Power management apparatus, power management system, power management method, and program

Abstract

To effectively utilize surplus power.SOLUTION: In a power management device 50, a load determination unit 513 determines a water heater to be made to consume power in a time zone in which surplus power is predicted to be generated within a jurisdiction from among water heaters of a plurality of consumers existing within the jurisdiction. The load control unit 514 causes the water heater determined by the load determination unit 513 to consume power in a time period in which surplus power is predicted to be generated within the jurisdiction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a power management device, a power management system, a power management method, and a program. [Background technology]

[0002] The use of renewable energy, typified by solar power generation, is being promoted. However, situations where surplus power is generated when power generation exceeds power demand are often observed. When surplus power is generated, economic benefits can be obtained by selling the surplus power to the power grid. However, in order to maintain the balance between power supply and demand in the power grid, output curtailment may be implemented to suppress the output of surplus power to the power grid. Output curtailment can lead to dissatisfaction among businesses and consumers who profit from selling power. To address such output curtailment, for example, Patent Document 1 discloses a technology in which a hot water heating and heating system operated by the same consumer as the solar power generation system is operated during a time period when reverse power is generated, thereby enabling the consumer to consume the generated power for themselves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5025835 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed in Patent Document 1 requires that one consumer own both a solar power generation system and a hot water supply and heating system, and that surplus electricity must be consumed within the consumer's own home. In addition, the technology disclosed in Patent Document 1 does not address the issue of output suppression, so dissatisfaction with output suppression cannot be resolved. In light of these issues, there is a need for a more effective use of surplus electricity.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a power management device and the like that can effectively utilize surplus power. [Means for solving the problem]

[0006] In order to achieve the above object, a power management device according to the present disclosure includes: a load determination means for determining, from among the hot water heaters of a plurality of consumers present within a jurisdiction, a hot water heater to consume power during a time period when surplus power is predicted to be generated within the jurisdiction; and a load control means for causing the water heater determined by the load determination means to consume the power during the time period. [Effects of the Invention]

[0007] In the present disclosure, a water heater that will consume power during a time period when surplus power is predicted to be generated within the jurisdiction is selected from among the water heaters of multiple consumers within the jurisdiction, and the selected water heater is made to consume power. Therefore, according to the present disclosure, surplus power can be effectively utilized. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an overall configuration of a power management system according to a first embodiment; [Figure 2] FIG. 1 is a block diagram showing a configuration of a power management device according to a first embodiment. [Figure 3] FIG. 1 is a diagram showing an example of transition of generated power and consumed power in the first embodiment. [Figure 4] FIG. 1 is a diagram showing an example of the amount of power that can be consumed by a plurality of water heaters according to the first embodiment. [Figure 5] FIG. 1 is a diagram showing an example of a request plan and a boiling plan according to the first embodiment. [Figure 6] FIG. 10 is a diagram showing an example of a request screen displayed on a terminal device according to the first embodiment; [Figure 7] FIG. 1 is a sequence diagram showing the flow of the overall process executed in the power management system according to the first embodiment; [Figure 8]FIG. 1 is a sequence diagram showing the flow of a water heater determination process executed in a power management system according to a first embodiment. [Figure 9] FIG. 10 is a diagram showing an example of request record data according to the second embodiment; [Figure 10] FIG. 13 is a diagram showing an example of a request screen displayed on a terminal device according to the fourth embodiment; [Figure 11] FIG. 13 is a diagram showing an example of a request screen displayed on a terminal device according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0010] (Embodiment 1) The power management system 1 according to the first embodiment is a system that manages power consumed within a power distribution system. Here, "within a power distribution system" refers to the area under the jurisdiction of the power management system 1, and within the scope of power management by the power management system 1. In other words, the power distribution system corresponds to the range of consumers that are under the control and management of the power management system 1 through a contract, agreement, or the like with a business that manages the power management system 1, such as a power company or resource aggregator. The power distribution system may be geographically diverse, and may, for example, be within a specific region or may extend over a wide area.

[0011] 1, the power management system 1 includes a plurality of water heaters 10, a plurality of power measurement devices 30, a plurality of terminal devices 40, a plurality of power generation facilities 20, and a power management device 50. The plurality of water heaters 10, the plurality of power measurement devices 30, the plurality of terminal devices 40, and the power management device 50 are connected to each other so as to be able to communicate with each other via an information communication network N1, which is a wide-area communication network. The plurality of water heaters 10 and the plurality of power generation facilities 20 are also connected to each other so as to be able to transmit power to each other via a power transmission and distribution network N2.

[0012] Consumers A to C shown in FIG. 1 are, for example, residents or managers of ordinary households, companies, factories, etc. Electric power companies X and Y are businesses that can supply electricity to consumers A to C. A water heater 10, a power metering device 30, and a terminal device 40 are installed on the premises of each of consumers A to C. A power generation facility 20 is installed on the premises of each of consumers A and B and electric power companies X and Y. Although not shown in the figure, in addition to the water heater 10, devices that consume power to operate, such as air conditioners, refrigerators, lighting, cooking appliances, televisions, etc., are also installed on the premises of each of consumers A to C. Hereinafter, these devices and the water heater 10 will be collectively referred to as "load devices."

[0013] Note that the power management system 1 is not limited to consumers A to C and power suppliers X and Y, and may include more consumers or power suppliers. Some consumers, such as consumers A and B, own power generation facilities 20, while others, such as consumer C, do not own power generation facilities 20. The premises of the consumers and the power suppliers are connected via a power transmission and distribution network N2, and power can be exchanged between them.

[0014] Each of the multiple water heaters 10 is a device that consumes electricity to boil water and store the hot water. Each water heater 10 can be used as a load device that uses electricity within the range required to boil water. As an example, each water heater 10 is a storage-type water heater that includes a heat pump unit, a hot water storage tank, and a hot water controller. Each water heater 10 is installed on the premises of each of consumers A to C.

[0015] The heat pump unit is a heat pump type heat source device that uses CO2 (carbon dioxide), HFC (hydrofluorocarbon), or the like as a refrigerant. The heat pump unit is connected to a hot water storage tank via a water pipe through which hot and cold water flows. The heat pump unit uses the surrounding air as a heat source to boil low-temperature water in the hot water storage tank into high-temperature water. The hot water supply controller, although not shown, is equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), a communication interface, a readable and writable non-volatile semiconductor memory, etc., and provides overall control of the hot water heater 10.

[0016] Each of the multiple power generation facilities 20 is a facility that generates electricity using sunlight, which is natural energy. Although not shown, each power generation facility 20 includes a photovoltaic (PV) panel that generates solar power and a PV-PCS that is a power conditioning system. The PV panel is, for example, a polycrystalline silicon solar panel. The PV panel generates solar power by converting solar energy into electrical energy.

[0017] The PV-PCS receives a supply of power generated by the PV panels, converts the supplied power from DC power to AC power, and outputs it. When the power generation facility 20 is installed on the customer's premises, the PV-PCS outputs the power generated by the PV panels to load devices on the premises, including the water heater 10, or to the power transmission and distribution network N2. When the power generation facility 20 is installed on the premises of an electric power company, the PV-PCS outputs the power generated by the PV panels to the power transmission and distribution network N2.

[0018] Each of the multiple power measurement devices 30 is a device that measures the power consumed within the premises of demand areas A to C. Each power measurement device 30 measures the power received or transmitted throughout the entire premises where the power measurement device 30 is installed, and the power received or transmitted for each load device, including the water heater 10, within the premises. Furthermore, if a power generation facility 20 is installed within the premises where the power measurement device 30 is installed, each power measurement device 30 measures the power generated by the power generation facility 20. Measurement information on the power measured by each power measurement device 30 is transmitted to the power management device 50 via the information and communication network N1.

[0019] Each of the multiple terminal devices 40 is a communication terminal operated by a consumer, such as a smartphone, tablet terminal, personal computer, dedicated equipment, etc. Each terminal device 40 may be a stationary device or a portable device. Although not shown, each terminal device 40 includes a CPU, ROM, RAM, a user interface, a communication interface, and a readable / writable non-volatile semiconductor memory. The user interface includes an operation unit such as a touch panel, physical buttons, keyboard, etc., and a display unit such as a liquid crystal display, organic EL (Electro Luminescence) display, etc.

[0020] Each terminal device 40 communicates with the power management device 50 via the information and communication network N1. The communication by each terminal device 40 may be wired or wireless. Each terminal device 40 communicates with the power management device 50 and receives messages transmitted from the power management device 50. Each terminal device 40 then communicates the received messages to consumers by displaying them on a display unit using images, text, etc. Note that each terminal device 40 may communicate the received messages to consumers by voice, rather than by display. Furthermore, each terminal device 40 receives the consumer's response to the received messages via an operation unit and transmits them to the power management device 50.

[0021] The power management device 50 is a device that manages the power management system 1. The power management device 50 is an information processing device such as a PC or a cloud server, and is installed under the management of the operator of the power management system 1. As shown in FIG. 2 , the power management device 50 includes a control unit 51, a storage unit 52, and a communication unit 53.

[0022] The control unit 51 includes a CPU, a ROM, and a RAM. The CPU is also called a central processing unit, a processor, a microprocessor, a microcomputer, etc., and functions as a central processing unit that executes processing and calculations related to the control of the power management device 50. In the control unit 51, the CPU reads programs and data stored in the ROM and uses the RAM as a work area to perform overall control of the power management device 50.

[0023] The storage unit 52 includes a nonvolatile semiconductor memory such as a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (Electrically Erasable Programmable ROM), and serves as a so-called secondary storage device or auxiliary storage device. The storage unit 52 stores programs and data used by the control unit 51 to perform various processes. The storage unit 52 also stores data generated or acquired by the control unit 51 performing various processes. Specifically, the storage unit 52 stores power generation record data 521, consumption record data 522, water heater data 523, a request plan 524, and a water heating plan 525. These will be described in detail later.

[0024] The communication unit 53 includes a communication interface for the power management device 50 to communicate with external devices. The communication unit 53 communicates with the external devices via the information and communication network N1. For example, the communication unit 53 communicates with each of the water heaters 10, power metering devices 30, and terminal devices 40 of each consumer present within the power pipe via the information and communication network N1.

[0025] The control unit 51 functionally includes a prediction unit 511 which is an example of a prediction means, an energy calculation unit 512 which is an example of an energy calculation means, a load determination unit 513 which is an example of a load determination means, a load control unit 514 which is an example of a load control means, and a fee calculation unit 515 which is an example of a fee calculation means. Each of these functions is realized in the control unit 51 by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the ROM or the storage unit 52. Then, in the control unit 51, the CPU executes the programs stored in the ROM or the storage unit 52 to realize each function.

[0026] The prediction unit 511 predicts a time period when surplus power will be generated within the power distribution area. Here, surplus power is power generated when the supply of power exceeds the demand for power. More specifically, surplus power at a certain point corresponds to the remaining power that is generated at that point and not consumed at that point.

[0027] Specifically, Figure 3 shows an example of the trends in power generation Pg and power consumption Pc for a certain consumer over a given day. The solid line in Figure 3 represents the trends in power generation Pg generated by the consumer's power generation facility 20, which increases throughout the day, peaking at noon when the amount of solar radiation is high. In contrast, the dashed line in Figure 3 represents the power consumption Pc consumed by load devices, including the water heater 10, on the consumer's premises, which generally increases from the afternoon through the evening when household power consumption increases.

[0028] When the generated power Pg is less than the consumed power Pc, as in periods T1 and T3 in Figure 3, the generated power Pg alone cannot supply the necessary power on the consumer's premises, and so the consumer must purchase power from the commercial power grid. In contrast, when the generated power Pg is greater than the consumed power Pc, as in period T2 in Figure 3, surplus power occurs on the consumer's premises. The surplus power is equivalent to "Pg - Pc," which is the generated power Pg minus the consumed power Pc.

[0029] When surplus power occurs, consumers can sell it to businesses by supplying it to the power grid as reverse power. This process of power being supplied from consumers to the power grid and then returned to the business is called reverse power flow. The power that flows reversely is called reverse power. When reverse power becomes too large, output may be restricted to maintain the balance between power supply and demand in the power grid.

[0030] The prediction unit 511 predicts whether or not such surplus power will occur throughout the entire power distribution pipe under the jurisdiction of the power management system 1. If surplus power will occur throughout the entire power distribution pipe, the prediction unit 511 predicts the time period during which the surplus power will occur and the amount of surplus power that will occur during that time period.

[0031] More specifically, when a predetermined timing arrives, the prediction unit 511 predicts a time period in the future when surplus power will be generated. Here, the future period is a period after the present time, such as the current day, the next day, or a period several days from now. As an example, the following will be described in the following, where the prediction unit 511 predicts whether surplus power will be generated during the daytime of the following day from the evening to nighttime. However, the prediction unit 511 is not limited to this, and may also predict whether surplus power will be generated during the daytime of the same day from the early hours of the morning of the same day.

[0032] To predict surplus power, the prediction unit 511 predicts the power generation power Pg and power consumption power Pc of each of a plurality of consumers located within the power distribution system, including consumers A to C. The prediction unit 511 also predicts the power generation power Pg of each of a plurality of power suppliers located within the power distribution system, including power suppliers X and Y.

[0033] First, the prediction unit 511 refers to the power generation record data 521 stored in the memory unit 52 to predict the power generation power Pg for each consumer and each electric power company in the electric power service area on the following day. The power generation record data 521 is record data of the power generation power Pg for a past period. The power generation record data 521 is data in which the amount of power generation power Pg for a past period is classified and recorded by parameters that affect power generation, such as weather, season, and time of day. The prediction unit 511 acquires data indicating the actual power generation power Pg for a past period measured by the power measuring device 30 for each of the multiple power generation facilities 20 in the electric power service area, and stores the data in the memory unit 52 as the power generation record data 521. The prediction unit 511 refers to the power generation record data 521 to predict the power generation power Pg for each consumer and each electric power company by time period corresponding to the weather and season for the following day.

[0034] The weather data for the next day is acquired from a weather server external to the power management device 50. The prediction unit 511 accesses the external weather server via the communication unit 53 and acquires from the weather server weather forecast data for the next day for each consumer and each power company within the power service area. The prediction unit 511 then predicts the power generation power Pg for the next day based on the acquired weather forecast data and power generation performance data 521.

[0035] Second, the prediction unit 511 refers to actual consumption data 522 stored in the memory unit 52 to predict the power consumption Pc for each consumer in the power distribution system for the next day. The actual consumption data 522 is actual data on the power consumption Pc for a past period. The actual consumption data 522 is data in which the amount of power consumption Pc for a past period is classified and recorded by parameters that affect power consumption, such as day of the week, season, time of day, etc. The prediction unit 511 acquires data indicating the actual power consumption Pc for a past period measured by the power metering device 30 for each of multiple consumers in the power distribution system, and stores this data in the memory unit 52 as actual consumption data 522. The prediction unit 511 refers to the actual consumption data 522 to predict the power consumption Pc for each consumer by time period corresponding to the next day's day of the week and season.

[0036] When the power generation power Pg and power consumption Pc in the power distribution area are predicted for each consumer and each power company in this manner, the prediction unit 511 predicts a time period in which the total predicted power generation power Pg exceeds the total predicted power consumption Pc as a time period in which surplus power will occur. As a result, the prediction unit 511 predicts a time period in which output suppression is likely to occur. Furthermore, the prediction unit 511 predicts the amount of surplus power as the integrated value of the difference between the power generation power Pg and the power consumption Pc in a time period in which surplus power will occur. Hereinafter, the time period predicted by the prediction unit 511 in which surplus power is predicted to occur in the power distribution area will be referred to as the "surplus time period."

[0037] 2, the power amount calculation unit 512 calculates the amount of power that can be consumed by each of the water heaters 10 of multiple consumers present in the power pipe during the surplus time period predicted by the prediction unit 511. Here, the amount of power that can be consumed by the water heater 10 is the amount of power consumed to boil water in the water heater 10. The power amount calculation unit 512 calculates how many liters of hot water each water heater 10 can boil during the surplus time period and how many kWh of power can be consumed to do so.

[0038] Specifically, the power calculation unit 512 calculates the amount of power that each water heater 10 can consume during a surplus time period based on the tank capacity, remaining hot water volume, and rated power consumption of each water heater 10. Here, tank capacity refers to the maximum amount of hot water that can be stored in the hot water storage tank. Remaining hot water volume refers to the amount of usable hot water currently remaining in the hot water storage tank. Rated power consumption refers to the power consumption required when the water heater 10 performs boiling operation.

[0039] The power amount calculation unit 512 communicates with each water heater 10 present in the power pipe via the communication unit 53 and acquires information such as the tank capacity of each water heater 10, the remaining amount of hot water in each water heater 10, and the rated power consumption of each water heater 10. The power amount calculation unit 512 then stores the acquired information in the water heater data 523. The rated power consumption of each water heater 10 acquired by the power amount calculation unit 512 may be a value that changes depending on the season. Alternatively, the power amount calculation unit 512 may be configured to specify the current season and acquire the rated power consumption for the corresponding season from each water heater 10. Alternatively, the power amount calculation unit 512 may be configured to acquire multiple rated power consumption values ​​for each season from each water heater 10 and select the rated power consumption corresponding to the current season. The power amount calculation unit 512 identifies the season from date and time information calculated by an operating clock (not shown) of the power management device 50 or the like. As shown in Fig. 4, the water heater data 523 is data that stores information on tank capacity, remaining hot water volume, and rated power consumption for each customer that owns the water heater 10. Note that the numerical values ​​for each item in Fig. 4 are examples and are not necessarily accurate values. The same applies to the following figures.

[0040] The power amount calculation unit 512 calculates the amount of hot water that can be boiled in each water heater 10 during a surplus time period based on the tank capacity and remaining hot water amount of each water heater 10 stored in the water heater data 523. Here, the amount of hot water that can be boiled in the water heater 10 is the amount of hot water that can be added and boiled from the hot water in the hot water storage tank of the water heater 10, and corresponds to the amount of heat that can be stored in the water heater 10. Specifically, the power amount calculation unit 512 calculates, for each water heater 10, the amount obtained by subtracting the remaining hot water amount from the tank capacity as the amount of hot water that can be boiled during a surplus time period. After calculating the amount of hot water that can be boiled in each water heater 10, the power amount calculation unit 512 stores this in the "amount of hot water that can be boiled" field in the water heater data 523.

[0041] Next, the power amount calculation unit 512 calculates the amount of power corresponding to the calculated amount of hot water as the amount of power that can be consumed by the water heater 10 during the surplus time period. Specifically, the power amount calculation unit 512 calculates the amount of power that will be required for each water heater 10 to boil the calculated amount of hot water, based on the rated power consumption of each water heater 10. After calculating the amount of power that can be consumed by each water heater 10, the power amount calculation unit 512 stores the calculated amount of power in the "consumable power amount" field in the water heater data 523. Note that if the rated power consumption differs depending on the season, such as winter, mid-season, summer, etc., the power amount calculation unit 512 uses the value of the rated power consumption that corresponds to the current season.

[0042] 2, the load determination unit 513 determines the water heater 10 that will consume power during the surplus time period from among the water heaters 10 of multiple consumers present within the power pipe, based on the amount of power calculated by the power amount calculation unit 512. Specifically, the power management device 50 causes the water heater 10 to boil water and consume power during the surplus time period in order to suppress the surplus power that is predicted to be generated. The load determination unit 513 determines the water heater 10 that will be the target for this purpose.

[0043] First, the load determination unit 513 creates a request plan 524 for power consumption during a surplus time period. Here, the request plan 524 is a plan for determining how much power consumption to request from each water heater 10. Specifically, as shown in the upper part of Fig. 5, the request plan 524 is data that defines, for each water heater 10 of a consumer, the amount of consumable power, the request order, and the requested amount of hot water in association with each other.

[0044] To create request plan 524, load determination unit 513 selects a candidate water heater 10 to boil water during a surplus time period from among the water heaters 10 of multiple consumers present within the power pipe, based on the amount of power calculated by power amount calculation unit 512. Specifically, load determination unit 513 selects as a candidate at least one water heater 10 whose amount of power calculated by power amount calculation unit 512 is greater than a predetermined threshold. The threshold is set to an appropriate value equal to or greater than 0.

[0045] Once the candidates are selected, the load determination unit 513 determines the order of requests for the selected candidates based on predetermined criteria. The request order is the order in which requests for power consumption during surplus time periods are made. Specifically, the request order is determined in descending order of the consumable power amounts calculated by the power amount calculation unit 512. The load determination unit 513 determines the request order in descending order of the consumable power amounts by referring to the consumable power amounts of the water heaters 10 of each consumer stored in the water heater data 523. In the example of the request plan 524 shown in FIG. 5, the consumable power amounts of consumer B, consumer K, consumer E, ... are greatest in this order, and therefore the request order is determined in that order.

[0046] Next, the load determination unit 513 determines a requested amount of hot water, which is the amount of hot water to be requested to boil during the surplus time period from each water heater 10 selected as a candidate. Specifically, the load determination unit 513 determines, for each water heater 10 selected as a candidate, the amount of hot water that can be boiled, which is calculated by the power amount calculation unit 512 and stored in the water heater data 523, as the requested amount of hot water. In this way, the load determination unit 513 creates a request plan 524 for at least one water heater 10 that is a candidate for boiling hot water during the surplus time period.

[0047] When the request plan 524 is created, the load determination unit 513 determines the water heater 10 to consume power during the surplus time period and the amount of power consumption based on a dialogue with the consumer. To do this, the load determination unit 513 requests power consumption during the surplus time period from a terminal device 40 corresponding to at least one water heater 10 selected as a candidate in the created request plan 524. Specifically, the load determination unit 513 generates request information indicating the surplus time period predicted by the prediction unit 511 and the requested hot water volume determined in the request plan 524 for each water heater 10 selected as a candidate. The load determination unit 513 then communicates with each of the multiple terminal devices 40 corresponding to the multiple water heaters 10 selected as candidates via the communication unit 53 and transmits the generated request information to each terminal device 40 in the request order determined in the request plan 524.

[0048] When the terminal device 40 receives the request information from the power management device 50, it displays the received request information on the display unit. The terminal device 40 displays, for example, a request screen shown in FIG. 6 on the display unit. The request screen shown in FIG. 6 shows an example of a request to a consumer to boil 200 liters of hot water during a surplus time period starting at 1:00 pm on the same day. Note that FIG. 6 shows the request screen for consumer B in FIG. 5. By displaying information about the amount of hot water requested to be boiled on the request screen in this way, it is possible to provide an easy-to-understand representation for the consumer.

[0049] When such a request screen is displayed on the terminal device 40, the consumer can operate the operation unit of the terminal device 40 to input a response to the request. For example, in request A in FIG. 6, the load determination unit 513 requests the consumer to boil 200 liters of hot water. The consumer inputs response A, either "yes" or "no," into the terminal device 40 depending on whether or not to allow such request A. The content of the input response A is transmitted from the terminal device 40 to the power management device 50.

[0050] 6, if the consumer inputs "No" as answer A, the load determination unit 513 requests the consumer to boil 100 liters of hot water in the next request B, which is less than the amount of hot water in request A. The consumer again inputs answer B, "Yes" or "No," into the terminal device 40 depending on whether or not to allow such request B. The content of the input answer B is transmitted from the terminal device 40 to the power management device 50.

[0051] As shown in FIG. 6, if the consumer inputs "Yes" as answer B, the load determination unit 513 requests the consumer to make a final confirmation that the contents of request B are confirmed. The consumer inputs either "confirm" or "cancel" as a response to such final confirmation. The content of the input response is transmitted from the terminal device 40 to the power management device 50. If the consumer inputs the response "confirm," the load determination unit 513 confirms that the amount of hot water to be boiled in the water heater 10 of the consumer is 100 liters, which is the amount of hot water requested in request B. In contrast, if the consumer inputs the response "cancel," the load determination unit 513 transmits request B again to the terminal device 40 and displays it.

[0052] Similarly, if the consumer inputs "Yes" as response A to request A, the load determination unit 513 requests the consumer to make a final confirmation that the content of request A is confirmed. If the consumer inputs the response "confirm," the load determination unit 513 confirms that the amount of hot water to be boiled in the water heater 10 of the consumer is 200 liters, which is the amount of hot water requested in request A.

[0053] Furthermore, if the consumer inputs "No" as response B to request B, the load determination unit 513 reduces the requested amount of hot water and sends a further request to the consumer. If the number of times "No" is selected reaches a predetermined number, or if the requested amount of hot water falls below a predetermined amount, the load control unit 514 gives up on having the water heater 10 of the consumer heat water during the surplus time period.

[0054] The load determination unit 513 interacts with the consumer via the terminal device 40, and if permission is obtained from the consumer for all or part of the requested hot water amount, it determines the water heater 10 owned by that consumer as the one to be made to heat hot water during the surplus time period. Furthermore, the load determination unit 513 determines the amount of hot water for which permission is obtained from the consumer during the interaction as the amount of hot water to be made to be heated by the water heater 10 owned by that consumer during the surplus time period. On the other hand, if permission is not obtained from the consumer at all, the load determination unit 513 excludes the water heater 10 owned by that consumer from the ones to be made to heat hot water during the surplus time period.

[0055] The load determination unit 513 transmits request information to the terminal devices 40 corresponding to each water heater 10 selected as a candidate in the request plan 524 in the request order defined in the request plan 524. Then, the load determination unit 513 determines the amount of hot water to be boiled during the surplus time period through dialogue with the consumer of each water heater 10. As a result, the load control unit 514 creates a water boiling plan 525 shown in the lower part of Fig. 5 from the request plan 524 shown in the upper part of Fig. 5.

[0056] 5 shows, as an example, a case in which consumer B has granted permission to boil 100 liters of hot water, which is a portion of the requested hot water amount, consumer K has granted permission for the entire requested hot water amount, and consumer E has granted no permission at all. In this case, the load determination unit 513 determines the water heaters 10 of consumers B and K as the hot water heaters to be heated, and determines the amount of hot water to be the amount of hot water for which permission has been granted. On the other hand, the load determination unit 513 excludes the water heater 10 of consumer E, for which permission has not been granted, from the hot water heaters to be heated.

[0057] When at least partial permission is obtained from a consumer, the load determination unit 513 calculates the amount of power consumption to be consumed when boiling the permitted amount of hot water from the permitted amount of hot water, and stores the calculated amount in the water boiling plan 525. Specifically, the load determination unit 513 calculates the amount of power consumption for each consumer's water heater 10 by multiplying the consumable amount of power in the water boiling plan 525 by the ratio of the permitted amount of hot water to the requested amount of hot water.

[0058] The load determination unit 513 transmits request information to the terminal device 40 of the consumer in the request order defined in the request plan 524, and repeats the process of determining the amount of hot water to be boiled through dialogue with the consumer, until the total amount of power consumption calculated for the water heaters 10 of each consumer reaches a predetermined reference amount. Here, the reference amount corresponds, for example, to the amount of surplus power predicted by the prediction unit 511. When the total amount of power consumption reaches the surplus power amount, the load determination unit 513 finalizes the water boiling plan 525.

[0059] At this time, the load determination unit 513 terminates the processing when the total amount of power consumption reaches the surplus power amount, even if the water heater 10 selected as a candidate in the request plan 524 has surplus power. Conversely, if the water heater 10 selected as a candidate in the request plan 524 does not have enough power to cover the consumption of the surplus power, the load determination unit 513 selects a water heater 10 that was not an initial candidate as a new candidate.

[0060] In this way, the load determination unit 513 makes interactive adjustments with each consumer and sequentially determines the amount of hot water to be heated and the amount of power consumed during surplus time periods for each consumer. The load determination unit 513 keeps track of the available capacity of the consumer's hot water storage tank, and the consumer can indicate the amount of available capacity that they wish to allow use of.

[0061] The above-described request processing by the load determination unit 513 requires dialogue with the consumer, and is therefore desirably performed before the surplus time slot and during a time slot when the consumer is available. Furthermore, the calculation processing by the power amount calculation unit 512 of the amount of hot water that can be boiled and the amount of consumable power is desirably performed by obtaining as recent information as possible about the amount of remaining hot water from each water heater 10. From this perspective, the processing by the power amount calculation unit 512 and the load determination unit 513 is performed, for example, in the morning of the day of the surplus time slot.

[0062] Returning to Fig. 2, the load control unit 514 causes the water heater 10 determined by the load determination unit 513 to consume power by boiling water during a surplus time period. The load control unit 514 generates a control command for realizing the water boiling plan 525 created by the load determination unit 513. In the control command, the load control unit 514 sets, for each of at least one water heater 10 determined in the water boiling plan 525 as a water boiling target, the time at which the water boiling operation will be performed and the amount of water to be boiled.

[0063] When the control command is generated, the load control unit 514 transmits the generated control command to each of at least one hot water heater 10 to be heated via the communication unit 53. For example, if it is determined in the heating plan 525 that the hot water heater 10 of a certain consumer will heat 100 liters of hot water from 1:00 PM on the current day, the load control unit 514 generates and transmits to the hot water heater 10 of that consumer a control command to heat 100 liters of hot water from 1:00 PM on the current day.

[0064] In addition, the load control unit 514 may set the amount of hot water to be boiled by the water heater 10 in units of a percentage of the tank capacity in the control command. The percentage can be calculated from the amount of hot water determined in the request plan 524 and the tank capacity stored in the water heater data 523.

[0065] In the water heater 10, when the water heater controller receives a control command from the power management device 50, it performs a boiling operation in accordance with the received control command. Specifically, the water heater controller starts the boiling operation at the time set in the received control command, and boils the amount of hot water set in the received control command.

[0066] The load control unit 514 monitors the boiling operation in the water heater 10 as necessary. For example, the load control unit 514 periodically transmits a control command to the water heater 10 to acquire the status of the boiling operation, and can grasp the status of the water heater 10 from the response. In this case, when the status of the water heater 10 indicated in the response is no longer in the boiling operation, the load control unit 514 can detect that the boiling operation has ended.

[0067] Returning to Fig. 2, the fee calculation unit 515 calculates the electricity fee for each of the multiple consumers present in the power service area. The electricity fee is a fee charged to the consumer based on the amount of electricity consumed on the consumer's premises. The fee calculation unit 515 calculates the electricity fee for the consumer who has accepted the consumption of electricity by the water heater 10 during the surplus time period, discounted based on the electricity consumption during the surplus time period.

[0068] More specifically, for each water heater 10 that performed a water heating operation during a surplus time period, the fee calculation unit 515 calculates the consumer's electricity fee based on the amount of power consumed in the water heating operation performed during the surplus time period, the unit price of electricity for that surplus time period, and the incentive for power consumption during that surplus time period. Specifically, the fee calculation unit 515 acquires power measurement values ​​obtained by the power metering device 30 before and after the water heating operation performed during the surplus time period. The fee calculation unit 515 then calculates the amount of power consumed in the water heating operation performed during the surplus time period from the difference between the power measurement values. The fee calculation unit 515 calculates the fee before discount based on the calculated amount of power consumption and the unit price of electricity for that surplus time period. The unit price of electricity for that surplus time period may be an amount determined according to each consumer's contract.

[0069] After calculating the pre-discount fee, the fee calculation unit 515 discounts the calculated fee by a discount rate according to the incentive for power consumption during the surplus time period. Here, the incentive means a reward for cooperation with a request to boil water using the water heater 10 during the surplus time period. The discount rate according to the incentive may be a uniform value such as 10%, 20%, etc., or may be a value that varies depending on the time period.

[0070] The fee calculation unit 515 uses a discount rate according to such an incentive to calculate the discount amount or the discounted fee from the pre-discount fee calculated from the amount of power consumption and the unit price of electricity.The fee calculation unit 515 then reflects the calculated discount amount or the discounted fee in the electricity fee of the consumer.Specifically, the fee calculation unit 515 may subtract the total discount amount from the electricity fee of the consumer that is tallied and calculated monthly, periodically, etc., or may add the discounted electricity fee to the tallied value of the electricity fee of the consumer each time.

[0071] The fee calculation unit 515 performs the calculation process of the electricity fee discounted according to such an incentive for each consumer who owns at least one water heater 10 that performed the heating operation during the surplus time period. By discounting the electricity fee according to the incentive in this way, it is possible to provide an economic benefit to the consumer who cooperated with the request.

[0072] Next, the flow of processing executed in the power management system 1 will be described with reference to Fig. 7. As an example, the processing shown in Fig. 7 is started when the time to predict the surplus power for the next day arrives. This time may be, for example, 11:00 PM or some other time. The processing shown in Fig. 7 is an example of a power management method.

[0073] When the process starts, the control unit 51 of the power management device 50 functions as a prediction unit 511 and predicts the power supply and demand in the power distribution system for the next day (step S1). Specifically, the control unit 51 predicts the power generation Pg by each power generation facility 20 in the power distribution system and the power consumption Pc within the premises of each consumer in the power distribution system based on past power generation performance data 521 and consumption performance data 522. The control unit 51 then determines whether the total power consumption Pc in the power distribution system exceeds the total power generation Pg, i.e., whether surplus power will be generated, in any time period. If it is determined that surplus power will be generated, the control unit 51 predicts the surplus time period in which the surplus power will be generated and the amount of surplus power in that time period. If it is determined that surplus power will not be generated, the control unit 51 skips the process from step S2 onwards and ends the process shown in FIG. 7.

[0074] After determining that surplus power will occur, in the morning of the day of the predicted surplus time period, control unit 51 transmits an inquiry about the tank capacity, remaining hot water amount, and rated power consumption to water heaters 10 of each consumer within the power pipe (step S2). In water heaters 10 of each consumer, when receiving the inquiry from power management device 50, the hot water supply controller transmits a response indicating the tank capacity, remaining hot water amount, and rated power consumption to power management device 50 as a response to the inquiry (step S3).

[0075] In addition, if the tank capacity and rated power consumption of a certain water heater 10 have already been obtained in the past, the control unit 51 can omit the process of obtaining the tank capacity and rated power consumption of that water heater 10 in steps S2 and S3.

[0076] In power management device 50, when control unit 51 receives a response from each water heater 10 of the consumer, it functions as power amount calculation unit 512 based on the received response and calculates the amount of power that can be consumed by each water heater 10 present in the power pipe (step S4). Specifically, control unit 51 calculates the amount of hot water that can be boiled for each water heater 10 by subtracting the remaining amount of hot water from the tank capacity. Then, control unit 51 calculates the amount of power required to boil the calculated amount of hot water for each water heater 10 using the rated power consumption.

[0077] After calculating the amount of power that can be consumed, control unit 51 functions as load determination unit 513 and executes a water heater determination process to determine, based on the calculated amount of power, the water heater 10 that will boil water during the surplus time period from among the water heaters 10 of multiple consumers present within the power pipe (step S5). Details of the water heater determination process will be described with reference to FIG. 8.

[0078] When the water heater determination process shown in Fig. 8 starts, the control unit 51 creates a request plan 524 for power consumption during the surplus time slot predicted in step S1 (step S51). Specifically, the control unit 51 selects at least one candidate water heater 10 that will consume power during the surplus time slot, and determines the amount of hot water to be boiled during the surplus time slot for each candidate water heater 10. The control unit 51 also determines the request order in descending order of the amount of power calculated in step S4. As a result, the control unit 51 creates a request plan 524 that associates the consumable amount of power, the request order, and the requested amount of hot water, as shown in Fig. 5.

[0079] When the request plan 524 is created, the control unit 51 selects the candidate that is first in the request order from among at least one candidate selected in the created request plan 524 (step S52). When one candidate is selected, the control unit 51 generates request information indicating the amount of hot water that is requested to be boiled by the water heater 10 of the selected candidate during the surplus time period. Then, the control unit 51 transmits the generated request information to the terminal device 40 corresponding to the selected candidate (step S53).

[0080] When the terminal device 40 receives the request information from the power management apparatus 50, it displays, for example, a request screen shown in FIG. 6 on the display unit based on the received request information (step S54). Then, the terminal device 40 accepts the consumer's response to the request on the displayed request screen (step S55). Upon accepting the consumer's response, the terminal device 40 transmits the accepted response to the power management apparatus 50 (step S56).

[0081] The control unit 51 repeats the process of transmitting the request information in step S53 while gradually reducing the amount of hot water requested as shown in Fig. 6 until permission for the request is obtained from the consumer or the dialogue with the consumer is terminated. Every time the terminal device 40 receives request information, the terminal device 40 repeats the processes of steps S54 to S56 and transmits the consumer's response to the request to the power management device 50.

[0082] In the power management device 50, when the control unit 51 receives a response from the terminal device 40, the control unit 51 determines the amount of hot water for which the consumer's permission has been obtained in the received response as the amount of hot water to be heated by the water heater 10 of that consumer during the surplus time period (step S57). On the other hand, if the consumer's permission has not been obtained, the control unit 51 excludes the water heater 10 of that consumer from the list of those that will heat hot water during the surplus time period.

[0083] Next, the control unit 51 calculates the amount of power consumption corresponding to the amount of hot water determined in step S57. Then, the control unit 51 determines whether the total amount of power consumption to be consumed by the water heater 10 during the surplus time period has reached the amount of surplus power predicted to occur during the surplus time period (step S58).

[0084] If the total amount of power consumption has not reached the surplus power amount (step S58; NO), the control unit 51 selects the next candidate for the request order (step S59). Then, the control unit 51 returns the process to step S53, and repeats the processes of steps S53 to S58 for the newly selected candidate water heater 10, and determines the amount of hot water to be boiled by that water heater 10 during the surplus time period. In this way, the control unit 51 selects the water heaters 10 one by one in descending order of the amount of power that can be consumed during the surplus time period, until the total amount of power consumption to be consumed by the water heaters 10 during the surplus time period reaches the surplus power amount. Then, the control unit 51 sequentially determines the amount of hot water to be boiled during the surplus time period through dialogue with the consumer of the selected water heater 10.

[0085] Finally, when the total amount of power consumption reaches the surplus power amount (step S58; YES), the control unit 51 finalizes the water boiling plan 525 indicating at least one water heater 10 that will boil water during the surplus time period and the amount of water to be boiled by each water heater 10 (step S60). This completes the water heater determination process shown in FIG. 8.

[0086] 7, when the water heater determination process is executed, control unit 51 functions as load control unit 514 and generates a control command instructing the water heater to boil the amount of hot water determined in step S57 during the surplus time period in accordance with water boiling plan 525. Then, control unit 51 transmits a control command for the water boiling operation to at least one target water heater 10 (step S6).

[0087] In the water heater 10, when the water heater controller receives the control command from the power management device 50, it performs the boiling operation in accordance with the received control command (step S7). Specifically, the water heater controller causes the water heater 10 to boil the amount of hot water instructed by the control command at the timing when the start time instructed by the control command arrives.

[0088] When the water heater 10 is performing the heating operation, the control unit 51 periodically transmits a status request to the water heater 10. When the water heater controller receives the status request, it transmits a response indicating whether or not the water heater is currently heating to the power management device 50. When the control unit 51 receives a response indicating that the water heater is not currently heating from the water heater controller, it detects the end of the heating operation.

[0089] When the end of the boiling operation is detected, the control unit 51 functions as the fee calculation unit 515 and calculates the electricity fee (step S8). Specifically, the control unit 51 calculates the electricity fee of the consumer who accepted the consumption of electricity by the water heater 10 during the surplus time period, which is discounted according to the electricity consumption during the surplus time period.

[0090] As described above, the power management device 50 according to the first embodiment determines, from among the water heaters 10 of multiple consumers present within a power pipe, a water heater 10 that will consume power during a time period when surplus power is predicted to be generated within the power pipe, and causes the determined water heater 10 to consume power. In this way, the power management device 50 causes the water heater 10 to consume power during a time period when surplus power is predicted to be generated, thereby suppressing the generation of surplus power. This reduces the possibility of output curtailment, and eliminates dissatisfaction with output curtailment among consumers or power companies that own power generation equipment 20.

[0091] Furthermore, because the power management device 50 according to the first embodiment searches for and determines the water heater 10 that will consume power during the time period when surplus power is predicted to be generated, within the wide area of ​​the power distribution network, the consumer or power utility that owns the power generation facility 20 does not necessarily need to own the water heater 10. This increases the degree of freedom in installing facilities for utilizing surplus power, and also reduces the cost burden. As described above, the power management device 50 according to the first embodiment can effectively utilize surplus power.

[0092] Furthermore, the power management device 50 according to the first embodiment selects a candidate water heater 10 from among a plurality of consumers that is to consume power during a surplus time period, transmits request information to the terminal device 40 corresponding to the selected candidate requesting power consumption during the surplus time period, and, if a response indicating permission for the request information is received from the terminal device 40, determines the selected candidate as the water heater 10 that is to consume power during the surplus time period. In this way, the power management device 50 determines the water heater 10 that is to consume power during the surplus time period only after obtaining permission from the consumer each time, so the consumer does not feel that the water heater 10 is being controlled arbitrarily. This can reduce consumer dissatisfaction. In particular, because consumers may forget that they have already signed a contract, reducing such consumer dissatisfaction is useful.

[0093] Furthermore, the power management device 50 according to the first embodiment calculates a discounted electricity rate according to the power consumption during the surplus time period as the electricity rate for the consumer who has accepted the consumption of power by the water heater 10 during the surplus time period. This allows consumers or power companies that own the power generation facility 20 to eliminate their dissatisfaction with output suppression because output is not suppressed, and also provides economic benefits to consumers that do not own the power generation facility 20 because they can consume power at the discounted electricity rate.

[0094] (Embodiment 2) Next, a description will be given of embodiment 2. Descriptions of the same configurations and functions as embodiment 1 will be omitted where appropriate.

[0095] In the above-described first embodiment, the load determination unit 513 requests power consumption during a surplus time period from each terminal device 40 corresponding to each water heater 10 selected as a candidate in descending order of the amount of consumable power calculated by the power amount calculation unit 512. In contrast to this, in the second embodiment, the load determination unit 513 determines the request order based on an index value other than the amount of consumable power.

[0096] Specifically, the load determination unit 513 determines the request order based on the past record of requests made to consumers by each water heater 10 selected as a candidate. The power management device 50 according to the second embodiment stores request record data 526 as shown in FIG. 9 in the storage unit 52. The request record data 526 is data indicating the past record of requests made to each consumer. Specifically, the request record data 526 defines, for each consumer, the number of requests, the total amount of requested power, the number of acceptances, and the total amount of accepted power, in association with each other.

[0097] Here, the number of requests is the total number of times that the load determination unit 513 has requested power consumption during a surplus time slot in the past. The total requested amount of power is the total amount of power that the load determination unit 513 has requested to be consumed during a surplus time slot in the past. The number of acceptances is the total number of times that consumers have permitted at least a portion of requests made by the load determination unit 513 in the past. The total accepted amount of power is the total amount of power that consumers have permitted to consume during a surplus time slot in the past.

[0098] In the second embodiment, the load determination unit 513 counts these values ​​each time a request is made to a consumer to consume power during a surplus time slot, and updates the request record data 526. When the prediction unit 511 predicts the occurrence of surplus power, the load determination unit 513 determines the order in which to request the terminal devices 40 of the consumers to consume power during the surplus time slot, based on the latest request record data 526 stored in the storage unit 52.

[0099] For example, the load determination unit 513 determines the order of requests in descending order of the number of acceptances or the total amount of accepted power in the request history data 526. By making requests in descending order of the number of acceptances or the amount of power accepted in the past, the acceptability of the next request can be increased. Alternatively, conversely, in order to distribute request destinations from the perspective of fairness, the load determination unit 513 may determine the order of requests in descending order of the number of requests or the total amount of requested power in the request history data 526. In this way, by using the request history data 526, the order of requests can be determined from various perspectives such as acceptability and fairness.

[0100] As a modification of the second embodiment, the load determination unit 513 may determine the order of requests based on an index value other than the request record data 526. For example, the load determination unit 513 may determine the order of requests based on the tank capacity of the water heater 10. Generally, the larger the tank capacity, the less likely the hot water in the hot water storage tank to cool down. Therefore, in order to prevent the boiled water from cooling down after it has been boiled, the load determination unit 513 may determine the order of requests in descending order of tank capacity.

[0101] More specifically, the load determination unit 513 may determine the order of requests in ascending order of the ratio of the amount of hot water that can be boiled to the tank capacity. In this case, if the amount of hot water that can be boiled is the same, the order of requests will be higher in the order of tank capacity. By determining the order of requests taking tank capacity into consideration in this way, it is possible to prevent the hot water boiled during surplus time periods from cooling down as much as possible.

[0102] Furthermore, when the amount of consumable power calculated by the power amount calculation unit 512 is less than the threshold, the load determination unit 513 may determine the order of requests in descending order of the amount of consumable power, while when the amount of consumable power is equal to or greater than the threshold, the load determination unit 513 may determine the order of requests based on an auxiliary index value. As the auxiliary index value, the track record of past requests shown in the request track record data 526 described above, the tank capacity, or a combination of these may be used.

[0103] Here, the threshold is set to an appropriate value in advance. For example, using equation (4) described in Japanese Patent Application Laid-Open No. 2017-99214, the boiling time th required to boil 200 liters of hot water from 10°C to 65°C using a water heater 10 with a boiling output of 6.0 kW and a power consumption of 1.5 kW is calculated as "th = (65 - 10) (°C) × 200 (L) / (6.0 (kW) × 860) ≒ 2 (h)". The amount of power required to boil the water in the required time th is calculated as "1.5 (kW) × 2 (h) = 3.0 (kWh)". From the above, the threshold can be set to 3.0 kWh.

[0104] (Embodiment 3) Next, a description will be given of embodiment 3. Descriptions of the same configurations and functions as those of embodiments 1 and 2 will be omitted where appropriate.

[0105] In the first embodiment, the load determination unit 513 executes the process of determining the water heater 10 that will boil water during the surplus time period in the morning of the same day as the surplus time period predicted by the prediction unit 511. However, depending on the water heater 10, the water heater operation is performed during the night when electricity rates are generally lower, and therefore, in the morning, there may be little free space in the tank, and there may not be enough hot water available to boil. To avoid this, in the third embodiment, the load determination unit 513 transmits the process of determining the water heater 10 that will boil water during the surplus time period at a timing prior to the nighttime water heater operation.

[0106] Specifically, after the prediction unit 511 predicts the next day's surplus time period during the night, the power calculation unit 512 executes a process to calculate the power consumption that can be consumed by each water heater 10, also during the night, and the load determination unit 513 executes a process to determine the water heater 10 that will boil water during the surplus time period.

[0107] When a plan for an operation to consume power before the surplus time period has been set for the water heater 10 determined by the load determination unit 513, the load control unit 514 changes the plan to a plan to perform that operation during the surplus time period. Here, the plan for an operation to consume power before the surplus time period specifically corresponds to a nighttime heating plan in which the water heater 10 heats water at night. Also, the plan to perform an operation during the surplus time period corresponds to a daytime heating plan in which the water heater 10 heats water during the day. In other words, when a nighttime heating plan is scheduled for the water heater 10 determined to be the water heater target during the surplus time period, the load control unit 514 shifts the nighttime heating plan to a daytime heating plan in which water is heated during the surplus time period.

[0108] The load control unit 514 generates a control command instructing such a change in plan and transmits it to the water heater 10. Upon receiving the control command, the water heater 10 cancels the nighttime heating plan in accordance with the received control command and waits for the arrival of a surplus time period before performing the heating operation. In this way, in the third embodiment, even if a nighttime heating plan was scheduled for the water heater 10 determined to be the target for heating water during the surplus time period, the load control unit 514 can effectively utilize surplus power by changing the nighttime heating plan to a daytime heating plan.

[0109] (Fourth embodiment) Next, a description will be given of embodiment 4. Descriptions of the same configurations and functions as those of embodiments 1 to 3 will be omitted where appropriate.

[0110] In the above-described first embodiment, when sending request information, the load determination unit 513 transmits to the terminal device 40 the amount of hot water that can be boiled, which is the amount of hot water that can be added from the hot water storage tank of the water heater 10, as the requested amount of hot water. In contrast, in the fourth embodiment, the load determination unit 513 transmits to the terminal device 40 a value converted into the amount of hot water when hot water dispensed from the hot water storage tank of the water heater 10 is adjusted to the temperature at which the hot water is used by the consumer by adding water outside the hot water storage tank after dispensing, as the requested amount of hot water for screen display.

[0111] In the following, an example will be described in which the water heater 10 of consumer B is selected as a candidate for the water heater 10 that will heat hot water during the surplus time period, and the amount of hot water that can be heated by the water heater 10 of consumer B is 200 liters. In the fourth embodiment, the load determination unit 513 transmits request information to the terminal device 40 of consumer B, indicating a value converted into the amount of hot water at the temperature used by consumer B as the requested amount of hot water to be heated during the surplus time period. Here, the amount of hot water at the temperature used by consumer B means the amount of hot water when hot water is dispensed from the hot water storage tank of the water heater 10 of consumer B and then adjusted to the temperature used by adding tap water to the dispensed hot water.

[0112] The load determination unit 513 calculates the requested hot water volume converted into the hot water volume at the usage temperature of consumer B from the requested hot water volume at the temperature inside the tank in the water heater 10 of consumer B according to the following formula (1). Here, the requested hot water volume at the temperature inside the tank is the requested hot water volume in embodiment 1, and corresponds to the boilable hot water volume, which is the amount of hot water that can be added and boiled from the hot water storage tank. Requested hot water volume converted to hot water volume at the usage temperature (L) = Requested hot water volume at the temperature inside the tank (L) × (Tank temperature (℃) - Tap water temperature (℃)) / (Usage temperature (℃) - Tap water temperature (℃)) ... (1)

[0113] In the above equation (1), the tank temperature is the temperature of the hot water present in the hot water storage tank of the water heater 10. The tap water temperature is the temperature of the tap water supplied to the consumer. The usage temperature is the temperature of the hot water when the hot water drawn from the hot water storage tank is cooled by adding tap water to the hot water to be used by consumer B in the bathroom, kitchen, etc. The usage temperature may be a value input by consumer B, or a predetermined typical value.

[0114] For example, if the usage temperature is 42°C, the requested hot water volume at the temperature inside the tank is 200 liters, the temperature inside the tank is 65°C, and the tap water temperature is 15°C, the load determination unit 513 calculates the requested hot water volume converted to the hot water volume at the usage temperature as approximately 370 liters using the following formula (2).In this case, the load determination unit 513 transmits request information indicating the calculated 370 liters as the requested hot water volume to be displayed on the screen to the terminal device 40 of consumer B. Requested hot water volume (L) converted to hot water volume at 42°C = 200(L) × (65(°C) - 15(°C)) / (42(°C) - 15(°C)) ≒ 370(L) … (2)

[0115] In the fourth embodiment, when the terminal device 40 of the consumer B receives request information from the power management device 50, it displays, for example, a request screen shown in Fig. 10 on the display unit. Fig. 10 shows an example in which the consumer B inputs "No" as answer A, and through request B and answer B, agrees on 185 liters, which is half of 370 liters, i.e., allows the boiling of hot water, which is equivalent to 185 liters when converted into the amount of hot water at the temperature used by the consumer B.

[0116] The load determination unit 513 determines the amount of hot water to be heated by the water heater 10 of consumer B during the surplus time period based on the amount of hot water permitted by consumer B, i.e., the amount of hot water agreed upon by consumer B, among the requested amounts of hot water indicated in the request information. Specifically, the load determination unit 513 converts the amount of hot water permitted by consumer B from the amount of hot water at the usage temperature to the amount of hot water at the temperature inside the tank according to the following equation (3), and determines the converted amount of hot water as the amount of hot water to be heated. For example, as shown in FIG. 10, if consumer B is permitted to boil 185 liters of hot water when converted to the amount of hot water at the usage temperature, the load determination unit 513 calculates the amount of hot water to be heated by the water heater 10 of consumer B to be approximately 100 liters. Amount of hot water to be boiled (L) = Amount of hot water agreed upon by the customer (L) x (Usage temperature (℃) - Tap water temperature (℃)) / (Temperature inside the tank (℃) - Tap water temperature (℃)) = 185(L)×(42(℃)-15(℃)) / (65(℃)-15(℃)) ≒ 100(L) …(3)

[0117] When the load determination unit 513 calculates the amount of hot water to be boiled for consumer B as 100 liters in this way, the load control unit 514 creates a boiling plan 525 based on the amount of hot water to be boiled for consumer B calculated by the load determination unit 513. In this way, in the fourth embodiment, the amount of hot water at the temperature at which the consumer will use the hot water is displayed on the request screen as the requested amount of hot water, making it possible to provide an expression that is even easier for the consumer to understand.

[0118] (Embodiment 5) Next, a description will be given of embodiment 5. Descriptions of the same configurations and functions as those of embodiments 1 to 4 will be omitted where appropriate.

[0119] In the above-described first embodiment, when the terminal device 40 receives the request information transmitted from the load determination unit 513, the terminal device 40 displays the request screen shown in Fig. 6. In contrast to this, in the fifth embodiment, when the terminal device 40 receives the request information transmitted from the load determination unit 513, the terminal device 40 displays the request screen shown in Fig. 11.

[0120] More specifically, on the request screen shown in FIG. 6, the consumer inputs a response regarding the amount of hot water to be boiled during the surplus time period by selecting either "Yes" or "No." In contrast, on the request screen shown in FIG. 11, if the consumer inputs "No" as response A, the load determination unit 513 requests the consumer to input a specific value for the amount of hot water to be boiled that the consumer is willing to allow in the next request B'. If the consumer selects "Answer" to such request B', the consumer inputs a specific value for the amount of hot water to be boiled in response B'. The content of the input response B is transmitted from the terminal device 40 to the power management device 50.

[0121] When the consumer inputs such an answer B', the load determination unit 513 requests the consumer to make a final confirmation that the content of the answer B' is confirmed. When the consumer inputs "confirm" as a response to such a final confirmation, the load determination unit 513 confirms the amount of hot water input in the answer B' as the amount of hot water to be boiled in the water heater 10 of the consumer.

[0122] In this way, in the fifth embodiment, the load determination unit 513 receives a specific value for the amount of hot water that the consumer allows to be boiled in dialogue with the consumer. This allows the consumer to input the amount of hot water that the consumer desires more flexibly, which leads to more effective use of surplus power.

[0123] (Variation) Although the embodiments have been described above, it is possible to combine the embodiments, or to modify or omit the embodiments as appropriate.

[0124] For example, in the above embodiment, the terminal device 40 displays the request screen shown in Fig. 6 or 11 on the display unit. However, the terminal device 40 is not limited to displaying the screen, and may output the request information transmitted from the power management device 50 as audio from a speaker. In other words, the load determination unit 513 may determine the amount of hot water to be boiled during the surplus time period through an audio dialogue with the consumer. Furthermore, a screen display and audio may be combined.

[0125] In the above embodiment, the power amount calculation unit 512 acquires information on the tank capacity, remaining hot water amount, and rated power consumption from each water heater 10, and calculates the amount of power that can be consumed by each water heater 10 based on the acquired information. However, if the water heater 10 has a property of a predicted value of the amount of power when the water heater 10 performs a boiling operation during the day, the power amount calculation unit 512 may acquire the property of the water heater 10 instead of the rated power consumption, and calculate the amount of power that can be consumed by the water heater 10 based on the predicted value of the amount of power indicated in the property.

[0126] Furthermore, the power amount calculation unit 512 may predict the remaining hot water amount from past performance data of the water heater 10. In this case, the power amount calculation unit 512 does not need to acquire information on the remaining hot water amount from the water heater 10. Alternatively, the power amount calculation unit 512 may correct the remaining hot water amount predicted from the past performance data based on the information on the remaining hot water amount acquired from the water heater 10.

[0127] In the above embodiment, each power generation facility 20 in the power management system 1 is a facility that generates power using solar energy. However, each power generation facility 20 is not limited to solar energy, and may be a facility that generates power using wind power, hydropower, biomass, or the like, as long as it is a facility that generates power using natural energy. Also, in the above embodiment, the load device to be controlled by the power management device 50 is the water heater 10. However, as long as the device is capable of suppressing the generation of surplus power by consuming power during a surplus power time period, the power management device 50 is not limited to causing the water heater 10 to boil water, and may also operate other load devices to consume power during a surplus power time period.

[0128] In the above embodiment, the power management apparatus 50 includes the control unit 51 having the functional configuration shown in FIG. 2 . However, this configuration is merely an example, and the functions of each unit may be provided in any device in the power management system 1. For example, the prediction unit 511, the power amount calculation unit 512, or the fee calculation unit 515 may be provided in an external device other than the power management apparatus 50. For example, if the prediction unit 511 is provided in an external device, the power management apparatus 50 acquires, via the communication unit 53, prediction data indicating a time period in which surplus power will be generated and the amount of surplus power predicted by the external device. If the power amount calculation unit 512 is provided in an external device, the power management apparatus 50 acquires, via the communication unit 53, water heater data 523 indicating the amount of power that can be consumed by each water heater 10, calculated by the external device. If the fee calculation unit 515 is provided in an external device, the power management apparatus 50 transmits fee information necessary for calculating the electricity fee to the external device via the communication unit 53. An external device then calculates the electricity fee based on the fee information transmitted from the power management device 50. Furthermore, each function of the power management device 50 may be divided into multiple devices, not limited to the prediction unit 511, the power amount calculation unit 512, or the fee calculation unit 515.

[0129] In the above embodiment, the CPU in the control unit 51 executes a program stored in the ROM or the storage unit 52, thereby functioning as each unit shown in FIG. 2. However, the control unit 51 may be dedicated hardware. Dedicated hardware is, for example, a single circuit, a composite circuit, a programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination of these. When the control unit 51 is dedicated hardware, the functions of each unit may be realized by individual hardware, or the functions of each unit may be realized together by a single piece of hardware.

[0130] In addition, some of the functions of each unit may be realized by dedicated hardware, and other parts may be realized by software or firmware. In this way, the control unit 51 can realize each of the above-mentioned functions by hardware, software, firmware, or a combination of these.

[0131] By applying a program that defines the operation of the control unit 51 to an existing computer such as a personal computer or an information terminal device, it is possible to make the computer function as an air conditioning control device.

[0132] Furthermore, the method of distribution of such a program is arbitrary, and for example, it may be stored on a computer-readable recording medium such as a CD-ROM (Compact Disk ROM), a DVD (Digital Versatile Disk), an MO (Magneto Optical Disk), or a memory card and distributed, or it may be distributed via a communication network such as the Internet.

[0133] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Furthermore, the above-described embodiments are intended to illustrate the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of equivalent disclosures are considered to be within the scope of the present disclosure.

[0134] Various aspects of the present disclosure are summarized below as appendices.

[0135] (Appendix 1) a load determination means for determining, from among the hot water heaters of a plurality of consumers present within a jurisdiction, a hot water heater to consume power during a time period when surplus power is predicted to be generated within the jurisdiction; and a load control means for causing the water heater determined by the load determination means to consume the power during the time period. Power management device. (Appendix 2) The load determining means selecting a candidate hot water heater to consume the power during the time period from among the plurality of hot water heaters of the consumers; transmitting request information to the terminal device corresponding to the selected candidate, the request information requesting power consumption during the time period; When a response indicating permission to the request information is received from the terminal device, the selected candidate is determined as the water heater that will consume the power during the time period. 2. The power management apparatus of claim 1. (Appendix 3) the load determination means determines the amount of power to be consumed by the candidate during the time period based on a dialogue between the terminal device and the consumer. 3. The power management apparatus of claim 2. (Appendix 4) The load determining means selecting a plurality of candidates for consuming the power during the time period from among the plurality of water heaters of the consumers; transmitting the request information to each of a plurality of terminal devices corresponding to the plurality of selected candidates in an order based on a predetermined criterion; 4. The power management device according to claim 2 or 3. (Appendix 5) The order is determined in descending order of the amount of power that can be consumed by each of the plurality of candidates in the time period. 5. The power management apparatus of claim 4. (Appendix 6) The order is determined based on past requests to each of the plurality of candidate consumers. 6. The power management device according to claim 4 or 5. (Appendix 7) The load determining means transmitting the request information indicating the amount of water to be boiled in the candidate during the time period to the terminal device; Among the hot water amounts indicated in the request information, the amount of hot water permitted by the consumer of the terminal device is determined as the amount of hot water to be boiled by the candidate during the time period. 7. A power management apparatus according to any one of claims 2 to 6. (Appendix 8) further comprising an electric energy calculation means for calculating an amount of electric energy that can be consumed by each of the hot water heaters of the plurality of consumers during the time period; the load determination means determines a water heater that will consume the power during the time period from among the water heaters of the plurality of consumers based on the amount of power calculated by the power amount calculation means. 8. A power management device according to any one of claims 1 to 7. (Appendix 9) The electric energy calculation means acquires information on the amount of remaining hot water from each of the hot water heaters of the plurality of consumers, and calculates the amount of additional hot water that can be boiled from the hot water in the hot water storage tanks of the hot water heaters of the plurality of consumers during the time period based on the amount of remaining hot water and the capacity of the hot water storage tank of the hot water heater from which the information on the amount of remaining hot water was acquired, as the amount of hot water that can be boiled by each of the hot water heaters of the plurality of consumers. 9. The power management apparatus of claim 8. (Appendix 10) When a plan for an operation that consumes power is set for the water heater determined by the load determination means before the time period, the load control means changes the plan to a plan for performing the operation during the time period. 10. A power management apparatus according to any one of claims 1 to 9. (Appendix 11) The system further includes a fee calculation means for calculating an electricity fee of the customer corresponding to the water heater determined by the load determination means, the electricity fee being discounted according to the power consumption during the time period. 11. A power management device according to any one of claims 1 to 10. (Appendix 12) a load determination means for determining, from among the hot water heaters of a plurality of consumers present within a jurisdiction, a hot water heater to consume power during a time period when surplus power is predicted to be generated within the jurisdiction; and a load control means for causing the water heater determined by the load determination means to consume the power during the time period. Power management system. (Appendix 13) determining, from among the hot water heaters of a plurality of consumers present within the jurisdiction, a hot water heater to consume power during a time period when surplus power is predicted to be generated within the jurisdiction; causing the determined water heater to consume the power during the time period; Power management methods. (Appendix 14) Computer, a load determination means for determining, from among the hot water heaters of a plurality of consumers present within the jurisdiction, a hot water heater that will consume power during a time period when surplus power is predicted to be generated within the jurisdiction; a load control unit that controls the water heater determined by the load determination unit to consume the power during the time period; program. [Explanation of symbols]

[0136] 1 Power management system, 10 Water heater, 20 Power generation equipment, 30 Power measurement device, 40 Terminal device, 50 Power management device, 51 Control unit, 52 Memory unit, 53 Communication unit, 511 Prediction unit, 512 Power amount calculation unit, 513 Load determination unit, 514 Load control unit, 515 Fee calculation unit, 521 Power generation result data, 522 Consumption result data, 523 Water heater data, 524 Request plan, 525 Boiling plan, 526 Request result data, N1 Information communication network, N2 Power transmission and distribution network

Claims

1. a load determination means for determining, from among the hot water heaters of a plurality of consumers present within a jurisdiction, a hot water heater to consume power during a time period when surplus power is predicted to be generated within the jurisdiction; and a load control means for causing the water heater determined by the load determination means to consume the power during the time period. Power management device.

2. The load determining means selecting a candidate hot water heater to consume the power during the time period from among the plurality of hot water heaters of the consumers; transmitting request information to the terminal device corresponding to the selected candidate, the request information requesting power consumption during the time period; When a response indicating permission to the request information is received from the terminal device, the selected candidate is determined as the water heater that will consume the power during the time period. The power management device of claim 1 .

3. the load determination means determines the amount of power to be consumed by the candidate during the time period based on a dialogue between the terminal device and the consumer. The power management device of claim 2 .

4. The load determining means selecting a plurality of candidates for consuming the power during the time period from among the plurality of water heaters of the consumers; transmitting the request information to each of a plurality of terminal devices corresponding to the plurality of selected candidates in an order based on a predetermined criterion; The power management device of claim 2 .

5. The order is determined in descending order of the amount of power that can be consumed by each of the plurality of candidates in the time period. The power management device of claim 4 .

6. The order is determined based on past requests to each of the plurality of candidate consumers. The power management device of claim 4 .

7. The load determining means transmitting the request information indicating the amount of water to be boiled in the candidate during the time period to the terminal device; Among the hot water amounts indicated in the request information, the amount of hot water permitted by the consumer of the terminal device is determined as the amount of hot water to be boiled by the candidate during the time period. The power management device of claim 2 .

8. further comprising an electric energy calculation means for calculating an amount of electric energy that can be consumed by each of the hot water heaters of the plurality of consumers during the time period; the load determination means determines a water heater that will consume the power during the time period from among the water heaters of the plurality of consumers based on the amount of power calculated by the power amount calculation means. The power management device of claim 1 .

9. The electric energy calculation means acquires information on the amount of remaining hot water from each of the hot water heaters of the plurality of consumers, and calculates the amount of additional hot water that can be boiled from the hot water in the hot water storage tanks of the hot water heaters of the plurality of consumers during the time period based on the amount of remaining hot water and the capacity of the hot water storage tank of the hot water heater from which the information on the amount of remaining hot water was acquired, as the amount of hot water that can be boiled by each of the hot water heaters of the plurality of consumers. The power management apparatus of claim 8 .

10. When a plan for an operation that consumes power is set for the water heater determined by the load determination means before the time period, the load control means changes the plan to a plan for performing the operation during the time period. The power management device of claim 1 .

11. The system further includes a fee calculation means for calculating an electricity fee of the customer corresponding to the water heater determined by the load determination means, the electricity fee being discounted according to the power consumption during the time period. The power management device of claim 1 .

12. a load determination means for determining, from among the hot water heaters of a plurality of consumers present within a jurisdiction, a hot water heater to consume power during a time period when surplus power is predicted to be generated within the jurisdiction; and a load control means for causing the water heater determined by the load determination means to consume the power during the time period. Power management system.

13. determining, from among the hot water heaters of a plurality of consumers present within the jurisdiction, a hot water heater to consume power during a time period when surplus power is predicted to be generated within the jurisdiction; causing the determined water heater to consume the power during the time period; Power management methods.

14. Computer, a load determination means for determining, from among the hot water heaters of a plurality of consumers present within the jurisdiction, a hot water heater that will consume power during a time period when surplus power is predicted to be generated within the jurisdiction; a load control unit that controls the water heater determined by the load determination unit to consume the power during the time period; program.

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