attachment device 76 for attaching the heavy load 10 to the endless wire 60. Since the second attachment device 76 is located on the vertical route of the endless wire 60, the weight of the heavy load 14 acts on the endless wire 20 as a force for making the endless wire 60 move in a circular motion as soon as the heavy load 14 is attached to the endless wire 60 by the second attachment device 76. As the endless wire 60 moves in a circular motion due to the weight of the heavy load 14, the generator-motor 48 is rotated and driven by the endless wire 60 to generate electricity. The heavy load 14 is delivered to the second attachment device 76 by a delivery device (not shown). The delivery device continuously delivers the heavy loads 14 stored in the second heavy load storage facility 4 to the second attachment device 76.

[0058] The first heavy load storage facility 2 is provided with a second detachment device 78. The second detachment device 78 is a device that continuously detaches the heavy loads 14 that have been lowered from the second heavy load storage facility 4 from the endless wire 60. The second detachment device 78 detaches the heavy loads 10 from the endless wire 20 by releasing the fasteners 16 from the endless wire 60. The heavy loads 10 detached from the endless wire 20 by the second detachment device 38 are carried out of the second detachment device 78 by a carrying-out device (not shown) and transported to a storage location.

[0059] According to the energy storage system 104 configured as above, in the energy storage mode, the weight 14 is raised vertically, thereby making it possible to suppress the energy loss occurring between the endless wire and the pulley supporting the endless wire. Also, in the energy release mode, the weight 14 is lowered vertically, thereby making it possible to suppress the energy loss occurring between the endless wire and the pulley supporting the endless wire.

[0060] The characteristic configuration of the energy storage system 102 according to the second embodiment can be applied to the energy storage system 104. Specifically, a generator-motor capable of reverse operation that can reverse the rotation direction of the endless wire 60 between the energy storage mode and the energy release mode can be provided, and each of the heavy object storage sites 2 and 4 can be provided with an attachment-detachment device in which an attachment device and a detachment device are integrated. The characteristic configuration of the energy storage system 103 according to the third embodiment can also be applied to the energy storage system 104. Specifically, a motor and a generator can be provided separately, and the endless wire 60 can be rotated by a dedicated motor in the energy storage mode, and the dedicated generator can be rotationally driven by the endless wire 60 in the energy release mode.

[0061] The orbiting motion route of the endless wire 60 included in the energy storage system 104 can be modified, for example, as shown in FIG. 10 or FIG. 11. In a first modified example of the energy storage system 104 shown in FIG. 10, the endless wire 60 is composed of a lower horizontal route 60h1 laid in the horizontal direction, a vertical route 60v laid in the vertical direction, and an upper horizontal route 60h2 laid in the horizontal direction. In a second modified example of the energy storage system 104 shown in FIG. 11, the endless wire 60 is composed of a lower horizontal route 60h1 laid in the horizontal direction, a lower diagonal route 60s1 laid in the diagonal direction, a vertical route 60v laid in the vertical direction, an upper diagonal route 60s2 laid in the diagonal direction, and an upper horizontal route 60h2 laid in the horizontal direction. In this way, the orbiting motion route of the endless wire 60 can be modified in various ways. Similarly, the orbiting motion route of the endless wire 20 included in the energy storage systems 101, 102, and 103 can also be modified in various ways.

[0062] 5. Other embodiments In each of the above embodiments, a method of attaching a heavy load to the endless wire can be adopted in which heavy loads are loaded onto containers attached to the endless wire at regular intervals. In this case, it is not necessary to load heavy loads onto all of the containers that are circulating. The loading intervals can be changed or the number of loads per container can be adjusted according to the required storage power or required discharge power.

[0063] In each of the above embodiments, a chain or a conveyor may be used instead of the endless wire. In other words, any endless track body that can move in a circular motion between a first position and a second position can be used as a means for transporting a heavy load in the energy storage system of the present disclosure. In addition, as a method for operating an endless track body including an endless wire, in addition to a method for operating the endless track body in a circular motion in one direction, a method for switching the operating direction so that the endless track body moves back and forth between a first position and a second position can also be used. [Explanation of symbols]

[0064] 2 Daiichi Heavy Goods Storage 4 Second bulk storage 10, 14 Heavy objects 12, 16 Fixtures 14a Relief groove 20, 60 endless wire 40, 48 Generators and motors 32, 72 First mounting device 34, 74 First release device 36, 76 Second mounting device 38, 78 Second release device 42 Reverse-operating generator / motor 44 Electric motor 46 Generator 52 First attachment / detachment device 54 Second attachment / detachment device 101, 102, 103, 104 Energy storage systems

Claims

1. 1. An energy storage system comprising: an endless wire that is disposed so as to be capable of moving in an orbit between a first position and a second position that is higher than the first position; A plurality of weights detachable from the endless wire; an electric motor configured to receive electrical energy to cause the endless wire to move in an orbit; a first attachment device configured to sequentially attach a plurality of weights at the first position to the endless wire while the electric motor is rotating the endless wire; a first detachment device configured to detach the weight lifted from the first position from the endless wire at the second position; a second attachment device configured to attach a plurality of weight objects at the second position to the endless wire successively, thereby causing the endless wire to move in an orbital motion due to the weights of the weight objects; a second detachment device configured to detach the weight that has been lowered from the second position from the endless wire at the first position; and a generator configured to generate electricity by being rotated by the endless wire when the endless wire moves in an orbit due to the weight of the attached heavy object.

1. An energy storage system comprising:

2. 2. The energy storage system of claim 1, The circular movement route of the endless wire includes a vertical route that is established in a vertical direction.

1. An energy storage system comprising:

3. 2. The energy storage system of claim 1, The circular movement route of the endless wire includes a diagonal route that is provided in a diagonal direction.

1. An energy storage system comprising:

4. 4. The energy storage system according to claim 2 or 3, The circular motion route comprises a horizontal route established in a horizontal direction.

1. An energy storage system comprising:

5. 2. The energy storage system of claim 1, The first attachment device is configured to continuously attach a weight at the first location to the endless wire with a number of attachments and an attachment interval according to a storage schedule of the electric energy.

1. An energy storage system comprising:

6. 2. The energy storage system of claim 1, The second attachment device is configured to continuously attach a weight at the second position to the endless wire with a number of attachments and an attachment interval according to the discharge schedule of the electrical energy.

1. An energy storage system comprising:

7. 1. A method of storing energy, comprising: an energy conversion step of converting electrical energy into potential energy; and an energy reconversion step of reconverting the potential energy into the electrical energy, The energy conversion process includes: operating an electric motor by the supply of electric energy, and causing an endless wire to move in a circular motion between a first position and a second position higher than the first position by the electric motor; continuously attaching a plurality of weights at the first position to the endless wire that moves in an orbit; and detaching the weight lifted from the first position from the endless wire at the second position. The energy reconversion step includes: a plurality of weight objects at the second position are successively attached to the endless wire, thereby causing the endless wire to move in an orbital motion due to the weights of the weight objects; detaching the weight that has been lowered from the second position from the endless wire at the first position; and rotating a generator by the endless wire that moves in an orbital motion, and obtaining the electric energy by generating electricity by the generator.

13. A method for storing energy comprising:

8. 8. The energy storage method according to claim 7, The energy conversion step includes sequentially attaching a plurality of weights at the first location to the endless wire with a number of attachments and an attachment interval corresponding to a storage schedule of the electric energy.

13. A method for storing energy comprising:

9. 8. The energy storage method according to claim 7, The energy reconversion step includes continuously attaching a plurality of weights at the second position to the endless wire with a number of attachments and an attachment interval according to the electrical energy release schedule.

13. A method for storing energy comprising:

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