A method for transferring energy storage media between a power generation float and a transport ship in an offshore power generation system.

Abstract

In an offshore power generation system, the transfer of energy storage media 3a and 3b generated by the power generation floating body 10 between the power generation floating body and the transport ship 20 can be achieved using power generation floating bodies and transport ships of any size and shape. [Solution] A method for transferring a storage medium at sea between a power generation floating body that generates electricity at sea and stores the energy obtained from that power generation in a storage medium and a transport ship that transports the storage medium includes: a first step of moving the power generation floating body to a predetermined sea area 300 and dropping a first storage medium loaded on the power generation floating body into the sea; a second step of moving the transport ship to a predetermined sea area and dropping a second storage medium loaded on the transport ship into the sea; a third step of having the power generation floating body recover the second storage medium dropped into the sea from the transport ship; and a fourth step of having the transport ship recover the first storage medium dropped into the sea from the power generation floating body.

Description

Technical Field

[0001] The present invention relates to a method for transferring an energy storage medium obtained from a floating body (power generation floating body) such as a ship equipped with an offshore generator in an offshore power generation system between an offshore transport ship and the power generation floating body at sea.

Background Art

[0002] As one of the methods for obtaining renewable energy, offshore wind power generation has attracted attention. Offshore, there are few restrictions on land and roads, and it is expected that the wind will blow steadily in the same direction and with the same intensity, and the advantage of wind power generation that can generate electricity stably even at night will be advantageously utilized. For this reason, various technologies related to offshore wind power generation have been proposed. For example, in Patent Document 1, in an offshore energy collection system including a plurality of floating power generation devices and a platform separated from these plurality of floating power generation devices, the floating power generation device includes a microwave power transmission unit that transmits the generated power while floating at sea by microwave, the platform includes a microwave power reception unit that receives the microwave transmitted from the microwave power transmission unit of the floating power generation device, the microwave power transmission unit and the microwave power reception unit have an array antenna in which a plurality of element antennas are arranged, the microwave power transmission unit transmits the generated power to the microwave power reception unit in a retro-directive operation, and the microwave power reception unit receives coherent microwaves having the same frequency and phase from a plurality of floating power generation devices. Such a configuration has been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Offshore power generation systems that utilize wind and tidal energy include bottom-fixed systems (systems that fix the generator to the seabed) which are installed in shallow waters relatively close to land, and floating systems (systems that install the generator on a floating structure such as a ship) which can be deployed in deeper waters. Of these systems, floating systems have the advantage of being able to move the power generation float to a sea area with stronger wind or tidal forces where power generation is more efficient, thereby enabling efficient energy recovery. However, regarding the delivery of energy obtained from offshore power generation to the point of consumption, unlike bottom-fixed systems, it is extremely difficult to lay power transmission cables from the floating system to land, and it may also be difficult to transmit power by microwave as described in Patent Document 1 (the transmission distance may be too long). Therefore, in the case of a floating system, the electrical energy generated by the power-generating float is either used to charge a battery, or the electrical energy is converted into the chemical energy contained in the hydrogen gas produced through a water splitting reaction induced by that energy. This hydrogen gas, or liquid hydrogen obtained by liquefying it, is then stored in a tank. The energy is stored in a storage medium (battery, hydrogen tank) loaded onto the power-generating float, and a transport ship is sent to the area where the power-generating float is located as needed. The energy-stored medium is then transferred from the power-generating float to the transport ship, and the medium to be used for energy storage is transferred from the transport ship to the power-generating float. This method has the advantage of allowing the storage medium to be recovered without moving the power-generating float too far from the area where the power generation takes place at sea, thus allowing for a longer power generation time on the power-generating float.

[0005] Regarding the transfer of storage media between a power generation float and a transport ship at sea as described above, the power generation float and the transport ship may have various sizes and shapes. If the transfer of media is possible regardless of the size and shape of the vessel, it would be advantageous as it would allow the use of power generation floats and transport ships of any size and shape. In this regard, for example, if the storage media is transferred by directly connecting the power generation float and the transport ship, there will be constraints on the size and shape of both the power generation float and the transport ship.

[0006] In light of the above circumstances, the main objective of the present invention is to enable the transfer of a storage medium for energy generated by a power-generating floating body between the power-generating floating body and a transport ship in an offshore power generation system, using power-generating floating bodies and transport ships of any size and shape. [Means for solving the problem]

[0007] According to the present invention, the above problem is solved by a method for transferring a storage medium at sea between a floating power generation vessel that generates electricity at sea and stores the energy obtained from that power generation in a storage medium, and a transport vessel that transports the storage medium. The first step involves moving the power generation float to a predetermined sea area and dropping the first storage medium, which was loaded onto the power generation float, into the ocean. A second step involves moving the transport vessel to the predetermined sea area and dropping the second storage medium, which was loaded onto the transport vessel, into the ocean. A third step involves causing the power generation float to recover the second storage medium that was dropped into the ocean from the transport ship, A fourth step involves having the transport ship recover the first storage medium that was dropped into the ocean from the power generation float. This is achieved by a method that includes [a specific method].

[0008] In the above configuration, the "power generation float" may typically be an offshore float equipped with any type of wind power generation system, which may be a kite-type power generation system, or any other power generation system that operates offshore. The "storage medium" is loaded onto the power generation float and stores the energy obtained from power generation in any form. Specifically, the "storage medium" may be a battery that directly charges electrical energy, or it may be a tank that stores hydrogen gas produced by a water splitting reaction using the electrical energy obtained from power generation, or liquid hydrogen obtained by liquefying it. On the power generation float, multiple storage mediums are loaded at appropriately configured loading locations, and during power generation, the power generation system mounted on the power generation float may be configured to sequentially charge the batteries, which are the storage mediums, with the generated electricity, or to sequentially store the hydrogen gas or liquefied hydrogen produced using the generated energy into the tanks, which are the storage mediums. The transport vessel may be any type of vessel capable of transporting the storage mediums. "The first storage medium" is typically a storage medium in which energy generated by a power generation floating body has been stored, and "the second storage medium" is typically a storage medium that is capable of storing energy or is empty. "The designated sea area" may be a suitably defined sea area where the transfer of the storage medium between the power generation medium and the transport vessel is possible.

[0009] According to the above configuration, in the first process, the power generation float is moved to a predetermined sea area, and the first storage medium loaded on the power generation float is dropped into the ocean; in the second process, the transport ship is moved to a predetermined sea area, and the second storage medium loaded on the transport ship is dropped into the ocean; in the third process, the second storage medium dropped into the ocean from the transport ship is recovered by the power generation float; and in the fourth process, the first storage medium dropped into the ocean from the power generation float is recovered by the transport ship. This makes it possible to transfer the storage medium between the power generation float and the transport ship, that is, to transfer the energy-stored medium from the power generation float to the transport ship, and to transfer the medium to be stored in energy from the transport ship to the power generation float, without directly docking the power generation float and the transport ship. Thus, the transfer of storage medium between power generation floats and transport ships of any size and shape can be achieved.

[0010] In the above configuration, it is preferable that within a predetermined sea area, there is a region where the first storage medium is dropped from the power generation float and a region where the second storage medium is dropped from the transport ship, so that the transport ship and the power generation float can selectively recover the first storage medium and the second storage medium, respectively. Therefore, the method of the present invention described above may preferably be configured such that, in the first step, the power generation float is moved to the first region within the predetermined sea area and the first storage medium is dropped; in the second step, the transport ship is moved to the second region and the second storage medium is dropped; in the third step, the power generation float is moved to the second region and the second storage medium is recovered into the power generation float; and in the fourth step, the transport ship is moved to the first region and the first storage medium is recovered into the transport ship.

[0011] Furthermore, in the above configuration, the first and second storage media, which are dropped into the ocean, can be easily recovered by the transport ship and the power generation float if they remain near the sea surface. Therefore, the first and second storage media may be configured to float on the ocean surface.

[0012] As described above, the recovery of the first and second storage media dropped into the ocean can be achieved by any method. In this regard, for example, as described in Patent Document 2, a method of deploying a large net into the ocean and scooping up the storage media from the ocean is possible, but in order to make the means for recovery more compact, in one embodiment, hooks may be provided on the first and second storage media, and the power generation float and the transport ship may each extend arms having engaging means to engage with the hooks into the ocean, and then shorten the arms to pull the first and second storage media towards the power generation float and the transport ship for recovery.

[0013] It is preferable that the recovery of the first and second storage media dropped into the ocean be achieved automatically or unmanned. Therefore, the power generation float and the transport ship may each have detection means for detecting the second and first storage media in the ocean, and may be configured to automatically recover the second and first storage media by identifying their locations using such detection means. In an embodiment, the storage media may be provided with means for emitting specific radio waves, light, etc., or means for reflecting specific radio waves, light, etc., emitted from the transport ship and power generation float, and the detection means on the transport ship and power generation float may detect the radio waves, light, etc., from the storage media, and means for recovering the storage media, such as an arm having an engagement means that engages with a hook on the storage media, is extended to the detected location of the radio waves, light, etc., the engagement means engages with the hook on the storage media, and then the arm is shortened to pull the storage media towards the power generation float and transport ship for recovery. [Effects of the Invention]

[0014] Thus, according to the method of the present invention, there are no restrictions on the size and shape of the power generation float and the transport ship when transferring the energy storage medium between them in an offshore power generation system, so power generation floats and transport ships of any size and shape can be used. In this regard, the transport ship and the power generation float do not need to be in close proximity, so the transfer of the storage medium can be carried out in various sea conditions. Furthermore, if a predetermined sea area is set, for example, at the edge of the power generation area of ​​the power generation float, it becomes unnecessary to move the power generation float far away from the power generation area for the transfer of the storage medium, improving the operating rate for power generation and thereby reducing costs.

[0015] Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention. [Brief explanation of the drawing]

[0016] [Figure 1]Fig. 1(A) is a schematic diagram of a power generation floating body used in an offshore wind power generation system to which the present embodiment is applied. Fig. 1(B) is a schematic perspective view of a storage medium used for energy storage in the power generation floating body. [Figure 2] Fig. 2 is a diagram for explaining the outline of the method of the present embodiment. [Figure 3] Figs. 3(A) and (B) are diagrams for explaining the process of transferring the storage medium between the power generation floating body and the transport ship according to the method of the present embodiment. (A) is the process of moving the power generation floating body to the first area of the storage medium transfer sea area and moving the transport ship to the second area of the storage medium transfer sea area, and (B) is the process of dropping the first storage medium from the power generation floating body and dropping the second storage medium from the transport ship. [Figure 4] Figs. 4(A) and (B) are diagrams for explaining the process of transferring the storage medium between the power generation floating body and the transport ship according to the method of the present embodiment. (A) is the process of recovering the second storage medium to the power generation floating body, and (B) is the process of recovering the first storage medium to the transport ship. [Figure 5] Figs. 5(A) to (E) are schematic diagrams sequentially showing the process of recovering the storage medium to the power generation floating body and the transport ship in one aspect of the method of the present embodiment. [Figure 6] Figs. 6(A) to (B) are schematic diagrams sequentially showing the process of recovering the storage medium to the power generation floating body and the transport ship in another aspect of the method of the present embodiment.

Explanation of Reference Numerals

[0017] 3... Storage medium, 3a... Energy-stored storage medium, 3b... Energy-storable or empty storage medium, 4... Frame of storage medium, 5... Main body of storage medium, 6... Float bag, 7... Hook, 8... Marker means (such as light-emitting means), 9... Detection means, 10... Power generation floating body, 10a... Floating body main body, 10b... Sail, 10c... Power generation kite, 11... Movement route of power generation floating body, 20... Transport ship, 30... Arm, 31... Engaging means, 32... Float bag, 100... Port, 101... Route of transport ship, 200... Power generation sea area, 300... Storage medium transfer sea area, 300b... First area, 300a... Second area

Best Mode for Carrying Out the Invention

[0018] The present invention will be described in detail below with reference to the attached drawings for several preferred embodiments. In the drawings, the same reference numerals denote the same parts.

[0019] Configuration of power generation float and storage medium The method according to this embodiment is applied to the offshore transfer of an energy storage medium between a transport ship and a power generation floating body in an offshore power generation system. The offshore power generation system may be, in particular, any form of wind power generation system or other power generation system (such as a system utilizing tidal current or tidal power) executed offshore. In such a system, the power generation floating body is configured to move to an area where power generation can be better performed offshore, execute power generation, and store the obtained energy in a storage medium in any manner. As the power generation floating body, for example, a floating body 10 having a driving sail 10b and the like on a floating body main body 10a floating offshore as schematically depicted in FIG. 1(A), equipped with a kite-type generator 10c, and having the energy obtained from power generation appropriately loaded onto a storage medium (not shown) in the main body 10a may be adopted.

[0020] As the energy storage method, as already mentioned in the summary section of the invention, the electrical energy obtained from power generation is converted into hydrogen energy (chemical energy possessed by hydrogen molecules) by generating hydrogen gas through a water decomposition reaction, and the hydrogen gas holding the energy is compressed or liquefied and accumulated in a tank, whereby the energy may be stored. In this case, the storage medium is a hydrogen tank. Alternatively, in another aspect, the obtained electrical energy may be stored by charging a battery. In this case, the storage medium is a battery.

[0021] In the method according to this embodiment, the storage medium is dropped into the ocean from the power generation float and the transport ship, respectively, as already mentioned in the section on the summary of the invention, and is then recovered by the transport ship and the power generation float. Preferably, the storage medium is configured to float on the water surface in order to facilitate recovery at sea. Specifically, as schematically depicted in Figure 1(B), the storage medium 3 has a configuration in which a main body 5, which may be a hydrogen tank or a battery, is housed in a frame 4 of any shape, and a float bag or other buoyancy device 6 may be attached around the frame 4 to float the storage medium 3 on the water surface. In addition, the outer surface of the storage medium 3 is provided with a hook 7 for engaging with an arm, etc., that pulls the storage medium 3 to the transport ship and the power generation float at sea, as described later, and a marker means 8 such as a light emitter or oscillator may be provided for the purpose of detecting the position of the storage medium 3 on the water surface from the transport ship and the power generation float. Furthermore, the storage medium 3 may be placed in any manner on the transport ship and on the power generation floating body.

[0022] Transfer of storage media (1) Overview In this embodiment, as described in the summary of the invention, the transfer of a storage medium (energy-storage medium) containing energy generated by the power-generating floating body from the power-generating floating body to the transport ship, and the transfer of a storage medium (energy-storage-capable or empty storage medium) for storing energy to be generated by the power-generating floating body from the transport ship to the power-generating floating body, are carried out in a predetermined area of ​​the ocean by the power-generating floating body and the transport ship each dropping the storage medium, after which the power-generating floating body retrieves the storage medium dropped by the transport ship, and the transport ship retrieves the storage medium dropped by the power-generating floating body.

[0023] More specifically, in a typical offshore power generation system, as schematically depicted in Figure 2, multiple power generation floats 10 operate by circulating along a predetermined course 11 appropriately set in a sea area 200 suitable for power generation, generating electricity and storing the obtained energy in storage media loaded thereon. Thus, the storage media in which energy has been stored in each power generation float 10 needs to be transported to a port 100 where a storage media collection base is located closer to the energy consumption site, and energy-storable or empty storage media needs to be loaded onto each power generation float 10. However, having each power generation float 10 call at port 100 for this purpose shortens the power generation period on the float by the amount of time required, making it inefficient. Therefore, in this embodiment, as shown in the figure, the transport ship 20 is sent from the port 100 to the sea area 300 on the periphery of the sea area 200 where the power generation floating body 10 circulates, and in the open sea of ​​that area, an exchange of energy-stored storage medium and energy-storable or empty storage medium is carried out between the power generation floating body 10 and the transport ship 20. This extends the period during which the power generation floating body 10 stays in the sea area 200, resulting in a longer power generation period.

[0024] Furthermore, as described above, if the transport ship 20 is sent to the sea area 300 and the storage medium is exchanged with the power generation floating body 10 there, directly connecting the power generation floating body 10 and the transport ship 20 would impose structural constraints on the power generation floating body 10 and the transport ship 20, which would make it impossible to use power generation floating bodies 10 and transport ships 20 of arbitrary size and shape. Therefore, in this embodiment, as described above, at the sea area 300 reached by the transport ship 20, the power generation floating body 10 and the transport ship 20 each drop their storage medium into the ocean, and the power generation floating body 10 retrieves the storage medium dropped by the transport ship 20, and the transport ship 20 retrieves the storage medium dropped by the power generation floating body 10, thereby enabling the exchange of storage medium at sea regardless of the size or shape of the power generation floating body 10 and the transport ship 20.

[0025] In the above configuration, the power generation floating body 10 may be, for example, a 300-ton class vessel. The transport ship 20 may be, for example, a 2000-ton class vessel capable of transporting approximately 100 10-ton class storage media.

[0026] (2) The process of transferring storage media The transfer of the storage medium at sea between the power generation floating body 10 and the transport ship 20 may be carried out as follows:

[0027] First, as shown in Figure 3(A), each of the power generation media 10 loaded with energy-storage media 3a is moved to the first area 300b within the sea area 300, while the transport ship 20 loaded with energy-storage-capable or empty storage media 3b is moved to the second area 300a within the sea area 300. Then, as shown in Figure 3(B), the storage media 3a is dropped from the power generation media 10 onto the water surface in the first area 300b, and the storage media 3b is dropped from the transport ship 20 onto the water surface in the second area 300a. The method of dropping can be carried out in any manner. As already mentioned, the storage media 3a and 3b are configured to float on the water surface, and therefore, the dropped storage media 3a and 3b remain on the water surface.

[0028] Subsequently, as shown in Figure 4(A), the power generation medium 10 moves to the second area 300a, where it retrieves and loads the storage medium 3b dropped from the transport ship 20, and the transport ship 20 then proceeds to the first area 300b. Then, as shown in Figure 4(B), the power generation medium 10 moves through the sea area 200 along a predetermined course 11, while the transport ship 20 moves through the first area 300b, retrieving the storage medium 3a dropped by the power generation medium 10, and returns to port 100.

[0029] According to the above configuration, the storage medium 3a dropped by the power generation medium 10 and the storage medium 3b dropped by the transport ship 20 will float in separate regions, making it easy to recover each of them. The first region 300b and the second region 300a may be set near the turning point of the movement course 11 of the power generation medium 10.

[0030] Salvage and recovery of storage media at sea In the above configuration, the retrieval of the storage media 3a and 3b dropped into the ocean by the power generation medium 10 and the transport ship 20 may be carried out in any manner. In this regard, it is preferable that the power generation medium 10 and the transport ship 20 and the storage media 3a and 3b are provided with a configuration that enables the power generation medium 10 and the transport ship 20 to detect the location of the storage media 3a and 3b, so that the power generation medium 10 and the transport ship 20 can efficiently recover the storage media 3a and 3b from the ocean. Furthermore, it is preferable that the retrieval and recovery of the storage media 3a and 3b by the power generation medium 10 and the transport ship 20 be achieved automatically and unmanned.

[0031] To that end, as already described, in this embodiment, first, as already described, the storage medium 3 is provided with a light emitter or transmitter that emits specific light or radio waves as a marker means 8, or a reflector that reflects light or radio waves emitted from the power generation medium 10 and the transport ship 20, while the power generation medium 10 and the transport ship 20 are provided with detection means (reference numeral 9 in Figure 5) that detect light or radio waves coming from the storage medium 3, thereby enabling the detection of the position of the storage medium 3 from the power generation medium 10 and the transport ship 20. When the power generation medium 10 and the transport ship 20 recover the storage medium 3 at sea, the means for recovery may be activated to recover the storage mediums 3a and 3b based on the detected position of the storage medium 3.

[0032] In one mode of recovering the storage medium 3 from the power generation medium 10 and the transport vessel 20, as schematically depicted in Figures 5(A) to (E), when the power generation medium 10 or the transport vessel 20 is moved as indicated by arrow v, and the detection means 9 detects the marker means 8 of the storage medium 3, an arm 30 having a hook 31 and a flotation device 32 at its tip is thrown from the edge of the power generation medium 10 or the transport vessel 20 to the vicinity of the storage medium 3 (A). The hook 7 of the storage medium 3 is then hooked onto the arm 30, which moves along with the power generation medium 10 or the transport vessel 20 (B). Subsequently, while moving the power generation medium 10 or the transport vessel 20, the arm 30 is shortened (C) (the flotation device 32 is retracted as appropriate), and the hook 7 of the storage medium 3 engages with the hook 31 of the arm 30 (D). Thereafter, the storage medium 3 is drawn to the edge of the power generation medium 10 and the transport vessel 20 (E), and may be slid up onto the ship along a movable ramp or the like (not shown) as indicated by arrow T. This series of processes can be performed automatically and unmanned. The connection between the storage medium 3 and the arm 30 may be achieved by any method other than mechanical means, such as a magnetic force or a negative pressure method.

[0033] As an alternative method for recovering the storage medium 3 from the power generation medium 10 or the transport vessel 20, if the power generation medium 10 and the transport vessel 20 have a catamaran structure in which parallel hulls 10R, 20R and hulls 10L, 20L are connected, as schematically depicted in Figures 6(A) and 6(B), the power generation medium 10 and the transport vessel 20 are moved as indicated by arrow v, and when the storage medium 3 enters between hulls 10R, 20R and hulls 10L, 20L, wires 10t and 20t are suspended between hulls 10R, 20R and hulls 10L, 20L, as shown in Figure 6(A), and the hooks 7 of the storage medium 3 are caught on the wires 10t and 20t by the movement of the power generation medium 10 and the transport vessel 20, the storage medium 3 can then be pulled towards the hull and recovered in any manner.

[0034] Thus, according to the above embodiment, the transfer of the storage medium between the power generation float and the transport ship is achieved without directly connecting the power generation float and the transport ship, making it possible to transfer the storage medium at sea between a power generation float 10 of any size and shape and a transport ship.

[0035] While the above description is made in relation to embodiments of the present invention, many modifications and changes are readily possible for those skilled in the art, and it will be clear that the present invention is not limited to the embodiments illustrated above, but can be applied to various devices without departing from the concept of the present invention.

Claims

1. A method for transferring a storage medium at sea between a floating power generation vessel that generates electricity at sea and stores the energy obtained from that generation in a storage medium, The first step involves moving the power generation float to a predetermined sea area and dropping the first storage medium, which was loaded onto the power generation float, into the ocean. A second step involves moving the transport vessel to the predetermined sea area and dropping the second storage medium, which was loaded onto the transport vessel, into the ocean. A third step involves causing the power generation float to recover the second storage medium that was dropped into the ocean from the transport ship, A fourth step involves having the transport ship recover the first storage medium that was dropped into the ocean from the power generation float. A method that includes this.

2. A method according to claim 1, comprising: in the first step, moving the power generation float to a first area within the predetermined sea area and dropping the first storage medium; in the second step, moving the transport ship to a second area within the predetermined sea area and dropping the second storage medium; in the third step, moving the power generation float to the second area and recovering the second storage medium onto the power generation float; and in the fourth step, moving the transport ship to the first area and recovering the first storage medium onto the transport ship.

3. The method according to claim 1, wherein the first and second storage media are configured to float on the ocean.

4. A method according to claim 3, wherein hooks are provided on the first and second storage media, the power generation float and the transport ship each extend arms having engaging means for engaging with the hooks out to sea, the engaging means engage with the hooks, and then the arms are shortened to recover the first and second storage media.

5. A method according to claims 1 to 4, wherein the power generation float and the transport vessel each have detection means for detecting the second and first storage media at sea, and the second and first storage media are automatically recovered.

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