The present invention mainly relates to a system and method for transporting energy between onshore facilities by a ship via a sea route.
Conventionally, in an offshore wind power generation system, for example, a power transmission cable is laid on the ocean floor or under the sea, and electricity generated by an offshore power generator is transmitted to an onshore power system via the undersea power transmission cable. For example, Patent Literature 1 discloses a wiring system in which, in order to lay a power transmission line regardless of the topography of the ocean floor, the power transmission line is installed in a floating state between a plurality of offshore power generation facilities. In addition, Patent Literature 2 discloses that in order to stably supply power generated offshore nationwide, a ring-shaped power transportation network is provided surrounding the land and connecting offshore power generation facilities, and discloses that a power transportation network system includes power transmission lines from this offshore transportation network to land.
Incidentally, in conventional systems, for example, a power transmission cable is installed on the ocean floor or under the sea in order to transmit electricity generated by an offshore power generation facility to a reception facility onshore, and electricity is transported by this power transmission cable. However, in addition to the time-consuming and costly installation and maintenance of power transmission cables, such conventional systems have the following various problems.
For example, in order to install power transmission cables in the sea, for example, since the procedures for obtaining permission from the national or local government and the installation work take time, it takes a lot of time until the power generation facility starts operating.
Moreover, in a case where a power transmission cable is installed in the sea, there is a risk of affecting the natural environment in the sea or on the ocean floor, and thus sufficient care must be taken when installing the power transmission cable, and depending on the environmental conditions, there are cases in which it may not be possible to install a power transmission cable.
In addition, since power transmission cables are fixed on the ocean floor or under the sea, there are no options as to where the power will be sent when using these power transmission cables. For example, in a case of transmitting power from an offshore power generation facility to an onshore reception facility via a power transmission cable, power can only be directly transmitted to specific reception facilities at any given time. Therefore, in order to transmit power from a power generation facility to any arbitrary location, it is always necessary to go through an onshore power system, which poses a problem of poor power transmission efficiency.
Therefore, a main object of the present invention is to provide a method for efficiently transporting an energy source such as electricity to an arbitrary reception facility without using a supply line such as an ocean floor power transmission cable.
As a result of intensive study on means for solving the problems of the known art, the inventor of the present invention has obtained knowledge that various problems faced by energy transportation methods using power transmission cables and the like can be solved by transporting energy by a ship via a sea route from a supply facility to a reception facility. Based on the above knowledge, the inventor of the present invention came up with an idea that the problems of the prior art could be solved, and completed the present invention. More specifically, the present invention has the following configurations or steps.
A first aspect of the present invention relates to an energy transportation system. The system according to the present invention basically includes: a transportation ship provided with holding means for holding an energy source; a supply facility located outside the transportation ship and configured to supply an energy source to the holding means of the transportation ship; and a reception facility located outside the transportation ship and configured to receive a supply of an energy source from the holding means of the transportation ship.
In the present invention, the “energy source” includes in addition to electricity, energy sources that are compatible with electricity. For example, in addition to electricity, energy sources include hydrogen, heat, potential energy, kinetic energy, and the like that are compatible with electricity and can be maintained for a certain period of time at a practical operational efficiency. Note that the energy source supplied from the supply facility to the transportation ship and the energy source supplied from the transportation ship to the reception facility do not necessarily have to be of the same type. For example, hydrogen may be supplied from a supply facility to a transportation ship, electricity may be generated from the hydrogen on the transportation ship, and electricity may be supplied from the transportation ship to a reception facility. The “supply facility” is a facility that can supply energy sources to transportation ships. For example, in a case where the energy source is electricity, a power transformer that is connected to a public power system and has the function of supplying power to a transportation ship and the like correspond to the supply facility referred to here. The “reception facility” is a facility that is capable of receiving an energy source from a transportation ship, and includes onshore facilities as well as ships, vehicles, trains, aircraft, and the like that are driven by an energy source supplied from a transportation ship. For example, in a case of electricity as an energy source, a power transformer that receives a supply of electricity from a transportation ship and transmits that electricity to a public power system and the like correspond to a reception facility referred to here. Note that the transportation ship may receive an energy source supplied from a power generation facility via a cable, or may supply an energy source to a reception facility via a cable. In this case, it is preferable that the transportation ship further includes a robot arm for suspending and holding the cable.
By transporting energy by a transportation ship via a sea route from the supply facility to the reception facility as in the above configuration, there are advantages, for example, as described below.
First, with the present invention, there is no need to lay a power transmission cable between the supply facility and the reception facility as in the past, and thus the initial investment for starting power transmission between those facilities can be reduced.
Moreover, the present invention also does not require an ocean floor power transmission cable, and thus the influence on the natural environment under the sea or on the ocean floor can be minimized.
Furthermore, in the present invention, the energy source is transported by a transportation ship rather than a power transmission cable, and thus the destination for energy transportation from the supply facility can be freely selected. For example, it becomes possible to transport energy sources directly to areas with high demand for electric power, commercial facilities, hospitals, public facilities, and the like.
In the present invention, holding means for holding an energy source is installed on the transportation ship, and thus timing of selling the electricity to a destination can be selected with some degree of freedom. For example, the unit sales price of an energy source can be increased by sending transportation ships to areas with high demand for electric power during times of high demand.
In the energy transportation system according to the present invention, the holding means of the transportation ship may be a storage battery (secondary battery). In this case, the electricity obtained by the power generation facility is supplied directly to the transportation ship after being transformed (voltage conversion and/or mutual conversion between direct current electricity and alternating current electricity) as necessary. “Storage batteries” include liquid batteries and all-solid-state batteries that convert electrical energy into chemical energy and store the energy, as well as mechanical batteries such as flywheel batteries and the like that convert electrical energy into physical energy such as rotational motion and store the energy. Mechanical batteries, when compared to liquid batteries, and the like, have an advantage in that the energy storage method is not a chemical reaction, so there is less risk of fire or explosion, and the lifespan thereof is longer than normal lithium batteries.
In the energy transportation system according to the present invention, the holding means of the transportation ship may be a hydrogen tank. In that case, hydrogen gas is generated by water electrolysis equipment or the like using electricity obtained from the power generation facility, and the obtained hydrogen gas is supplied to the hydrogen tank of the transportation ship. In addition, hydrogen gas will be supplied from the transportation ship to the reception facility, where the hydrogen gas will be used to generate electricity using fuel cells, or the like. Note that the water electrolysis equipment may be provided at a power generation facility, a supply facility, or on a transportation ship. Moreover, the fuel cell may be provided at the reception facility or may be provided on the transportation ship.
The energy transportation system according to the present invention further includes a power generation facility that supplies an energy source to the supply facility. Power is transmitted from the power generation facility to the supply facility, for example, via a known power system. As the “power generation facility”, equipment that generates power by known methods such as wind power generation, solar power generation, tidal power generation, geothermal power generation, hydropower generation, biomass power generation, thermal power generation, and nuclear power generation may be employed. Note that the power generation facility includes various equipment necessary for supplying an energy source to a transportation ship, such as a power generator, a power transformer, power transmission equipment, power storage equipment, and energy source conversion equipment.
In the energy transportation system according to the present invention, the supply facility and the reception facility may be located onshore, such as on a remote island or on a coast. For example, power generated by an onshore power generation facility is transmitted via a public power system to a supply facility installed on the coast, and the supply facility supplies power to a transportation ship. The transportation ship then transports power via a sea route to a reception facility installed on the coast. In this way, power can be transported from the onshore supply facility to the reception facility using a transportation ship.
A second aspect of the present invention relates to an energy transportation method. In the transportation method according to the present invention, an energy source is transported by a transportation ship provided with energy source holding means from a supply facility outside the transportation ship to a reception facility outside the transportation ship. For example, the transportation method according to the present invention includes a step of supplying an energy source from a supply facility to a transportation ship, a step of transporting the energy source by the transportation ship, and a step of supplying the energy source from the transportation ship to a reception facility.
With the present invention, an energy source such as electricity can be efficiently transported to an arbitrary reception facility without using a supply line such as a power transmission cable.
Hereinafter, embodiments for implementing the present invention are described using the drawings. The present invention is not limited to the embodiments described below, but also includes embodiments that are appropriately modified from the embodiments described below within a range that would be obvious to a person skilled in the art.
As illustrated in
In this way, in the present invention, basically electrical energy is transported from an onshore supply facility 20 to a reception facility 30 on another shore, and eventually to a power system (power transmission network) by the transportation ship 10 provided with a storage battery. Although depending on the power source of the transportation ship 10, for example, even a motor-type transportation ship 10 using electricity as a power source can navigate approximately 300 to 500 km on the ocean without recharging. Therefore, the distance from the supply facility 20 to the reception facility 30 can be approximately 300 to 500 km.
As illustrated in
The container 10a is an element for holding an energy source (specifically, electricity) to be transported from the supply facility 20 to the reception facility 30. The electricity stored in the container 10a is intended for transportation from the supply facility 20 to the reception facility 30, and thus during transportation, the electricity is basically held as is without being consumed as a power source for the transportation ship 10 and the equipment inside the ship. However, as will be described later, in an emergency or the like, the electricity stored in the container 10a may also be used as a power source for the transportation ship 10, or the like.
The container 10a includes a charging/discharging port 11, a plurality of battery cells 12, and a battery control device 13. The charging/discharging port 11, into which a charging/discharging cable 40 (see
Note that in this embodiment, the container 10a is configured to be removable from the hull 10b, but it may also be configured such that each battery cell 12 is removable from the container 10a. On the other hand, in a case where each battery cell 12 is removably attached to the container 10a, the container 10a itself may be fixed to the hull 10b in a non-removable manner. Furthermore, in this embodiment, the battery control device 13 is installed inside the container 10a; however, instead of this configuration, the battery control device 13 may also be installed on the hull 10b side.
The hull 10b of the transportation ship 10 basically has the same configuration as a general motor-type ship using electricity as a power source. That is, the hull 10b includes a drive battery 14, an inverter 15, and a motor 16. The drive battery 14 holds electricity that is consumed as a power source for the transportation ship 10 and internal equipment. The inverter 15 controls or converts the electricity output from the drive battery 14 and supplies the electricity to the motor 16. The motor 16 converts the electricity received from the inverter 15 into power. For example, the motor 16 obtains a propulsion force for the transportation ship 10 by rotating a screw propeller via a shaft (not illustrated).
In this way, the hull 10b has the drive battery 14 that is separate from the battery cells 12 for storing electricity for transportation, and therefore navigating is possible without consuming the electricity in the battery cells 12. However, in this embodiment, the drive battery 14 is electrically connected to the battery cells 12 via the battery control device 13. Therefore, in an emergency or the like, electricity in the battery cells 12 may be supplied to the drive battery 14. As a result, the transportation ship 10 is also able to navigate using the electricity in the battery cells 12 as a power source.
In addition, although not illustrated, the transportation ship 10 may transport hydrogen instead of electricity as an energy source. In this case, a hydrogen tank may be installed in the container 10a instead of the battery cells 12. Moreover, the transportation ship 10 may be one that navigates using hydrogen as a power source. In this case, a fuel cell may be installed in the hull 10b instead of the drive battery 14. Note that hydrogen can be transported by the transportation ship 10 that uses electricity as a power source, and electricity can also be transported by the transportation ship 10 that uses hydrogen as a power source.
In the system illustrated in
In addition, the robot arm 50 preferably includes a stabilizer mechanism for maintaining the spatial position (horizontal position and vertical position) of the gripped site of the charging/discharging cable 40 constant. The stabilizer mechanism may mechanically maintain the spatial position of the gripped site. Further, the stabilizer mechanism may electronically perform control so as to maintain the spatial position of the gripped site based on detection information from a sensor device such as an acceleration sensor, a gyro sensor, or the like. The supply of electric power to the transportation ship 10 is performed at sea, and is easily affected by waves and tides. Therefore, by installing a stabilizer mechanism on the robot arm 50 of the transportation ship 10, it is possible to prevent the charging/discharging cable 40 from accidentally falling off from the charging/discharging port, or it is possible to prevent failure or disconnection of the charging/discharging cable 40 from occurring. Note that although not illustrated, it is also possible to supply electricity from the supply facility to the transportation ship 10 with the charging/discharging cable 40 floating on the sea surface and without the robot arm 50 being mounted on the transportation ship 10.
In the system illustrated in (a) of
In the example illustrated in (b) of
In addition, although not illustrated, the supply destination (reception facility) of the energy source from the transportation ship 10 may be a vehicle (EV or FCV) that is onshore, and it is also possible to directly supply an energy source to various locations such as commercial facilities, hospitals, residences, and public transportation facilities. In this manner, with the present invention, it becomes possible to freely select a destination for transporting the energy source by the transportation ship 10.
Moreover, electric power is supplied from the transportation ship 10 to the reception facility 30 similarly using high-voltage DC electricity. Therefore, it is necessary to provide the current collector board 33 and the power transformer 31 for high-voltage DC electricity on the reception facility 30 side as well. The electricity held by the battery cells of the transportation ship 10 is supplied to the power transformer 31 via the current collector board 33. The power transformer 31 converts the high-voltage DC electricity into AC electricity of about 100V to 250V that meets the standards of each region, and then transmits the electricity to the power system 200 via the power transmission cable 32.
Next, an application example of an embodiment of the present invention described above will be explained with reference to
Moreover, in the embodiment described above, electricity is used as an energy source for transportation. That is, the supply facility 20 supplies electricity acquired from the power system 200 to the transportation ship 10. The transportation ship 10 charges the battery cells 12 with electricity in this manner and transports the power via sea route. For this reason, as in the transportation system illustrated in the upper part of
On the other hand, in the application example of
When the filling of the hydrogen tank 17 is completed, the transportation ship 10 navigates toward the reception facility 30. In a case where hydrogen is used as an energy source for transportation, a fuel cell 35 is provided at the reception facility 30. Hydrogen gas is supplied to the fuel cell 35 from the hydrogen tank 17 of the transportation ship 10 via a supply nozzle (supply line). The fuel cell 35 generates electricity by causing a chemical reaction between hydrogen supplied from the transportation ship 10 and oxygen in the air. The electricity obtained by the fuel cell 35 is transformed as necessary and then transmitted to the power system 200. In this way, by transporting hydrogen by the transportation ship 10, the energy source obtained at the supply facility 20 can be delivered to the reception facility 30.
The energy transportation system 100 according to the present invention may include either the electricity transportation system (upper example) or the hydrogen transport system (lower example) illustrated in
As mentioned above, in this specification, in order to express the content of the present invention, embodiments of the present invention have been described with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and includes modifications and improvements that are obvious to those skilled in the art based on the matters described in this specification.
The present invention relates to an energy transportation system and an energy transportation method. For example, the present invention may be suitably used in the power generation business and the power transmission business.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-132402 | Aug 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/030729 | 8/12/2022 | WO |