Hydrogen Production System

Abstract

A hydrogen production system is provided that can stably operate a hydrogen production unit while reducing imbalance. [Solution] The system comprises a solar power generation unit 10, a hydrogen production device 40 capable of producing hydrogen using power generated by the solar power generation unit 10, and a control device 60 that creates an operation plan for the hydrogen production device 40. The control device 60 calculates the average power generation forecast value and the 90% percentile power generation forecast value (step S101), calculates the average surplus power forecast value from the difference between the average power generation forecast value and the power demand forecast value, and calculates the 90% percentile surplus power forecast value from the difference between the 90% percentile power generation forecast value and the power demand forecast value (step S103), and determines the power to be used when the hydrogen production device 40 is operating (steps S109, S112, and S115) based on the planned surplus difference, which is the difference between the average surplus power forecast value and the 90% percentile surplus power forecast value (step S104).

Description

[Technical Field]

[0001] The present invention relates to a technology for a hydrogen production system that utilizes electricity generated by natural energy such as sunlight. [Background technology]

[0002] In the solar power generation business, the FIT (Feed-in Tariff) system will be replaced by the FIP (Feed-in Premium) system due to the revision of the purchase system. Under the FIP system, power generation companies will be required to bear the cost of the imbalance, which is the difference between the power generation plan and the actual power generation, something that they were previously exempt from. Therefore, there is a demand to reduce the imbalance.

[0003] Patent Document 1 describes a power supply system that includes a solar power generation system capable of generating electricity using sunlight and a hydrogen production system that can produce hydrogen using the electricity generated by the solar power generation system. In the power supply system described in Patent Document 1, the hydrogen production system is operated using surplus electricity generated by the solar power generation system, thereby reducing the imbalance.

[0004] However, because the amount of power generated by a solar power generation system is determined by the circumstances, in the power supply system of Patent Document 1, if the hydrogen production system is operated to reduce the imbalance, there is a risk that the hydrogen production system will be turned on and off frequently, or that it will be operated continuously at partial load, which could result in a decrease in hydrogen production efficiency, and therefore the operation of the hydrogen production system may become unstable. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-54085 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention was made in consideration of the above-mentioned circumstances, and the problem it aims to solve is to provide a hydrogen production system that can stably operate the hydrogen production unit while reducing imbalance. [Means for solving the problem]

[0007] The problem to be solved by the present invention is as described above, and the means for solving this problem will now be described.

[0008] That is, in claim 1, the system comprises a power generation unit capable of generating electricity using natural energy, a hydrogen production unit capable of operating to produce hydrogen using the electricity generated by the power generation unit, and a planning unit that creates an operation plan for the hydrogen production unit, wherein the planning unit obtains a predicted generated electricity value, which is a predicted value of the electricity generated by the power generation unit, and a predicted electricity demand value, which is a predicted value of the electricity demand, and determines the amount of electricity to be used when the hydrogen production unit operates based on the difference between the predicted generated electricity value and the predicted electricity demand value.

[0009] In claim 2, the planning unit calculates an average surplus power forecast value, which is the average value of the difference between the predicted power generation value and the predicted power demand value during the scheduled operation time of the hydrogen production unit, and sets the average surplus power forecast value as the power usage during the scheduled operation time.

[0010] In claim 3, when the average surplus power predicted value is smaller than the lower limit value of power consumption, which is the minimum power consumption required to operate the hydrogen production unit, the planning unit shortens the scheduled operating time so that the average surplus power predicted value increases.

[0011] In claim 4, when the average surplus power predicted value is greater than the upper power consumption limit value, which is the power consumption when the hydrogen production unit is operating at maximum capacity, the planning unit reduces the difference between the generated power predicted value and the power demand predicted value to the upper power consumption limit value.

[0012] In claim 5, the system comprises a fuel cell capable of generating electricity using fuel, and an execution unit that executes operation of the hydrogen production unit based on the operation plan created by the planning unit, and if the power consumption of the hydrogen production unit is insufficient when the hydrogen production unit is operated based on the operation plan, the execution unit compensates for the power consumption of the hydrogen production unit with power from the fuel cell.

[0013] In claim 6, the system is provided with a storage battery capable of charging and discharging electricity, and if the power usage of the hydrogen production unit is insufficient when the hydrogen production unit is operated based on the operation plan, the execution unit compensates for the power usage of the hydrogen production unit with power from the storage battery.

[0014] In claim 7, the execution unit reduces the amount of hydrogen produced by the hydrogen production unit when the shortage of power consumption cannot be resolved.

[0015] In claim 8, the execution unit is configured to charge the storage battery with the surplus generated power when the hydrogen production unit is operated based on the operation plan and the power generation unit generates surplus power.

[0016] In claim 9, the execution unit increases the amount of hydrogen produced by the hydrogen production unit when the generated power remains in excess even after the power generated by the power generation unit is charged into the storage battery.

[0017] In claim 10, the system includes a water purification device capable of purifying water using the power generated by the power generation unit, and the execution unit operates the water purification device using the surplus generated power when there is still surplus power generated by the power generation unit even after increasing the amount of hydrogen produced by the hydrogen production unit. [Effects of the Invention]

[0018] The present invention has the following effects.

[0019] According to claim 1, the hydrogen production unit can be operated stably while reducing the imbalance.

[0020] According to claim 2, the hydrogen production unit can be operated more stably.

[0021] According to claim 3, the hydrogen production unit can be easily operated.

[0022] According to claim 4, the amount of hydrogen produced by the hydrogen production unit can be increased.

[0023] According to claim 5, stable operation of the hydrogen production unit can be maintained.

[0024] According to claim 6, stable operation of the hydrogen production unit can be maintained.

[0025] According to claim 7, stable operation of the hydrogen production unit can be maintained.

[0026] According to claim 8, surplus generated power can be consumed in-house.

[0027] According to claim 9, surplus generated power can be consumed in-house.

[0028] According to claim 10, surplus generated power can be consumed in-house. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a block diagram showing the configuration of a hydrogen production system according to an embodiment of the present invention. [Figure 2] 10 is a flowchart showing planned control. [Figure 3] 4 is a graph showing an example of actual values ​​and predicted values ​​of power generated by a solar power generation unit. [Figure 4] Graph showing the planned surplus difference and the average planned surplus difference. [Figure 5]10 is a flowchart showing execution control. [Figure 6] 10 is a flowchart showing execution control. [Figure 7] FIG. 10 is a diagram showing an example of a transition in power consumption when execution control is performed. DETAILED DESCRIPTION OF THE INVENTION

[0030] A hydrogen production system 1 according to one embodiment of the present invention will be described below.

[0031] The hydrogen production system 1 shown in Fig. 1 produces hydrogen using electric power. The hydrogen production system 1 is mainly used in factories, residential areas, etc. The hydrogen production system 1 supplies electric power from a power grid (not shown) or electric power generated using solar light to a load H, which is an electric power load in the factory, residential area, etc. The hydrogen production system 1 mainly comprises a solar power generation unit 10, a storage battery 20, a fuel cell 30, a hydrogen production device 40, a water purification device 50, and a control device 60.

[0032] The solar power generation unit 10 is a device that generates power using sunlight. The solar power generation unit 10 is configured with a solar cell panel or the like. The solar power generation unit 10 is installed in a sunny location, such as on the roof of a house.

[0033] The storage battery 20 is configured to be able to charge and discharge power. The storage battery 20 is configured, for example, as a lithium-ion battery. The storage battery 20 is configured to be able to charge power generated by the solar power generation unit 10 (power generated by the solar power generation unit 10). The storage battery 20 is also configured to be able to discharge the charged power to the load H and a hydrogen production device 40, which will be described later. The storage battery 20 can perform load following operation, which adjusts the power to be charged and discharged, based on the results of detection of power from the system power supply by a sensor (not shown). The power charged and discharged from the storage battery 20 can also be adjusted by a control device 60, which will be described later.

[0034] The fuel cell 30 is a device that generates electricity using gas fuel such as hydrogen. The fuel cell 30 is configured as a polymer electrolyte fuel cell (PEFC) or a solid oxide fuel cell (SOFC). The fuel cell 30 is configured to be able to output the generated electricity to a load H and a hydrogen production device 40 (described later). The fuel cell 30 can perform load-following operation, adjusting the output power based on the detection results of power from a system power supply by a sensor (not shown). The power output from the fuel cell 30 can also be adjusted by a control device 60 (described later). The fuel cell 30 can also store exhaust heat generated during power generation as hot water in a hot water storage tank.

[0035] The hydrogen production device 40 produces hydrogen using electric power. The hydrogen production device 40 produces hydrogen by electrolyzing water. The hydrogen production device 40 mainly uses the electric power generated by the solar power generation unit 10 as the electric power used to produce hydrogen. The hydrogen production device 40 can also use the discharged electric power from the storage battery 20, the electric power from the fuel cell 30, and the electric power from the system power supply as the electric power used to produce hydrogen.

[0036] Water purification device 50 purifies water to produce pure water. Water purification device 50 can use the power generated by solar power generation unit 10, the power discharged from storage battery 20, the power from fuel cell 30, and the power from the grid power supply as power sources for its operation.

[0037] The control device 60 controls the operations of the storage battery 20, the fuel cell 30, and the hydrogen production device 40. The control device 60 includes a memory unit such as a RAM, a ROM, and a HDD, and an arithmetic processing unit such as a CPU. The control device 60 creates an operation plan for the hydrogen production device 40. The control device 60 also operates the hydrogen production device 40 based on the operation plan.

[0038] Planned control by the control device 60 will be explained below with reference to Fig. 2. Planned control shown in Fig. 2 is used to create an operation plan for the hydrogen production device 40. In the operation plan, the amount of hydrogen produced by the hydrogen production device 40 is determined for each time period (for example, in 30-minute increments). In this embodiment, the operation plan is created the day before the day on which the hydrogen production device 40 is actually operated. Hereinafter, the day on which the hydrogen production device 40 is actually operated will be referred to as "the day," and the day on which the operation plan is created, i.e., the day before the day, will be referred to as "the day before."

[0039] 2, the control device 60 predicts the power generation amount of the solar power generation unit 10 on that day. In this process, the control device 60 calculates a predicted value of the power generation amount of the solar power generation unit 10 (hereinafter referred to as the "predicted power generation value") based on data on the past power generation amount of the solar power generation unit 10, as well as the weather forecast and solar radiation prediction for that day. More specifically, the control device 60 calculates two types of predicted power generation values: an average predicted power generation value and a 90% percentile predicted power generation value.

[0040] Here, the "average power generation forecast value" refers to a forecast value that will result in a 50% increase in the actual power generation value, and the "90% percentile power generation forecast value" refers to a forecast value that will result in a 90% increase in the actual power generation value.

[0041] Fig. 3 shows an example of the actual value, the average predicted value, and the 90% percentile predicted value of the power generated by the solar power generation unit 10. As shown in Fig. 3, the 90% percentile predicted value of the power generated is smaller than the average predicted value of the power generated.

[0042] After performing the process of step S101, the control device 60 proceeds to step S102.

[0043] In step S102, the control device 60 predicts the power demand of the load H. In this process, the control device 60 calculates a predicted value of the power demand of the load H (hereinafter referred to as a "power demand prediction value") based on data on the past power demand of the load H, the weather forecast for the day, etc.

[0044] After performing the process of step S102, the control device 60 proceeds to step S103.

[0045] In step S103, the control device 60 predicts surplus power. In this process, the control device 60 calculates two types of predicted surplus power values ​​(hereinafter referred to as "surplus power predicted values") by subtracting the power demand predicted value calculated in step S102 from each generated power predicted value calculated in step S101.

[0046] Specifically, the control device 60 calculates a surplus power prediction value based on the average power generation prediction value (hereinafter referred to as "average surplus power prediction value") by subtracting the power demand prediction value calculated in step S102 from the average power generation prediction value calculated in step S101. Furthermore, the control device 60 calculates a surplus power prediction value based on the 90% percentile power generation prediction value (hereinafter referred to as "90% percentile surplus power prediction value") by subtracting the power demand prediction value calculated in step S102 from the 90% percentile power generation prediction value calculated in step S101.

[0047] After performing the process of step S103, the control device 60 proceeds to step S104.

[0048] In step S104, the control device 60 calculates the average value of the planned surplus difference. Here, the "planned surplus difference" refers to the difference between the predicted values ​​of two types of surplus power. More specifically, the planned surplus difference is a value calculated by subtracting the 90% percentile surplus power predicted value from the average surplus power predicted value. The planned surplus difference is calculated for each time period (for example, every 30 minutes). Then, the control device 60 calculates the average value of the planned surplus difference (hereinafter referred to as the "average planned surplus difference") by averaging the planned surplus differences at each time period when the planned surplus difference occurs (see FIG. 4).

[0049] Although details will be described later, the operation plan is basically constructed assuming that the hydrogen production device 40 produces hydrogen using the amount of power equivalent to the planned surplus difference. In the example shown in Fig. 4, the time period from 5:00 to 18:00, when the planned surplus difference occurs, is the time period during which the hydrogen production device 40 is scheduled to operate (hereinafter referred to as "scheduled operation time").

[0050] After performing the process of step S104, the control device 60 proceeds to step S105.

[0051] In step S105, the control device 60 determines whether the planned surplus difference average is smaller than the lower limit of the power consumption of the hydrogen production device 40 (planned surplus difference average<lower limit of power consumption). Here, the "power consumption" of the hydrogen production device 40 refers to the power used to produce hydrogen in the hydrogen production device 40. In the hydrogen production device 40, minimum and maximum values ​​for the amount of hydrogen produced per unit time (e.g., 30 minutes) are determined. The lower limit of the power consumption of the hydrogen production device 40 (hereinafter referred to as the "lower limit of power consumption") is the power used when the amount of hydrogen produced in the hydrogen production device 40 is at its minimum. In other words, the lower limit of power consumption of the hydrogen production device 40 is the minimum power consumption required for the operation of the hydrogen production device 40.

[0052] When the control device 60 determines that the planned surplus difference average<the power usage lower limit value ("YES" in step S105), the process proceeds to step S106.

[0053] Note that "YES" in step S105 indicates that the planned surplus difference average is insufficient and the hydrogen production device 40 cannot produce hydrogen using the amount of electricity equal to the planned surplus difference average. On the other hand, "NO" in step S105 indicates that the hydrogen production device 40 can produce hydrogen using the amount of electricity equal to the planned surplus difference average.

[0054] In step S106, the control device 60 shortens the time used to average the planned surplus difference in step S105 (i.e., the planned operation time of the hydrogen production device 40). In this process, the control device 60 shortens the planned operation time of the hydrogen production device 40 to a time within the planned operation time for which the planned surplus difference is greater than an appropriate threshold. In the example shown in FIG. 4, for example, the control device 60 shortens the planned operation time of the hydrogen production device 40 (5:00 to 18:00) to 10:00 to 14:00, for which the planned surplus difference is large. Alternatively, the control device 60 may calculate a shortened time (from the original planned operation time) such that the new planned surplus difference average (calculated based on the shortened time) is equal to or greater than the lower limit of power usage of the hydrogen production device 40, and allocate the calculated time to a time period with a large planned surplus difference.

[0055] After performing the process of step S106, the control device 60 proceeds to step S107.

[0056] In step S107, the control device 60 determines whether the scheduled operation time of the hydrogen production device 40 is less than the lower limit of the scheduled operation time (scheduled operation time<lower limit). Since the hydrogen production device 40 consumes a lot of power at startup, an extremely short operation time reduces efficiency. For this reason, a lower limit of the scheduled operation time is set for the hydrogen production device 40.

[0057] If the control device 60 determines that the scheduled operation time is less than the lower limit ("YES" in step S107), the process proceeds to step S108. On the other hand, if the control device 60 determines that the scheduled operation time is not less than the lower limit ("NO" in step S107), the process returns to step S104.

[0058] By returning the process to step S104, the planned surplus difference average is calculated again in step S104. The control device 60 calculates the planned surplus difference average for the shortened scheduled operation time (10:00 to 14:00). The recalculated planned surplus difference average is greater than the original planned surplus difference average.

[0059] In addition, if the answer to step S107 is "YES," this indicates that even if the scheduled operating time of the hydrogen production device 40 is shortened to the lower limit of the scheduled operating time, the planned surplus difference average will fall below the lower limit of the power usage of the hydrogen production device 40 (i.e., the hydrogen production device 40 will not be able to produce hydrogen using the amount of power equal to the planned surplus difference average).

[0060] In step S108, the control device 60 submits to the electric power company a power generation plan based on the predicted average power generation value of the solar power generation unit 10. Here, the "power generation plan" refers to the planned value of the power generated by the hydrogen production system 1, and more specifically, the power that is scheduled to be reverse-flowed to the grid power supply. After performing the processing of step S108, the control device 60 proceeds to step S109.

[0061] In step S109, the control device 60 creates an operation plan for the current day (the day after the current time) assuming that hydrogen will not be produced by the hydrogen production device 40. After performing the process of step S109, the control device 60 ends the planned control shown in FIG.

[0062] On the other hand, in step S105, if the control device 60 determines that the planned surplus difference average is not less than the lower limit of power consumption of the hydrogen production device 40 (the planned surplus difference average is greater than or equal to the lower limit of power consumption) ("NO" in step S105), it proceeds to step S110.

[0063] In step S110, the control device 60 determines whether the planned surplus difference average is greater than the upper limit of the power consumption of the hydrogen production device 40 (planned surplus difference average > upper limit of power consumption). As described above, the hydrogen production device 40 has minimum and maximum values ​​for the amount of hydrogen produced per unit time. The upper limit of the power consumption of the hydrogen production device 40 (hereinafter referred to as the "upper limit of power consumption") is the power used when the amount of hydrogen produced by the hydrogen production device 40 is at its maximum. In other words, the upper limit of power consumption of the hydrogen production device 40 is the power used when the hydrogen production device 40 is operating at maximum capacity.

[0064] When the control device 60 determines that the planned surplus difference average is not greater than the power usage upper limit (planned surplus difference average≦power usage upper limit) (“NO” in step S110), the control device 60 proceeds to step S111.

[0065] In addition, if the answer to step S105 is "NO" and the answer to step S110 is "NO", this indicates that the lower limit of the power consumption of the hydrogen production device 40 is equal to or less than the planned surplus difference average and the upper limit of the power consumption of the hydrogen production device 40.

[0066] In step S111, the control device 60 submits to the electric power company a power generation plan based on the 90% percentile predicted power generation value of the solar power generation unit 10. After performing the process of step S111, the control device 60 proceeds to step S112.

[0067] In step S112, the control device 60 constructs an operation plan for the day, assuming that the hydrogen production device 40 will always use the amount of power equal to the planned surplus difference average during the scheduled operation time to produce hydrogen (the power consumption of the hydrogen production device 40 will always be the planned surplus difference average during the scheduled operation time). After performing the processing of step S112, the control device 60 ends the planned control shown in FIG. 2.

[0068] On the other hand, in step S110, when the control device 60 determines that the planned surplus difference average is greater than the upper limit of the power usage of the hydrogen production device 40 ("YES" in step S110), the process proceeds to step S113.

[0069] Note that if the answer to step S110 is "YES," this means that the planned surplus difference average is too large, and even if the hydrogen production device 40 produces hydrogen using electricity equivalent to the planned surplus difference average during the scheduled operating time, there will still be excess electricity (i.e., the hydrogen production device 40 will not be able to use up all of the electricity equivalent to the planned surplus difference average when producing hydrogen).

[0070] In step S113, the control device 60 corrects the power generation plan. In this process, the control device 60 reduces the planned surplus difference to the upper limit of power usage of the hydrogen production device 40. Specifically, in step S104, the planned surplus difference is calculated by subtracting the 90% percentile surplus power predicted value from the average surplus power predicted value, but the 90% percentile surplus power predicted value is replaced with a surplus power predicted value greater than the 90% percentile surplus power predicted value so that the planned surplus difference = the upper limit of power usage. After performing the process of step S113, the control device 60 proceeds to step S114.

[0071] In step S114, the control device 60 submits the power generation plan corrected in step S113 to the electric power company. Specifically, the submitted power generation plan is a power generation plan based on the predicted value (a predicted value greater than the 90% percentile surplus power predicted value) replaced with the 90% percentile surplus power predicted value in step S113. After performing the process of step S114, the control device 60 proceeds to step S115.

[0072] In step S115, the control device 60 constructs an operation plan for the day, assuming that the hydrogen production device 40 will always use the upper limit of power usage to produce hydrogen during the scheduled operation time (the power usage of the hydrogen production device 40 will always be the upper limit of power usage during the scheduled operation time). After performing the process of step S115, the control device 60 ends the planned control shown in FIG.

[0073] In this way, an operation plan for the day (the day after the day the operation plan is created) is created. On that day, the hydrogen production device 40 is operated based on the operation plan.

[0074] The execution control by the control device 60 will be explained below with reference to Figures 5 and 6. The execution control shown in Figures 3 and 4 controls the actual operation of the hydrogen production device 40, storage battery 20, and fuel cell 30 on the day. The execution control shown in Figures 3 and 4 is executed repeatedly in real time. In the following, it is assumed that the operation of the storage battery 20 and fuel cell 30 is controlled by the control device 60.

[0075] In step S201, the control device 60 calculates a surplus difference actual result. Here, the "surplus difference actual result" is a value calculated by (power generation actual result - demand actual result - power generation plan). Note that the "power generation actual result" refers to the actual power generation of the solar power generation unit 10 (and the fuel cell 30). The "demand actual result" refers to the actual power consumption of the load H. Also, the "power generation plan" refers to the power that is submitted in step S108, S111, or S114 of FIG. 2 and is scheduled to be reverse-flowed to the grid power supply as described above. After performing the processing of step S201, the control device 60 proceeds to step S202.

[0076] In step S202, the control device 60 determines whether the surplus difference actual result - the hydrogen production planned value is less than 0. Here, the "hydrogen production planned value" refers to the power consumption of the hydrogen production device 40 scheduled in the operation plan established the previous day. If the control device 60 determines that the surplus difference actual result - the hydrogen production planned value is less than 0 (YES in step S202), the control device 60 proceeds to step S204. On the other hand, if the control device 60 determines that the surplus difference actual result - the hydrogen production planned value is not less than 0 (NO in step S202), the control device 60 proceeds to step S203.

[0077] Note that "YES" in step S202 indicates that if the hydrogen production device 40 produces hydrogen according to the planned hydrogen production values, there will be a shortage of surplus power (hereinafter sometimes simply referred to as "surplus power") from the power generated by the solar power generation unit 10. On the other hand, "NO" in step S202 indicates that there will be sufficient surplus power even if the hydrogen production device 40 produces hydrogen according to the planned hydrogen production values.

[0078] In step S203, the control device 60 determines whether the surplus difference actual result - the hydrogen production planned value > 0. If the control device 60 determines that the surplus difference actual result - the hydrogen production planned value > 0 (YES in step S203), the control device 60 proceeds to step S211 shown in Fig. 6. On the other hand, if the control device 60 determines that the surplus difference actual result - the hydrogen production planned value > 0 is not true (the surplus difference actual result - the hydrogen production planned value ≦ 0) (NO in step S203), the control device 60 proceeds to step S217.

[0079] Note that a "YES" result in step S203 indicates that there will be surplus electricity if the hydrogen production device 40 produces hydrogen based on the planned hydrogen production values. On the other hand, a "NO" result in step S202 and a "NO" result in step S203 indicates that the surplus electricity will be used up exactly when the hydrogen production device 40 produces hydrogen based on the planned hydrogen production values ​​(the actual value of the surplus electricity = the electricity used by the hydrogen production device 40).

[0080] In step S217, the control device 60 controls the operation of the hydrogen production device 40 so that the hydrogen production device 40 produces hydrogen at the planned hydrogen production values ​​(based on the operation plan).

[0081] Meanwhile, in step S204, the control device 60 determines whether or not (surplus difference actual result - hydrogen production planned value + storage battery discharge capacity) is less than 0. Here, "storage battery discharge capacity" refers to the maximum discharge power of the storage battery 20. If the control device 60 determines that (surplus difference actual result - hydrogen production planned value + storage battery discharge capacity) is less than 0 ("YES" in step S204), the control device 60 proceeds to step S205. On the other hand, if the control device 60 determines that (surplus difference actual result - hydrogen production planned value + storage battery discharge capacity) is not less than 0 ("NO" in step S204), the control device 60 proceeds to step S209.

[0082] Note that "YES" in step S204 indicates that even if the storage battery 20 is discharged at the maximum discharge power, there will be a shortage of power consumption when the hydrogen production device 40 produces hydrogen at the planned hydrogen production value. On the other hand, "NO" in step S204 indicates that even if the storage battery 20 is discharged at the maximum discharge power, there will be a sufficient amount of power consumption when the hydrogen production device 40 produces hydrogen at the planned hydrogen production value.

[0083] In step S209, the control device 60 discharges the storage battery 20 so that the hydrogen production device 40 can produce hydrogen at the planned hydrogen production value. After performing the process of step S209, the control device 60 proceeds to step S217. This allows the hydrogen production device 40 to produce hydrogen at the planned hydrogen production value.

[0084] Meanwhile, in step S205, the control device 60 determines whether or not (surplus difference actual result - hydrogen production planned value + storage battery discharge capacity + FC power generation capacity) is less than 0. Here, "FC power generation capacity" refers to the maximum generated (output) power of the fuel cell 30. If the control device 60 determines that (surplus difference actual result - hydrogen production planned value + storage battery discharge capacity + FC power generation capacity) is less than 0 (YES in step S205), the control device 60 proceeds to step S207. On the other hand, if the control device 60 determines that (surplus difference actual result - hydrogen production planned value + storage battery discharge capacity + FC power generation capacity) is not less than 0 (surplus difference actual result + storage battery discharge capacity + FC power generation capacity≧0) (NO in step S205), the control device 60 proceeds to step S206.

[0085] Note that a "YES" result in step S205 indicates that even if the storage battery 20 and the fuel cell 30 are made to output power at their maximum capacities, there will be a shortage of power consumption when the hydrogen production device 40 produces hydrogen at the planned hydrogen production values. On the other hand, a "NO" result in step S205 indicates that even if the storage battery 20 and the fuel cell 30 are made to output power at their maximum capacities, there will be a sufficient amount of power consumption when the hydrogen production device 40 produces hydrogen at the planned hydrogen production values.

[0086] In step S206, the control device 60 controls the fuel cell 30 to output electric power so that the hydrogen production device 40 can produce hydrogen at the planned hydrogen production value when electric power is output from the storage battery 20 at its maximum capacity. After performing the process of step S206, the control device 60 proceeds sequentially to step S209 and step S217. This allows the hydrogen production device 40 to produce hydrogen at the planned hydrogen production value.

[0087] On the other hand, in step S207, the control device 60 corrects the hydrogen production planned value. In this process, the control device 60 reduces the hydrogen production planned value to the surplus difference actual result + the battery discharge capacity. After performing the process of step S207, the control device 60 proceeds to step S208.

[0088] In step S208, the control device 60 determines whether the planned hydrogen production value is equal to or greater than the lower limit of power usage of the hydrogen production device 40 (planned hydrogen production value≧lower limit). If the control device 60 determines that the planned hydrogen production value≧lower limit (YES in step S208), it proceeds to step S209. On the other hand, if the control device 60 determines that the planned hydrogen production value is not equal to or greater than the lower limit (planned hydrogen production value<lower limit) (NO in step S208), it proceeds to step S210.

[0089] Note that if step S208 returns "YES," it means that the hydrogen production planned value corrected in step S207 is equal to or greater than the lower limit of power consumption of the hydrogen production device 40, and therefore the hydrogen production device 40 can operate with the corrected planned hydrogen production value. On the other hand, if step S208 returns "NO," it means that the hydrogen production planned value corrected in step S207 is less than the lower limit of power consumption of the hydrogen production device 40, and therefore the hydrogen production device 40 cannot operate with the corrected planned hydrogen production value.

[0090] In step S209, which is entered after step S208, the control device 60 discharges the storage battery 20 so that the hydrogen production device 40 can produce hydrogen based on the planned hydrogen production values ​​corrected in step S207. After performing the process of step S209, the control device 60 proceeds to step S217, whereby the hydrogen production device 40 can produce hydrogen based on the planned hydrogen production values ​​corrected in step S207.

[0091] On the other hand, in step S210, the control device 60 stops the operation of the hydrogen production device 40. As a result, the production of hydrogen by the hydrogen production device 40 is stopped.

[0092] As described above, if the control device 60 determines "YES" in step S203, the control device 60 proceeds to step S211 shown in FIG. 6. In step S211, the control device 60 determines whether or not (surplus difference actual result - hydrogen production planned value + storage battery charging capacity) is greater than 0. Here, "storage battery charging capacity" refers to the maximum charging power of the storage battery 20. If the control device 60 determines that (surplus difference actual result - hydrogen production planned value + storage battery charging capacity) is greater than 0 ("YES" in step S211), the control device 60 proceeds to step S212. On the other hand, if the control device 60 determines that (surplus difference actual result - hydrogen production planned value + storage battery charging capacity) is not greater than 0 (surplus difference actual result - hydrogen production planned value + storage battery charging capacity≦0) ("NO" in step S211), the control device 60 proceeds to step S216.

[0093] Note that "YES" in step S211 indicates that there will be surplus power if the hydrogen production device 40 produces hydrogen according to the planned hydrogen production values ​​and the storage battery 20 is charged with the maximum charging power. On the other hand, "NO" in step S211 indicates that there will be no surplus power if the hydrogen production device 40 produces hydrogen according to the planned hydrogen production values ​​and the storage battery 20 is charged (i.e., all of the surplus power can be charged to the storage battery 20).

[0094] In step S216, the control device 60 causes the surplus power generated by the solar power generation unit 10 to be charged into the storage battery 20. After performing the process of step S216, the control device 60 proceeds to step S217 shown in Fig. 5, thereby allowing the hydrogen production device 40 to produce hydrogen according to the planned hydrogen production values.

[0095] On the other hand, in step S212, the control device 60 corrects the planned hydrogen production value of the hydrogen production device 40. In this process, the control device 60 raises the planned hydrogen production value to the surplus difference actual value + storage battery charging capacity. After performing the process of step S212, the control device 60 proceeds to step S213.

[0096] In step S213, the control device 60 determines whether the planned hydrogen production value is greater than the upper limit of power usage of the hydrogen production device 40 (planned hydrogen production value > upper limit). If the control device 60 determines that the planned hydrogen production value > the upper limit ("YES" in step S213), the control device 60 proceeds to step S214.

[0097] On the other hand, if the control device 60 determines that the planned hydrogen production value is not greater than the upper limit value (the planned hydrogen production value is less than or equal to the upper limit value) ("NO" in step S213), the process proceeds to step S216 and then to step S217 shown in Fig. 5. This allows the hydrogen production device 40 to produce hydrogen using the planned hydrogen production value corrected in step S212.

[0098] Note that if step S213 returns "YES," this indicates that the hydrogen production planned value corrected in step S212 exceeds the upper limit of power consumption of the hydrogen production device 40, and therefore the hydrogen production device 40 cannot operate with the corrected planned hydrogen production value. On the other hand, if step S213 returns "NO," this indicates that the hydrogen production planned value corrected in step S212 is equal to or less than the upper limit of power consumption of the hydrogen production device 40, and therefore the hydrogen production device 40 can operate with the corrected planned hydrogen production value.

[0099] On the other hand, in step S214, the control device 60 corrects the hydrogen production planned value. In this process, the control device 60 raises the hydrogen production planned value to the upper limit of power usage. After performing the process of step S214, the control device 60 proceeds to step S215.

[0100] In step S215, the control device 60 operates the water purification device 50. After performing the process of step S215, the control device 60 proceeds sequentially to step S216 and step S217 shown in Figure 5. This allows the hydrogen production device 40 to produce hydrogen using the planned hydrogen production values ​​corrected in step S214.

[0101] After performing the process of step S217, the control device 60 ends the execution control shown in FIGS.

[0102] An example of the transition of power in the hydrogen production system 1 will be described below with reference to FIG.

[0103] In the example shown in Fig. 7, it is assumed that the planned surplus difference average is calculated to be 154 kW (see step S104 in Fig. 2 and Fig. 4). An operation plan is made for the hydrogen production device 40 to operate (produce hydrogen) using 154 kW of power during the scheduled operation time (5:30 to 17:30).

[0104] However, in the morning (5:30 to 7:30), the operation of the hydrogen production device 40 consumes more electricity than the actual surplus difference, so the electricity used by the hydrogen production device 40 is compensated for by electricity from the storage battery 20 and fuel cell 30 from 5:30 to 6:30, and by discharged electricity from the storage battery 20 from 6:30 to 7:30.

[0105] From morning until the daytime (7:30 to 11:30), any power remaining after hydrogen is produced by the hydrogen production device 40 is charged into the storage battery 20. When the storage battery 20 is fully charged, the amount of hydrogen produced by the hydrogen production device 40 is increased. Any power remaining after this is used to operate the water purification device 50 (11:30 to 13:00).

[0106] Since the hydrogen production device 40 runs short of electricity during the daytime and evening hours (13:30-17:30), the electricity used by the hydrogen production device 40 is replenished by the discharged power from the storage battery 20 between 13:30 and 15:30, and by the power from the storage battery 20 and the fuel cell 30 between 15:30 and 17:30.

[0107] As described above, the hydrogen production system 1 according to this embodiment uses two types of predicted power generation values ​​(the average predicted power generation value and the 90th percentile predicted power generation value) and creates an appropriate power generation plan taking into account the upper and lower limits of the power consumption of the hydrogen production device 40. This makes it possible to easily absorb prediction errors in the power generation by operating the hydrogen production device 40. Furthermore, if the actual surplus power of the hydrogen production device 40 is insufficient compared to the planned power consumption, the power consumption of the hydrogen production device 40 is compensated for by power from the storage battery 20 and, if necessary, the fuel cell 30. On the other hand, if the actual surplus power of the hydrogen production device 40 is greater than the planned power consumption, the surplus power is used to charge the storage battery 20 or to operate the water purification device 50, thereby making it possible to easily absorb prediction errors in the power generation. This reduces the imbalance.

[0108] Furthermore, since the amount of hydrogen produced by the hydrogen production device 40 does not fluctuate significantly over time (it is nearly constant), frequent ON / OFF switching of the hydrogen production device 40 can be suppressed. Furthermore, continuous partial load operation of the hydrogen production device 40 is suppressed, so deterioration of hydrogen production efficiency can be suppressed. In this way, stable operation of the hydrogen production device 40 is possible in the hydrogen production system 1.

[0109] As described above, the hydrogen production system 1 according to this embodiment includes a solar power generation unit 10 (power generation unit) capable of generating power using natural energy, a hydrogen production device 40 (hydrogen production unit) operable to produce hydrogen using power generated by the solar power generation unit 10, and a control device 60 (planning unit) that creates an operation plan for the hydrogen production device 40. The control device 60 (planning unit) acquires a power generation forecast value that is a forecast value of power generated by the solar power generation unit 10, and a power demand forecast value that is a forecast value of power demand, and the power generation forecast value includes an average power generation forecast value (first power generation forecast value) and a 90% percentile that is smaller than the average forecast value. The calculation includes calculating an average surplus power forecast value (first surplus power forecast value) from the difference between the average power forecast value and the power demand forecast value, and calculating a 90% percentile surplus power forecast value (second surplus power forecast value) from the difference between the 90% percentile power forecast value and the power demand forecast value (step S103).The calculation then determines the power consumption when the hydrogen production device 40 operates based on a planned surplus difference, which is the difference between the average surplus power forecast value and the 90% percentile surplus power forecast value (steps S109, S112, and S115).

[0110] With this configuration, the hydrogen production device 40 can be operated stably while reducing the imbalance. Specifically, the imbalance can be reduced by using the surplus power of the solar power generation unit 10 to produce hydrogen by the hydrogen production device 40. Furthermore, because the power usage of the hydrogen production device 40 is determined in advance based on the planned surplus difference, it is possible to suppress fluctuations in the amount of hydrogen produced by the hydrogen production device 40 over time, which in turn prevents the hydrogen production device 40 from being turned on and off frequently. It is also possible to prevent the hydrogen production device 40 from operating continuously at partial load, which in turn prevents a deterioration in hydrogen production efficiency. In this way, the hydrogen production system 1 enables stable operation of the hydrogen production device 40.

[0111] In addition, the control device 60 (planning unit) calculates the average value of the planned surplus difference during the scheduled operation time of the hydrogen production device 40 (step S104), and sets this average value as the power consumption during the scheduled operation time (step S112).

[0112] With this configuration, the hydrogen production device 40 can be operated more stably. Specifically, the hydrogen production device 40 operates with power equivalent to the average planned surplus difference during the scheduled operation time, which reduces fluctuations in the amount of hydrogen produced by the hydrogen production device 40 over time and thereby prevents the hydrogen production device 40 from being frequently turned on and off. Furthermore, continuous partial load operation of the hydrogen production device 40 is prevented, which in turn prevents a deterioration in hydrogen production efficiency.

[0113] In addition, if the average value of the planned surplus difference is smaller than the lower limit value of power consumption, which is the minimum power consumption required to operate the hydrogen production device 40 (YES in step S105), the control device 60 (planning unit) shortens the scheduled operating time so that the average value of the planned surplus difference increases (step S106).

[0114] With this configuration, the hydrogen production device 40 can be easily operated. Specifically, even if the power generation by the solar power generation unit 10 is not expected to be high throughout the day, the hydrogen production device 40 can be operated during times when the predicted value of power generation is relatively high.

[0115] In addition, if the average value of the planned surplus difference is greater than the upper limit of power usage, which is the power usage when the hydrogen production device 40 is operating at maximum capacity (YES in step S110), the control device 60 (planning unit) reduces the planned surplus difference to the upper limit of power usage (step S113).

[0116] With this configuration, the amount of hydrogen produced by the hydrogen production device 40 can be increased. Specifically, the hydrogen production device 40 can be operated at maximum capacity, and the amount of hydrogen produced can be maximized.

[0117] Furthermore, the hydrogen production system 1 according to this embodiment comprises a storage battery 20 capable of charging and discharging electricity, and a control device 60 (execution unit) that executes the operation of the hydrogen production device 40 based on the operation plan created by the control device 60 (planning unit), and if the electricity usage is insufficient when the hydrogen production device 40 is operated based on the operation plan (YES in step S202), the control device 60 (execution unit) compensates for the electricity usage of the hydrogen production device 40 with electricity from the storage battery 20 (step S209).

[0118] With this configuration, the hydrogen production device 40 can be maintained in stable operation. Specifically, the discharged power from the storage battery 20 can be used to power the hydrogen production device 40, so that frequent ON / OFF switching of the hydrogen production device 40 and operation at partial load can be suppressed.

[0119] In addition, the hydrogen production system 1 according to this embodiment is equipped with a fuel cell 30 capable of generating electricity using fuel, and if the power consumption of the hydrogen production device 40 is insufficient when the hydrogen production device 40 is operated based on the operation plan (YES in step S202), the control device 60 (execution unit) compensates for the power consumption of the hydrogen production device 40 with power from the fuel cell 30 (step S206).

[0120] With this configuration, the hydrogen production device 40 can be maintained in stable operation. Specifically, since the power from the fuel cell 30 can be used to power the hydrogen production device 40, frequent ON / OFF switching of the hydrogen production device 40 and operation at partial load can be suppressed.

[0121] Furthermore, if the shortage of power usage cannot be resolved (YES in step S205), the control device 60 (execution unit) reduces the amount of hydrogen produced by the hydrogen production device 40 (step S207).

[0122] With this configuration, the hydrogen production device 40 can be maintained in stable operation. Specifically, by reducing the amount of hydrogen produced by the hydrogen production device 40, it may be possible to cover the power consumption of the hydrogen production device 40 with the power generated by the solar power generation unit 10. This makes it possible to suppress frequent ON / OFF switching of the hydrogen production device 40 and operation at partial load.

[0123] Furthermore, if the operation of the hydrogen production device 40 based on the operation plan results in surplus power generated by the solar power generation unit 10 (YES in step S203), the control device 60 (execution unit) charges the surplus generated power to the storage battery 20 (step S216 in Figure 6).

[0124] With this configuration, surplus generated power (surplus power) can be consumed in-house. Specifically, instead of selling the surplus electricity from the solar power generation unit 10, the surplus electricity is stored in the storage battery 20, and the surplus electricity can be used to power the load H or the hydrogen production device 40.

[0125] Furthermore, if there is still surplus power generated by the solar power generation unit 10 even after the power is charged into the storage battery 20 (YES in step S211), the control device 60 (execution unit) increases the amount of hydrogen produced by the hydrogen production device 40 (step S212).

[0126] With this configuration, surplus generated power (surplus power) can be consumed in-house. Specifically, the amount of surplus power consumed by the solar power generation unit 10, which is used for power consumption by the hydrogen production device 40, can be increased.

[0127] Furthermore, the hydrogen production system 1 according to this embodiment is equipped with a water purification device 50 capable of purifying water using the power generated by the solar power generation unit 10, and when there is still surplus power generated by the solar power generation unit 10 even after increasing the amount of hydrogen produced by the hydrogen production device 40 (YES in step S211, YES in S213), the control device 60 (execution unit) operates the water purification device 50 using the surplus generated power (step S215).

[0128] With this configuration, surplus generated power (surplus power) can be consumed in-house. Specifically, by operating water purification apparatus 50 using surplus power, the amount of surplus power consumed can be increased.

[0129] Although the embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0130] For example, in this embodiment, the two types of predicted power generation values ​​are the average predicted power generation value and the 90% percentile predicted power generation value, but the present invention is not limited to these. In particular, instead of the 90% percentile predicted power generation value, any value from the 50% to 100% (more than 50 and less than 100) percentile predicted power generation value may be used.

[0131] The hydrogen production system 1 may be configured so that the hydrogen produced in the hydrogen production device 40 is used as fuel for power generation by the fuel cell 30. [Explanation of symbols]

[0132] 1. Hydrogen production system 10. Solar Power Generation Department 20 Storage battery 30 Fuel Cell 40 Hydrogen production equipment 50 Water purification equipment 60 Control device

Claims

1. A power generation unit that can generate electricity using natural energy, a hydrogen production unit operable to produce hydrogen using the power generated by the power generation unit; a planning unit that creates an operation plan for the hydrogen production unit; Equipped with The planning unit acquiring a power generation forecast value that is a forecast value of power generated by the power generation unit and a power demand forecast value that is a forecast value of power demand; determining the power to be used when the hydrogen production unit is operating based on the difference between the predicted power generation value and the predicted power demand value; Hydrogen production system.

2. The planning unit calculating an average surplus power prediction value, which is an average value of the difference between the predicted power generation value and the predicted power demand value during the scheduled operation time of the hydrogen production unit, and setting the average surplus power prediction value as the power usage during the scheduled operation time; The hydrogen production system according to claim 1 .

3. The planning unit When the average surplus power predicted value is smaller than a power consumption lower limit value, which is the minimum power consumption required for operation of the hydrogen production unit, the planned operation time is shortened so that the average surplus power predicted value increases. The hydrogen production system according to claim 2 .

4. The planning unit If the average surplus power prediction value is greater than a power usage upper limit value, which is the power usage when the hydrogen production unit is operating at maximum capacity, the difference between the power generation prediction value and the power demand prediction value is reduced to the power usage upper limit value. The hydrogen production system according to claim 2 or 3.

5. a fuel cell capable of generating electricity using fuel; an execution unit that executes operation of the hydrogen production unit based on the operation plan created by the planning unit; The execution unit: If the power consumption is insufficient when the hydrogen production unit is operated based on the operation plan, the power consumption of the hydrogen production unit is compensated for by the power from the fuel cell. The hydrogen production system according to claim 1 .

6. Equipped with a storage battery capable of charging and discharging power, The execution unit: If the power consumption is insufficient when the hydrogen production unit is operated based on the operation plan, the power consumption of the hydrogen production unit is compensated for by the power from the storage battery. The hydrogen production system according to any one of claims 1 to 5.

7. The execution unit: If the shortage of power usage cannot be resolved, the amount of hydrogen produced by the hydrogen production unit is reduced. The hydrogen production system according to claim 5 or 6.

8. The execution unit: When the hydrogen production unit is operated based on the operation plan and the power generation unit generates surplus power, the surplus power is charged into the storage battery. The hydrogen production system according to claim 6 .

9. The execution unit: When the generated power is still surplus even after the power generated by the power generation unit is charged into the storage battery, the amount of hydrogen produced by the hydrogen production unit is increased. The hydrogen production system according to claim 8 .

10. a water purifier capable of purifying water using the power generated by the power generation unit; The execution unit: when the power generated by the power generation unit remains in excess even after increasing the amount of hydrogen produced by the hydrogen production unit, the excess power is used to operate the water purification device. The hydrogen production system according to claim 9 .

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