Hydrogen management system using unused hydroelectric energy

Abstract

We provide a hydrogen management system that utilizes surplus electricity from hydroelectric power generation. [Solution] The surplus electricity purchased by hydrogen aggregators includes not only the surplus electricity generated by the normal operation of existing hydroelectric power plants, but also surplus electricity generated due to transmission constraints and electricity generated by small hydroelectric power plants that use water flow in low-flow areas. One example of surplus electricity generated due to transmission constraints is when an existing power plant is updated with new power generation equipment, and by installing a hydroelectric generator that matches the water volume in the low-flow area, it becomes possible to effectively utilize unused energy (such as the unused water volume in low-flow areas).

Description

[Technical Field]

[0001] The present invention relates to a system for producing, storing, and supplying hydrogen using unused energy generated at hydroelectric power plants. [Background technology]

[0002] Power generation facilities set an upper limit on output so as not to exceed the required power supply, and accordingly limit the amount of water used and released. In addition, when the water volume is below the lower limit of the equipment's performance, it is below the operating range of the turbine, so it is not used for power generation and is released into the river.

[0003] Patent Document 1 discloses a system that includes a hydrogen production device capable of producing hydrogen by electrolyzing water using surplus electricity generated by a solar power generation unit relative to the power demand, a hydrogen storage device that can store hydrogen produced by the hydrogen production device, a fuel cell that can generate electricity using hydrogen stored in the hydrogen storage device, and a control device that controls the operation of the hydrogen production device and the fuel cell based on an operating plan that has been created, and that when the operating plan predicts that the amount of hydrogen that the hydrogen production device can produce using the surplus electricity will exceed the hydrogen demand, the control device enables the fuel cell to generate electricity using the hydrogen stored in the hydrogen storage device.

[0004] Patent Document 1 describes that the control device acquires various information from the outside (such as weather forecasts and solar radiation forecasts), calculates a predicted value for the amount of power generated by the solar power generation unit based on this acquired information, and further calculates predicted values for power demand and hydrogen demand based on the information acquired from the outside and past data on the power demand of the power load and the hydrogen demand of the hydrogen load, and performs planning control to create operating plans for the storage battery, fuel cell, pure water production system, and hydrogen production system based on the predicted value for the amount of solar power generation and the predicted values for power demand and hydrogen demand.

[0005] Patent Document 2 proposes a system that converts surplus electricity generated by a private power generation device (mainly solar power generation) into another form of energy (hydrogen) when a power transmission grid is not established.

[0006] The system disclosed in Patent Document 2 specifically consists of multiple buildings and a management device, and the buildings have a fuel cell power generation device, a first cartridge for storing hydrogen, and a first battery, and the management device performs, for each building, a first acquisition process to acquire the value of the remaining energy in the first battery, a second acquisition process to acquire the value of the amount of energy that the fuel cell power generation device can generate from the remaining amount of hydrogen in the first cartridge, a first prediction process to predict the value of the amount of energy consumed in the building, and a determination process to determine whether or not to replace the first cartridge with a second cartridge and whether or not to replace the first battery with a second battery based on the value of the remaining energy acquired by the first acquisition process, the value of the amount of energy that can be generated acquired by the second acquisition process, and the value of the amount of energy consumed predicted by the first prediction process.

[0007] Patent Document 3 proposes a system (device) that effectively supports energy management, including electricity and hydrogen. This system stores predicted values for electricity demand in a specified area, predicted values for hydrogen demand in that area, and information on the costs of electricity generation and hydrogen production, and formulates an integrated energy plan that includes a power generation plan and a hydrogen production plan based on the information on the costs of electricity generation and hydrogen production under conditions that make it possible to supply the amount of electricity required for hydrogen production based on the predicted values for electricity demand and hydrogen demand, and to supply the predicted value for hydrogen demand.

[0008] Patent Document 4 proposes that at a hydroelectric power plant, hydrogen is produced by electrolyzing water using the power generated by a generator (surplus power) as a power source during times when power demand is at its lowest, and that power is then obtained from a fuel cell that uses the hydrogen as fuel during times when power demand is at its peak. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2025-004284 [Patent Document 2] Patent No. 7626885 [Patent Document 3] Japanese Patent Application Publication No. 2024-070064 [Patent Document 4] Japanese Patent Application Publication No. 4-165931 Summary of the Invention [Problem to be solved by the invention]

[0010] In Patent Document 1, surplus electricity generated at hydroelectric power plants cannot be effectively utilized. That is, surplus electricity is estimated from predicted values of solar power generation and power demand, and hydrogen is produced using this estimated surplus electricity, but there is a problem in that water is not used for power generation and is discharged from hydroelectric power plants, and is not effectively utilized.

[0011] The technology disclosed in Patent Document 2 is excellent for producing hydrogen using surplus electricity generated by individual homes equipped with solar power generation facilities, but it does not solve the problem of water not being used for power generation being discharged as is at hydroelectric power plants.

[0012] Patent Document 3 compares the predicted demand for electricity and hydrogen within a specific area with the costs of power generation and hydrogen production, and proposes the most cost-effective method of utilizing surplus electricity. However, this does not solve the problems specific to hydroelectric power generation mentioned above.

[0013] Patent Document 4 describes the production of hydrogen by electrolyzing water during times when electricity demand in hydroelectric power plants is at its lowest. However, Patent Document 4 does not address the issues of the existence of large amounts of unused water outside of those times, and the inability to fully utilize the capacity of power generation facilities due to constraints in the power transmission system.

[0014] As mentioned above, hydroelectric power plants have traditionally had unique problems, namely, the amount of unused water that is released outside the operating range of the turbine generator without contributing to power generation, and the fact that although the power generation capacity has increased through the renewal of the power generation equipment, the diameter of the transmission lines remains narrow, making it impossible to transmit the increased power.Furthermore, from the perspective of guaranteeing the output of the turbine generator, a margin of error is designed, but in this case, too, in accordance with the contract with the general electricity transmission and distribution company, the amount of water used is limited to within the output upper limit, resulting in unused water. Furthermore, although the operating range differs depending on the turbine model, in the low water flow range, the turbine may experience problems such as cavitation, so the water is not used for power generation and is instead released into the river. At power plants with relatively large output, the amount of unused water in this low water flow range is significant. [Means for solving the problem]

[0015] In order to solve the above problems, the hydrogen management system of the present invention, which uses surplus hydroelectric power, is constructed using a server computer that manages and processes hydrogen-related data held by a hydrogen aggregator that optimizes the hydrogen supply and demand balance, and a client computer held by a hydrogen business operator that produces hydrogen using surplus hydroelectric power based on information from the hydrogen aggregator and supplies the hydrogen to hydrogen consumers.The hydrogen aggregator purchases surplus power generated by hydroelectric power plants due to supply and demand relationships, as well as surplus power generated by hydroelectric power plants due to transmission restrictions, and power generated by small-scale hydroelectric power generation facilities that use water in low-flow areas that is not used for power generation at hydroelectric power plants.The server computer stores at least current power supply and demand data and the current unit price of electricity.The hydrogen business operator can access the server computer via the client computer and purchases electricity for hydrogen production via the hydrogen aggregator based on the information obtained from the server computer and hydrogen supply and demand information.

[0016] The surplus electricity caused by the transmission restrictions is mainly generated by updating power generation facilities, and the small hydroelectric power generation facilities also include power generation facilities installed in agricultural irrigation channels. [Effects of the Invention]

[0017] According to the present invention, surplus electricity that has not been used in hydroelectric power generation until now, or electricity generated by using water in low water volume areas that has not been used for power generation, can be used to produce hydrogen without waste. In particular, the existence of hydrogen aggregators allows hydrogen instructors to obtain real-time information on hydrogen supply and demand, enabling them to effectively utilize electricity that would previously have been wasted without being consumed. [Brief explanation of the drawings]

[0018] [Figure 1] Overall configuration of the hydrogen management system according to the present invention [Figure 2] A graph comparing the relationship between turbine efficiency and water consumption for existing hydroelectric power generation facilities, updated hydroelectric power generation facilities, and small hydroelectric power generation facilities. [Figure 3] A graph comparing the number of operating days for existing hydroelectric power generation facilities, replacement hydroelectric power generation facilities, and small hydroelectric power generation facilities. DETAILED DESCRIPTION OF THE INVENTION

[0019] As shown in Figure 1, the hydrogen management system according to the present invention is composed of a server computer owned by a hydrogen aggregator and a client computer owned by a hydrogen business operator that can communicate with the server computer. Both the server computer and the client computer can be cloud-based or on-premise.

[0020] The hydrogen aggregator manages and processes data related to hydrogen to optimize the balance between supply and demand of electricity and hydrogen, and the hydrogen business produces hydrogen by electrolyzing water using electricity purchased through the hydrogen aggregator, stores the produced hydrogen in, for example, a hydrogen storage alloy, and supplies the stored hydrogen in response to requests from hydrogen consumers. Here, hydrogen consumers include not only general consumers but also public facilities and hydrogen stations.

[0021] The hydrogen supplier is not limited to a single entity, but multiple hydrogen suppliers may be involved with one hydrogen aggregator. In this case, the hydrogen management system is composed of a single server computer and multiple client computers. It is also conceivable that hydrogen operators may be located within existing hydroelectric power plants, with electricity still purchased through a hydrogen aggregator.

[0022] The hydrogen aggregator purchases electricity generated by hydroelectric power plants other than the electricity to be supplied to consumers. Here, the electricity to be supplied to consumers includes surplus electricity generated during normal operation of existing hydroelectric power plants, surplus electricity generated due to transmission restrictions, and electricity generated by small hydroelectric power plants that generate electricity using water flow in low-flow areas.

[0023] To operate a water turbine at a hydroelectric power plant, a certain level of head and water volume is required, and although this differs depending on the turbine model, it is operated within the operating range of the efficiency curve corresponding to the amount of water used. Here, the efficiency of a water turbine is the ratio of how much output the turbine can actually extract from the energy of the water flow used. As shown in Figure 2, at water volumes in the low water volume range below a flow rate ratio of 25%, the turbine cannot rotate, so it either stops or operates extremely inefficiently even if it rotates. For this reason, in the past, water in the low water volume range was not used for power generation and was released. The River Law stipulates that normal flow rates must be maintained, taking into consideration the protection of flora and fauna, fishing, scenery, and maintaining the cleanliness of flowing water. This normal flow rate (river maintenance flow rate) is different from the low water flow area mentioned above.

[0024] Since the water flow in the low-flow region also contains energy, it is desirable to make effective use of this. Therefore, in this invention, power is generated using a small-scale hydroelectric power generation facility that can operate even in low-flow regions, and if there are no grid connection constraints (power transmission constraints), the power is sold as is. If there are constraints, the power is purchased as surplus power by a hydrogen aggregator. Note that various types of small-scale hydroelectric power generation facilities are possible, including Pelton type, Francis type, cross-flow type, and screw type.

[0025] As shown in Figure 2, when comparing the water usage and turbine efficiency of the existing turbine, the additional turbine (small hydroelectric power generation equipment), and the turbine resulting from equipment upgrades, the small hydroelectric power generation equipment is more advantageous for generating electricity in low water flow areas than the existing turbine. Also, when equipment is upgraded, not only will there be electricity that cannot be transmitted due to the transmission contract, but it will also be possible to utilize the water flow in low water flow areas to a certain extent.

[0026] An example of surplus power generated by transmission constraints is when an existing power plant is replaced with new power generation equipment. In this case, performance improves, so output increases if the effective head and maximum water usage remain the same. Furthermore, when various tests are conducted to check whether the efficiency of the turbines and generators is performing as expected, the design is usually designed with a margin to prevent malfunctions such as underperformance. In such cases, if the plant is operated at the maximum water usage rate of the permitted water right, the output performance will exceed that of the connection contract, so the water usage is adjusted to limit the output to the upper limit. Furthermore, while updating power generation equipment will improve its capacity, if the size of the transmission lines remains the same as before, it will not be possible to transmit the increased power generation.

[0027] In such cases, there is no point in updating the permitted water right by lowering the maximum water use for power generation to match the original transmission power. Therefore, as shown in Figure 3, the maximum water use for the permitted water right is left unchanged, and the potential is maximized by updating to the latest power generation equipment. The increased output from the equipment upgrade is then not transmitted via the general electricity transmission company, and the amount that cannot be transmitted due to transmission constraints is purchased by the hydrogen aggregator as surplus electricity.

[0028] In this way, the hydrogen aggregator that purchased surplus electricity stores the purchased amount in a server computer. The server computer also stores electricity supply and demand information and electricity unit price information obtained from the electricity aggregator. The stored information is displayed on the display unit of the client computer in response to a request from the client computer. In addition to the above information, the server computer may also include electricity supply and demand forecasts that take into account weather conditions and geopolitical factors.

[0029] Power aggregators purchase and supply electricity from and to power retailers to balance supply and demand, and also issue instructions to energy storage companies to store electricity.The energy storage companies receive these instructions and store electricity, and when a power shortage is predicted, they supply electricity to retailers.

[0030] Hydrogen aggregators can not only purchase electricity from hydroelectric power plants, but also from energy storage providers when the unit price of electricity is low.

[0031] The hydrogen business operator accesses the hydrogen aggregator's server computer from a client computer to receive information from the server computer, and then purchases electricity from the hydrogen aggregator and produces hydrogen, taking into account the received information and the hydrogen supply and demand situation among hydrogen consumers.

[0032] The hydrogen aggregator may store the purchased electricity in its own storage device, or it may purchase surplus electricity from the hydroelectric power plant in the amount ordered by the hydrogen business operator, and transmit the surplus electricity directly from the hydroelectric power plant to the hydrogen business operator. [Industrial Applicability]

[0033] The hydrogen management system of the present invention is expected to have the effect of local production and consumption of electricity in areas near large-scale hydroelectric power plants built in mountainous regions far from ports where hydrogen is imported from overseas, where surplus electricity is likely to be generated.

Claims

1. A hydrogen management system using surplus hydroelectric power, constructed by a server computer that manages and processes data related to hydrogen held by a hydrogen aggregator that optimizes the balance of supply and demand for hydrogen, and a client computer held by a hydrogen business operator that produces hydrogen using surplus hydroelectric power based on information from the hydrogen aggregator and supplies hydrogen to hydrogen consumers, The hydrogen aggregator purchases surplus electricity generated by hydroelectric power plants due to supply and demand, as well as surplus electricity generated by hydroelectric power plants due to transmission restrictions, or electricity generated by small hydroelectric power generation facilities that use water in low-flow areas that is not used for power generation at hydroelectric power plants, The server computer stores at least current supply and demand data of electricity and current electricity unit prices, A hydrogen management system that utilizes surplus electricity from hydroelectric power generation, characterized in that the hydrogen business operator can access the server computer via a client computer and purchases electricity for hydrogen production via the hydrogen aggregator based on information obtained from the server computer and hydrogen supply and demand information.

2. 2. A hydrogen management system utilizing surplus electricity generated by hydroelectric power generation as described in claim 1, characterized in that the server computer is also accessible to hydrogen consumers who use hydrogen.

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