Energy storage device and energy storage method

Abstract

To provide an energy storage device and an energy storage method capable of further suppressing space and cost related to structure of a facility.SOLUTION: An energy storage device according to an embodiment comprises: a support unit that supports a weight so that it can rise and lower accompanied with rotating motion of a rotary body; a control unit for raising or lowering the weight according to a predetermined condition or a predetermined signal; and a power generating unit for generating power by the rotating motion of the rotary body when the weight lowers. The support unit is installed above the water or at a position within a predetermined distance from a water surface so that the weight lowers in the water.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an energy storage device and method. [Background technology]

[0002] In recent years, research and development has been conducted into the utilization of renewable energy that contributes to energy efficiency, in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. In this regard, a technology is known in which a suspended weight is raised at night or during times of low electricity demand to store potential energy, and then the weight is lowered under its own weight to generate electricity and supply the generated electricity during times of high demand (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-147097 [Patent Document 2] Japanese Patent Publication No. 2020-197205 Summary of the Invention [Problem to be solved by the invention]

[0004] However, technologies related to the utilization of renewable energy have the problem of requiring high-rise buildings to ensure the distance the weight falls, and of installing a deceleration mechanism to stabilize the speed of the weight falling under its own weight, which requires structural space and costs.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide an energy storage device and an energy storage method that can further reduce the structural space and costs of the equipment in order to solve the above problems, thereby contributing to energy efficiency. [Means for solving the problem]

[0006] The energy storage device and the energy storage method according to the present invention employ the following configuration. (1): One embodiment of the energy storage device of the present invention includes a support unit that supports a sinker so that it can rise and fall in accordance with the rotational movement of a rotating body, a control unit that raises or lowers the sinker under predetermined conditions or in response to a predetermined signal, and a power generation unit that generates electricity through the rotational movement of the rotating body when the sinker descends, wherein the support unit is located above the water or within a predetermined distance from the water surface so that the sinker descends underwater.

[0007] (2) In the above aspect (1), the weight has a space that can be filled with water and an opening through which the water can be supplied and removed.

[0008] (3) In the above aspect (2), the openings are provided at a plurality of positions including the bottom and top of the weight.

[0009] (4) In the above aspect (1), a plurality of pairs of the weight and the rotating body are provided, and the control unit controls power generation by sequentially lowering one or more of the plurality of weights.

[0010] (5): In the above aspect (4), the control unit derives the amount of power shortage based on the amount of power demand, and determines the number of sinkers to be lowered into the water from among the plurality of sinkers in accordance with the amount of power shortage thus derived.

[0011] (6): In the above aspect (1), the wind turbine is installed within a predetermined distance from a wind power generation facility that generates electricity by rotating a propeller due to wind power, and is physically or electrically connected to some of the components used when generating electricity by the wind power generation facility.

[0012] (7): In one aspect of the energy storage method of the present invention, a computer of an energy storage device supports a weight so that it can rise and fall in accordance with the rotational movement of a rotating body using a support part, raises or lowers the weight under predetermined conditions or under predetermined signals, and generates electricity through the rotational movement of the rotating body as the weight falls, and the support part is located on the water or within a predetermined distance from the water surface so that the weight falls underwater. [Effects of the Invention]

[0013] According to the above aspects (1) to (7), the structural space and costs of the equipment can be further reduced. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating the configuration of an energy storage device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the functional configuration of a control unit 140. [Figure 3] 1 is a diagram for explaining the mechanism of energy storage and power generation in the energy storage device 100. FIG. [Figure 4] 10A and 10B are diagrams illustrating an example of another weight that is applied to the embodiment. [Figure 5] 5 is a diagram for explaining a state in which the weight 180A shown in FIG. 4 is dropped. [Figure 6] FIG. 1 is a diagram for explaining an energy storage device 100 installed near other power generation equipment. [Figure 7] 3 is a flowchart illustrating an example of a process executed in the energy storage device 100 according to the embodiment. [Figure 8] 1A and 1B are diagrams illustrating a modification of the energy storage device 100. [Figure 9] 10A and 10B are diagrams for explaining a coupling mechanism with a plurality of rotary shafts. [Figure 10] 10 is a flowchart illustrating an example of a process executed by an energy storage device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an energy storage device and an energy storage method according to the present invention will be described with reference to the drawings.

[0016] [Overall configuration] FIG. 1 is a configuration diagram of an energy storage device according to an embodiment. The energy storage device 100 is installed on water or within a predetermined distance from the water surface. On water refers to, for example, a location with a depth of at least a predetermined distance, such as the ocean or a lake. A location within a predetermined distance from the water surface includes, for example, land close enough to allow a sinker (described later) to be dropped into the water (descending underwater) in the ocean, lake, or the like. In the example of FIG. 1, the energy storage device 100 is installed on a floating body 10 floating on the ocean. The floating body 10 has buoyancy that allows it to float on the ocean surface with at least the energy storage device 100 installed thereon. The floating body 10 may have any form, such as a floating island or a large ship. The floating body 10 is a platform for carrying out work related to the power generation (e.g., offshore power generation) of this embodiment. The following description will be given assuming that the energy storage device 100 is installed on the ocean.

[0017] The energy storage device 100 includes, for example, a support unit 110, a speed adjustment unit 120, a motor 130, and a control unit 140. The motor 130 is an example of a "power generation unit." The support unit 110 supports a weight 180 connected to the end of a rope 170 that is wound or unwound by the rotation of the rotor 160 so that the weight 180 can rise and fall as the rotor 160 rotates. The rope 170 is, for example, a cable such as a wire. Details of the weight 180 will be described later.

[0018] The speed adjustment unit 120 has an adjustment mechanism that adjusts the rotation speed of the rotor 160 so that the falling speed (descent speed) of the sinker 180 is constant. The constant speed is a speed at which power can be generated by the rotation of the rotor 160 (more specifically, the rotation shaft 162). In this embodiment, the sinker 180 is dropped into the sea, and therefore deceleration is performed using the resistance of seawater. This reduces the load on the speed adjustment unit 120 compared to when the sinker is dropped in the air, and eliminates the need for an expensive speed adjustment unit 120 with performance that can withstand high loads, thereby reducing equipment costs.

[0019] The motor 130 generates electricity by converting the rotational energy (kinetic energy) of the rotor 160 in the forward direction (the direction of rotation when the sinker 180 falls) into electrical energy. The electricity generated by the motor 130 is supplied to electricity consumers and the like via a power transmission system (not shown). The motor 130 also rotates the rotor 160 in the direction opposite to the direction of rotation when the sinker 180 falls, for example, by using an external power supply, and pulls up the sinker 180 that has fallen to the seabed by the rotational action (reverse rotational action).

[0020] The control unit 140 has a function of controlling the energy storage device 100. For example, the control unit 140 controls the raising or lowering of the weight 180 in response to a predetermined condition or a predetermined signal. FIG. 2 is a diagram illustrating an example of the functional configuration of the control unit 140. The control unit 140 includes, for example, a communication unit 141, a storage unit 142, a power generation control unit 143, an adjustment control unit 144, and a drive control unit 145. The power generation control unit 143, the adjustment control unit 144, and the drive control unit 145 are realized by a hardware processor such as a central processing unit (CPU) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as a large-scale integration (LSI), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a graphics processing unit (GPU), or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device (a storage device with a non-transitory storage medium) such as an HDD (Hard Disk Drive) or flash memory, or may be stored in a removable storage medium (a non-transitory storage medium) such as a DVD or CD-ROM, and installed by inserting the storage medium into a drive device.

[0021] The communication unit 141 is a communication interface that communicates with, for example, the support unit 110, the speed adjustment unit 120, and the motor 130. The communication unit 141 may also communicate with an external device. The external device may be, for example, another power generation facility such as an offshore wind power generation facility or an ocean current power generation facility, or may be a management server that manages the energy storage device 100 or other power generation facilities.

[0022] The storage unit 142 is realized by the various storage devices described above. Alternatively, the storage unit 142 may be realized by an SSD (Solid State Drive), an EEPROM (Electrically Erasable Programmable Read Only Memory), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The storage unit 142 stores, for example, programs executed by the control unit 140, setting information, and various other information.

[0023] The power generation control unit 143 lowers the weight 180 to generate power when a first predetermined condition is met. The first predetermined condition is, for example, when an external power generation facility experiences a power shortage and it becomes necessary to generate power to make up for the shortage. Furthermore, instead of determining whether the first predetermined condition is met, the power generation control unit 143 may, when it receives a predetermined signal from an external device instructing it to lower the weight 180 or generate power, execute a process corresponding to the signal.

[0024] When generating electricity, the power generation control unit 143 drops the weight 180 to the seabed and rotates the rotating body 160 in the forward direction (forward rotation) while it is falling, thereby generating electricity using the motor 130 connected to the rotating shaft 162 of the rotating body 160.

[0025] The adjustment control unit 144 controls the rotation speed of the rotor 160 so that the speed adjustment unit 120 causes the weight 180 to fall at a constant, uniform speed. By causing the weight 180 to fall at a constant speed, a stable amount of power can be generated. The adjustment control unit 144 may also perform control to stop the weight 180 mid-fall so that surplus power beyond the required amount is not generated.

[0026] The drive control unit 145 performs control to raise the sinker 180 that has fallen to the seabed when a second predetermined condition is satisfied. The second predetermined condition is, for example, when there is surplus power enough to just raise the sinker 180 or when electricity rates are low, such as at night. Note that, instead of determining whether the second predetermined condition is satisfied, the drive control unit 145 may, when receiving a predetermined signal from an external device instructing to raise (pull up) the sinker 180, execute processing corresponding to the signal. Furthermore, when pulling up the sinker 180, the drive control unit 145 drives the motor 130 to rotate the rotor 160 in a direction opposite to the forward direction (reverse rotation), and executes control to reel in the rope 170.

[0027] 1, when weight 180 is dropped from the position of rotation axis 162 of rotor 160, the distance D1 from the position (height) of rotation axis 162 to the seabed can be held as potential energy, and the movement of weight 180 to the seabed can convert the potential energy into kinetic energy of rotor 160, and the rotation of rotor 160 can generate electricity using motor 130. Furthermore, because energy storage device 100 floats on the ocean, it does not need to be installed in a high position on a building or the like, reducing weight restrictions.

[0028] Next, the mechanism of energy storage and power generation in the embodiment shown in Fig. 1 will be described with reference to the drawings. Fig. 3 is a diagram for explaining the mechanism of energy storage and power generation in the energy storage device 100. Note that the example in Fig. 3 shows a schematic diagram of how the potential energy of the weight 180 is converted into operating energy by rotating the rotor 160 in accordance with a change in the potential energy. In the example in Fig. 3, time T11 is assumed to be the earliest, followed by times T12 and T13 in that order.

[0029] At time T11, for example, external power (or motive power) is used to rotate the rotor 160 in the reverse direction and reel in the rope 170, thereby raising the sinker 180 to near the sea surface. At time T1, the potential energy is assumed to be at its maximum. The power at this time may be surplus renewable energy power, or may be power from other power facilities such as offshore wind power generation facilities, solar power generation facilities, or ocean current power generation facilities attached to the energy storage device 100, as will be described later. After raising the sinker 180 at time T1, the sinker 180 is fixed near the sea surface by attaching a float or providing a ratchet mechanism to the rotating shaft 162 to prevent forward rotation except when power is being generated.

[0030] At time T12, when power is needed due to a power shortage or the like, the sinker 180 is dropped toward the seabed, and power is generated by the motor 130 connected to the rotating shaft 162. By dropping the sinker 180 into the sea, the potential energy of the sinker 180 is converted into kinetic energy of the rotating body 160. Time T13 shows the state in which the sinker 180 has fallen to the seabed. In this state, the rotating body 160 stops rotating, and no power is generated.

[0031] Since the sinker 180 is to be placed in the sea, it must be made of a metal that does not corrode or is resistant to corrosion and must have a predetermined weight. The predetermined weight is at least the weight of seawater plus α. α is, for example, the sum of a weight that exceeds the resistance force at the start of movement of the motor 130 (power generating unit) or the rotating body 160 and a weight that exceeds the resistance in seawater. α may also be, for example, the sum of a weight that exceeds the resistance required to keep the moving motor 130 or the rotating body 160 rotating when energy is separately provided for the initial speed of the motor 130 or the rotating body 160 to start moving and a weight that exceeds the resistance in seawater. The resistance in seawater may include, for example, the influence of ocean currents, etc.

[0032] Furthermore, the shape of the sinker 180 is not limited to the example shown in FIG. 1, and may be, for example, a shape that allows neutral buoyancy to be utilized (for example, a shape that allows the inside of the sinker to be hollow to allow seawater to flow in and out).

[0033] Fig. 4 is a diagram showing an example of another weight applied to the embodiment. Fig. 4 is a diagram showing an example of a vertical cross section of another weight 180A. Weight 180A includes, for example, eyebolt 181, main body 182, lower opening 183, and upper opening 184. In the example of Fig. 4, one lower opening 183 is provided at the bottom of main body 182, and one upper opening 184 is provided at the top of main body 182, but each of lower opening 183 and upper opening 184 may be provided at multiple positions.

[0034] The eyebolt 181 has a ring-shaped head and is used to tie the end of the rope 170. The main body 182 is a hollow weight having a space (cavity) inside. The space can be filled with water (liquid such as seawater). The lower opening 183 and the upper opening 184 are openings that allow water to be supplied and removed. The lower opening 183 is a hole through which seawater is injected into the main body when the weight 180 is placed in the sea. The upper opening 184 is a hole through which air is discharged from inside the main body when seawater is injected from the lower opening 183. Conversely, when the weight 180 is taken out of the sea and into the air, the lower opening 183 becomes a hole through which seawater is discharged from inside the weight 180, and the upper opening 184 becomes a hole through which air is injected into the main body.

[0035] Fig. 5 is a diagram for explaining the state when the sinker 180A shown in Fig. 4 is dropped. Fig. 5 simply shows the state when seawater is poured into the main body of the sinker 180A. In Fig. 5, time T21 is the earliest, followed by times T22 and T23 in that order.

[0036] Time T21 shows the state at the time when sinker 180 is dropped into the sea. As sinker 180 is dropped into the sea, seawater is gradually poured into sinker 180A from lower opening 183, and air is expelled from upper opening 184 as the amount of seawater poured in increases (time T22). At time T23, the sinker is filled with seawater (completely depleted of air). This increases the surface area in contact with seawater compared to a simple spherical sinker with no hollow, resulting in greater resistance from seawater and allowing the falling speed of sinker 180A to be somewhat suppressed. In this way, adjusting the shape of the sinker according to the falling speed makes it easier to adjust the falling speed to a stable level.

[0037] The energy storage device 100 of the above-described embodiment may be installed (alongside) within a predetermined distance from an existing power generation facility such as a wind power generation facility, an ocean current power generation facility, etc. For example, when the energy storage device 100 is installed alongside a wind power generation facility that generates electricity by rotating a propeller due to wind power, the rotor 160 may be physically connected to the rotating shaft of the propeller of the wind power generation facility, or may be electrically connected to the wind power generation facility so as to utilize the power generation unit or power transmission system of the wind power generation facility.

[0038] Fig. 6 is a diagram illustrating an energy storage device 100 installed near another power generation facility. In the example of Fig. 6, a wind power generation facility 200 is shown as an example of the other power generation facility. The wind power generation facility 200 converts, for example, the kinetic energy of wind into rotational energy using a windmill (wind turbine), and converts that energy into electric power (electrical energy) by outputting it to a power generation unit.

[0039] In the example of Fig. 6, the wind power generation facility 200 has a tower 204 installed on a foundation 202 provided on the floating body 10, and a plurality of propellers (blades) 206 are provided on the top of the tower 204 to rotate around a rotation shaft 208. The wind power generation facility 200 also includes, for example, a speed increaser 210 that increases the rotation speed of the rotation shaft 208 to a number required for power generation, a braking device 212 that stops or slows down the rotation of the rotation shaft 208, and a generator (an example of a power generation unit) 214 that converts rotational energy into electric power. In the example of Fig. 6, a power transmission system PG is also provided to supply electric power generated by the generator 214 of the wind power generation facility 200 to consumers. The communication unit 141 of the energy storage device 100 is connected to the wind power generation facility 200 in a communicative state.

[0040] Here, energy supply when the energy storage device 100 and the wind power generation facility 200 are installed side by side will be described. In the example of FIG. 6, the control unit 140 of the energy storage device 100 communicates with the wind power generation facility 200, acquires the required power demand requested from the outside and the amount of power that can be generated by the wind power generation facility 200, and determines whether there is a power shortage by subtracting the amount of power that can be generated from the required power demand. If there is a power shortage, the control unit 140 performs control to drop the weight 180 to generate power. Note that the control unit 140 may perform control to drop the weight 180 to generate power when it receives information about the power shortage directly from the wind power generation facility 200 or when it receives a power generation instruction. The control unit 140 may also predict a future power shortage based on, for example, weather forecasts, information on disaster occurrences, past statistical information, etc., and perform power generation control based on the predicted power shortage.

[0041] 6 , the energy storage device 100 may be physically or electrically connected to some of the components used when the wind power generation facility 200 generates power. In this case, when the wind power generation facility 200 is not generating wind power, the control unit 140 may perform control to physically connect the rotating shaft 162 of the rotating body 160 to the generator 214 using a clutch mechanism or the like, and use the generator 214 to generate power based on the rotation of the rotating shaft 162. The control unit 140 may also perform control to connect the rotating body 160 to the rotating shaft 208 of the propeller 206 using a clutch mechanism or the like, so that the rotating shaft 208 rotates with the rotation of the rotating body 160.

[0042] Furthermore, the control unit 140 may use switching control to electrically connect to the power transmission system PG of the wind power generation facility 200 and supply the power generated by the motor 130 to consumers. In this way, by using the generator 214 of the wind power generation facility 200 instead of the motor 130 or by using the power transmission system PG of the wind power generation facility 200, the installation costs of the energy storage device 100 can be further reduced.

[0043] Furthermore, when pulling up the sinker 180, the control unit 140 may use the electricity generated by the wind power generation facility 200. In the embodiment, for example, surplus electricity from wind power generation or the like is converted into another energy for pulling up the sinker on the spot and stored as potential energy, and when there is a shortage, the sinker is dropped to the seabed and converted back into electricity, thereby eliminating the need to store the electricity in a battery or the like and enabling the electricity to be used effectively without waste.

[0044] For example, wind power generation facilities 200, solar power generation facilities, ocean current power generation facilities, etc., may not be able to supply a stable amount of power every day because the amount of power generated each day varies greatly depending on the weather, etc. Therefore, by installing the energy storage device 100 of the embodiment, the shortfall in power can be compensated for by the power generated by the energy storage device 100, and conversely, surplus power generated due to the weather can be effectively used as power to pull up the sinker 180. Furthermore, renewable energy facilities such as wind power generation facilities 200 and solar power generation facilities are often installed offshore (on water) where there are no buildings, etc., and therefore have a very high affinity with the energy storage device 100 of the embodiment.

[0045] [Processing flow] Fig. 7 is a flowchart showing an example of processing executed in the energy storage device 100 according to the embodiment. In the example of Fig. 7, the control unit 140 derives, for example, the amount of power demand (step S100). Note that in the processing of step S100, the amount of power demand of other power generation facilities installed near (within a predetermined distance from) the energy storage device 100 may be used instead of (or in addition to) the individual amount of power demand of the energy storage device 100.

[0046] Next, the control unit 140 determines whether there is a power shortage (step S102). If it determines that there is a power shortage, the control unit 140 drops the sinker 180 to the seabed to rotate the rotor 160 in the forward direction (step S104), and converts the rotational energy of the rotor 160 into electrical energy to generate power (step S106). Next, the control unit 140 supplies the generated power to power consumers via a power transmission system or the like (step S108).

[0047] Furthermore, if it is determined in step S102 that there is no power shortage, the control unit 140 determines whether the sinker 180 has fallen to the seabed (step S110). If it is determined that the sinker 180 has fallen to the seabed, the control unit 140 uses existing surplus power or surplus power obtained from an external source to rotate the rotor 160 in the reverse direction and pull up the sinker 180 (step S112). This makes it possible to effectively utilize the surplus power. Furthermore, if it is determined in the processing of step S110 that the sinker 180 has not fallen, the processing of this flowchart ends.

[0048] <Modification> Next, a modified example will be described. The energy storage device 100 in this embodiment includes, for example, a plurality of pairs of a weight and a rotor, and the control unit 140 controls power generation by sequentially lowering one or more of the plurality of weights. In this case, the control unit 140 may adjust the number of weights to be lowered depending on the amount of power required.

[0049] Fig. 8 is a diagram showing a modified example of the energy storage device 100. In the example of Fig. 8, the energy storage device 100 is assumed to be installed near a wind power generation facility 200, and further, only the relationship between the rotor 160, the rotation shaft 162, and the weight 180 of the energy storage device 100 is shown in schematic form.

[0050] In this modification, a plurality of rotating bodies 160 that rotate independently are provided on a rotating shaft 162, and each rotating body 160 has a rope 170 that is reeled out or wound up by rotation, with a weight 180 attached to the end of each rope 170. In the example of Fig. 8, two rotating shafts 162A and 162B are provided with a plurality of rotating bodies 160-a1 to 160-a12 and 160-b1 to 160-b12, respectively, and ropes 170 and weights 180-a1 to 180-a12 and 180-b1 to 180-b12 are provided corresponding to each rotating body. Also, a mechanism is provided in which the rotation of one of the plurality of rotating bodies arranged in parallel on the rotating shafts 162A and 162B rotates the rotating shaft, but the other rotating bodies do not rotate.

[0051] By dropping the plurality of rotating bodies in sequence, the control unit 140 can rotate the rotating shafts 162A and 162B for a long period of time, so that power can be generated even when a large amount of power is required.

[0052] For example, in a modification shown in FIG. 8 , the control unit 140 obtains the amount of power shortage from the amount of power demand required for the wind power generation facility 200 and the amount of power that can be generated by the wind power generation facility 200, and determines the number of weights 180 to be dropped to the seabed based on the obtained amount of power shortage. In this case, the control unit 140 manages the amount of power generated by dropping one weight 180, thereby determining the number of weights to be dropped based on the amount of power shortage. The control unit 140 also performs control to sequentially drop the determined number of weights 180 to generate power. Note that, to prevent the rope 170 from becoming tangled in the sea due to the influence of ocean currents or the like when dropping parallel weights 180, the control unit 140 may install weights 180 with a predetermined offset between them, or may drop weights 180 that are spaced apart from each other among the parallel weights 180.

[0053] Furthermore, when the energy storage device 100 has two rotating shafts 162A and 162B as shown in FIG. 8, the energy storage device 100 may be provided with a coupling mechanism between the rotating shafts 162A and 162B so that the motor 130 can generate electricity by rotating each shaft.

[0054] FIG. 9 is a diagram illustrating a coupling mechanism for multiple rotating shafts. In the example of FIG. 9, a gear 164 is provided on a rotating shaft 162 connected to the motor 130, and gears 164A and 164B are also provided on each of the rotating shafts 162A and 162B. In the example of FIG. 9, the rotating bodies 160-a1 to 160-a12 and 160-b1 to 160-b12 shown in FIG. 8 are simplified and shown as rotating bodies 160-a and 160-b. For example, the control unit 140 identifies the rotating shaft to be coupled to the motor 130 according to the position of the weight to be dropped. Specifically, the control unit 140 identifies the rotating shaft that rotates when the weight is dropped as the rotating shaft to be coupled to the motor 130. Then, the control unit 140 performs switching control so that the gear 164A or 164B provided on the identified rotating shaft meshes with the gear 164 of the rotating shaft 162 connected to the motor 130, and the rotational energy of the rotating shaft due to the weight is transmitted to the motor 130 via each gear. This allows the motor 130 to be used interchangeably even when there are multiple rotating shafts.

[0055] In addition, when there are multiple rotating shafts as shown in Fig. 8, a motor that generates electricity may be provided for each rotating shaft. Furthermore, the weights shown in the modified example may have the same weight and shape, or may have different weights and shapes. Furthermore, in the example of Fig. 8, a plurality of support units 110 each having a rotating body 160 may be provided so as to support the multiple weights so that they can be raised and lowered independently, and a switching mechanism may be provided so that a number of support units corresponding to the amount of power shortage are selectively connected to the rotating shaft 162 to rotate the rotating shaft 162.

[0056] [Processing flow] Fig. 10 is a flowchart showing an example of processing executed by an energy storage device in a modified example. Fig. 10 differs from the processing of steps S100 to S112 shown in Fig. 7 in that steps S120 to S124 are included instead of steps S104 and S110. Therefore, the following description will mainly focus on the processing of steps S120 to S124.

[0057] If it is determined in the process of step S102 that there is a power shortage, the control unit 140 determines the number of sinkers 180 to be dropped onto the seabed according to the amount of power shortage (step S120). For example, the control unit 140 then drops the determined number of sinkers onto the seabed in order to rotate them in the forward direction (step S122). The kinetic energy of the rotating body is converted into electrical energy by the motor 130 to generate power (step S106).

[0058] Furthermore, if it is determined in the processing of step S102 that there is no power shortage, the control unit 140 determines whether at least one weight 180 has fallen (step S124), and if it determines that at least one weight 180 has fallen, it uses surplus power or the like to reverse the rotation of the rotating body and lift up the weight (step S122).

[0059] According to the embodiment described above, the energy storage device 100 includes a support unit 110 that supports the weight 180 so that it can rise and fall with the rotation of the rotor 160, a control unit 140 that raises or lowers the weight 180 in response to a predetermined condition or a predetermined signal, and a motor (an example of a power generator) 130 that generates electricity through the rotation of the rotor 160 when the weight 180 descends. The support unit 110 is located above the water or within a predetermined distance from the water surface so that the weight 180 descends underwater, thereby making it possible to supply electricity while further reducing structural space and costs, which in turn contributes to energy efficiency.

[0060] For example, according to an embodiment, by utilizing the ocean surface or the length of the seabed, it is possible to effectively utilize natural topography to generate power without building vertical structures to secure potential energy. Furthermore, according to an embodiment, a weight and a rotating shaft are installed at an offshore power plant, and the weight is raised using surplus power. When power is insufficient, the weight is dropped into the sea, converting potential energy into rotational energy, which then rotates a generator and converts it into electricity. Furthermore, according to an embodiment, by setting the weight of the weight to the same mass as seawater plus α, it can be moved into the sea at a uniform velocity due to neutral buoyancy, making it easier to maintain a constant rotational speed of the generator. This allows for stable power generation and reduces the load on components such as a speed adjustment unit.

[0061] The above-described embodiment can be expressed as follows. a storage device storing a program; a hardware processor; The hardware processor executes the program, The support portion supports the weight so that the weight can rise and fall in accordance with the rotation of the rotating body; Raising or lowering the weight in response to a predetermined condition or a predetermined signal; generating electricity by the rotation of the rotor when the weight descends; The support portion is provided on the water or at a position within a predetermined distance from the water surface so that the sinker descends in the water. The energy storage device is configured as follows.

[0062] The above describes the form for carrying out the present invention using an embodiment, but the present invention is not limited to such an embodiment, and various modifications and substitutions can be made within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0063] 10...floating body, 100...energy storage device, 110...support unit, 120...speed adjustment unit, 130...motor, 140...control unit, 141...communication unit, 142...memory unit, 143...power generation control unit, 144...adjustment control unit, 145...drive control unit, 160...rotating body, 162...rotating shaft, 170...rope, 180...weight

Claims

1. a support portion that supports the weight so that the weight can rise and fall in accordance with the rotation of the rotating body; a control unit that raises or lowers the weight under a predetermined condition or in response to a predetermined signal; a power generation unit that generates electricity by the rotational movement of the rotor when the weight descends, The support portion is provided on the water surface or within a predetermined distance from the water surface so that the sinker descends in the water, The weight has a space that can be filled with water and an opening that can supply and remove the water, The openings are provided at a plurality of positions including the bottom and top of the weight. Energy storage device.

2. a support portion that supports the weight so that the weight can rise and fall in accordance with the rotation of the rotating body; a control unit that raises or lowers the weight under a predetermined condition or in response to a predetermined signal; a power generation unit that generates electricity by the rotational movement of the rotor when the weight descends, The support portion is provided on the water surface or within a predetermined distance from the water surface so that the sinker descends in the water, a plurality of pairs of the weight and the rotating body; The control unit sequentially lowers one or more of the plurality of spindles to perform power generation control. Energy storage device.

3. The control unit derives the amount of power shortage based on the amount of power demand, and determines the number of sinkers to be lowered into the water from among the plurality of sinkers according to the amount of power shortage.

3. The energy storage device of claim 2.

4. It is installed within a specified distance from wind power generation equipment that generates electricity by rotating propellers due to wind power, It is physically or electrically connected to a part of the configuration used when generating power by the wind power generation facility.

3. The energy storage device of claim 1 or 2.

5. The energy storage device's computer The support portion supports the weight so that the weight can rise and fall in accordance with the rotation of the rotating body; Raising or lowering the weight in response to a predetermined condition or a predetermined signal; generating electricity by the rotation of the rotor when the weight descends; The support portion is provided on the water surface or within a predetermined distance from the water surface so that the sinker descends in the water, The weight has a space that can be filled with water and an opening that can supply and remove the water, The openings are provided at a plurality of positions including the bottom and top of the weight. Energy conservation methods.

6. The energy storage device's computer The support portion supports the weight so that the weight can rise and fall in accordance with the rotation of the rotating body; Raising or lowering the weight in response to a predetermined condition or a predetermined signal; generating electricity by the rotation of the rotor when the weight descends; The support portion is provided on the water surface or within a predetermined distance from the water surface so that the sinker descends in the water, a plurality of pairs of the weight and the rotating body; One or more of the plurality of weights are sequentially lowered to control power generation. Energy conservation methods.

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