Renewable energy control system, renewable energy control method

Abstract

To provide a renewable energy control system that can store electricity taking into account the characteristics of a storage battery and a hydrogen storage system.SOLUTION: A renewable energy control system includes a power management unit that calculates the difference between a planned supply amount, which is the planned amount of renewable energy power generation to be procured on the basis of the corporate PPA, and a forecasted power demand amount, which predicts the demand for electricity required at the operation base where the EV community buses to be operated are to be charged, and that formulates a charging plan in which, of the difference, the surplus amount that occurs during a short period shorter than the first period when the forecasted power demand amount exceeds the planned supply amount is charged into a storage battery installed at the operation base, and the surplus amount that occurs during a long period longer than the first period is charged into a hydrogen storage system installed at the operation base.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a renewable energy control system and a renewable energy control method. [Background technology]

[0002] In recent years, the use of electric vehicle (EV) community buses has been increasing. The introduction of EV community buses is expected to contribute to decarbonization of EV community bus operations and their bases. Compared to regular route buses, EV community buses depart later from their offices (bases) and are also planned to return earlier in the evening. This means that they will be parked at bases for longer periods of time, which has the advantage of making it easier to secure time to charge the EV community bus's batteries. In addition, companies and other entities working to reduce carbon emissions are considering introducing corporate power purchase agreements (PPAs) to use and procure renewable energy electricity without using the FIT (Feed-in Tariff) system. In recent years, the use of a hydrogen storage system that produces and stores hydrogen has also been considered as one of the configurations for storing electricity. Patent Document 1 discloses that hydrogen is produced using surplus electricity, collected by a hydrogen transport vehicle, stored in a hydrogen storage alloy, and reused. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-122399 Summary of the Invention [Problem to be solved by the invention]

[0004] However, while it would be ideal if the electricity demand forecast based on the operation status of the EV community bus and the planned supply amount of electricity planned by the corporate PPA matched, this is difficult. In such cases, the surplus of the planned supply amount compared to the electricity demand forecast could be stored in storage batteries or hydrogen storage systems installed at the EV community bus operating base. When storing electricity, it is desirable to be able to store electricity while taking into consideration the characteristics of the storage battery and the hydrogen storage system.

[0005] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a renewable energy control system and a renewable energy control method that can store electricity taking into account the characteristics of a storage battery and a hydrogen storage system. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, one aspect of the present invention is a renewable energy control system having a power management unit that calculates the difference between a supply plan, which is the planned amount of renewable energy power generation to be procured based on a corporate PPA, and a power demand forecast, which predicts the demand for electricity required at an operation base where an EV community bus to be operated is charged, and that formulates a charging plan in which, for the surplus of the difference where the power demand forecast exceeds the supply plan, the surplus that occurs over a short period shorter than a first period is charged into a storage battery installed at the operation base, and the surplus that occurs over a long period longer than the first period is charged into a hydrogen storage system installed at the operation base.

[0007] Another aspect of the present invention is a renewable energy control method executed by a computer that controls a storage battery and a hydrogen storage system installed at an operation base where an EV community bus is operated, the renewable energy control method including: calculating the difference between a planned supply amount, which is the planned amount of renewable energy power generation to be procured based on a corporate PPA, and a forecasted electricity demand amount, which predicts the demand for electricity required at the operation base where the EV community bus to be operated is charged; and developing a charging plan in which, with respect to the surplus of the difference where the forecasted electricity demand amount exceeds the planned supply amount, the surplus that occurs over a short period shorter than a first period is charged into a storage battery installed at the operation base, and the surplus that occurs over a long period longer than the first period is charged into a hydrogen storage system installed at the operation base. [Effects of the Invention]

[0008] As described above, according to the present invention, electricity can be stored taking into consideration the characteristics of the storage battery and the hydrogen electricity storage system. [Brief explanation of the drawings]

[0009] [Figure 1] This is a conceptual diagram showing the concept of a business collaboration agreement related to building a model for introducing EV buses. [Figure 2] 1 is a schematic functional block diagram showing the configuration of a power system S. FIG. [Figure 3] FIG. 2 is a schematic functional block diagram illustrating the functions of the renewable energy control system SA. [Figure 4] This diagram shows the configuration and information flow of the control system for an EV community bus operating base that procures and stores renewable energy electricity. [Figure 5] 4 is a flowchart illustrating the operation of the power system S. [Figure 6] 4 is a flowchart illustrating the operation of the power system S. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a renewable energy control system according to an embodiment of the present invention will be described with reference to the drawings. Electric vehicle (EV) community buses, which have been gaining popularity in recent years, are one type of EV bus. Industry groups that use EV buses have set a goal of introducing a total of 10,000 EV buses by 2030. There are three reasons for promoting the introduction of EV buses, for example: (1) Reducing CO2 emissions through the shift to EVs According to a survey by the Ministry of Land, Infrastructure, Transport and Tourism, it is possible to achieve a reduction in CO2 emissions of around 20-30% for large vehicles and around 18% for medium-sized vehicles. (2) Running costs are reduced by about two-thirds compared to conventional diesel buses. It is expected that operating costs (fuel and oil costs or charging costs) will be reduced by 8 to 44%, and vehicle maintenance costs (vehicle inspection and maintenance costs, maintenance costs other than vehicle inspection) will be reduced by up to 55%. (3) Low noise and excellent driving performance.

[0011] In Japan, EV buses (hereafter referred to as EV community buses) that are smaller in size and have smaller battery capacities than standard buses, and can travel short distances and require frequent charging are mainly being introduced. The reasons for this are thought to be as follows: (A) Community buses depart from offices later than regular route buses and return earlier in the evening, making it easier to plan and implement charging times. (B) The battery capacity is relatively small to keep vehicle weight down, so charging time is short.

[0012] On the other hand, the following points are thought to be reasons why progress has not been made in converting standard-specification buses used on route routes into EVs. (a) Route buses depart from their offices all at once early in the morning (for example, around 6:00) and return all at once late at night (for example, around 12:00), which places great constraints on charging planning and implementation. (b) Because the battery capacity is large, peak power usage occurs due to the need to charge all of the day's worth of trips at once overnight, and the charging time per vehicle is approximately two hours, compared to the time required to refuel a conventional diesel bus, which is only a few minutes.

[0013] On September 14, 2023, it was announced that the Tokyo Metropolitan Bureau of Transportation and Tokyo Electric Power Company HD will collaborate to conduct research and studies into the issues surrounding the introduction of EV buses, as described above. Figure 1 is a conceptual diagram released by the Tokyo Metropolitan Bureau of Transportation showing the concept of the business partnership agreement for building a model for the introduction of EV buses. The following points will be considered in this business partnership agreement: (i) Ideal charging environment (ii) Development of energy management systems (iii) Charging using green electricity (iv) Use of electric buses in times of disaster, etc. (v) VPP (Virtual Power Plant) using EV buses as an energy source

[0014] Not only are electric buses being introduced, but commercial electric vehicles are also being introduced, and transportation companies are also moving forward with the introduction and full-scale operation of electric vehicles. Some examples of the features of using electric vehicles in transportation companies are as follows: Both electric buses and commercial electric vehicles have common operational challenges. (A) Employing electric vehicles for multiple delivery vehicles (a) Install solar power generation equipment at collection and delivery centers to generate renewable energy. (c) Introduction of a power leveling system to mitigate uneven peak power usage caused by simultaneous EV charging at night (d) Install a storage battery and use the electricity generated by the solar power generation facility during the day for powering the building and charging EVs.

[0015] The Tokyo Metropolitan Bureau of Transportation and transportation companies have identified the following current issues regarding charging using green electricity and the use of EV buses in times of disaster as items for investigation and consideration. <<Methods of procuring renewable energy such as green electricity and its technical challenges>> The conditions for procuring renewable energy set by RE100, a corporate alliance that aims to convert all electricity used in business activities to renewable energy (hereinafter referred to as renewable energy), are as follows: Self-generation: (1) Power generation using power generation facilities owned by a company Purchased electricity: (2) Purchasing electricity from facilities owned by other companies installed on the company's premises ;〈3〉 Direct purchase via dedicated lines from power generation facilities installed outside the company's premises 4. Direct procurement via the grid from power generation facilities installed outside the company's premises ;〈5〉Contract with electricity retailer (renewable energy electricity menu) ;〈6〉Purchase of renewable energy certificates 7. Procurement from a grid where the electricity supplier purchases renewable energy certificates in an amount equal to the amount of electricity supplied. ;〈8〉 Procurement from grids with a high proportion of renewable energy-derived electricity

[0016] Companies working towards decarbonization are increasingly seeking to use and procure renewable energy power without using the FIT system. In particular, the introduction of solar power generation is being promoted using a wide range of introduction methods, including corporate PPAs (power purchase agreements) and self-consignment from remote locations. Corporate PPAs, in which companies enter into long-term contracts to procure electricity from non-FIT solar power plants, can be divided into "physical PPAs," in which renewable energy electricity and environmental value are traded together, and "virtual PPAs," in which electricity and environmental value are traded separately. Applying the procurement conditions 1 to 7 set out in the RE100 mentioned above, they can be categorized as follows. Corporate PPAs are the mainstream form of renewable energy procurement. A. Self-consumption B. Corporate PPA (Third-party ownership model) C. Court Rate PPA (private line) D. Corporate PPA (Physical PPA), Self-Consignment E. Renewable energy electricity menu F. Corporate PPA (Virtual PPA) G. Corporate PPA (Virtual PPA)

[0017] When procuring electricity through corporate PPAs and other such arrangements, the "same-time, equal-volume, planned value" rule applies, and there is an obligation to balance the amount of electricity generated at the same time. The power generation plan established in advance must be matched to the actual power generation performance in 30-minute increments. If the plan and performance do not match, an "imbalance fee" must be paid according to the amount. The use of storage batteries as an adjustment capacity to comply with the simultaneous-time, equal-volume, planned value rule for renewable energy power generation is promising, as is the renewable energy hydrogen production method, in which hydrogen is produced using surplus renewable energy power and then stored.

[0018] Technology that converts surplus renewable energy electricity into CO2-free hydrogen and stores it (hereinafter referred to as hydrogen energy storage) is attracting attention, and "hydrogen production by water electrolysis using electricity derived from renewable energy sources, etc." (hereinafter referred to as renewable energy hydrogen) was selected as a Green Innovation Fund project at the end of fiscal year 2020, and large-scale demonstration projects have begun in Fukushima and Yamanashi prefectures. Compared to storage batteries, hydrogen storage has a superior energy density and no power loss during the storage period, making it advantageous for long-term, large-scale storage. While there are various methods for storing hydrogen, high-pressure gas and hydrogen storage alloys are suitable for storing renewable hydrogen, a domestic resource. Compared to storage batteries, hydrogen storage has advantages such as "higher volumetric energy density than storage batteries," "no storage loss due to self-discharge, making it suitable for long-term storage," and "nearly no energy is required to maintain the storage capacity."

[0019] (Utilizing electric buses in times of disaster, etc.) Efforts to utilize EV storage batteries as emergency power sources in the event of a disaster are being demonstrated in various locations. For example, the Tokyo Electric Power Company Group is developing and demonstrating an emergency power supply system called the "V2X System," which uses EVs, quick charging stations, stationary storage batteries, solar power generation, etc. to enable a stable supply of power to important loads at facilities during disasters. Additionally, on October 20, 2021, Yamanashi Kotsu announced that it had signed a partnership agreement to dispatch its electric buses, which have begun operation, to evacuation centers and government offices in Yamanashi Prefecture in the event of a disaster, to supply electricity as an emergency power source.

[0020] One aspect of the present invention FIG. 2 is a system configuration diagram showing a schematic configuration of a power system S according to an embodiment of the present invention. The power system S includes a renewable energy control system that enables EV community bus operation during normal times, decarbonization of operation bases, and operation of EV community buses in emergencies such as power outages on the existing power grid. This paper explains the power supply system and control method installed at EV community bus operation bases for this renewable energy control system. More specifically, the renewable energy control system has the function of procuring renewable energy electricity that has environmental value, such as through corporate PPAs, and has a storage battery and hydrogen storage system to store the renewable energy electricity, as well as a charging function for EV community buses.

[0021] In the power system S, the power supply system 1 and the renewable energy control system SA are connected via a power network and also via a communication network. The power supply system 1 can supply power generated from renewable energy to the renewable energy control system SA based on the corporate PPA. The power supply system 1 has a computer and can perform various calculations. The renewable energy control system SA is installed at an operation base Ba such as a bus office. The operation base Ba is the operation base for the EV community bus CB, such as a bus office. The operation base Ba has a relatively large site and is equipped with an energy management system EMS, power receiving and transforming equipment PR, solar power generation equipment PV, hydrogen storage system HS, storage battery BT, charger CH, etc.

[0022] The energy management system EMS manages the power consumption of each device and system within the operation base Ba. The power receiving and transforming equipment PR receives shared power from the power supply system 1, transforms the power as needed, and supplies the power to each unit within the operation base Ba. The photovoltaic power generation device PV receives sunlight and generates electricity using a photovoltaic power generation panel installed on the roof of a building BLD or the like.

[0023] The hydrogen storage system HS is capable of producing hydrogen using externally supplied electricity, storing the produced hydrogen, and generating and supplying electricity from the stored hydrogen using a fuel cell. The hydrogen storage system HS is composed of a hydrogen production device such as a water electrolysis device, a hydrogen storage device such as a high-pressure gas tank or a hydrogen absorbing alloy tank, and a fuel cell, etc. Compared to the storage battery BT, the hydrogen storage system HS has zero loss during the storage period, making it suitable for long-term storage of electricity for more than about a week. The storage battery BT stores power supplied from an external source and supplies power by discharging it as needed. The hydrogen storage system HS and storage battery BT are capable of storing renewable energy power supplied from the power supply system 1 by receiving it through a power receiving and transforming device, and supplying the stored power to each device within the operation base Ba. The hydrogen storage system HS and storage battery BT are an example of a renewable energy storage facility. While the renewable energy storage facility will be described as using the hydrogen storage system HS and storage battery BT, it may also include at least one of the following energy storage technologies: a superconducting flywheel, a superconducting energy storage coil, an ice thermal storage system, compressed air storage, etc.

[0024] The charger CH supplies power from at least one of the storage battery BT and the hydrogen storage system HS to the storage battery of the EV community bus CB, thereby charging the storage battery. The charger CH may be a rapid charger.

[0025] At the operation base Ba, the electricity consumed in the building BLD and the electricity used to charge the EV community bus CB are used. Here, it is usually difficult to cover all of the electricity required for business activities at the operation base Ba using only solar power generation equipment PV, so a function such as a corporate PPA is implemented to procure renewable energy electricity with environmental value from outside the site. The corporate PPA applied here is a measure in which, as mentioned above, an electricity consumer (for example, a business owner who operates from operation base Ba) enters into a long-term power purchase agreement directly with a renewable energy power generation company, and procures renewable energy electricity generated by newly installed solar power generation facilities at a long-term, fixed price via the existing power grid.

[0026] The surplus renewable energy electricity, which is a combination of renewable energy electricity procured through corporate PPAs, etc., and surplus electricity generated by solar power generation installed on the roofs of buildings such as EV community bus operation bases that cannot be consumed by the buildings themselves, will be stored in a "renewable energy storage facility" consisting of storage batteries BT and a hydrogen storage system HS.

[0027] Under normal circumstances, the storage batteries installed on the EV community bus CB are charged via chargers CH, etc. with electricity supplied by the corporate PPA and renewable energy electricity with environmental value generated through self-consumption by the solar power generation device PV, and are discharged while the EV community bus CB is in motion to drive the EV community bus CB's traction motor, etc., and used for operation.

[0028] Similarly, the electricity and heat demand required at the EV community bus CB operation base Ba under normal circumstances will be met by the electricity obtained through the corporate PPA and the electricity generated by the solar power generation equipment PV, which will be used for self-consumption, thereby making the EV community bus operation base a ZEB (Net Zero Energy Building).However, if there is a surplus or shortage of electricity due to the corporate PPA and self-consumption of solar power, it is possible to adjust the power consumption by operating the renewable energy storage equipment to charge or discharge the electricity.

[0029] In the event of a power outage or other emergency, the power supply from the corporate PPA via the existing power grid will be cut off. In this case, the independent power supply function of the renewable energy storage facility can be used to establish voltage and frequency, allowing the EV community bus CB to be charged together with the solar power generation system PV installed on the roof of the building BLD, enabling the EV community bus CB to operate. This also ensures the business continuity plan (BCP) functions of the EV community bus CB's operating base Ba, such as its evacuation shelter function. If a larger-capacity renewable energy storage facility were constructed, it would be possible to charge EVs owned by residents in the surrounding area of the operating base Ba and provide power outlets for IT (Information Technology) devices, and it could also function as a disaster prevention base.

[0030] FIG. 3 is a schematic functional block diagram illustrating the functions of the renewable energy control system SA. The renewable energy control system SA includes a storage unit 201, a communication unit 202, a planning unit 203, an acquisition unit 204, and a power management unit 205. All or part of the functions of the renewable energy control system SA may be installed in an energy management system EMS.

[0031] The storage unit 201 stores various types of data. The storage unit 201 is configured by a storage medium, such as a hard disk drive (HDD), flash memory, electrically erasable programmable read-only memory (EEPROM), random access read / write memory (RAM), read-only memory (ROM), or any combination of these storage media. The storage unit 201 can be, for example, a nonvolatile memory.

[0032] The communication unit 202 has a function to communicate with various devices within the operation base Ba, as well as a function to communicate with devices external to the operation base Ba. The devices within the operation base Ba may be, for example, a solar power generation system PV, a power receiving and transforming facility PR, a hydrogen storage system HS, a storage battery BT, and a charger CH. The devices external to the operation base Ba may be, for example, a computer provided in the power supply system 1, a weather server that distributes weather forecast data, etc. The communication unit 202 may also be an electronic device installed in the EV community bus CB that is charged by the charger CH. The communication unit 202 may be connected to a device with which to communicate via a wired connection or wireless connection.

[0033] The planner 203 makes various predictions regarding the use of power at the operation base Ba to generate predicted amounts and planned amounts, thereby formulating various plans regarding the use of power. For example, in order to properly manage electricity at the operation base Ba using the energy management system EMS, various predictions are made to perform predictive control, such as the predicted amount of electricity generated by renewable energy sources such as photovoltaic power generation devices (PV), the predicted amount of electricity demand at the EV community bus operation base Ba, and the predicted heat demand at the EV community bus operation base Ba. The renewable energy control system (hereinafter referred to as REMS) SA is composed of the predicted power output, power metering, and communications of renewable energy power generation output from multiple solar power generation systems and other renewable energy sources distributed over a wide area within the framework of a corporate PPA, as well as the prediction, metering, and communications of the power and heat demand of the EV community bus operation base Ba, including the operation plan for the EV community bus CB, and predicts surplus renewable energy power. For example, the renewable energy control system SA uses weather forecast data, historical electricity demand data representing the amount of electricity used at operation base Ba in the past, historical heat demand data representing the amount of heat used at operation base Ba in the past, and an EV community bus operation plan to predict the power generation of the solar power generation device PV, and the electricity demand and heat demand at operation base Ba.

[0034] The planning unit 203 generates a supply plan amount, which is the planned amount of renewable energy power generation to be procured based on the corporate PPA. The supply plan amount is determined according to a supply power plan based on the contents of a contract concluded by the corporate PPA for the long-term purchase of renewable energy power supply from a power generation company. The planning unit 203 may generate the supply plan amount by acquiring the supply plan amount input from a terminal device by the administrator of the renewable energy control system SA. The planner 203 also calculates the predicted amounts of various types of power at the operation base Ba. For example, the planner 203 calculates the predicted amount of power demand by predicting the demand for power required at the operation base for charging the EV community bus to be operated. The planning unit 203 also calculates a predicted power generation amount that predicts the amount of power generated by the photovoltaic power generation device PV installed at the operation base Ba. This predicted power generation amount is calculated using future meteorological information (weather, temperature, etc.), past power generation results by the photovoltaic power generation device PV during a similar period in the past for the prediction target period, etc.

[0035] Here, we will explain the case where the planning unit 203 creates various plans regarding power usage by making various predictions regarding power usage at the operation base Ba and generating predicted and planned amounts, but plans may also be created by obtaining predicted and planned amounts generated by other equipment or computers from those equipment or computers.

[0036] The acquisition unit 204 acquires various pieces of information from each device in the renewable energy control system SA via the communication unit 202.

[0037] The power management unit 205 calculates the difference between the planned supply amount, which is the planned amount of renewable energy power generation to be procured based on the corporate PPA, and the predicted power demand amount, which predicts the demand for electricity required at the operation base where the EV community buses to be operated will be charged. Furthermore, the power management unit 205 formulates a charging plan for charging at least one of the storage battery BT and the hydrogen storage system HS with the surplus power of the calculated difference. For example, the power management unit 205 creates a charging plan for the surplus (surplus power from renewable energy) of the calculated difference, which is the amount of power demand forecast exceeding the planned supply amount, in which the surplus occurring over a short period shorter than the first period is charged to a storage battery installed at the operation base, and the surplus occurring over a long period longer than the first period is charged to a hydrogen storage system installed at the operation base. More specifically, the power management unit 205 allocates and stores the surplus renewable energy power in the storage battery BT, which serves to adjust the supply and demand balance for a first period of about several days, and in the hydrogen storage system HS, which serves to adjust the supply and demand balance for a period longer than the first period, such as about a week. In other words, the planned supply amount and the forecasted power demand amount are each calculated for about two to three weeks into the future. Of these, the power management unit 205 formulates a plan so that, for example, any surplus power generated within the first three days from the current day is charged to the storage battery BT, and any surplus power generated from the fourth day onwards from the current day is charged to the hydrogen storage system HS.

[0038] In addition, when calculating the difference, the power management unit 205 may calculate a total amount by adding up the planned supply amount and the predicted power generation amount that predicts the amount of power generated by the solar power generation device PV installed at the operation base Ba, calculate the difference between the total amount and the predicted power demand amount, and create a charging plan based on the surplus portion of the calculated difference.

[0039] Furthermore, on the day when power control is performed, the power management unit 205 smooths out power fluctuations with a fluctuation period of less than a first period, which are the difference between the power generated by the photovoltaic power generation device PV and the power supplied based on renewable energy power generation, by charging or discharging the storage battery, and stores the surplus power after smoothing, which is the difference between the power generated by the photovoltaic power generation device PV and the power supplied based on renewable energy power generation, in the hydrogen storage system. The first cycle is, for example, a cycle with a fluctuation period of less than about 1 minute, and for sudden fluctuations in power with a fluctuation period of less than about 1 minute, the difference is eliminated by charging or discharging the storage battery BT, and then, if a gradual surplus of power with a fluctuation period of more than about 1 minute occurs, the surplus is supplied to the hydrogen storage system HS and stored in the hydrogen storage system HS.

[0040] Furthermore, the power management unit 205 controls the various devices in the operation base Ba so that they are charged or discharged in accordance with the various plans that have been drawn up. Here, the power management unit 205 may send control commands to the various devices to control them, or may send control commands to the energy management system EMS to control the various devices from the energy management system EMS. For example, the power management unit 205 periodically creates a charging plan, such as once a week or once every three weeks, and performs daily charging control in accordance with the most recently created plan until the next charging plan is created. If a deviation from the plan occurs on the day of control, the power management unit 205 controls the various loads, storage battery BT, and hydrogen storage system HS within the operation base Ba in real time to bring the plan closer to reality. In other words, even if the power management unit 205 predicts the amount of power generated by the photovoltaic power generation device PV, the actual amount of power generated may not match the predicted amount due to weather, etc. In such cases, real-time control is performed to reduce the error from the prediction. In this way, the power management unit 205 controls the renewable energy storage equipment (storage battery, hydrogen storage system) in accordance with the ever-changing balance between supply and demand, based on information such as forecasted amounts and planned values.

[0041] The communication unit 202, the planning unit 203, the acquisition unit 204, and the power management unit 205 may be configured as a processing unit such as a CPU (Central Processing Unit) or a dedicated electronic circuit.

[0042] Figure 4 shows the configuration and information flow of the control system for an EV community bus operation base that procures and stores renewable energy electricity. The computer of the Organization for Cross-regional Coordination of Transmission Operators receives data representing a wheeling plan and outputs plan approval data indicating the approval result for the wheeling plan. The computer of the corporate PPA system that supplies electricity based on the corporate PPA stores renewable energy power generation output forecast data, power transmission plan data, power supply plan data, etc., and has an imbalance monitoring function. The renewable energy control system SA stores in the storage unit 201 operation plan data for the EV community bus, charging plan data for the EV community bus, solar power generation forecast data that predicts power generation by the solar power generation device PV, power and heat demand forecast data that predicts power and heat demand at the operation base Ba, corporate PPA power procurement plan data that indicates a plan to procure power from the corporate PPA, equipment operation plan data (short term) for storage batteries, power storage operation plan data (long term) for the hydrogen storage system, equipment operation plan data for fuel cells, etc. The renewable energy control system SA also has an imbalance monitoring function, a storage battery real-time charge and discharge control function, a hydrogen production / hydrogen storage real-time control function, a power generation control function for fuel cells, etc.

[0043] 5 and 6 are flowcharts illustrating the operation of the power system S including the power supply system 1 and the renewable energy control system SA. <Widely distributed renewable energy source; Corporate PPA system (power supply system 1)> The computer of the power supply system 1 executes the processes of the following steps S101 to S103. The power supply system 1 acquires weather forecast data, performance data on power generation and supply based on the corporate PPA, and data from the Organization for Cross-regional Coordination of Transmission Operators from various devices such as an external server. The data from the Organization for Cross-regional Coordination of Transmission Operators may be data indicating the result of plan approval for the wheeling plan.

[0044] (Step S101) The computer of the power supply system 1 calculates a predicted solar power generation output value that predicts the amount of power generated by the solar power generation device within a certain period from the day after the control target day, based on weather forecast data and actual data on power generated by the solar power generation device that constitutes the power supply system.

[0045] (Step S102) Next, the power supply system 1 calculates a predicted solar radiation amount based on weather forecast data. Based on the calculated solar radiation amount prediction, the power supply system 1 calculates and predicts the total renewable energy power generation output of distributed solar power generation systems, etc. for the next day. The power supply system 1 then creates (generates) a supply plan for the EV community bus to the operation base Ba for the day after the target control day.

[0046] (Step S103) Next, the power supply system 1 notifies the computer of the Organization for Cross-regional Coordination of Transmission Operators of a wheeling plan that uses the spot market or the like on the day before the control target day.

[0047] Next, on the day of the control target, the power supply system 1 detects the SOC (State Of Charge) of the storage batteries installed in the power supply system 1 to grasp the output fluctuations of the total renewable energy power generation output, such as solar power generation, distributed in various locations, so as to achieve the planned value of simultaneous equality by controlling the charging and discharging of the storage batteries in the renewable energy storage equipment within the EV community bus operation base, and performs charging and discharging operations to adjust the fluctuations in power generation output that occur in the power supply system 1.

[0048] (Step S104) Next, the power supply system 1 generates planned power by combining the total output of widely distributed renewable energy generation with the charging and discharging of the storage battery in the power supply system 1, and supplies it to the EV community bus operation base Ba via the power grid as needed. As a result, the power supplied from the power supply system 1 is consigned to the operation base Ba.

[0049] <EV Community Bus Operation Base; Renewable Energy Control System SA> The acquisition unit 204 of the renewable energy control system SA acquires weather forecast data from an external server device and acquires a corporate PPA supply plan from the power supply system 1. The acquisition unit 204 also acquires EV community bus operation plan data representing a plan to operate an EV community bus at operation base Ba from the operation system. The EV community bus operation plan data includes the route the EV community bus will operate, time periods, the expected number of passengers, the number of trips, the power consumed by the storage battery when the EV community bus operates, etc.

[0050] (Step S201) The planner 203 creates an operation plan for the storage battery BT. Here, the planner 203 plans a period for charging the storage battery BT, a period for discharging from the storage battery BT, a charge amount, a discharge amount, and the like. For example, the planning unit 203 uses weather forecast data and past performance data of power / heat demand at the operation base Ba to predict the power generation of the photovoltaic power generation device PV, the power load demand at the operation base Ba, and the heat load demand at the operation base Ba for a future period for which an operation plan is to be created. The future period may be a predetermined time period within a long period from the target control date. Based on the results of such power generation prediction and demand prediction, the planning unit 203 creates an operation plan for charging or discharging the storage battery BT for each time period.

[0051] (Step S202) The power management unit 205 adjusts the SOC (state of charge) of the storage battery and completes preparation of the storage battery.

[0052] (Step S203) Power management unit 205 determines whether the SOC of storage battery BT on the day of control is less than a set value.

[0053] (Step S250) This set value is a value determined by the operation plan of the storage battery. If the SOC of storage battery BT is not less than the set value (if the SOC of storage battery BT is equal to or greater than the set value) (step S203-NO), power management unit 205 monitors the imbalance state, and if an imbalance occurs, transmits a request signal to power supply system 1 to request that the power supply system 1 correct the power wheeling plan value by notifying the power supply system 1 of the SOC of storage battery BT, etc.

[0054] (Step S204) On the other hand, if the SOC of the storage battery BT is less than the set value (step S203-YES), the power management unit 205 develops an operation plan for the hydrogen storage system HS, including hydrogen production using a water electrolysis device, etc., and the hydrogen storage system HS using a high-pressure hydrogen tank and a hydrogen storage alloy.

[0055] (Step S205) The power management unit 205 sets control values according to the operation plan for the proposed hydrogen storage system HS, thereby completing preparations for operation of the hydrogen storage system HS.

[0056] (Step S206) Next, the planning unit 203 predicts the power demand of each section within the operation base Ba, and also predicts the heat demand of each section within the operation base Ba. For example, the planning unit 203 predicts the power and heat demand, including charging of the EV community bus, based on the next day's and long-term weather forecasts, the EV community bus operation plan, various performance data, and the like.

[0057] (Step S207) Next, the planning unit 203 calculates a predicted value of the amount of power generated by the photovoltaic power generation device PV within a certain period based on the control target date, based on weather forecast data, past actual values of power generated by the photovoltaic power generation device PV, etc. For example, the planning unit 203 predicts renewable energy power generation such as solar power generation installed on the rooftop of a building, based on the following day / long-term weather forecast, performance data showing the past power generation results by the solar power generation device PV, past weather forecasts and actual weather during the period when the performance data was obtained, etc.

[0058] (Step S208) The power management unit 205 determines whether the corporate PPA supply plan is sufficient to cover the predicted power and heat demand for the next day by referring to the corporate PPA supply plan for the next day and the total predicted power value of renewable energy such as solar power generation installed on the building roof, etc. For example, the power management unit 205 determines whether the corporate PPA supply plan value is greater than the predicted power demand value for the day after the control target day.

[0059] (Steps S230, S231) If the determination result in step S208 is that the corporate PPA supply plan value is not greater than the power demand forecast value for the day after the control day (step S208-NO), that is, if the corporate PPA supply plan value is smaller than the power demand forecast value, the power management unit 205 determines that the corporate PPA supply plan alone will not provide enough power. In this case, the shortfall must be made up by discharging from the renewable energy storage equipment, so the power management unit 205 formulates a discharge plan for the storage battery and an operation plan for hydrogen release and fuel cell.

[0060] (Step S232) Next, the power management unit 205 determines whether the amount of hydrogen stored in the hydrogen storage system HS is less than a predetermined set value. This set value is a value that is lower by a certain amount than the upper limit of hydrogen storage capacity, and may be predetermined and stored in the storage unit 201. Alternatively, this set value may be a value determined according to the amount of additional hydrogen that can be stored, such as half the upper limit of storage capacity.

[0061] (Step S233) If the amount of hydrogen stored in the hydrogen storage system HS is not less than a predetermined set value, i.e., if the amount of hydrogen stored is equal to or greater than the set value (step S232-NO), the power management unit 205 formulates a plan to discharge from the storage battery BT.

[0062] (Step S234) On the control day, the power management unit 205 generates power using the hydrogen storage system HS based on the established plan and supplies it to the load at operation base Ba, and also supplies it to the load within operation base Ba by discharging from the storage battery BT. In this way, the amount of power that is insufficient to be supplied based on the corporate PPA can be covered by discharging from the hydrogen storage system HS and the storage battery BT, and the required power can be supplied from green power.

[0063] (Step S209) If the corporate PPA supply plan value is greater than the predicted power demand value for the day after the control day (step S208-YES), the power management unit 205 determines that the corporate PPA supply plan is excessive, and therefore formulates a charging plan to store the amount of power needed for short-term supply and demand balance adjustment in the storage battery for a few days, and also formulates a charging plan to store the amount of power needed for long-term supply and demand balance adjustment for a period of more than one week in the hydrogen storage system HS.

[0064] (Step S210) The power management unit 205 determines, based on the created power receiving plan, whether there is a charging plan for storing the amount for supply and demand balance adjustment in the short term, or whether there is a charging plan for storing the amount for supply and demand balance adjustment in the long term.

[0065] (Step S211) If there is a surplus of the power distributed for the short term (step S210-short term), power management unit 205 allocates the surplus distributed for the short term as power to be charged to storage battery BT. Then, power management unit 205 performs imbalance monitoring.

[0066] (Step S212) The power management unit 205 formulates a battery charging plan for charging the power allocated for the short term to the storage battery BT. Here, the power management unit 205 formulates a plan for charging the power allocated for the short term to the storage battery BT in a first period, which is a short term.

[0067] (Step S213) Then, on the target control day, power management unit 205 charges storage battery BT in accordance with the charging plan established in step S212.

[0068] (Step S220) If there is a surplus of the power distributed for the long term (step S210-long term), the power management unit 205 allocates the surplus distributed for the long term as power to charge the hydrogen storage system HS. The power management unit 205 then determines whether the amount of hydrogen stored in the hydrogen storage system HS is less than a set value.

[0069] (Step S221) If the amount of hydrogen stored in the hydrogen storage system HS is less than the set value (step S220-YES), the power management unit 205 creates a storage plan to produce hydrogen from the power allocated for the long term and store it in a hydrogen storage device. Here, the power management unit 205 creates a hydrogen storage plan to use the power allocated for the long term as power to produce hydrogen in the hydrogen storage system HS for a period after the first long-term period, and to store the produced hydrogen in a hydrogen storage device.

[0070] (Step S222) Then, on the target control day, the power management unit 205 causes the hydrogen storage system HS to store hydrogen in accordance with the hydrogen storage plan formulated in step S221.

[0071] (Steps S240, S241) The power management unit 205 monitors the difference between the total of the corporate PPA supply plan value from widely distributed renewable energy sources and the predicted renewable energy power value from solar power generation systems installed on building rooftops, etc., and the actual value, and if there is a difference, it uses storage batteries and a hydrogen storage system to perform real-time control to eliminate the difference, thereby meeting the demand for electricity and heat. Here, on the day when power control is performed, if there is a power fluctuation with a fluctuation period less than the first period among the difference between the power generated by the photovoltaic power generation device PV and the power supplied based on renewable energy power generation, the power management unit 205 smooths out the power fluctuation by charging or discharging the storage battery BT. If any surplus occurs in the power fluctuations after smoothing, the power management unit 205 supplies the surplus to the hydrogen storage system HS for storage.

[0072] This makes it possible to reduce large fluctuations in the input current to the water electrolysis device in the hydrogen storage system HS when performing real-time control of electric power. Large fluctuations in the input current to the hydrogen electrolysis device are likely to lead to a decrease in the durability and electrolysis efficiency of the hydrogen electrolysis device, but because the input current can be supplied to the hydrogen electrolysis device with reduced fluctuations, it is possible to suppress a decrease in the durability of the hydrogen electrolysis device and reduce a decrease in the electrolysis efficiency of the hydrogen electrolysis device.

[0073] The power management unit 205 performs such real-time control by synthesizing control values to smooth out power fluctuations less than the first period while charging or discharging in accordance with a plan for charging or discharging the storage battery. Also, the power management unit 205 performs such real-time control by controlling the hydrogen storage system HS based on a hydrogen storage plan according to the surplus power that occurs after the first period, while supplying the surplus power of power fluctuations that exceed the first period to the hydrogen storage system HS, thereby controlling the storage battery BT by synthesizing control values.

[0074] (Step S242) From the evening to the night of the day subject to control, the storage battery installed on the EV community bus is charged from the storage battery BT and hydrogen storage system HS according to the EV community bus operation plan for the next day.

[0075] <<Emergency Response Systems (REMS)>> In the event of a power outage, the power supply provided by the corporate PPA will be cut off. In this case, when the power management unit 205 detects a power outage, it rewrites the planned value of power supply by the corporate PPA to zero, and then controls the supply of power from the renewable energy storage system to each of the loads within the operation base Ba. In the event of a power outage, the power required to operate the renewable energy control system may be supplied from the storage battery BT. Although not shown, the storage battery BT is equipped with a voltage-controlled power conversion device and is responsible for establishing voltage and frequency within the range of independent operation in the event of a power outage in the existing power grid.

[0076] Effect According to the embodiment described above, the following effects can be obtained. Electricity can be stored taking into account the characteristics of the storage battery and the hydrogen storage system. The storage battery BT has good responsiveness, making it easy to handle short-term charging. The hydrogen storage system HS also makes it easy to handle charging when there is little or gradual fluctuation in input power. In this way, it is possible to create a charging plan based on the characteristics of each. The power system S described above will enable the realization of decarbonization and disaster-resistant resilient urban development, with the EV community bus operating base Ba at its core. In addition, by supplying electricity generated from multiple renewable energy sources, such as solar power plants, located in various locations to the EV community bus operating base Ba through a corporate PPA, it is possible to further reduce CO2 emissions associated with bus operation, which is the main reason for introducing EV community buses. Similarly, the electricity and heat demand at the EV community bus operation base Ba can be met through a corporate PPA and self-consumption of solar power, making it possible to achieve ZEB status at the EV community bus operation base. In emergencies such as power outages, BCP functions such as charging and operation of EV community buses and the functioning of the base station Ba as an evacuation shelter can be ensured.

[0077] The Sustainable Development Goals (SDGs) are 17 international goals adopted at the United Nations Summit in September 2015. The renewable energy control system and renewable energy control method according to this embodiment can contribute to achieving one of the 17 SDGs, for example, goal 7, "Affordable and clean energy."

[0078] The communication unit 202, the planning unit 203, the acquisition unit 204, and the power management unit 205 in the above-described embodiments may be implemented by a computer. In this case, a program for implementing these functions may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed. Note that the term "computer system" as used herein includes hardware such as an OS and peripheral devices. Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into a computer system. Furthermore, the term "computer-readable recording medium" may also include devices that dynamically store programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or telephone lines, or devices that store programs for a fixed period of time, such as volatile memory within a computer system serving as a server or client. The program may be for implementing only a portion of the above-described functions, or may be capable of implementing the above-described functions in combination with a program already stored in the computer system, or may be implemented using a programmable logic device such as an FPGA (Field Programmable Gate Array). [Explanation of symbols]

[0079] 1 Power supply system, 201 Memory unit, 202 Communication unit, 203 Planning unit, 204 Acquisition unit, 205 Power management unit, Ba Operation base, BLD Building, BT Storage battery, CB EV community bus, CH Charger, EMS Energy management system, HS Hydrogen storage system, PV Photovoltaic power generation equipment, S Power system, SA Renewable energy control system

Claims

1. A planned supply volume, which is the planned amount of renewable energy power generation procured based on the corporate PPA; and The difference between the estimated power demand and the estimated power demand at the operation base where the EV community bus to be operated is charged is calculated. Of the difference, the surplus amount of the forecasted power demand amount exceeding the planned supply amount is Any surplus generated during a short period shorter than the first period is charged into a storage battery installed at the operation base; For any surplus generated over a period exceeding the first period, a charging plan will be developed to charge the hydrogen storage system installed at the operation base. Power management department A renewable energy control system with

2. The power management unit The supply plan amount; a predicted power generation amount that predicts the amount of power generated by a solar power generation device installed at the operation base; and Find the total amount by adding up the above. The difference between the total amount and the predicted amount of power demand is calculated, and the charging plan is created based on the surplus of the calculated difference. The renewable energy control system according to claim 1 .

3. The power management unit On the day of power control, smoothing power fluctuations having a fluctuation period shorter than a first period among the difference between the power generated by the solar power generation device installed at the operation base and the power supplied based on the renewable energy power generation by charging or discharging the storage battery; The surplus power after the smoothing of the difference between the power generated by the solar power generation device and the power supplied based on the renewable energy power generation is stored in the hydrogen storage system. The renewable energy control system according to claim 1 or 2.

4. A renewable energy control method executed by a computer that controls a storage battery and a hydrogen storage system provided at an operation base that is a base for operating an EV community bus, A planned supply volume, which is the planned amount of renewable energy power generation procured based on the corporate PPA; and The difference between the estimated power demand and the estimated power demand at the operation base where the EV community bus to be operated is charged is calculated. Of the difference, the surplus amount of the forecasted power demand amount exceeding the planned supply amount is Any surplus generated during a short period shorter than the first period is charged into a storage battery installed at the operation base; For any surplus generated over a period exceeding the first period, a charging plan will be developed to charge the hydrogen storage system installed at the operation base. A renewable energy control method including:

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