Cogeneration system

Abstract

To properly supply power.SOLUTION: A cogeneration system 1 comprises: a cogeneration unit 20; a hot water storage tank 26; a temperature sensor; an operation control unit 50 for deriving a hot water storage tank calorie indicating a calorie which is accumulated in the hot water storage tank 26 on the basis of hot water tank temperature, permitting an operation of the cogeneration unit 20 when the hot water storage tank calorie is lower than a prescribed threshold, and stopping the cogeneration unit 20 when the hot water storage tank calorie is equal to or higher than the prescribed threshold; a data acquisition unit 52 for making a storage device 24 store the hot water storage tank calorie which is derived at each prescribed first time; a prediction value derivation unit 54 for deriving a prediction value of the hot water storage tank calorie at each first time on a further specified date on the basis of the past hot water storage tank calorie which has been stored in the storage device 24; and a supply adaptability determination unit 56 for determining the adaptability of the supply of power to a power system 36 from the cogeneration unit 20 on the specified date on the basis of the prediction value of the hot water storage tank calorie at each first time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cogeneration system. [Background technology]

[0002] For example, Patent Document 1 discloses a cogeneration system equipped with a cogeneration unit that generates heat in conjunction with power generation. This technology performs peak-cut operation, which aligns the operating time period for covering the predicted heat load of the cogeneration unit with the time period of peak electricity demand. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-287132 Summary of the Invention [Problem to be solved by the invention]

[0004] It is desirable to supply the electricity generated by a cogeneration unit to the power grid, allowing the cogeneration unit to contribute as a resource for the power grid's power balancing capability. In the power supply and demand balancing market, bidding is held the day before to determine whether or not power can be supplied for the next day's power adjustment. In order to respond to such bids, it is necessary to predict the future power generation status of the cogeneration unit.

[0005] However, the cogeneration unit generates electricity and heats a heat transfer medium with the heat generated by the power generation, and the heated heat transfer medium is stored in a hot water storage tank. When the amount of heat stored in the hot water storage tank exceeds a predetermined threshold, the cogeneration unit is stopped and is unable to generate electricity. Therefore, depending on the amount of heat stored in the hot water storage tank, the cogeneration unit may not be able to supply power to the power grid. This may result in an inability to submit an accurate bid for the next day's power adjustment bid.

[0006] In view of the above problems, an object of the present invention is to provide a cogeneration system that can appropriately supply electric power. [Means for solving the problem]

[0007] In order to solve the above problem, the cogeneration system of the present invention includes a cogeneration unit that consumes fuel gas to generate electricity, heats a heat medium as the electricity is generated, and is capable of supplying the electricity generated by the power generation to an electric power grid; a hot water tank for storing the heat medium; a temperature sensor that detects the hot water tank temperature, which indicates the temperature of the heat medium in the hot water tank; an operation control unit that derives a hot water tank heat quantity, which indicates the amount of heat stored in the hot water tank, based on the hot water tank temperature, and allows the cogeneration unit to operate if the hot water tank heat quantity is less than a predetermined threshold, and stops the cogeneration unit if the hot water tank heat quantity is equal to or greater than the predetermined threshold; a data acquisition unit that stores the hot water tank heat quantity derived for each predetermined first hour in a memory device; a predicted value derivation unit that derives a predicted value of the hot water tank heat quantity for each first hour on a specific future day based on the past hot water tank heat quantities stored in the memory device; and a supply feasibility determination unit that determines whether or not to supply electricity from the cogeneration unit to the electric power grid on the specific day based on the predicted value of the hot water tank heat quantity for each first hour.

[0008] In order to solve the above problems, the cogeneration system of the present invention includes a cogeneration unit configured to consume fuel gas to generate electricity, heat a heat medium as the electricity is generated, and supply the generated electricity to an electric power grid; a hot water tank for storing the heat medium; a temperature sensor for detecting a hot water tank temperature that indicates the temperature of the heat medium in the hot water tank; an operation control unit that derives a hot water tank heat quantity that indicates the amount of heat stored in the hot water tank based on the hot water tank temperature, and allows the cogeneration unit to operate when the hot water tank heat quantity is less than a predetermined threshold, and stops the cogeneration unit when the hot water tank heat quantity is equal to or greater than the predetermined threshold; The system includes a data acquisition unit that defines the time when the cogeneration unit switches from a stopped state to an operating state as a start time, defines the time when the cogeneration unit switches from an operating state to a stopped state as a stop time, and stores the start time in a storage device each time the cogeneration unit switches from a stopped state to an operating state and stores the stop time in the storage device each time the cogeneration unit switches from an operating state to a stopped state, and a supply feasibility determination unit that determines whether or not power can be supplied from the cogeneration unit to the power grid on a specific future date based on the past start times and stop times stored in the storage device.

[0009] In addition, if the entire requested time period, which indicates the time period during which power adjustment is required, is not included in the supplyable time period, which indicates the time period during which power can be supplied, the system may further include a time period adjustment unit that controls the change of the operating time period of the cogeneration unit on a specific day so that the entire requested time period is included in the supplyable time period. [Effects of the Invention]

[0010] According to the present invention, it is possible to supply power appropriately. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a block diagram showing the configuration of a cogeneration system 1 according to the first embodiment. [Figure 2]FIG. 2 is a diagram showing an example of the time transition of the amount of power generated in the cogeneration unit and an example of the time transition of the amount of heat in the hot water tank. [Figure 3] FIG. 3 is a flowchart illustrating the flow of operations of the data acquisition unit. [Figure 4] FIG. 4 is a diagram for explaining an outline of the operations of the predicted value derivation unit and the supply availability determination unit. [Figure 5] FIG. 5 is a flowchart illustrating the flow of operations of the predicted value derivation unit and the supply availability determination unit. [Figure 6] FIG. 6 is a flowchart illustrating the flow of the supply availability determination process. [Figure 7] FIG. 7 is a flowchart illustrating the flow of operations of the data acquisition unit in the second embodiment. [Figure 8] FIG. 8 is a diagram illustrating an outline of the operations of the predicted value derivation unit and the supply availability determination unit in the second embodiment. [Figure 9] FIG. 9 is a flowchart illustrating the flow of operations of the predicted value derivation unit and the supply availability determination unit in the second embodiment. [Figure 10] FIG. 10 is a diagram illustrating an outline of a modified example of the second embodiment. [Figure 11] FIG. 11 is a block diagram showing the configuration of a cogeneration system according to the third embodiment. [Figure 12] FIG. 12 is a flowchart illustrating the flow of operations of the time period adjustment unit. [Figure 13] FIG. 13 is a diagram illustrating an example of the time period adjustment process. [Figure 14] FIG. 14 is a diagram illustrating another example of the time period adjustment process. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0013] (First embodiment) 1 is a block diagram showing the configuration of a cogeneration system 1 according to the first embodiment. The cogeneration system 1 includes a distributed power supply device 10, a server device 12, and an electricity supply and demand adjustment market 14.

[0014] The distributed power supply system 10 is installed in a building such as a house. The distributed power supply system 10 may be installed across multiple buildings. The distributed power supply system 10 includes a cogeneration unit 20, a communication device 22, a storage device 24, a hot water storage tank 26, a first temperature sensor 28, a second temperature sensor 30, a level meter 32, and a control device 34.

[0015] The cogeneration unit 20 consumes fuel gas to generate electricity, generates heat as the electricity is generated, and uses the generated heat to heat a heat medium. The fuel gas is city gas, but is not limited to this example, and may be propane gas or hydrogen gas. The heat medium is, for example, water, but is not limited to this example, and may be any fluid capable of transferring heat. The cogeneration unit 20 is, for example, a fuel cell unit, but is not limited to this example, and may be anything that consumes fuel gas to generate electricity and heat.

[0016] The cogeneration unit 20 can be electrically connected to the power grid 36. The cogeneration unit 20 is configured to be able to supply the power generated by power generation to the power grid 36. In other words, in the distributed power supply device 10, the cogeneration unit 20 can contribute as a resource for adjusting power in the power grid 36.

[0017] The communication device 22 can establish communication with the server device 12 via wired or wireless communication. The storage device 24 is configured with a nonvolatile storage element. The nonvolatile storage element may include an electrically readable and writable nonvolatile storage element such as a flash memory.

[0018] Hot water storage tank 26 is a container capable of storing a heat medium therein. Hot water storage tank 26 is connected to cogeneration unit 20 and stores the heat medium heated by cogeneration unit 20. The heat medium in hot water storage tank 26 is sent to heat load equipment such as a heat exchanger, and the heat of the heat medium is consumed by the heat load equipment. Also, new unheated heat medium may be supplied to hot water storage tank 26.

[0019] First temperature sensor 28 is disposed in hot water tank 26. First temperature sensor 28 detects the hot water tank temperature, which indicates the temperature of the heat medium in hot water tank 26. For example, multiple (e.g., four) first temperature sensors 28 are disposed in a dispersed manner in the depth direction of hot water tank 26. In this case, first temperature sensor 28 detects the temperature of the heat medium at each depth.

[0020] The second temperature sensor 30 is disposed, for example, in a pipe that supplies new, unheated heat medium to the hot water storage tank 26. The second temperature sensor 30 detects the temperature of the new, unheated heat medium supplied to the hot water storage tank 26, i.e., a reference temperature that indicates the temperature of the heat medium before it is heated.

[0021] Level meter 32 detects the total amount of heat medium in hot water storage tank 26. For example, level meter 32 detects the depth of the heat medium stored in hot water storage tank 26, thereby indirectly detecting the total amount of heat medium in hot water storage tank 26.

[0022] The control device 34 has a processor 40 and a memory 42. The processor 40 controls the entire distributed power generation system 10 in cooperation with a program stored in the memory 42. By executing the program, the processor 40 also functions as an operation control unit 50, a data acquisition unit 52, a predicted value derivation unit 54, and a supply feasibility determination unit 56.

[0023] The operation control unit 50 derives the hot water tank heat quantity, which indicates the amount of heat stored in the hot water tank 26, based on the hot water tank temperature. More specifically, the operation control unit 50 derives the temperature difference by subtracting a reference temperature from the hot water tank temperature. The operation control unit 50 multiplies the derived temperature difference by the total amount of heat medium in the hot water tank 26 to derive the hot water tank heat quantity.

[0024] For example, if multiple first temperature sensors 28 that detect the hot water tank temperature are distributed along the depth direction of hot water tank 26, operation control unit 50 acquires the hot water tank temperature corresponding to each depth from each first temperature sensor 28. Operation control unit 50 also acquires a reference temperature from second temperature sensor 30. For each depth corresponding to each first temperature sensor 28, operation control unit 50 subtracts the reference temperature from the hot water tank temperature measured by first temperature sensor 28 to derive the temperature difference.

[0025] The operation control unit 50 also acquires the total amount of heat medium in the hot water storage tank 26 from the level meter 32. Based on the acquired total amount of heat medium, the operation control unit 50 derives the amount of heat medium at each depth corresponding to each first temperature sensor 28. The operation control unit 50 multiplies the temperature difference corresponding to each first temperature sensor 28 by the amount of heat medium at the depth corresponding to that first temperature sensor 28 to derive the heat quantity of the heat medium corresponding to that first temperature sensor 28 for each first temperature sensor 28. The operation control unit 50 sums the heat quantities of the heat medium for each first temperature sensor 28 to derive the hot water storage tank heat quantity.

[0026] The operation control unit 50 allows the cogeneration unit 20 to operate when the heat quantity of the hot water tank is less than a predetermined threshold. The predetermined threshold is set to the heat quantity when the hot water tank 26 is fully charged with a heat medium at 60°C, for example, but is not limited to this example and can be set arbitrarily depending on the heat utilization mode. Allowing the cogeneration unit 20 to operate means that the cogeneration unit 20 is capable of generating electricity.

[0027] When the heat quantity of the hot water tank is equal to or greater than a predetermined threshold, the operation control unit 50 stops the cogeneration unit 20. In other words, in this case, the cogeneration unit 20 cannot generate power. The data acquisition unit 52, the predicted value derivation unit 54, and the supply feasibility determination unit 56 will be described in detail later.

[0028] The server device 12 is managed by, for example, an aggregator. The server device 12 can be involved in the control of the distributed power supply system 10. The aggregator refers to an entity that provides a service that manages the supply and demand of power for consumers. The administrator of the server device 12 (for example, the aggregator) manages the supply and demand of power for consumers that have distributed power supply systems 10 (i.e., cogeneration units 20).

[0029] The server device 12 includes a communication device 60 , a storage device 62 , a user interface 64 and a control device 66 .

[0030] The communication device 60 can establish communication with the distributed power supply device 10 via wired communication or wireless communication. The communication device 60 can also establish communication with the electricity supply and demand balancing market 14. The storage device 62 is configured with a nonvolatile storage element. Note that the nonvolatile storage element may include an electrically readable and writable nonvolatile storage element such as a flash memory.

[0031] The user interface 64 includes an output device, such as a display device, that presents various information and images to the user, and an input device, such as a keyboard or a mouse, that accepts input operations by the user.

[0032] The control device 66 has a processor 70 and a memory 72. The processor 70 controls the entire server device 12 in cooperation with a program stored in the memory 72. The processor 70 also functions as a server control unit 80 by executing the program.

[0033] In the electricity supply and demand adjustment market 14, bidding for the adjustment capacity of power for the next day is held the day before. Aggregators can respond to the bids through the server device 12. When the bids are agreed upon, an instruction to execute the power adjustment is transmitted from the electricity supply and demand adjustment market 14 to the server device 12 on the day the power adjustment is to be performed.

[0034] When the server control unit 80 of the server device 12 receives the execution instruction, it controls the power generated by the distributed power supply system 10 in accordance with the execution instruction. Under the control of the server control unit 80, the operation control unit 50 of the distributed power supply system 10 controls the power generated by the cogeneration unit 20 and supplies the power generated by the cogeneration unit 20 to the power grid 36.

[0035] Fig. 2 shows an example of the time evolution of the amount of power generated in the cogeneration unit 20 and an example of the time evolution of the amount of heat in the hot water tank. Fig. 2(a) shows an example of the time evolution of the amount of power generated, and Fig. 2(b) shows an example of the time evolution of the amount of heat in the hot water tank. The time axis in Fig. 2(a) and the time axis in Fig. 2(b) are the same.

[0036] 2, it is assumed that there is a heat demand predicted at a future time point T5. The operation control unit 50 controls the cogeneration unit 20 so that the amount of heat is gradually stored toward the future time point T5.

[0037] For example, as shown in Figure 2(a), the operation control unit 50 starts the cogeneration unit 20 at time T1 to start power generation, and gradually increases the amount of power generation. After time T2 when the amount of power generation reaches power generation amount P2, the operation control unit 50 maintains power generation amount P1. Then, as shown in Figure 2(b), as the cogeneration unit 20 starts up, the hot water tank heat quantity increases from the hot water tank heat quantity H1 before the cogeneration unit 20 started up.

[0038] As shown in Fig. 2(b), at time T3 when the hot water tank heat quantity reaches hot water tank heat quantity H2, the operation control unit 50 reduces the power generation amount of the cogeneration unit 20 from power generation amount P1 to power generation amount P2 as shown in Fig. 2(a). Because power generation itself continues, the hot water tank heat quantity further increases from hot water tank heat quantity H2 as shown in Fig. 2(b).

[0039] As shown in FIG. 2(b), it is assumed that at time T4, the hot water tank heat quantity reaches hot water tank heat quantity H3, which corresponds to a predetermined threshold. At time T4 when the hot water tank heat quantity reaches the predetermined threshold, operation control unit 50 stops cogeneration unit 20, which had been operating, as shown in FIG. 2(a). When cogeneration unit 20 is stopped, the amount of power generation becomes zero. After time T4 when cogeneration unit 20 is stopped, hot water tank 26 retains the heat of the heat medium therein. In other words, the hot water tank heat quantity is maintained at hot water tank heat quantity H3 after time T4.

[0040] At time T5 after time T4, the heat medium in hot water tank 26 is supplied to the heat load equipment, consuming the heat in hot water tank 26, and the hot water tank heat quantity decreases as shown in Fig. 2(b). Then, at time T6, the hot water tank heat quantity has decreased to hot water tank heat quantity H1.

[0041] 2(a) and 2(b), the hot water tank heat quantity is equal to or greater than the hot water tank heat quantity H3, which corresponds to the predetermined threshold, during the time period from time T4 to time T5. Therefore, during this time period, the operation control unit 50 keeps the cogeneration unit 20 in a stopped state, and the cogeneration unit 20 is unable to generate power.

[0042] That is, during the time period when the hot water tank heat quantity is equal to or greater than the predetermined threshold, the cogeneration unit 20 cannot generate power, and therefore cannot supply power to the power grid 36. In other words, during the time period when the hot water tank heat quantity is less than the predetermined threshold, the cogeneration unit 20 can generate power, and therefore can supply power to the power grid 36.

[0043] Depending on the heat demand prediction results, the cogeneration unit 20 may be in a stopped state even during a time period when the hot water tank heat quantity is below the predetermined threshold, such as earlier than time T1 in Fig. 2. However, if the hot water tank heat quantity is below the predetermined threshold, the operation of the cogeneration unit 20 is permitted, and therefore it is possible to control the cogeneration unit 20 to operate even during a time period when the hot water tank heat quantity is below the predetermined threshold and the cogeneration unit 20 is in a stopped state.

[0044] 2, depending on the value of the hot water tank heat quantity, it may be impossible to supply power from the cogeneration unit 20 to the power grid 36. In this case, the aggregator may not be able to submit an accurate bid for adjustment capacity in the power supply and demand adjustment market 14. For example, if the time period in which power adjustment is required in a contracted bid overlaps with the time period in which the cogeneration unit 20 cannot generate power, a situation may arise in which power cannot be supplied to the power grid 36.

[0045] Therefore, the cogeneration system 1 of the first embodiment has the following configuration so that the aggregator can know whether or not power can be supplied to the power grid 36 in the future.

[0046] 3 is a flowchart illustrating the operation of data acquisition unit 52. Data acquisition unit 52 stores the hot water tank heat quantity calculated every predetermined first hour in memory device 24. The predetermined first hour is set to, for example, 10 minutes, but is not limited to this example and can be set arbitrarily.

[0047] 3, the data acquisition unit 52 determines whether a predetermined acquisition execution timing set for each predetermined first hour has arrived (S10). If the predetermined acquisition execution timing has not arrived (NO in S10), the data acquisition unit 52 waits until the predetermined acquisition execution timing arrives.

[0048] When the predetermined acquisition execution timing arrives (YES in S10), the data acquisition unit 52 acquires the current hot water tank temperature using the first temperature sensor 28 (S11). Next, the data acquisition unit 52 acquires the current reference temperature using the second temperature sensor 30 (S12). Next, the data acquisition unit 52 acquires the current total amount of heat medium in the hot water tank 26 (i.e., the current storage amount) using the level meter 32 (S13).

[0049] Next, data acquisition unit 52 derives the current hot water tank heat quantity based on the hot water tank temperature, the reference temperature, and the storage volume (S14). For example, data acquisition unit 52 derives the hot water tank heat quantity by multiplying the temperature difference between the hot water tank temperature and the reference temperature by the storage volume. More specifically, data acquisition unit 52 may derive the hot water tank heat quantity using the same method as the method for deriving the hot water tank heat quantity in operation control unit 50 described above.

[0050] Next, data acquisition unit 52 stores the calculated current hot water tank heat quantity in memory device 24 in association with the current time (S15), and ends the processing for this acquisition execution timing. In this way, actual values ​​of the hot water tank heat quantity for each first hour are accumulated in memory device 24.

[0051] 4 is a diagram illustrating an overview of the operation of the predicted value derivation unit 54 and the supply feasibility determination unit 56. In FIG. 4, the predicted value of the hot water tank heat quantity for each first hour on a specific day is illustrated by a black circle. The specific day is, for example, the day after the day (e.g., today) on which a bid for adjustment capacity is submitted in the electricity supply and demand adjustment market 14, and is the day on which power adjustment is requested (the day on which power supply is executed as a result of the agreement). The first hour is the same as the first hour at which the actual value of the hot water tank heat quantity is accumulated by the data acquisition unit 52.

[0052] The predicted value derivation unit 54 derives a predicted value of the hot water tank heat quantity for each first hour on a specific future date based on the past hot water tank heat quantities stored in the storage device 24. As a result, for example, predicted values ​​of the hot water tank heat quantity, such as those indicated by black circles in Fig. 4, are derived for each time point separated by the first hour.

[0053] For example, the predicted value derivation unit 54 sets any time point at which a predicted value of the hot water tank heat quantity for a specific day should be derived as the derivation target time point. The predicted value derivation unit 54 may set the average value of the actual values ​​of the hot water tank heat quantity at the same time point as the derivation target time point during a predetermined past period (for example, from the present to one month ago) as the predicted value of the hot water tank heat quantity at the derivation target time point. Note that the specific method for deriving the predicted value of the hot water tank heat quantity is not limited to the derivation method exemplified above, and any method may be used.

[0054] The supply possibility determination unit 56 determines whether or not to supply power from the cogeneration unit 20 to the power grid 36 on the specific day, based on the predicted value of the heat quantity of the hot water tank for each first hour.

[0055] For example, supply possibility determination unit 56 determines whether the predicted value of the hot water tank heat quantity is equal to or greater than a predetermined threshold value Th shown by the dashed dotted line in Fig. 4 for each predicted value of the hot water tank heat quantity (in other words, for each time point corresponding to the predicted value of the hot water tank heat quantity). The predetermined threshold value Th is set to an arbitrary value based on the threshold value of the hot water tank heat quantity at which cogeneration unit 20 is stopped, for example.

[0056] If the predicted value of the hot water tank heat quantity at any time point is equal to or greater than predetermined threshold Th, supply feasibility determination unit 56 determines that supply is not possible for that time point. If the predicted value of the hot water tank heat quantity at any time point is less than predetermined threshold Th, supply feasibility determination unit 56 determines that supply is possible for that time point. Supply feasibility determination unit 56 makes such a determination for all time points corresponding to the predicted values ​​of the hot water tank heat quantity.

[0057] The supply availability determination unit 56 extracts consecutive time periods that are consecutive time periods that do not include any time periods that are determined to be supply unavailable within the range of the specific day. In the example of Fig. 4, the time period between time points T11 and T12 and the time period between time points T13 and T14 are consecutive time periods.

[0058] The supply availability determination unit 56 determines whether the continuous time, which is the time from the start point to the end point of the continuous time period, is equal to or longer than a predetermined second time. The predetermined second time is set to, for example, 30 minutes, but is not limited to this example and can be set arbitrarily according to the time when power adjustment is required. The predetermined second time is set to be equal to or longer than the first time.

[0059] If the continuous time period in a consecutive time period is equal to or longer than a predetermined second hour, the supply feasibility determination unit 56 determines the consecutive time period as a supply possible time period, which is a time period during which power can be supplied from the cogeneration unit 20 to the power grid 36. If the continuous time period in a consecutive time period is less than the predetermined second hour, the supply feasibility determination unit 56 determines the consecutive time period as a supply impossible time period, which is a time period during which power cannot be supplied from the cogeneration unit 20 to the power grid 36. The supply feasibility determination unit 56 performs this determination of time periods for all extracted consecutive time periods.

[0060] In the example of Fig. 4, the continuous time period between time points T11 and T12 is equal to or longer than the second hour, making it a supply-enabled time period. Also, in the example of Fig. 4, the continuous time period between time points T13 and T14 is equal to or longer than the second hour, making it a supply-disabled time period.

[0061] The supply availability determination unit 56 transmits the result of this determination to the server device 12 via the communication device 22. When the server control unit 80 of the server device 12 receives the determination result from the distributed power supply apparatus 10, it can display the received determination result on the display device of the user interface 64. This allows the aggregator to recognize the time periods during which the distributed power supply apparatus 10 can and cannot supply power. As a result, the aggregator can accurately submit bids in the electricity supply and demand adjustment market 14.

[0062] 5 is a flowchart illustrating the operation of the predicted value derivation unit 54 and the supply feasibility determination unit 56. For example, when responding to a bid in the electricity supply and demand adjustment market 14, the aggregator inputs, via the user interface 64, to the server device 12, an instruction to execute a determination as to whether or not to supply electricity on a specific future date. In response to the input, the server control unit 80 transmits, via the communication device 60, a determination execution command to the distributed power supply device 10, instructing the execution of a determination as to whether or not to supply electricity.

[0063] In addition, the determination execution command may include not only information instructing the execution of a determination as to whether or not power can be supplied, but also, for example, information on a specific day, information on a requested time period indicating a time period during which power adjustment is required, and the like.

[0064] The predicted value derivation unit 54 of the distributed power supply device 10 determines whether or not a determination execution command has been received at each predetermined interrupt timing that occurs at a predetermined cycle (S20). If the predicted value derivation unit 54 has not received a determination execution command (NO in S20), it ends the processing at the current interrupt timing.

[0065] When the determination execution command is received (YES in S20), the predicted value derivation unit 54 reads necessary data, for example, past actual values ​​of the heat quantity of the hot water tank, from the storage device 24 (S21).

[0066] The predicted value deriving unit 54 derives a predicted value of the hot water tank heat quantity on a specific future date for each time point separated by a first time period, based on the read past hot water tank heat quantities (S22).

[0067] Next, the supply availability determination unit 56 executes a supply availability determination process (S23) to determine whether or not power can be supplied. The flow of the supply availability determination process (S23) will be described later. The supply availability determination unit 56 transmits the result of the supply availability determination process (S23) to the server device 12 via the communication device 22 (S24), and ends the processing at this interrupt timing.

[0068] 6 is a flowchart illustrating the flow of the supply availability determination process (S23). The supply availability determination unit 56 first determines an arbitrary time point from among a plurality of time points separated by a first time period on a specific day as the time point to be determined (S30). Hereinafter, the time point to be determined may be referred to as the determination time point.

[0069] Next, supply possibility determination unit 56 determines whether or not the predicted value of the amount of heat in the hot water tank at the time of determination is equal to or greater than a predetermined threshold value Th (S31).

[0070] If the predicted value of the hot water tank heat quantity at the time of determination is equal to or greater than the predetermined threshold value Th (YES in S31), supply possibility determination unit 56 determines that supply is not possible at the time of determination (S32), and proceeds to the processing of step S .

[0071] If the predicted value of the hot water tank heat quantity at the time of determination is less than the predetermined threshold value Th (NO in S31), supply possibility determination unit 56 determines that supply is possible at the time of determination (S33), and proceeds to the processing of step S .

[0072] In step S34, the supply availability determination unit 56 determines whether the determination has been completed for all of the multiple time points separated by the first time on the specific day (S34). If there is a time point for which the determination has not been completed among the multiple time points (NO in S34), the supply availability determination unit 56 returns to step S30 and performs the comparison in step S31 on any of the multiple time points for which the determination has not been completed as the time point to be determined.

[0073] When the determination has been completed for all of the plurality of time points (YES in S34), the supply availability determination unit 56 extracts a continuous time period in which the plurality of time points determined to be supply available are consecutive (S35).

[0074] The supply availability determination unit 56 determines any of the extracted consecutive time periods as the consecutive time period to be subjected to determination (S36). Hereinafter, the consecutive time period to be subjected to determination may be referred to as the determination subject consecutive time period.

[0075] Next, the supply availability determination unit 56 determines whether or not the continuous time period in the determination target continuous time period is equal to or longer than a second time period (S37).

[0076] If the continuous time period in the determination target continuous time period is equal to or longer than the second time period (YES in S37), the supply availability determination unit 56 determines that the determination target continuous time period is a supply available time period (S38), and proceeds to the processing of step S40.

[0077] If the continuous time in the determination target continuous time period is less than the second time period (NO in S37), the supply availability determination unit 56 determines that the determination target continuous time period is a supply unavailable time period (S39), and proceeds to the processing of step S40.

[0078] In step S40, the supply availability determination unit 56 determines whether the determination has been completed for all of the extracted consecutive time periods (S40). If there are consecutive time periods among the extracted consecutive time periods for which the determination has not been completed (NO in S40), the supply availability determination unit 56 returns to step S36 and performs the comparison in step S37 on any consecutive time period among the extracted consecutive time periods for which the determination has not been completed as the consecutive time period to be determined.

[0079] When the determination has been completed for all of the extracted consecutive time periods (YES in S40), the supply feasibility determination unit 56 ends the supply feasibility determination process (S23). If the result of the supply feasibility determination process (S23) shows that there is no time period in which power can be supplied, this corresponds to the fact that power cannot be supplied from the cogeneration unit 20 to the power grid 36 on the specific day. If the result of the supply feasibility determination process (S23) shows that there is a time period in which power can be supplied, this corresponds to the fact that power can be supplied from the cogeneration unit 20 to the power grid 36 on the specific day.

[0080] 5, the supply availability determination unit 56 transmits at least information about the supply available time slot to the server device 12. The information about the supply available time slot may include whether or not there is a supply available time slot (whether or not power can be supplied), the start and end points of the supply available time slot, and the time from the start to the end point of the supply available time slot.

[0081] As described above, in the cogeneration system 1 of the first embodiment, a predicted value of the hot water tank heat quantity for each first hour on a specific future day is derived based on the past hot water tank heat quantity stored in the storage device 24. Then, in the cogeneration system 1 of the first embodiment, a determination is made as to whether or not to supply power from the cogeneration unit 20 to the power grid 36 on the specific day based on the predicted value of the hot water tank heat quantity for each first hour.

[0082] As a result, in the cogeneration system 1 of the first embodiment, the aggregator can refer to the determination result of whether or not power can be supplied on a specific future date, thereby determining whether or not power can be supplied to the power grid 36 in the future. As a result, the aggregator can accurately submit a bid for adjustment capacity in the power supply and demand adjustment market 14. Therefore, the cogeneration system 1 of the first embodiment allows power to be appropriately supplied from the cogeneration unit 20.

[0083] Furthermore, in the cogeneration system 1 of the first embodiment, the supply available time period is also specified. This allows the aggregator to grasp in detail the time period on a specific day during which power can be supplied to the power grid 36. As a result, the aggregator can more accurately submit bids for adjustment power in the electricity supply and demand adjustment market 14.

[0084] (Second embodiment) In the first embodiment, whether or not to supply power from the cogeneration unit 20 to the power grid 36 on a specific future day was determined based on the predicted value of the hot water tank heat quantity for each first hour. In contrast, in the second embodiment, the time period during which the cogeneration unit 20 will operate on a specific future day is predicted from the actual operation history of the cogeneration unit 20, and whether or not to supply power to the power grid 36 on the specific future day is determined based on the prediction result.

[0085] In the second embodiment, the processing contents of the data acquisition unit 52, the predicted value derivation unit 54, and the supply availability determination unit 56 are different from those of the first embodiment, but the other configurations are similar to those of the first embodiment. In the second embodiment, differences from the first embodiment will be described, and a description of the configurations similar to those of the first embodiment will be omitted.

[0086] Hereinafter, the time when the cogeneration unit 20 switches from a stopped state to an operating state may be referred to as a start-up time. Also, the time when the cogeneration unit 20 switches from an operating state to a stopped state may be referred to as a stop time.

[0087] 7 is a flowchart illustrating the flow of operation of the data acquisition unit 52 in the second embodiment. In the second embodiment, the data acquisition unit 52 stores the start time in the storage device 24 each time the cogeneration unit 20 is switched from a stopped state to an operating state. The data acquisition unit 52 stores the stop time in the storage device 24 each time the cogeneration unit 20 is switched from an operating state to a stopped state. In other words, information on the start time and stop time of the cogeneration unit 20 is accumulated in the storage device 24.

[0088] 7, the data acquisition unit 52 acquires cogeneration status information indicating the current status of the cogeneration unit 20 from the cogeneration unit 20 at each predetermined interrupt timing that occurs at a predetermined cycle (S40). The cogeneration status information includes, for example, information indicating whether the current status of the cogeneration unit 20 is a stopped state or an operating state.

[0089] Next, the data acquisition unit 52 determines whether the cogeneration unit 20 has been switched from a stopped state to an operating state based on the cogeneration state information (S41). For example, if the cogeneration state information acquired at the previous interrupt timing indicates a stopped state and the cogeneration state information acquired at the current interrupt timing indicates an operating state, the data acquisition unit 52 determines that the cogeneration unit 20 has been switched from a stopped state to an operating state.

[0090] If it is determined that the cogeneration unit 20 has been switched from a stopped state to an operating state (YES in S41), the data acquisition unit 52 stores the time at which the determination was made in the memory device 24 as the start-up time (S42), and ends processing at this interrupt timing.

[0091] If it is determined that the cogeneration unit 20 has not been switched from the stopped state to the operating state (NO in S41), the data acquisition unit 52 determines whether the cogeneration unit 20 has been switched from the operating state to the stopped state based on the cogeneration state information (S43). For example, if the cogeneration state information acquired at the previous interrupt timing indicates the operating state and the cogeneration state information acquired at the current interrupt timing indicates the stopped state, the data acquisition unit 52 determines that the cogeneration unit 20 has been switched from the operating state to the stopped state.

[0092] If it is determined that the cogeneration unit 20 has been switched from an operating state to a stopped state (YES in S43), the data acquisition unit 52 stores the time at which the determination was made as the stop time in the storage device 24 (S43), and ends the processing at the current interrupt timing. On the other hand, if it is determined that the cogeneration unit 20 has not been switched from an operating state to a stopped state (NO in S43), the data acquisition unit 52 ends the processing at the current interrupt timing.

[0093] FIG. 8 is a diagram illustrating an outline of the operations of the predicted value derivation unit 54 and the supply availability determination unit 56 in the second embodiment.

[0094] The predicted value derivation unit 54 derives a predicted value of the start-up time of the cogeneration unit 20 on a specific future date based on the past start-up times stored in the storage device 24. As a result, predicted values ​​of the start-up times indicated by time points T21 and T22 in FIG. 8 are derived, for example.

[0095] Furthermore, the predicted value derivation unit 54 derives a predicted value of the stop time of the cogeneration unit 20 on a specific future date based on the past stop times stored in the storage device 24. As a result, predicted values ​​of the start times indicated by time T32 and time T24 in FIG. 8 are derived, for example.

[0096] For example, the predicted value derivation unit 54 may use the average value of the actual values ​​of past start times over a predetermined period of the past (e.g., from the present to one month ago) as the predicted value of the start time. Similarly, the predicted value derivation unit 54 may use the average value of the actual values ​​of past stop times over a predetermined period of the past (e.g., from the present to one month ago) as the predicted value of the stop time. Note that the specific method for deriving the predicted values ​​of the start time and the stop time is not limited to the derivation method exemplified above, and any method may be used.

[0097] The supply feasibility determination unit 56 determines whether or not power can be supplied from the cogeneration unit 20 to the power grid 36 on a specific future day, based on the past start-up times and stop times stored in the storage device 24. More specifically, the supply feasibility determination unit 56 determines whether or not power can be supplied from the cogeneration unit 20 to the power grid 36 on a specific future day, based on the predicted values ​​of the start-up time and the stop time derived by the predicted value derivation unit 54.

[0098] The supply availability determination unit 56 extracts, within the range of the specific day, a predicted start time and a predicted operating time slot, which is the time slot from the predicted start time to the predicted first stop time. In the example of Fig. 8, the time slots between time points T21 and T23 and between time points T22 and T24 are the predicted operating time slots.

[0099] The supply availability determination unit 56 determines whether the predicted operating time, which is the time from the start point to the end point of the predicted operating time slot, is equal to or longer than a predetermined second time.

[0100] If the predicted operating time in a predicted operating time slot is equal to or greater than a predetermined second hour, the supply feasibility determination unit 56 determines that predicted operating time slot as a supply possible time slot, which is a time slot during which power can be supplied from the cogeneration unit 20 to the power grid 36. If the predicted operating time in a predicted operating time slot is less than the predetermined second hour, the supply feasibility determination unit 56 determines that predicted operating time slot as a supply impossible time slot, which is a time slot during which power cannot be supplied from the cogeneration unit 20 to the power grid 36. The supply feasibility determination unit 56 performs this time slot determination for all extracted predicted operating time slots.

[0101] In the example of Fig. 8, the predicted operating time of the predicted operating time slot between time points T21 and T23 is equal to or longer than the second hour, and this predicted operating time slot is a supply-available time slot. In the example of Fig. 8, the predicted operating time slot between time points T22 and T24 is shorter than the second hour, and this predicted operating time slot is a supply-unavailable time slot.

[0102] The supply availability determination unit 56 transmits the result of this determination to the server device 12 via the communication device 22. When the server control unit 80 of the server device 12 receives the determination result from the distributed power supply apparatus 10, it can display the received determination result on the display device of the user interface 64. This allows the aggregator to recognize the time periods during which the distributed power supply apparatus 10 can and cannot supply power. As a result, the aggregator can accurately submit bids in the electricity supply and demand adjustment market 14.

[0103] 9 is a flowchart illustrating the operation of the predicted value derivation unit 54 and the supply availability determination unit 56 in the second embodiment. The predicted value derivation unit 54 determines whether or not a determination execution command has been received at each predetermined interrupt timing that occurs at a predetermined cycle (S50). If the predicted value derivation unit 54 has not received a determination execution command (NO in S50), it ends the processing at the current interrupt timing.

[0104] When the determination execution command is received (YES in S50), the predicted value derivation unit 54 reads necessary data, such as past performance values ​​of start times and stop times, from the storage device 24 (S21).

[0105] The predicted value derivation unit 54 derives a predicted value of the start time on a specific future date based on the read past start times (S52).The predicted value derivation unit 54 derives a predicted value of the stop time on a specific future date based on the read past stop times (S53).

[0106] The supply availability determination unit 56 extracts a predicted operating time period based on the predicted values ​​of the start time and the stop time (S54).

[0107] The supply availability determination unit 56 determines any one of the extracted predicted operating time periods as the predicted operating time period to be determined (S55). Hereinafter, the predicted operating time period to be determined may be referred to as the "determination subject predicted operating time period."

[0108] Next, the supply availability determination unit 56 determines whether the predicted operating time in the determination target predicted operating time slot is equal to or longer than the second time (S56).

[0109] If the predicted operating time in the determination target predicted operating time slot is equal to or longer than the second hour (YES in S56), the supply availability determination unit 56 determines that the determination target predicted operating time slot is a supply possible time slot (S57), and proceeds to the processing of step S59.

[0110] If the predicted operating time in the determination target predicted operating time slot is less than the second hour (NO in S56), the supply availability determination unit 56 determines that the determination target predicted operating time slot is a supply unavailable time slot (S58), and proceeds to the processing of step S59.

[0111] In step S59, the supply feasibility determination unit 56 determines whether determination has been completed for all of the extracted predicted operating time periods (S59). If there are any of the extracted predicted operating time periods for which determination has not been completed (NO in S59), the supply feasibility determination unit 56 returns to step S55 and performs the comparison in step S56 on any of the extracted predicted operating time periods for which determination has not been completed, as the predicted operating time period to be determined.

[0112] When the determination has been completed for all of the extracted predicted operating time periods (YES in S59), the supply availability determination unit 56 transmits the result including at least the information on the supply available time periods to the server device 12.

[0113] The processing from step S54 to step S59 in the second embodiment corresponds to the supply availability determination processing (S23) in the first embodiment. Furthermore, if there is no supply available time slot, it corresponds to the fact that power cannot be supplied from the cogeneration unit 20 to the power grid 36 on the specific day. If there is a supply available time slot, it corresponds to the fact that power can be supplied from the cogeneration unit 20 to the power grid 36 on the specific day.

[0114] As described above, in the cogeneration system 1 of the second embodiment, whether or not to supply power from the cogeneration unit 20 to the power grid 36 on a specific future date is determined based on the past start-up and stop times stored in the storage device 24.

[0115] As a result, in the cogeneration system 1 of the second embodiment, the aggregator can refer to the determination result of whether or not power can be supplied on a specific future date, thereby determining whether or not power can be supplied to the power grid 36 in the future. As a result, the aggregator can accurately submit a bid for adjustment power in the power supply and demand adjustment market 14. Therefore, the cogeneration system 1 of the second embodiment allows power to be appropriately supplied from the cogeneration unit 20.

[0116] Furthermore, in the cogeneration system 1 of the second embodiment, the time periods during which power can be supplied are also specified. This allows the aggregator to grasp in detail the time periods on a specific day during which power can be supplied to the power grid 36. As a result, the aggregator can more accurately submit bids for adjustment power in the electricity supply and demand adjustment market 14.

[0117] (Modification of the second embodiment) Fig. 10 is a diagram illustrating an outline of a modified example of the second embodiment. Time point T31 in Fig. 10 corresponds to the most recent stop time in the past, with the present as the reference point. From time point T31 to the present, the cogeneration unit 20 has been maintained in a stopped state.

[0118] Now, let us assume that the stopped state of the cogeneration unit 20 will continue into the future. In this case, as the time that the stopped state of the cogeneration unit 20 is maintained increases, the heat stored in the hot water tank 26 will gradually be released. As a result, the amount of heat stored in the hot water tank may fall from a value equal to or greater than a predetermined threshold to a value below the predetermined threshold. When the amount of heat stored in the hot water tank falls below the predetermined threshold, the cogeneration unit 20 will be able to generate electricity.

[0119] Therefore, supply availability determination unit 56 may determine that a time period on a specific future date that is a predetermined time or more after the most recent past stop time is a time period (supply available time period) during which power can be supplied from cogeneration unit 20 to power grid 36. The predetermined time period is set to a time period sufficient for the heat in hot water tank 26 to be naturally released and for the hot water tank heat quantity equal to or greater than the predetermined threshold to fall below the predetermined threshold.

[0120] 10, the specific day includes time T32, which is a predetermined time after time T31, the most recent stop time in the past. In this example, the time period from time T32 to time T33, the end of the specific day, is the supply available time period.

[0121] In the modification of the second embodiment, similarly to the second embodiment, the aggregator can refer to the determination result of whether or not power can be supplied on a specific future date, thereby making it possible for the aggregator to ascertain whether or not power can be supplied to the power grid 36 in the future. As a result, the aggregator can accurately submit a bid for adjustment capacity in the power supply and demand adjustment market 14. Therefore, according to the modification of the second embodiment, power can be appropriately supplied from the cogeneration unit 20.

[0122] (Third embodiment) 11 is a block diagram showing the configuration of a cogeneration system 100 according to the third embodiment. The cogeneration system 100 of the third embodiment differs from the first embodiment in that the processor 40 in the distributed power supply device 10 also functions as a time zone adjustment unit 158, but other configurations are the same as those of the first embodiment. In the third embodiment, only the differences from the first embodiment will be described, and a description of the configurations that are the same as those of the first embodiment will be omitted.

[0123] In the first embodiment, if there is a time slot available for supply on a specific future date, it is determined that power can be supplied to the power grid 36. However, for example, in bidding in the electricity supply and demand adjustment market 14, a time slot in which power adjustment capacity is required, i.e., a time slot in which power adjustment is required, may be determined in advance. Hereinafter, the time slot in which power adjustment is required may be referred to as a requested time slot.

[0124] When a requested time slot for a specific day is determined, even if there is a supplyable time slot on the specific day, a situation may arise in which not all of the requested time slot is included in the supplyable time slot. If not all of the requested time slot is included in the supplyable time slot, it may not be possible to properly supply power to the power grid 36 on the specific day. As a result, the aggregator may miss an opportunity to bid for adjustment capacity in the electricity balancing market 14.

[0125] Therefore, in the third embodiment, if the entire requested time period is not included in the supplyable time period, the time period adjustment unit 158 ​​controls to change the operating time period of the cogeneration unit 20 on a specific day so that the entire requested time period is included in the supplyable time period.

[0126] Fig. 12 is a flowchart illustrating the flow of operations of the time period adjustment unit 158. Fig. 12 is obtained by adding processing related to the time period adjustment unit 158 ​​to the flowchart of Fig. 5 of the first embodiment.

[0127] 12, after the supply availability determination process (S23), the time slot adjustment unit 158 ​​determines whether or not the entire requested time slot is included in the supply available time slot obtained in the supply availability determination process (S23) (S70). The requested time slot is included in, for example, the execution start command received in step S20.

[0128] For example, if the start point of the requested time period is later than the start point of the supplyable time period and the end point of the requested time period is earlier than the end point of the supplyable time period, the time period adjustment unit 158 ​​determines that the entire requested time period is included in the supplyable time period.

[0129] If it is determined that the entire requested time slot is included in the supplyable time slot (YES in S70), the supply availability determination unit 56 transmits a result including at least information on the supplyable time slot to the server device 12 (S24). In this case, even if the operating time slot of the cogeneration unit 20 on the specific day is not changed, by operating the cogeneration unit 20 within the supplyable time slot, it is possible to supply power to the power grid 36 during the entire requested time slot.

[0130] If it is determined that at least a part of the requested time slot is not included in the supply available time slot (NO in S70), the time slot adjustment unit 158 ​​performs time slot adjustment processing (S71) to adjust the operating time slot of the cogeneration unit 20 on the specific day. The time slot adjustment processing (S71) will be described later.

[0131] After the time slot adjustment process (S71), the supply availability determination unit 56 transmits a result including information on the supply available time slots and information on the adjusted operating time slots of the cogeneration unit 20 on the specific day to the server device 12 (S24). The information on the adjusted operating time slots may include, for example, whether or not the operating time slots have been adjusted, the start and end points of the adjusted operating time slots, and the time from the start to the end points of the adjusted operating time slots.

[0132] When the time slot adjustment process (S71) is performed, information about the adjusted operating time slots is stored in the storage device 24. Then, when the specific day arrives, the operation control unit 50 reads out the information about the adjusted operating time slots from the storage device 24 and controls the operation of the cogeneration unit 20 in accordance with the information about the adjusted operating time slots.

[0133] FIG. 13 is a diagram illustrating an example of the time slot adjustment process (S71). FIG. 13(a) shows a case where at least a portion of the requested time slot arrives earlier than the supply available time slot on a specific day. FIG. 13(b) shows an example in which the operating time slot of the cogeneration unit 20 is adjusted compared to FIG. 13(a). FIG. 13(c) shows another example in which the operating time slot of the cogeneration unit 20 is adjusted compared to FIG. 13(a).

[0134] As shown in Figure 13(a), for example, suppose the cogeneration unit 20 is started at the start of the available supply time slot and stopped at the end of the available supply time slot. In this case, the available supply time slot corresponds to the operating time slot of the cogeneration unit 20 on a specific day. However, in Figure 13(a), part of the requested time slot falls outside the available supply time slot, so power cannot be supplied appropriately to the power grid 36.

[0135] Therefore, the time slot adjustment unit 158 ​​can adjust the entire operating time slot corresponding to the supply available time slot so that it shifts earlier (closer to the present), as shown in Figure 13(b). For example, as shown in Figure 13(b), the start time in the operating time slot is adjusted to be earlier than the start point of the requested time slot, and the stop time in the operating time slot is adjusted to be later than the end point of the requested time slot. In the example of Figure 13(b), the shift amount of the start time and the shift amount of the stop time in the operating time slot are the same, and the time from the start time to the stop time is the same before and after the shift.

[0136] In a time period earlier than the start-up time before the adjustment (FIG. 13(a)), the hot water tank heat quantity is estimated to be equal to or greater than predetermined threshold value Th. Therefore, as shown in FIG. 13(b), time period adjustment unit 158 ​​performs control so that at least a portion of the heat medium stored in hot water tank 26 is forcibly discharged to the outside of hot water tank 26 during an arbitrary period before the adjusted start-up time. This makes it possible to make the hot water tank heat quantity less than predetermined threshold value Th before the adjusted start-up time is reached, and to appropriately start up cogeneration unit 20 at the adjusted start-up time.

[0137] 13(b), the entire requested time slot is included in the operating time slot. Then, by operating the cogeneration unit 20 during the adjusted operating time slot, it is possible to appropriately supply power to the power grid 36.

[0138] In the example of Fig. 13(b), the stop time of cogeneration unit 20 is earlier than the stop time before adjustment shown in Fig. 13(a). Even if the stop time is earlier, heat is stored in hot water tank 26 during the period from the stop time after adjustment to the stop time before adjustment, so that the impact on heat demand after the stop time before adjustment can be reduced.

[0139] 13(c), the time slot adjustment unit 158 ​​can adjust the start time of the operating time slot corresponding to the supply available time slot so that it is earlier than the start time of the requested time slot (closer to the present) without changing the stop time. That is, in FIG. 13(c), the operating time slot is extended in the earlier direction (closer to the present).

[0140] 13(c), time period adjustment unit 158 ​​performs control so that at least a portion of the heat medium stored in hot water tank 26 is forcibly discharged to the outside of hot water tank 26 during any period before the adjusted startup time. This makes it possible to make the hot water tank heat quantity less than predetermined threshold value Th before the adjusted startup time is reached, and to appropriately start up cogeneration unit 20 at the adjusted startup time.

[0141] In the example of FIG. 13(c), the time slot adjustment unit 158 ​​further controls the output per unit time of the cogeneration unit 20 to be reduced compared to before the adjustment of the operating time slot. By reducing the output of the cogeneration unit 20, the rate of increase in the heat content of the hot water tank can be reduced, making it possible to appropriately extend the operating time slot. Furthermore, since the stop time does not change before and after the adjustment, the impact on heat demand after the stop time can be further reduced. Note that reducing the output reduces the power that can be supplied during the requested time slot, so it is preferable to send information indicating the reduction in power that can be supplied during the requested time slot to the server device 12 to alert the aggregator.

[0142] 13(c), the entire requested time period is included in the operating time period. Then, by operating the cogeneration unit 20 during the adjusted operating time period, it is possible to appropriately supply power to the power grid 36.

[0143] FIG. 14 is a diagram illustrating another example of the time slot adjustment process (S71). FIG. 14(a) illustrates a case where at least a portion of the requested time slot arrives later than the supply time slot on a specific day. FIG. 14(b) illustrates an example in which the operating time slot of the cogeneration unit 20 is adjusted relative to FIG. 14(a). FIG. 14(b) illustrates another example in which the operating time slot of the cogeneration unit 20 is adjusted relative to FIG. 14(a).

[0144] As shown in Figure 14(a), for example, suppose the cogeneration unit 20 is started at the start of the available supply time slot and stopped at the end of the available supply time slot. In this case, the available supply time slot corresponds to the operating time slot of the cogeneration unit 20 on a specific day. However, in Figure 14(a), part of the requested time slot falls outside the available supply time slot, so power cannot be supplied appropriately to the power grid 36.

[0145] Therefore, the time slot adjustment unit 158 ​​can adjust the entire operating time slot corresponding to the supply available time slot so that it is shifted later (away from the present time) as shown in Figure 14(b). For example, as shown in Figure 14(b), the start time in the operating time slot is adjusted to be earlier than the start point of the requested time slot, and the stop time in the operating time slot is adjusted to be later than the end point of the requested time slot. In the example of Figure 14(b), the shift amount of the start time and the shift amount of the stop time in the operating time slot are the same, and the time from the start time to the stop time is the same before and after the shift.

[0146] 14(b), the entire requested time period is included in the operating time period. Then, by operating the cogeneration unit 20 during the adjusted operating time period, it is possible to appropriately supply power to the power grid 36.

[0147] 14(b), the cogeneration unit 20 is started at the start-up time before the adjustment of the operating time slot, and is stopped at any time between the start-up time before the adjustment of the operating time slot and the start-up time after the adjustment of the operating time slot.The cogeneration unit 20 is then started again at the start-up time after the adjustment of the operating time slot.This makes it possible to appropriately respond to heat demand that occurs before the requested time slot.

[0148] 14(c), the time slot adjustment unit 158 ​​can adjust the stop time of the operating time slot corresponding to the supply available time slot so that it is later than the end point of the requested time slot (moving away from the present time) without changing the start time. That is, in FIG. 14(c), the operating time slot is extended in the later direction (moving away from the present time).

[0149] In the example of FIG. 14(c), the time slot adjustment unit 158 ​​further controls the output per unit time of the cogeneration unit 20 to be reduced compared to before the adjustment of the operating time slot. By reducing the output of the cogeneration unit 20, the rate of increase in the heat content of the hot water tank can be reduced, making it possible to appropriately extend the operating time slot. Furthermore, because the start-up time remains unchanged before and after the adjustment, the impact on the heat demand between the start-up time and the start of the requested time slot can be further reduced. Note that reducing the output reduces the power that can be supplied during the requested time slot, so it is preferable to send information indicating the reduction in the power that can be supplied during the requested time slot to the server device 12 to alert the aggregator.

[0150] 14(c), the entire requested time slot is included in the operating time slot. Then, by operating the cogeneration unit 20 in the adjusted operating time slot, it is possible to appropriately supply power to the power grid 36.

[0151] Furthermore, as shown in FIG. 14(d), the time zone adjustment unit 158 ​​can adjust the stop time of the operating time zone corresponding to the supply available time zone to be later than the end point of the requested time zone (moving away from the present time) without changing the start time.

[0152] In the example of FIG. 14(d), the output of cogeneration unit 20 is not suppressed. Instead, in the example of FIG. 14(d), control is performed to forcibly discharge at least a portion of the heat medium stored in hot water tank 26 to the outside of hot water tank 26 during any period between the start-up time and the start of the requested time slot. By forcibly discharging the heat from hot water tank 26, the rate of increase in the heat quantity in the hot water tank can be suppressed without suppressing the output of cogeneration unit 20, making it possible to appropriately extend the operating time slot. Furthermore, because the start-up time does not change before and after the adjustment, the impact on heat demand between the start-up time and the start of the requested time slot can be further reduced.

[0153] 14(d), the entire requested time slot is included in the operating time slot. Then, by operating the cogeneration unit 20 during the adjusted operating time slot, it is possible to appropriately supply power to the power grid 36.

[0154] As described above, in the cogeneration system 100 of the third embodiment, if the entire requested time period is not included in the supplyable time period, the operating time period of the cogeneration unit 20 on a particular day is controlled to be changed so that the entire requested time period is included in the supplyable time period.

[0155] As a result, in the cogeneration system 100 of the third embodiment, the cogeneration unit is controlled so that the entire requested time slot is included in the supplyable time slot, and therefore, power can be appropriately supplied to the power grid 36 during the requested time slot. As a result, in the cogeneration system 100 of the third embodiment, even if the requested time slot is predetermined in a bid in the electricity supply and demand adjustment market 14, it is possible to increase the opportunities to bid in such a bid.

[0156] In the third embodiment, an example has been described in which the time period adjustment unit 158 ​​is added to the configuration of the first embodiment. However, the time period adjustment unit 158 ​​may be added to the configuration of the second embodiment.

[0157] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention.

[0158] For example, in each of the above embodiments, the processor 40 of the control device 34 of the distributed power supply apparatus 10 functions as the data acquisition unit 52, the predicted value derivation unit 54, the supply feasibility determination unit 56, and the time slot adjustment unit 158. However, the data acquisition unit 52, the predicted value derivation unit 54, the supply feasibility determination unit 56, and the time slot adjustment unit 158 ​​are not limited to being realized by the processor 40 of the distributed power supply apparatus 10. Some or all of the data acquisition unit 52, the predicted value derivation unit 54, the supply feasibility determination unit 56, and the time slot adjustment unit 158 ​​may be realized by the processor 70 of the server device 12, or may be realized in any computer. [Explanation of symbols]

[0159] 1,100 Cogeneration system 20 Cogeneration unit 24 Storage device 26 Hot Water Tank 28 First temperature sensor 36 Power system 50 Operation control unit 52 Data Acquisition Section 54 Prediction value derivation part 56 Supply availability determination section 158 Time Zone Adjustment Department

Claims

1. a cogeneration unit configured to consume fuel gas to generate electricity, heat a heat medium in conjunction with the power generation, and supply the generated electricity to an electric power grid; a hot water tank for storing the heat medium; a temperature sensor for detecting a hot water tank temperature indicating the temperature of the heat medium in the hot water tank; an operation control unit that derives a hot water tank heat quantity indicating the amount of heat stored in the hot water tank based on the hot water tank temperature, and allows the cogeneration unit to operate when the hot water tank heat quantity is less than a predetermined threshold, and stops the cogeneration unit when the hot water tank heat quantity is equal to or greater than the predetermined threshold; a data acquisition unit that stores the calculated hot water tank heat quantity every predetermined first time period in a storage device; a predicted value deriving unit that derives a predicted value of the hot water tank heat quantity for each first hour on a specific future date based on the past hot water tank heat quantities stored in the storage device; a supply availability determination unit that determines whether or not power can be supplied from the cogeneration unit to an electric power grid on the specific day based on the predicted value of the hot water storage tank heat quantity for each first hour; A cogeneration system equipped with:

2. a cogeneration unit configured to consume fuel gas to generate electricity, heat a heat medium in conjunction with the power generation, and supply the generated electricity to an electric power grid; a hot water tank for storing the heat medium; a temperature sensor for detecting a hot water tank temperature indicating the temperature of the heat medium in the hot water tank; an operation control unit that derives a hot water tank heat quantity indicating the amount of heat stored in the hot water tank based on the hot water tank temperature, and allows the cogeneration unit to operate when the hot water tank heat quantity is less than a predetermined threshold, and stops the cogeneration unit when the hot water tank heat quantity is equal to or greater than the predetermined threshold; a data acquisition unit that defines a time when the cogeneration unit switches from a stopped state to an operating state as a start time, defines a time when the cogeneration unit switches from the operating state to a stopped state as a stop time, and stores the start time in a storage device every time the cogeneration unit switches from the stopped state to the operating state, and stores the stop time in the storage device every time the cogeneration unit switches from the operating state to the stopped state; a supply availability determination unit that determines whether or not power can be supplied from the cogeneration unit to the power grid on a specific future date based on the past start-up times and stop times stored in the storage device; and A cogeneration system equipped with:

3. 3. The cogeneration system according to claim 1, further comprising a time zone adjustment unit that, when a requested time zone indicating a time zone for which power adjustment is requested is not entirely included in a supplyable time zone indicating a time zone for which power can be supplied, controls to change the operating time zone of the cogeneration unit on the specific day so that the requested time zone is entirely included in the supplyable time zone.

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