Power storage system

Abstract

To provide a power storage system that enables efficient energy utilization in accordance with the usage of electricity generated by renewable energy.SOLUTION: A power storage system includes: a main storage system 110 configured to be capable of navigating a water surface and provided in an electric power generation floating body 10 for generating electric power using renewable energy, where the electric power α obtained by the electric power generation is irreversibly stored in the electric power generation floating body 10; and a sub-storage system 120 in which the electric power obtained by the electric power generation is reversibly stored in the electric power generation floating body 10.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a power storage system that stores power obtained by generating electricity using renewable energy. [Background technology]

[0002] As a power storage system that stores power obtained by power generation using renewable energy, a system in which surplus power obtained by solar power generation is charged and recovered in a storage battery is known (see, for example, Patent Document 1). Also known is a power supply system in which power generated by solar power generation and power generated by fuel cells are supplied as appropriate in addition to power from a grid power supply (see, for example, Patent Document 2). In this power supply system, the power generated by solar power generation and the power generated by fuel cells are charged into a common storage battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-001490 [Patent Document 2] Patent Publication No. 2021-158809 Summary of the Invention [Problem to be solved by the invention]

[0004] However, storage batteries have the disadvantage of self-discharge when stored for long periods of time. Therefore, depending on the intended use of the generated electricity, there are various technical problems, such as the inability to efficiently manage energy using storage batteries alone.

[0005] An object of the present invention is to provide a power storage system that enables efficient energy management according to the use of electricity generated by renewable energy. [Means for solving the problem]

[0006] One form of the present invention provides an electric power storage system that is installed on a power generating float that is configured to be able to navigate on the water surface and generates electricity using renewable energy, and includes a main storage system in which the electricity obtained by the power generation is irreversibly stored in the power generating float, and a sub-storage system in which the electricity obtained by the power generation is reversibly stored in the power generating float. [Effects of the Invention]

[0007] A power storage system according to one embodiment of the present invention includes two storage systems, a main storage system and a sub-storage system, depending on the use of electricity generated by renewable energy, enabling efficient energy management. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of a power-generating float. [Figure 2] FIG. 2 is a schematic configuration diagram of the storage unit shown in FIG. 1. [Figure 3] FIG. 2 is an explanatory diagram showing an example of the flow of power in a power-generating float. [Figure 4] 10 is a flowchart showing an example of the flow of a distribution adjustment process. DETAILED DESCRIPTION OF THE INVENTION

[0009] The power storage system according to the present invention is provided on a power-generating float that is configured to be navigable on the water surface and generates power using renewable energy. In this embodiment, as an example, a case will be described in which the power storage system according to the present invention is provided on a power-generating float 10 shown in Fig. 1.

[0010] (Configuration of the power generating float 10) First, the power-generating float 10 in this embodiment will be described. The power-generating float 10 may be, for example, a sailing-type float that can navigate rivers, lakes, the sea, etc. In this embodiment, the power-generating float 10 is described as a sailing-type float that navigates the sea. The power-generating float 10 has, for example, a hull 11 that floats on the water surface, and may further have, for example, a storage unit 100, a power generation unit 130, a navigation unit 140, and a control unit 150. The power-generating float 10 may further have a communication unit (not shown) that enables wireless communication with the outside.

[0011] The power generation unit 130 may include multiple elements used for wind power generation. For example, the power generation unit 130 may be configured to generate wind power using kites 131 connected to the hull 11 via tethers 132. As shown in FIG. 1 , the power generation unit 130 may include a winch 133 and a generator 134 in addition to the tethers 132 and kites 131. The winch 133 has a rotating shaft 133a as its rotation axis, and the rotating shaft 133a is connected to the rotating shaft of the generator 134. The tether 132 is wound around the rotating shaft 133a. When the kites 131 rise, the tether 132 is unwound from the winch 133 in conjunction with this rise. This unwinding action of the tether 132 rotates the rotating shaft 133a. The rotating shaft of the generator 134 rotates in conjunction with the rotation of the kites 131 as they rise, thereby generating power. When the rotating shaft 133a rotates in a direction to reel in the tether 132, the tether 132 is retrieved and the kite 131 descends. When the tether 132 is retrieved, the generator 134 may rotate the rotating shaft 133a based on a command from the control unit 150.

[0012] The navigation unit 140 may include multiple elements for sailing the power-generating float 10 on the sea. The navigation unit 140 may be configured to be capable of sailing (i.e., sailing) on ​​the sea using wind energy received by a sail 141 as a power source. In addition to the sail 141, the navigation unit 140 may be provided with, for example, a rudder 142 for determining the direction of the hull 11 and a centerboard 143 for generating lateral force. Furthermore, the power-generating float 10 may include, for example, a propeller 145 and a motor 144 as a power source as the navigation unit 140 so that it can be moved by electric power in addition to movement by wind power. For example, the motor 144 may be driven by electric power generated by the power generation unit 130. Furthermore, the navigation unit 140 may include sensors necessary for navigation on the sea. The sensors may include, for example, a wind direction and speed sensor, a wind volume sensor, an acceleration sensor, an angular velocity sensor, and a speed sensor.

[0013] The control unit 150 controls various processes in the power-generating float 10. The control unit 150 may be configured as a control unit including, for example, a CPU (Central Processing Unit), a storage device and an input / output interface required for the CPU's operation. The storage device may include, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), and a data storage. The control unit 150 may be connected to each of the units 100, 130, and 140 via, for example, an input / output interface and a data bus. The control unit 150 may issue control instructions to each of the units 100, 130, and 140 via, for example, the data bus. The control unit 150 may acquire various information from each of the units 100, 130, and 140 via, for example, the data bus.

[0014] The ROM may store, for example, a computer program for implementing processing in the control unit 150. The control unit 150 may load a computer program stored in the ROM or a data storage. Alternatively, the control unit 150 may acquire (i.e., download) a computer program from a device (not shown) arranged outside the power-generating float 10 via a communication unit (not shown), and load the acquired computer program. The control unit 150 executes the loaded computer program. As a result, logical function blocks for controlling the operation of the power-generating float 10 are implemented within the control unit 150. FIG. 1 shows an example of logical function blocks implemented within the control unit 150. In the example shown in FIG. 1, a power adjustment unit 151 is implemented within the control unit 150. The operation of the power adjustment unit 151 will be described in detail below.

[0015] (Storage unit configuration) The storage unit 100 is a unit configured to store power generated by a power generation unit 130. The storage unit 100 of this embodiment may include, for example, a power distribution device 101, a main storage system 110, and a sub-storage system 120. Each element of the storage unit 100 will be described with reference to FIG. 2.

[0016] The power distribution device 101 distributes and outputs the power generated by the power generation unit 130 to each of the main storage system 110 and the sub-storage system 120. The power distribution device 101 may be configured, for example, to distribute and output the input power using a known method in accordance with control instructions from a power adjustment unit 151, which will be described later.

[0017] The main storage system 110 is a system configured to store the electricity generated by the power generation units 130 for transport from the power generating float 10 to an external location (e.g., a demand area, etc.). The sub-storage system 120 is a system configured to store the electricity generated by the power generation units 130 for use within the power generating float 10. The electricity used within the power generating float 10 may be, for example, the electricity required for the operation of the power generating float itself. Details of the operation of the power generating float itself will be described later. The main storage system 110 may employ a power storage method that requires larger-scale equipment for storing electricity and more processing steps than the sub-storage system 120. The configurations of the main storage system 110 and the sub-storage system 120 will be described below.

[0018] (Main storage system configuration) The main storage system 110 will now be described. The main storage system 110 is configured to store power in a manner suitable for long-distance mass transportation. For example, a method with high energy density may be adopted as a method for storing power in the main storage system 110. For example, a CO2-free hydrogen carrier (including hydrogen itself and hydrogen compounds) may be adopted as a method for storing power in the main storage system 110. The hydrogen carrier adopted in the main storage system 110 may be, for example, any of compressed hydrogen, liquefied hydrogen, hydrogen storage alloys, ammonia, methylcyclohexane, etc. In this embodiment, a case where a hydrogen storage alloy is adopted as a method for storing power will be described.

[0019] 2, the main storage system 110 of this embodiment may include, for example, a main power input unit 111, a hydrogen carrier generation unit 112, and a main storage 113. The main power input unit 111 functions as an interface of the main storage system 110 for the power generated by the power generation unit 130. That is, the power generated by the power generation unit 130 is input to the main storage system 110 via the main power input unit 111.

[0020] The hydrogen carrier generation unit 112 may include, for example, a water separator and a water electrolysis system. The water separator may be, for example, a device that separates water from seawater or the like. If water can be prepared separately, the water separator may be omitted. The water electrolysis system may be configured, for example, to generate hydrogen by electrolyzing water separated by the water separator using generated electricity.

[0021] The hydrogen carrier generation unit 112 may include various devices necessary for generating the hydrogen carrier, depending on the hydrogen carrier used. For example, if the hydrogen carrier is compressed hydrogen, the hydrogen carrier generation unit 112 may include a compressor for compressing the hydrogen. For example, if the hydrogen carrier is liquefied hydrogen, the hydrogen carrier generation unit 112 may include a compressor for compressing the hydrogen and a liquefaction unit for liquefying the compressed hydrogen. For example, if the hydrogen carrier is methylcyclohexane, the hydrogen carrier generation unit 112 may include a reactor for hydrogenating toluene and a reaction environment maintenance unit for maintaining the reaction temperature and reaction pressure. For example, if the hydrogen carrier is ammonia, the hydrogen carrier generation unit 112 may include an air separation unit for obtaining nitrogen from the air, a reactor for reacting nitrogen with hydrogen, and a reaction environment maintenance unit for maintaining the reaction temperature and reaction pressure. The main storage system 110 may include various devices necessary for storing the hydrogen carrier, depending on the hydrogen carrier used. For example, if the hydrogen carrier is liquefied hydrogen, the main storage 113 may include a cooling device for cooling the main storage 113 in which the liquefied hydrogen is stored.

[0022] The main storage 113 may be composed of, for example, at least one hydrogen storage alloy tank. In the main storage 113, hydrogen generated in the hydrogen carrier generation unit 112 is stored in the hydrogen storage alloy tank. The main storage system 110 may have an electricity storage sensor (not shown) that detects the amount of electricity stored in the main storage 113 (i.e., the amount of electricity stored).

[0023] The main storage system 110 has a main power input section for inputting electric power, but does not have an output section for outputting electric power or hydrogen. In this way, the main storage system 110 is configured so that the electric power generated by the power generation units 130 is stored in the main storage 113 irreversibly with respect to the power-generating float 10. In other words, the main storage 113 is a storage in which the electric power generated by the power generation units 130 is stored irreversibly with respect to the power-generating float 10.

[0024] (Sub-storage system configuration) Next, the sub-storage system 120 will be described. As described above, the sub-storage system 120 is configured to store the power required for its own operation. The power required for its own operation may include the power required for the operation of each of the units 100, 130, 140, and 150. The operation of the storage unit 100 may include, for example, the operation of the main storage system 110 (such as the operation of the hydrogen carrier generation section 112 and the operation of the main storage 113). The operation of the storage unit 100 may also include, for example, the operation of the sub-storage system 120. The operation of the power generation unit 130 may include, for example, the operation of the winch 133 and the operation of the kite 131. The operation of the navigation unit 140 may include, for example, the operation of the sail 141, the operation of the rudder 142, the operation of the motor 144, and the operation of the propeller 145. The operation of the control unit 150 may include, for example, inputting and outputting information to and from a storage device, various calculations to control the operation of each unit 100, 130, 140, and sending and receiving information (including control instructions) to and from each unit 100, 130, 140.

[0025] 2, the sub-storage system 120 of this embodiment may have, for example, a sub-power input unit 121, a sub-storage 122, and a sub-power output unit 123. The sub-power input unit 121 functions as an interface of the sub-storage system 120 for the power generated by the power generation unit 130. In other words, the power generated by the power generation unit 130 is input to the sub-storage system 120 via the sub-power input unit 121.

[0026] The sub-storage 122 stores the power input via the sub-power input unit 121. The sub-storage 122 may employ a power storage method that allows the stored power to be stored in a manner that makes it immediately (or simply) usable. For example, a repeatedly chargeable and dischargeable storage battery may be employed as the sub-storage 122. The sub-storage system 120 may have a power storage sensor (not shown) that detects the amount of power stored in the sub-storage 122 (i.e., the amount of power storage). Note that, since the sub-storage 122 only needs to secure the amount of power necessary for its own operation, the power storage capacity of the sub-storage system 120 may be significantly smaller than the power storage capacity of the main storage system 110, in which power is stored for transportation. In other words, the power storage capacity of the main storage system 110 may be significantly larger than the power storage capacity of the sub-storage system 120.

[0027] The sub-power output unit 123 is an output unit that outputs the power stored in the sub-storage system 120 to each element of the power-generating float 10. That is, the power stored in the sub-storage system 120 is output to each element of the power-generating float 10 via the sub-power output unit 123. The sub-storage system 120 may be configured to output power in response to a control instruction from the control unit 150, for example.

[0028] The sub-storage system 120 has a sub-power input section to which power is input, as well as a sub-power output section to which power is output. In this way, the sub-storage system 120 is configured so that the power generated by the power generation units 130 is stored in the sub-storage 122 reversibly with respect to the power-generating float 10. In other words, the sub-storage 122 is a storage in which the power generated by the power generation units 130 is stored reversibly with respect to the power-generating float 10.

[0029] (Power flow in a power generating float) Here, the flow of power generated by the power generating unit 130 will be described with reference to FIG. 3. The power α generated by the power generating unit 130 is distributed between the main storage system 110 and the sub-storage system 120 by the power distribution device 101. The power α may be adjusted, for example, by a control instruction ω from the power adjustment unit 151 of the control unit 150 to the power distribution device 101. The processing performed by the power adjustment unit 151 will be described later. The sub-storage system 120 may output stored power, for example, in accordance with a control instruction ψ from the control unit 150. The control instruction ψ may indicate, for example, the output destination and output amount of power. The power β output from the sub-storage system 120 in accordance with the control instruction ψ may be output to each element of the units 100, 130, 140, 150 of the power-generating float 10 based on the control instruction ψ. The power β may be output to, for example, each element of the storage unit 100, each element of the power generation unit 130, each element of the navigation unit 140, or each element of the control unit 150 in accordance with the control instruction ψ.

[0030] (Allocation adjustment processing) As described above, the power α generated by the power generation unit 130 is distributed between the main storage system 110 and the sub-storage system 120. The power adjustment unit 151 may perform, for example, a distribution adjustment process to adjust the distribution between the main storage system 110 and the sub-storage system 120 (hereinafter referred to as "storage distribution"). Figure 4 shows an example of the distribution adjustment process. The distribution adjustment process may be performed repeatedly, for example. The distribution adjustment process may be performed in response to a predetermined trigger, for example.

[0031] In the distribution adjustment process, first, the power adjusting unit 151 may predict the expected power demand in the power generating float 10 (step S200). The expected power demand may be, for example, the amount of power required to operate the power generating float 10. The power adjusting unit 151 may predict, for example, the expected power demand of each unit 100, 130, 140, and 150 as the expected power demand. The power adjusting unit 151 may predict the expected power demand based on various information. The various information may include, for example, various sensor information obtained from various sensors provided in the power generating float 10. The various information may also include sea condition information and wind condition information obtained from a predetermined source via a communication unit (not shown). Next, the power adjusting unit 151 may acquire the amount of stored power in the sub-storage 122 (step S210). The power adjusting unit 151 may acquire, for example, power storage information obtained from a power storage sensor (not shown) in the sub-storage system 120. The power storage information may include the amount of stored power and / or the power storage rate. For example, the power adjustment unit 151 may consider the energy loss from the time when the power stored in the sub-storage 122 is supplied to the power consumer as the amount of stored power in the sub-storage 122.

[0032] Next, the power adjusting unit 151 may perform an allocation determination process (step S220). In the allocation determination process, the power adjusting unit 151 may, for example, determine storage allocation based on the predicted expected power demand. The power adjusting unit 151 may, for example, determine storage allocation so that the amount of power stored in the sub-storage 122 ensures the expected power demand. The power adjusting unit 151 may, for example, determine the difference between the amount of power stored in the sub-storage 122 and the expected power demand as the amount of power to be supplied to the sub-storage system 120. The power adjusting unit 151 may, for example, determine storage allocation so that power in excess of the amount of power supplied to the sub-storage system 120 is supplied to the main storage system 110. For example, if the amount of power stored in the sub-storage 122 exceeds the expected power demand, the power adjusting unit 151 may determine the storage allocation to the sub-storage system 120 to be zero.

[0033] After the allocation determination process, the power adjustment unit 151 may proceed to control instruction process (step S250). In the control instruction process, the power adjustment unit 151 may issue a control instruction ω so that the power α is allocated according to the storage allocation determined by the allocation determination process, for example.

[0034] The power storage system according to the present invention is realized by the storage unit 100 and the power adjustment unit 151.

[0035] (Other forms) The sub-storage system 120 may use compressed hydrogen as a method for storing power. When the main storage system 110 also uses a hydrogen carrier, the hydrogen carrier generation unit 112 may be shared between the sub-storage system 120 and the main storage system 110. The sub-storage 122 may be composed of, for example, at least one compressed hydrogen cylinder. The sub-storage system 120 may be equipped with a fuel cell that generates power using the stored compressed hydrogen. The sub-storage system 120 may further be equipped with, for example, a hydrogen compressor that compresses hydrogen, a dispenser that supplies hydrogen to the fuel cell, and the like. When compressed hydrogen is used to store power in the sub-storage system 120, it is desirable that the main storage system 110 be a larger system than the sub-storage system 120. When compressed hydrogen is used to store power in the sub-storage system 120, the main storage system 110 may use, as a hydrogen carrier, any of a hydrogen storage alloy, methylcyclohexane, ammonia, and liquefied hydrogen.

[0036] Additional notes The following additional notes are provided regarding the above-described embodiment.

[0037] [Appendix 1] The power storage system described in Appendix 1 is installed on a power-generating float that is configured to be able to navigate on the water surface and generates electricity using renewable energy, and comprises a main storage system in which the electricity obtained by the power generation is irreversibly stored in the power-generating float, and a sub-storage system in which the electricity obtained by the power generation is reversibly stored in the power-generating float.

[0038] According to the power storage system described in Appendix 1, two types of storage systems, a main storage system and a sub-storage system, are provided in the power-generating float. These two types of storage systems differ in the storage state of the generated power. The storage state of power in the main storage system is irreversible with respect to the power-generating float. Therefore, it is suitable for storing power that is not used by the power-generating float. On the other hand, the storage state of power in the sub-storage system is reversible with respect to the power-generating float. Therefore, it is suitable for storing power that is used by the power-generating float. In this way, the power storage system described in Appendix 1 can store power in a storage state that suits the application.

[0039] [Appendix 2] The power storage system according to claim 1, wherein the power storage capacity of the main storage system is greater than the power storage capacity of the sub-storage system.

[0040] The power storage system described in Appendix 2 allows a larger amount of power to be stored in the main storage system than in the sub-storage system. This allows for a larger amount of power to be supplied to external demand areas. Furthermore, the sub-storage system can be configured more compactly than the main storage system.

[0041] [Appendix 3] The power storage system described in Appendix 3 is a power storage system described in Appendix 1 or 2, further comprising a power adjustment unit that adjusts the distribution of the power obtained by the power generation between the amount of power stored in the sub-storage system and the amount of power stored in the main storage system.

[0042] The power storage system described in Appendix 3 allows the allocation of power between the main storage and the sub-storage to be adjusted based on various situations and conditions, rather than being uniform.

[0043] [Appendix 4] The power storage system described in Appendix 4 is the power storage system described in Appendix 3, wherein the power adjustment unit predicts the expected power demand to be used for the local base operation and adjusts the distribution so that the amount of power of the sub-storage system ensures the expected amount of power.

[0044] According to the power storage system described in Appendix 4, the expected power demand according to the operating status of the power-generating float (for example, navigation status, power generation status, etc.) is predicted and secured. Therefore, it is possible to adjust the power distribution between the main storage system and the sub-storage system so as not to interfere with the operation of the power-generating float.

[0045] [Appendix 5] The power storage system described in Appendix 5 includes a hydrogen carrier generation unit that generates hydrogen carriers from electricity obtained from the power generation, and in the main storage system, the power is stored as the hydrogen carriers, and in the sub-storage system, the power is stored in a storage battery. The power storage system described in any one of Appendixes 1 to 4.

[0046] According to the power storage system described in Appendix 5, power is stored as a hydrogen carrier in the main storage system. Hydrogen based on the stored hydrogen carrier is used as power, for example, via a fuel cell in a demand area. In this way, the power storage system described in Appendix 5 can contribute to the realization of a decarbonized society.

[0047] The present invention can be modified as appropriate within the scope of the claims and the entire specification without departing from the gist or concept of the invention, and power storage systems incorporating such modifications are also included in the technical concept of the present invention. [Explanation of symbols]

[0048] 10 Power-generating Floating Structure 110 Main Storage System 120 Sub-storage System 130 power generating units 140 Navigation Unit 151 Power adjustment section

Claims

1. The power generating float is configured to be navigable on the water surface and generates electricity using renewable energy. a main storage system in which the power generated by the power generation is irreversibly stored in the power-generating float; a sub-storage system in which the power generated by the power generation is reversibly stored in the power-generating float; A power storage system comprising:

2. The power storage system according to claim 2 , wherein the power storage capacity of the main storage system is greater than the power storage capacity of the sub-storage system.

3. The power storage system according to claim 1 or 2, further comprising a power adjustment unit that adjusts the distribution of the power obtained by the power generation between the amount of power stored in the sub-storage system and the amount of power stored in the main storage system.

4. 4. The power storage system according to claim 3, wherein the power adjustment unit predicts an expected power demand to be used for the local base operation and adjusts the distribution so that the amount of power of the sub-storage system ensures the expected amount of power.

5. a hydrogen carrier generating unit that generates hydrogen carriers from the electricity obtained from the power generation; In the main storage system, the electricity is stored as the hydrogen carrier, 5. The power storage system according to claim 1, wherein in the sub-storage system, the power is stored in a storage battery.

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