Hot water supply system and hot water supply method

Abstract

A hot water supply system (100) comprises: an acquisition unit (120) which acquires a plurality of pieces of hot water supply information each including a water boiling amount of a hot water supply device (11) and a use start time of the hot water supply device (11) and first reference electric power of a plurality of residences provided with a plurality of hot water supply devices (11); a determination unit (130) which, when it has been determined, on the basis of the water boiling amounts included in the acquired plurality of pieces of hot water supply information, that electric power demand of the whole of the plurality of residences will exceed the first reference electric power if the plurality of hot water supply devices (11) simultaneously start water boiling, determines a schedule to start water boiling by the hot water supply devices (11) in ascending order of latest water boiling start time, which is the latest time to start water boiling, so that no shortage of hot water occurs at the use start times included in the hot water supply information; and a control unit (140) which controls water boiling by the plurality of hot water supply devices (11) on the basis of the determined schedule.

Description

Hot water supply system and hot water supply method

[0001] The present invention relates to a hot water supply system and a hot water supply method.

[0002] Patent Document 1 discloses a hot water supply system using a storage tank. This type of hot water supply system generally stores hot water boiled during times when the unit price of electricity is low in a hot water storage tank and supplies the hot water when needed. The time when the unit price of electricity is low is, for example, during the night.

[0003] Japanese Patent Application Laid-Open No. 2012-225601

[0004] For example, in an apartment building containing multiple dwellings, multiple hot water heaters such as those disclosed in Patent Document 1 may be installed. In such a case, if multiple hot water heaters start heating water simultaneously during the nighttime hours, the overall power demand for the apartment building at that time may become very large.

[0005] Incidentally, one type of contract for supplying electricity to an apartment building is called a high-voltage bulk power receiving contract. In this contract, the management company or management association of the apartment building enters into a contract with the electric power company, and the users of each unit enter into a contract with the manager or management association of the apartment building. In a high-voltage bulk power receiving contract, a standard power consumption, which is the standard value (upper limit) for the entire power demand of the apartment building, is set, and if this standard power consumption is exceeded, a contract with a higher basic fee with a higher standard power consumption is required for the current month and for the following 11 months.

[0006] Therefore, as mentioned above, if the total power demand of an apartment complex containing multiple residences becomes very large due to the heating of multiple hot water heaters, the power demand (more specifically, the maximum power demand) may exceed the standard power, which may result in a higher basic charge.Furthermore, when the power demand becomes too high, problems such as breakers tripping may occur.

[0007] The present invention provides a hot water supply system and the like that can suppress the maximum value of the overall power demand of a plurality of residences.

[0008] A hot water supply system according to one embodiment of the present invention comprises an acquisition unit that acquires a plurality of pieces of hot water information including the amount of water heated by the water heating devices and the start time of use of the water heating devices, and a first reference power of a plurality of residences in which the plurality of water heating devices are installed; a determination unit that, when it is determined based on the amount of water heated by the acquired plurality of pieces of hot water information that if the plurality of water heating devices start heating at the same time, the total power demand of the plurality of residences will exceed the acquired first reference power, determines a schedule to start heating among the plurality of water heating devices in order of the water heating device with the earliest latest heating start time, which is the latest time to start heating so that hot water does not run out at the start time of use included in the hot water heating information for that water heating device; and a control unit that controls the heating of the plurality of water heating devices based on the determined schedule.

[0009] A hot water supply method according to one aspect of the present invention is a hot water supply method executed by a hot water supply system, and includes: an acquisition step of acquiring multiple pieces of hot water information including the amount of water heated by the hot water supply devices and the start time of use of the hot water supply devices, and a first reference power of multiple residences in which multiple hot water supply devices are installed; a determination step of, when it is determined based on the amount of water heated by the multiple pieces of hot water information acquired that if multiple hot water supply devices start heating at the same time, the total power demand of the multiple residences will exceed the acquired first reference power, determining a schedule to start heating among the multiple hot water supply devices in order of the hot water supply device with the earliest latest start time of heating, which is the latest time to start heating so that hot water does not run out at the start time of use included in the hot water supply information for that hot water supply device; and a control step of controlling the heating of the multiple hot water supply devices based on the determined schedule.

[0010] The hot water supply system of the present invention can suppress the maximum value of the total power demand of a plurality of houses.

[0011] FIG. 1A is a block diagram showing a functional configuration of a hot water supply system according to an embodiment. FIG. 1B is a diagram showing an example of a unit price of electricity according to an embodiment. FIG. 2 is a flowchart of Operation Example 1 according to an embodiment. FIG. 3 is a diagram showing a schedule of Operation Example 1 according to an embodiment. FIG. 4 is a more detailed flowchart of step S30 of Operation Example 1 according to an embodiment. FIG. 5 is another diagram showing a schedule of Operation Example 1 according to an embodiment. FIG. 6 is a flowchart of Operation Example 2 according to an embodiment. FIG. 7 is a diagram showing a schedule of Operation Example 2 according to an embodiment. FIG. 8 is a flowchart of Operation Example 3 according to an embodiment. FIG. 9 is a diagram showing a schedule of Operation Example 3 according to an embodiment. FIG. 10 is a flowchart of Operation Example 4 according to an embodiment. FIG. 11 is a diagram showing a schedule of Operation Example 4 according to an embodiment. FIG. 12 is a flowchart of Operation Example 5 according to an embodiment. FIG. 13 is a diagram showing a schedule of Operation Example 5 according to an embodiment. FIG. 14 is a flowchart of Operation Example 6 according to an embodiment. FIG. 15 is a diagram showing a schedule of Operation Example 6 according to an embodiment. FIG. 16 is a flowchart of Operation Example 7 according to an embodiment. FIG. 17 is a flowchart of an eighth operation example according to an embodiment. FIG. 18 is a diagram showing a schedule and electricity charges for the eighth operation example according to an embodiment. FIG. 19 is a flowchart of a ninth operation example according to an embodiment. FIG. 20 is a diagram showing a schedule for the ninth operation example according to an embodiment. FIG. 21 is a flowchart of a tenth operation example according to an embodiment. FIG. 22 is a flowchart of an eleventh operation example according to an embodiment. FIG. 23 is a flowchart of a twelfth operation example according to an embodiment. FIG. 24 is a block diagram showing the functional configuration of a hot water supply system according to a first modification of an embodiment. FIG. 25 is a block diagram showing the functional configuration of a hot water supply system according to a second modification of an embodiment. FIG. 26 is a block diagram showing the functional configuration of a hot water supply system according to a third modification of an embodiment.

[0012] Hereinafter, the embodiments will be described in detail with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection forms, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, among the components in the following embodiments, components not recited in independent claims will be described as optional components.

[0013] It should be noted that the drawings are schematic diagrams and are not necessarily strict illustrations. In addition, in the drawings, substantially the same components are denoted by the same reference numerals, and overlapping descriptions may be omitted or simplified.

[0014] (Embodiment) [Configuration] The configuration of a hot water supply system 100 according to this embodiment will be described.

[0015] FIG. 1A is a block diagram showing the functional configuration of a hot water supply system 100 according to this embodiment.

[0016] Hot water supply system 100 is a system installed in apartment building 40. Therefore, Fig. 1A shows a block diagram illustrating the functional configuration of apartment building 40 and other components other than hot water supply system 100. Hot water supply system 100 controls multiple hot water heaters 11 installed in multiple homes included in apartment building 40 to suppress the maximum value of the overall power demand of apartment building 40.

[0017] In the apartment building 40 according to this embodiment, a high-voltage bulk power receiving contract is selected as the contract type for supplying power to the apartment building 40. The contract also provides for two types of time periods with different unit prices of power, for example, a first time period and a second time period with a lower unit price of power than the first time period. The contract may also provide for three types of time periods with different unit prices of power, for example, a first time period, a second time period with a lower unit price of power than the first time period, and a third time period with a higher unit price of power than the first time period. The contract may also provide for four or more types of time periods with different unit prices of power.

[0018] Furthermore, the unit price of electricity and the time period will be described with reference to FIG. 1B.

[0019] FIG. 1B is a diagram showing an example of a unit price of electric energy according to this embodiment. More specifically, (a) of FIG. 1B is a diagram showing an example in which two types of time periods with different unit prices of electric energy are provided in one day, and (b) of FIG. 1B is a diagram showing an example in which the unit price of electric energy fluctuates every predetermined time (e.g., 30 minutes) in one day. In this embodiment, as described above, two types of time periods may be provided, or three or more types of time periods may be provided, or the unit price of electric energy may fluctuate every predetermined time (e.g., 30 minutes) as shown in (b) of FIG. 1B. Hereinafter, unless otherwise specified, this embodiment will be described assuming that two types of time periods with different unit prices of electric energy are provided.

[0020] For example, the first time period is a time period other than nighttime, and the second time period is a time period during nighttime. Unless otherwise specified, the first time period, during which the unit price of electricity is higher, is from 7:00 to 23:00, and the second time period, during which the unit price of electricity is lower, is from 23:00 to 7:00 the next day, and the first and second time periods are consecutive time periods. Generally, the hot water stored in the water heater 11 is used more and more frequently during the first time period, which is a time period other than nighttime, and used less and less frequently during the second time period, which is a nighttime period.

[0021] Hot water supply system 100 according to the present embodiment determines a schedule for the heating of water by multiple water heating devices 11 before the heating of water by multiple water heating devices 11 begins, and controls multiple water heating devices 11 based on this determined schedule. For example, hot water supply system 100 determines a schedule for the heating of water by multiple water heating devices 11 before the second time slot begins, that is, during the first time slot, and controls multiple water heating devices 11 based on this determined schedule.

[0022] The housing complex 40 is a facility that includes a plurality of dwelling units (i.e., a plurality of houses) and a common area 20, and is, for example, an apartment building.

[0023] The number of dwelling units provided in the apartment building 40 may be, for example, a dozen, several tens, or several hundred, but is not limited to this. Here, each of the multiple dwelling units is a resident's private section 10 (i.e., a residence), and for the purpose of identification, they may be referred to as the first private section 10a, the second private section 10b, the third private section 10c, the fourth private section 10d, and the fifth private section 10e. Furthermore, the multiple dwelling units include multiple other private sections 10 in addition to the first to fifth private sections 10a to 10e. Note that when there is no particular need to distinguish them, each of the first to fifth private sections 10a to 10e may be simply referred to as the private section 10.

[0024] Each of the multiple dwelling units is equipped with a water heater 11, electrical appliances 12, and a control device 13. In other words, each of the multiple water heaters 11 installed in the multiple residences is a water heater provided in each of the multiple dwelling units, and more specifically, is a hot water storage type water heater. For the sake of distinction, the water heaters 11 provided in the first to fifth exclusive use areas 10a to 10e are referred to as first to fifth water heaters 11a to 11e. In other words, the multiple water heaters 11 include first to fifth water heaters 11a to 11e. Furthermore, when there is no particular need to distinguish them, each of the first to fifth water heaters 11a to 11e may be simply referred to as a water heater 11. Each of the multiple water heaters 11 communicates with each of the multiple control devices 13.

[0025] The electrical equipment 12 and the control device 13 have similar functions in each of the multiple dwelling units, so here, as an example, we will explain the electrical equipment 12 and the control device 13 provided in the first exclusive use section 10a.

[0026] Electrical equipment 12 refers to all electrical equipment in first exclusive use portion 10a except for first hot water supply apparatus 11a. For example, electrical equipment 12 is home appliances such as lighting fixtures and air conditioners in first exclusive use portion 10a.

[0027] Control device 13 is a device that communicates with and controls first hot water supply apparatus 11a and electrical appliances 12 in first exclusive unit 10a. More specifically, control device 13 is a so-called HEMS (Home Energy Management System) controller that communicates with first hot water supply apparatus 11a and electrical appliances 12 and monitors or controls the operating status of first hot water supply apparatus 11a and electrical appliances 12. For example, through communication, control device 13 obtains the remaining amount of hot water (also referred to as hot water storage amount) in the hot water storage tank of first hot water supply apparatus 11a from first hot water supply apparatus 11a. Control device 13 also communicates with hot water supply system 100.

[0028] Control device 13 also has a reception unit that receives operations from the owner (e.g., resident) of first exclusive use unit 10a. Specifically, this reception unit is realized by a touch panel or the like. This reception unit receives, from the owner of first exclusive use unit 10a, an operation to specify, for example, a target amount of water to be heated by first hot water supply device 11a.

[0029] The target boiling amount is the target amount of hot water remaining (hot water storage amount) in the hot water storage tank of first hot water supply device 11a when hot water supply system 100 finishes boiling water for first hot water supply device 11a. The target boiling amount may also be the amount of hot water planned to be used by the owner of first exclusive section 10a. Note that control device 13 may determine the boiling amount of first hot water supply device 11a as the value obtained by subtracting the acquired amount of hot water remaining in the hot water storage tank of first hot water supply device 11a (more specifically, the amount of hot water stored before boiling) from the target boiling amount indicated in the received instruction.

[0030] Furthermore, the reception section of control device 13 receives an operation from the owner of first exclusive section 10a to specify the use start time, which is the time to start using the hot water stored in first hot water supply device 11a.

[0031] Control device 13 outputs hot water supply information for first hot water supply device 11a to hot water supply system 100. The hot water supply information for first hot water supply device 11a is information that includes the determined amount of water to be heated (i.e., the amount of water to be heated by first hot water supply device 11a) and the start time of use indicated by the instruction received by the reception unit of control device 13 (i.e., the start time of use of first hot water supply device 11a).

[0032] Furthermore, the control device 13 outputs exclusive area power information regarding the power usage of the electrical appliances 12 to the hot water supply system 100 .

[0033] The private area power information includes information indicating expected power usage based on expected usage of the electrical appliances 12. The information indicating the expected power usage is the expected usage of the electrical appliances 12, and is based on the expected usage for a predetermined time period (e.g., the second time period) of a certain day. For example, at 10:00 p.m., which corresponds to the first time period of the day, the control device 13 predicts and determines the expected power usage for the second time period starting at 11:00 p.m. of the certain day based on the past power usage of the electrical appliances 12 for that day. In this case, the control device 13 determines the average power usage of the electrical appliances 12 during the second time period over a predetermined past period (e.g., from the day before the day to one week before the day) as the expected power usage for the electrical appliances 12 for that day. The private area power information also includes information indicating the current power usage of the electrical appliances 12 during a predetermined time period (e.g., the second time period) of a certain day. The control device 13 outputs this private area power information to the hot water supply system 100. Note that the predetermined time period of a certain day is not limited to the second time period and may be the first time period.

[0034] The common area 20 of the apartment complex 40 is, for example, a place other than the multiple dwelling units (residences) of the apartment complex 40, such as a shared space such as a corridor, rooftop, garden, or stairs.

[0035] Electrical equipment 21 and a power measurement device 22 are installed in the common area 20. For example, lighting, an elevator, a water pump, etc. correspond to the electrical equipment 21. The power measurement device 22 measures the power consumption of the electrical equipment 21 and outputs the measured power consumption to the hot water supply system 100.

[0036] Furthermore, the power metering device 22 outputs common area power information regarding the power usage of the electrical appliances 21 to the hot water supply system 100. The common area power information includes information indicating expected power usage based on the expected usage of the electrical appliances 21. The information indicating the expected power usage is the expected usage of the electrical appliances 21, and is information based on the expected usage for a predetermined time slot (e.g., a second time slot) of a certain day. For example, at 10:00 p.m., which corresponds to a first time slot of the certain day, the power metering device 22 predicts and determines the expected power usage for a second time slot starting at 11:00 p.m. of the certain day based on the past power usage of the electrical appliances 21 for the certain day. In this case, the power metering device 22 determines the average value of the power usage of the electrical appliances 21 during the second time slot over a predetermined past period (e.g., from the day before the certain day to one week before the certain day) as the expected power usage for the electrical appliances 21 for the certain day. The common area power information also includes information indicating the current power usage of the electrical appliances 21 during a predetermined time slot (e.g., the second time slot) of the certain day. The control device 13 outputs such common area power information to the hot water supply system 100. Note that the above-mentioned predetermined time period in a certain day is not limited to the second time period, and may be the first time period.

[0037] Furthermore, power supply equipment 23 is installed in the common area 20, and for example, a solar power generation equipment, a charging equipment, etc. correspond to the power supply equipment 23. That is, in this embodiment, the apartment building 40 is equipped with the power supply equipment 23, and the power supply equipment 23 has a solar power generation equipment and a charging equipment (for example, a storage battery and an electric vehicle).

[0038] The power output from the power supply facility 23 is supplied to a plurality of dwelling units (for example, a plurality of hot water heaters 11).

[0039] In addition, the power supply equipment 23 outputs power supply equipment information indicating the amount of power generated and charged by the power supply equipment 23 to the power measurement device 22, and the power measurement device 22 outputs the acquired power supply equipment information to the hot water supply system 100.

[0040] Here, the components of the hot water supply system 100 will be described.

[0041] 1A, hot water supply system 100 includes communication unit 110, acquisition unit 120, determination unit 130, control unit 140, and storage unit 150. Hot water supply system 100 is, for example, a personal computer, but may also be a server device or the like.

[0042] The communication unit 110 is a communication circuit that enables the hot water supply system 100 to communicate with the control device 13 provided in each of the multiple dwelling units and the power measurement device 22 in the common area 20. In this embodiment, the communication unit 110 is a circuit for performing wireless communication, and performs wireless communication in accordance with various communication standards. Note that the communication unit 110 may also be a circuit for performing wired communication.

[0043] Communication unit 110 acquires hot water supply information for each of multiple hot water supply devices 11 from control device 13 for each of multiple dwelling units. That is, for example, communication unit 110 acquires hot water supply information for first hot water supply device 11a from control device 13 in first exclusive use unit 10a, and acquires hot water supply information for second hot water supply device 11b from control device 13 in second exclusive use unit 10b.

[0044] Acquisition unit 120 is a processing unit that acquires multiple pieces of hot water supply information and a first reference power. More specifically, acquisition unit 120 acquires the hot water supply information for each of multiple hot water supply devices 11 acquired by communication unit 110, and acquires the first reference power stored in storage unit 150. Note that this first reference power is the reference power for multiple residences (here, apartment buildings 40) in which multiple hot water supply devices 11 are installed, and is, for example, the reference power for a second time slot. The first reference power for the second time slot is the reference power specified in a high-voltage bulk power receiving contract, and is the first reference power for apartment building 40 in which multiple hot water supply devices 11 are installed. If the total power demand for apartment building 40 exceeds the first reference power, a contract with a higher basic fee with an increased first reference power is required for the current month and for 11 months from the following month.

[0045] The determination unit 130 determines a schedule based on the plurality of pieces of hot water information acquired by the acquisition unit 120 and the first reference power acquired by the acquisition unit 120. The schedule indicates the scheduled start time and scheduled end time of water heating for each of the plurality of water heating devices 11. The schedule is, for example, a schedule for water heating for each of the plurality of water heating devices 11 in a second time slot. However, the schedule is not limited to this, and may be, for example, a schedule for water heating for each of the plurality of water heating devices 11 in a first, second, and third time slot. The schedule also indicates a power supply source that provides the power required for water heating for each of the plurality of water heating devices 11. Examples of the power supply source include a power company and power supply facility 23.

[0046] Control unit 140 is a processing unit that controls the heating of water by multiple water heating devices 11 based on the schedule determined by determination unit 130. Here, control unit 140 causes communication unit 110 to output, to each of multiple control devices 13, a control signal that instructs multiple water heating devices 11 to heat water according to the determined schedule.

[0047] As a result, each of the plurality of control devices 13 controls each of the plurality of water heating devices 11 in accordance with the control signal output from communication unit 110 .

[0048] The acquiring unit 120, the determining unit 130, and the control unit 140 are each realized by, for example, a microcomputer, but may also be realized by a processor or a dedicated circuit. The functions of the acquiring unit 120, the determining unit 130, and the control unit 140 are realized by hardware such as a microcomputer that constitutes each of the acquiring unit 120, the determining unit 130, and the control unit 140 executing software stored in the storage unit 150.

[0049] Storage unit 150 is a storage device that stores information necessary for information processing to control multiple water heating devices 11, such as software executed by acquisition unit 120, determination unit 130, and control unit 140. Storage unit 150 is realized by, for example, a semiconductor memory.

[0050] Next, the operation of the hot water supply system 100 according to the present embodiment configured as above will be described.

[0051] [Operation Example 1] FIG. 2 is a flowchart of Operation Example 1 according to this embodiment.

[0052] 2, steps S10, S20, S30, and S40 are processes performed in a first time period, and step S90 is a process performed in a second time period. Note that the flowcharts shown in the following figures may indicate the time period in which each step is performed.

[0053] Note that, in this operation example, an example is shown in which a schedule is determined for a first time slot and the plurality of hot water heating devices 11 heat water during a second time slot, but this is not limited thereto. As described above, hot water heating system 100 may determine a schedule for the heating of the plurality of hot water heating devices 11 before the plurality of hot water heating devices 11 begin heating water, and control the heating of the plurality of hot water heating devices 11 based on this determined schedule. Therefore, for example, a schedule may be determined for a second time slot, and the plurality of hot water heating devices 11 may heat water during a first time slot. Also, for example, in the example shown in FIG. 1B (b), a schedule may be determined before the start of a predetermined time slot (e.g., 12:00 to 14:00), and the plurality of hot water heating devices 11 may heat water during the predetermined time slot.

[0054] First, acquisition unit 120 acquires a plurality of pieces of hot water supply information, including the boiling amount and the start time of use, and a first reference power (S10). Here, acquisition unit 120 acquires the first reference power for the second time period. Acquisition unit 120 acquires the plurality of pieces of hot water supply information acquired by communication unit 110, and acquires the first reference power stored in memory unit 150. Note that, before step S10 is processed, each of multiple control devices 13 outputs hot water supply information for hot water supply device 11 to hot water supply system 100, as described above.

[0055] In step S10 , acquisition unit 120 may also acquire the target boiling amount and the remaining hot water amount in the hot water storage tank of each of the plurality of water heaters 11 acquired by communication unit 110 .

[0056] Step S10 corresponds to the acquisition step.

[0057] Furthermore, in operation example 1, in the processing of step S10, the acquisition unit 120 acquires private part power information about the power consumption of the electrical device 12 and shared part power information about the power consumption of the electrical device 21. More specifically, the communication unit 110 acquires the private part power information from each of the multiple control devices 13 and the shared part power information from the power measurement device 22, and the acquisition unit 120 acquires the private part power information and the shared part power information acquired by the communication unit 110.

[0058] Therefore, the acquisition unit 120 acquires information indicating the expected power usage based on the expected usage amount for the second time slot for the electrical appliances 12 included in the private area power information. Similarly, the acquisition unit 120 acquires information indicating the expected power usage based on the expected usage amount for the second time slot for the electrical appliances 21 included in the common area power information. In the present embodiment, all of the electrical appliances 12 in the multiple dwelling units and the electrical appliances 21 in the common area 20 make up the electrical appliances in the apartment building 40 excluding the multiple hot water heaters 11. Therefore, it can also be said that the acquisition unit 120 acquires second power usage based on the expected usage amount for the second time slot for the electrical appliances in the apartment building 40 excluding the multiple hot water heaters 11.

[0059] The second power usage is information that combines the expected power usage during the second time period for the electrical equipment 12 indicated by the private area power information and the expected power usage during the second time period for the electrical equipment 21 indicated by the shared area power information.

[0060] Thus, in operation example 1, the acquisition unit 120 acquires the second power consumption corresponding to the expected amount of power during the second time period for electrical appliances in the apartment building 40 excluding multiple water heaters 11 in the processing of step S10.

[0061] Based on the boiling amounts included in the plurality of pieces of hot water information acquired by acquisition unit 120, determination unit 130 determines whether the total power demand of apartment building 40 will exceed the acquired first reference power when a plurality of water heating devices 11 start boiling water simultaneously (S20). Here, determination unit 130 determines whether the total power demand of apartment building 40 will exceed the acquired first reference power when a plurality of water heating devices 11 start boiling water simultaneously in the second time slot. More specifically, determination unit 130 makes the above determination based on the boiling amounts included in the plurality of pieces of hot water information and the acquired second power usage (estimated power amount in the second time slot).

[0062] Next, when the determination unit 130 determines that the power demand will exceed the first reference power (Yes in S20), the determination unit 130 determines the following schedule before the second time slot, i.e., in this case, for the first time slot. The determination unit 130 determines a schedule to start water heating among the multiple water heating devices 11 in order of the latest water heating start time (S30). The latest water heating start time is the latest time to start water heating so that hot water does not run out at the start time of use included in the hot water supply information for that water heating device 11. For example, for first water heating device 11a, if the start time of use is 6:00 and the time required for water heating is 3 hours, the latest water heating start time of first water heating device 11a is 3:00. In this case, if the start time of boiling water for the first hot water supply device 11a is determined to be 5:50, there is a high possibility that there will not be enough hot water remaining at 6:00, when use begins, and the water will run out (the hot water will run out).

[0063] Steps S20 and S30 will be described in more detail with reference to FIG.

[0064] Fig. 3 is a diagram showing a schedule of operation example 1 according to the present embodiment. More specifically, Fig. 3(a) is a diagram showing a schedule when multiple water heating devices 11 (first to third water heating devices 11a to 11c) start heating water simultaneously, and Fig. 3(b) is a diagram showing a schedule when the start of heating water by third water heating device 11c is delayed.

[0065] In Figure 3, the period from t0 to t1, which indicates the time, corresponds to the second time period, and the period from t1 onwards corresponds to the first time period. In step S20, determination unit 130 determines whether the power demand will exceed the first reference power when multiple water heating devices 11 start heating water at t0, the time when the second time period begins. The power demand is the total value of all power consumption by multiple water heating devices 11, multiple electrical appliances 12, and electrical appliance 21 in apartment building 40. Note that the power consumption (power consumption) required to heat water by water heating device 11 is proportional to the amount of water heated by that water heating device 11. Furthermore, the smaller the amount of water heated, the shorter the time required for water heating by that water heating device 11.

[0066] In the schedule shown in FIG. 3A, the power demand exceeds the first reference power, and the determining unit 130 determines that the power demand will exceed the first reference power.

[0067] 3, the latest boiling start time of first water heater 11a is t11, the latest boiling start time of second water heater 11b is t12, and the latest boiling start time of third water heater 11c is t13. t11 is earlier than t12 and t13, and t12 is earlier than t13.

[0068] In such a case, the determination unit 130 determines a schedule (the schedule shown in FIG. 3(b)) that advances the start of boiling water by the first and second water heating devices 11a and 11b, which have an earlier latest boiling time than the third water heating device 11c, among the first to third water heating devices 11a to 11c. In other words, the determination unit 130 determines a schedule that delays the start of boiling water by the third water heating device 11c, which has the later latest boiling time, among the first to third water heating devices 11a to 11c. In this case, the determination unit 130 determines a schedule such that the demand power in the second time slot does not exceed the first reference power.

[0069] 3B, the first and second water heating devices 11a and 11b simultaneously start heating water at time t0, when the second time slot begins. However, this is not limited to this. A hypothetical case will be described in which the demand power exceeds the first reference power if the first and second water heating devices 11a and 11b simultaneously start heating water. In this case, the determination unit 130 determines a schedule that advances the start of heating water for the first water heating device 11a, which has an earlier latest heating time than the second water heating device 11b.

[0070] In this way, determination unit 130 determines a schedule for starting water heating in the order of water heating apparatus 11 with the earliest latest water heating start time.

[0071] Steps S20 and S30 correspond to the determination step.

[0072] Furthermore, if determination unit 130 determines that the demand power does not exceed the first reference power (No in S20), determination unit 130 determines the following schedule before the second time slot, that is, in this case, during the first time slot: Determination unit 130 determines a schedule in which multiple water heating devices 11 start heating water simultaneously (step S40).

[0073] Furthermore, control unit 140 controls the heating of water by multiple water heating devices 11 based on the schedule determined by determination unit 130 in step S30 or S40 (S90). Here, control unit 140 controls the heating of water by multiple water heating devices 11 during the second time slot based on the determined schedule. More specifically, control unit 140 controls communication unit 110 to output control signals to each of multiple control devices 13, instructing the multiple water heating devices 11 to heat water as indicated by the determined schedule. As a result, each of multiple control devices 13 controls each of multiple water heating devices 11 based on the control signals obtained from communication unit 110. For example, control device 13 in first exclusive unit 10a heats water by first water heating device 11a, setting time t0 shown in FIG. 3(b) as the heating start time for first water heating device 11a. Furthermore, for example, control device 13 of second exclusive section 10b sets time t0 shown in Fig. 3(b) as the start time of second hot water supply device 11b, and causes second hot water supply device 11b to heat up. Furthermore, for example, control device 13 of third exclusive section 10c sets time t13 shown in Fig. 3(b) as the start time of third hot water supply device 11c, and causes third hot water supply device 11c to heat up. Note that step S90 corresponds to the control step.

[0074] In this way, when determination unit 130 determines that the demand power will exceed the first reference power during the first time slot (Yes in S20), determination unit 130 determines the following schedule: Determination unit 130 determines a schedule for starting water heating among multiple water heating devices 11 in order of the water heating device 11 with the earliest latest water heating start time.

[0075] As a result, in Operation Example 1, the hot water supply system 100 is realized that can suppress the overall power demand (more specifically, the maximum value of power demand) of the apartment building 40. For example, as shown in (b) of Fig. 3, the maximum value of power demand is suppressed from exceeding the first reference power. Therefore, the basic charge for the apartment building 40 is less likely to become high.

[0076] A water heater 11 with an earlier latest water heating start time has a shorter time window for changing the water heating start time than a water heater 11 with a later latest water heating start time. For example, as shown in Figure 3, if the second water heater 11b does not start heating between time t0 and time t12, the second water heater 11b will run out of hot water. On the other hand, the third water heater 11c only needs to start heating between time t0 and time t13, and unlike the second water heater 11b, the third water heater 11c will not run out of hot water even if it starts heating between time t12 and time t13.

[0077] In this way, the determination unit 130 determines the water heating schedule by prioritizing the water heating device 11 (here, the second water heating device 11b) that has a shorter time window in which the water heating start time can be changed, making it less likely that the second water heating device 11b will run out of hot water.

[0078] The process in step S30 will now be described in more detail with reference to FIGS.

[0079] Fig. 4 is a more detailed flowchart of step S30 in operation example 1 according to the present embodiment. Fig. 5 is another diagram showing a schedule for operation example 1 according to the present embodiment. More specifically, Fig. 5(a) is a diagram showing a schedule when multiple water heating devices 11 start heating water simultaneously, as in Fig. 3(a), and Fig. 5(b) shows a schedule when the start of heating water by second water heating device 11b is delayed.

[0080] 4 and 5, the latest boiling start time of first water heater 11a is t11, the latest boiling start time of second water heater 11b is t12, and the latest boiling start time of third water heater 11c is t13. t11 is earlier than t12 and t13, and t12 and t13 are the same time.

[0081] As shown in FIG. 4, in step S30, determination unit 130 determines a schedule for starting water heating among a plurality of water heating devices 11 in descending order of the latest water heating start time.

[0082] More specifically, determination unit 130 determines whether or not there are two water heating apparatuses 11 among a plurality of water heating apparatuses 11 that have the same latest boil-up start time (S30a).

[0083] When there are two water heating apparatuses 11 with the same latest boiling start time (Yes in step S30a), determination unit 130 determines the following schedule: In this case, determination unit 130 determines a schedule for starting boiling in order of the water heating amount included in the hot water supply information for that water heating apparatus 11 (S30b).

[0084] Steps S30a and S30b will be described in more detail with reference to FIG.

[0085] As described above, t11 is earlier than t12 and t13. Therefore, first, determination unit 130 determines a schedule that advances the start of boiling water for first water heating device 11a, of first to third water heating devices 11a to 11c, whose latest boiling time is earlier than second and third water heating devices 11b and 11c.

[0086] t12 and t13 are the same time. The amount of water to be heated included in the hot water supply information for third water heating apparatus 11c is greater than the amount of water to be heated included in the hot water supply information for second water heating apparatus 11b. Therefore, determination unit 130 determines a schedule (the schedule shown in FIG. 5B) that advances the start of water heating for third water heating apparatus 11c, which has a greater amount of water to be heated than second water heating apparatus 11b, out of second and third water heating apparatuses 11b and 11c.

[0087] Next, the process of step S90 is performed.

[0088] The larger the water heating capacity of a water heating apparatus 11, the longer the time required to heat the water. In operation example 1 shown in Figures 4 and 5, a schedule is determined so that a water heating apparatus 11 with a large water heating capacity (e.g., third water heating apparatus 11c) is given priority for heating, making it less likely that the water heating apparatus 11 will run out of hot water. Furthermore, by heating water from a water heating apparatus 11 with a large water heating capacity during a time period (second time period) when the unit price of electricity is lower, the effect of reducing electricity charges is greater than when the water heating apparatus 11 heats water during the first time period. Therefore, by determining a schedule so that a water heating apparatus 11 with a large water heating capacity is given priority for heating, the electricity charges paid by the owner of the water heating apparatus 11 will be lower.

[0089] Moreover, the first operational example may be as follows.

[0090] The first to fifth hot water supply devices 11a to 11e may have different boiling rates, and the first to fifth hot water supply devices 11a to 11e may have different start times for use. In other words, the owners of the first to fifth exclusive use units 10a to 10e can set their preferred values ​​by operating the reception unit of control device 13.

[0091] As described above, the hot water supply information for each of first to fifth water heating devices 11a to 11e includes the amount of water heated and the start time of use for that water heating device 11. In the present embodiment, the hot water supply information for each of first to fifth water heating devices 11a to 11e is determined by the owner operating the reception unit of control device 13, but this is not limited to this.

[0092] For example, the manager of hot water supply system 100 may obtain information about the amount of hot water to be heated and the start time of use by conducting a survey of the owners of each of the first to fifth exclusive use units 10a to 10e regarding hot water usage. The manager controls an information terminal such as a smartphone, tablet, or personal computer, and the information about the amount of hot water to be heated and the start time of use is transmitted to communication unit 110 of hot water supply system 100. Acquisition unit 120 of hot water supply system 100 may obtain the information about the amount of hot water to be heated and the start time of use and determine this as the amount of hot water to be heated and the start time of use for each of first to fifth hot water supply devices 11a to 11e. The survey also asks the owners about the type of hot water usage (bathing, showering, or other housework) for each season in each of the first to fifth exclusive use units 10a to 10e, the amount of hot water used for each type, and the timing of the usage.

[0093] Furthermore, for example, the hot water supply information for the first to fifth water heating apparatuses 11a to 11e may be determined based on past usage data rather than the above-mentioned questionnaire. The storage unit 150 of the hot water supply system 100 may store, as past usage data, the amount of water heated and the start time of use for the first water heating apparatus 11a over a predetermined period of time in the past. The predetermined period of time in the past may be, for example, a period from the day before the current day to one week in the past, but is not limited to this. The acquisition unit 120 may acquire hot water supply information based on past usage data. For example, the amount of water heated included in the hot water supply information based on past usage data is the average value of the amount of water heated over the predetermined period of time in the past. For example, the start time of use included in the hot water supply information based on past usage data is the average value of the start time of use over the predetermined period of time in the past.

[0094] For example, the hot water supply information for the first to fifth hot water supply devices 11a to 11e may be determined based on daily schedule information acquired from an information terminal of the owner of the first to fifth exclusive use units 10a to 10e. When the owner uses a schedule management app on a smartphone, which is an example of an information terminal, the control device 13 may acquire daily schedule information indicating the owner's daily schedule from the information terminal. The amount of water to be heated and the start time of use included in the hot water supply information may be determined based on the acquired daily schedule information. Furthermore, the information terminal may receive an operation from the owner specifying a target amount of water to be heated and an operation specifying a start time of use, and output information specifying the target amount of water to be heated and the start time of use to the control device 13. In this manner, the hot water supply information may be determined.

[0095] [Operation Example 2] Fig. 6 is a flowchart of Operation Example 2 according to this embodiment. Fig. 7 is a diagram showing a schedule of Operation Example 2 according to this embodiment.

[0096] In operation example 2, three types of time periods (first to third time periods) with different unit electricity prices are provided, and an example is described in which a schedule for boiling water for one water heating device 11 (here, the first water heating device 11a) is determined.

[0097] As shown in FIG. 6, first, the process of step S10 is carried out in the same manner as in FIG.

[0098] The acquiring unit 120 then acquires the first unit price of electricity for the first time slot and the second unit price of electricity for the second time slot. More specifically, the acquiring unit 120 acquires the first unit price of electricity for the first time slot, the second unit price of electricity for the second time slot, and the third unit price of electricity for the third time slot (S11). The acquiring unit 120 acquires the first unit price of electricity, the second unit price of electricity, and the third unit price of electricity stored in the storage unit 150, for example.

[0099] The unit price of electricity is the charge per kWh, and varies depending on the time of day. The first unit price of electricity is Y yen / kWh, the second unit price of electricity is X yen / kWh, and the third unit price of electricity is Z yen / kWh. The second unit price of electricity is cheaper than the first unit price of electricity, and the first unit price of electricity is cheaper than the third unit price of electricity.

[0100] In addition, in operation example 2, the second time period is from 11:00 PM to 7:00 AM the next day, the first time period is from 7:00 PM to 12:00 PM, and the third time period is from 12:00 PM to 11:00 PM. The second time period, the first time period, and the third time period are consecutive time periods.

[0101] Determination unit 130 determines a schedule so as to reduce the electricity bill for heating water for each of multiple water heating apparatuses 11, based on the first and second unit prices of electricity acquired by acquisition unit 120. In this operation example, a schedule is determined so as to reduce the electricity bill for heating water for first water heating apparatus 11a, based on the first to third unit prices of electricity acquired by acquisition unit 120 (S31).

[0102] Step S31 will be described in more detail with reference to FIG.

[0103] As described above, since the second unit price of electricity is cheaper than the first unit price of electricity, and the first unit price of electricity is cheaper than the third unit price of electricity, determination unit 130 determines the schedule so that first water heating apparatus 11a heats up water during the second time slot, when the unit price of electricity is lowest. Furthermore, as shown in Figure 7, if first water heating apparatus 11a does not complete heating up water within the second time slot, determination unit 130 determines the schedule so that the remaining heating up water is performed during the first time slot, when the unit price of electricity is second lowest.

[0104] Then, the process of step S90 is carried out in the same manner as in FIG.

[0105] In operation example 2, the water heater 11 (for example, the first water heater 11a) heats water during a time period when the unit price of electricity is lower, thereby reducing the electricity bill paid by the owner of the water heater 11.

[0106] [Operation Example 3] Fig. 8 is a flowchart of Operation Example 3 according to the present embodiment. Fig. 9 is a diagram showing a schedule of Operation Example 3 according to the present embodiment. Fig. 9(a) shows a schedule in which first hot water heating device 11a heats water during a second time slot starting from an earlier time, and Fig. 9(b) shows a schedule in which first hot water heating device 11a heats water during a second time slot starting from a later time.

[0107] In operation example 3, two types of time periods (first and second time periods) with different unit prices of electricity are provided, and an example will be described in which a schedule for heating water for one water heating apparatus 11 (here, first water heating apparatus 11a) is determined. Note that in this operation example, two second time periods are provided per day, that is, multiple second time periods are provided. For ease of identification, the second time period starting at an earlier time shown in FIG. 9 will be referred to as second time period A, and the second time period starting at a later time will be referred to as second time period B.

[0108] As shown in FIG. 8, first, the process of step S10 is carried out in the same manner as in FIG.

[0109] The acquiring unit 120 then acquires the first unit price of electricity for the first time period and the second unit price of electricity for the second time period (S12). The acquiring unit 120 acquires the first unit price of electricity and the second unit price of electricity stored in the storage unit 150, for example.

[0110] As in the second operational example, the first unit price of power is Y yen / kWh and the second unit price of power is X yen / kWh. The second unit price of power is lower than the first unit price of power.

[0111] The determination unit 130 determines the following schedule based on the first and second unit prices of electricity acquired by the acquisition unit 120 and the start time of use included in each of the plurality of pieces of hot water supply information acquired by the acquisition unit 120. The determination unit 130 determines the schedule so that the electricity bill for heating water for each of the plurality of hot water supply devices 11 is reduced and so that the time difference between the start time of use and the first estimated completion time, which is the estimated time when heating water for each of the plurality of hot water supply devices 11 is completed, is shortened (S32). In this operation example, the determination unit 130 determines the schedule based on the first and second unit prices of electricity and the start time of use so that the electricity bill for heating water for the first hot water supply device 11a is reduced and so that the time difference between the first estimated completion time and the start time of use is shortened. In this way, the determination unit 130 determines the schedule so that the time difference between the first estimated completion time and the start time of use is shortened, and more specifically, so that the time difference is within a predetermined time. The predetermined time may be, for example, 30 minutes or more and 8 hours or less, and may be a time determined in advance by the manager of the hot water supply system 100, for example.

[0112] Step S32 will be described in more detail with reference to FIG.

[0113] As described above, because the second unit price of electricity is lower than the first unit price of electricity, determination unit 130 determines a schedule so that first water heating apparatus 11a heats up water during the second time slot, when the unit price of electricity is lowest. Furthermore, if first water heating apparatus 11a does not complete heating up water within the second time slot, determination unit 130 determines a schedule so that the remaining heating up water is performed during the first time slot, when the unit price of electricity is second lowest. As a result, two different schedules may be determined, as shown in (a) and (b) of Figure 9.

[0114] Furthermore, in this operation example, as shown in Fig. 9, the end of second time slot B, which starts later, is the start time of use when the owner starts to heat the water. Also, the first scheduled completion time is the time when hot water heater 11 (first hot water heater 11a in this case) completes heating in the schedule. In the example shown in Fig. 9(a), the first scheduled completion time is included in the first time slot, and in the example shown in Fig. 9(b), the first scheduled completion time is the end of second time slot B, which is included in second time slot B.

[0115] Then, determination unit 130 determines a schedule for first water heating apparatus 11a so that the time difference between the first estimated completion time and the start time of use is short. The time difference between the first estimated completion time and the start time of use in the schedule shown in Fig. 9(b) is shorter than the time difference between the first estimated completion time and the start time of use in the schedule shown in Fig. 9(a). Therefore, determination unit 130 determines the schedule shown in Fig. 9(b) as a schedule that reduces the electricity fee for heating water by first water heating apparatus 11a and shortens the time difference between the first estimated completion time and the start time of use.

[0116] Then, the process of step S90 is carried out.

[0117] In operation example 3, the water heater 11 (for example, the first water heater 11a) heats water during a time period when the unit price of electricity is lower, thereby reducing the electricity bill paid by the owner of the water heater 11.

[0118] Furthermore, for example, as shown in (a) of Figure 9, if the time between the first estimated completion time and the start time of use is long, the boiled water may cool down. However, in operation example 3, as shown in (b) of Figure 9, the time difference between the first estimated completion time and the start time of use is short, so this problem is unlikely to occur.

[0119] [Operation Example 4] Fig. 10 is a flowchart of Operation Example 4 according to this embodiment. Fig. 11 is a diagram showing a schedule of Operation Example 4 according to this embodiment.

[0120] Operation example 4 is an operation performed while control unit 140 is controlling the heating of multiple water heating devices 11 (first and second water heating devices 11a and 11b) during the second time slot based on the schedule determined in step S90 in operation example 1. More specifically, this is an operation performed while first and second water heating devices 11a and 11b are heating water.

[0121] As described above, in operation example 1, acquisition unit 120 acquires second power usage corresponding to the predicted amount of power during the second time period of the electrical appliances in apartment building 40, excluding the plurality of hot water heaters 11. However, it is also assumed that power consumption will exceed the predicted amount of power. Operation example 4 is an operation that assumes that the amount of power consumed by the electrical appliances in apartment building 40, excluding the plurality of hot water heaters 11, will exceed the predicted amount of power when the plurality of hot water heaters 11 are heating water in step S90.

[0122] The acquisition unit 120 acquires the first power consumption at the current time of the electrical appliances in the apartment building 40, excluding the plurality of hot water heaters 11, during the second time period (step S13). The acquisition unit 120 acquires the first power consumption as follows.

[0123] In step S13, acquisition unit 120 acquires private area power information regarding the power usage of electrical appliances 12 and shared area power information regarding the power usage of electrical appliances 21 via communication unit 110. As described above, in the present embodiment, the electrical appliances excluding the plurality of hot water heaters 11 consist of all of the plurality of electrical appliances 12 in the plurality of dwelling units and electrical appliances 21 in the shared area 20. The first power usage is information that combines the power usage at the current time (second time period) for electrical appliances 12 indicated by the private area power information and the power usage at the current time (second time period) for electrical appliances 21 indicated by the common area power information.

[0124] In other words, by acquiring the private area power information and the common area power information, the acquisition unit 120 acquires the first power usage at the current time during the second time period of the electrical appliances in the apartment building 40, excluding the plurality of hot water heaters 11. The first power usage can also be said to be the actual measured value of the power of the electrical appliances, excluding the plurality of hot water heaters 11, at the current time (second time period).

[0125] Next, determination unit 130 determines whether the total power demand of apartment building 40 at the current time (second time slot) exceeds the acquired first reference power based on the heating amounts included in the multiple hot water supply information and the acquired first power consumption (S23). That is, in step S23, it is determined whether the power demand will still exceed the first reference power even if the start of heating of any of water heating devices 11 is delayed in step S30 of operation example 1. In other words, after the start of the second time slot (step S23), determination unit 130 predicts and determines whether the power demand will exceed the reference power based on the first power consumption, which is the actual measured value of the power of electrical appliances excluding multiple water heating devices 11.

[0126] Furthermore, if it is determined that the power demand exceeds the first reference power during the second time slot (Yes in step S23), determination unit 130 updates the schedule based on the determined schedule as follows. That is, determination unit 130 updates the schedule determined in step S30 so as to stop water heating of water heating device 11 with the largest time difference between the second estimated completion time and the third estimated completion time (S33). Note that the second estimated completion time is the estimated time at which water heating will be completed as indicated by the schedule determined in step S30. The third estimated completion time is the estimated time at which water heating will be completed when water heating is started at the latest water heating start time.

[0127] The process of step S33 will be described with reference to FIG.

[0128] 11(a) is a diagram showing a schedule when it is determined that the power demand will exceed the first reference power. For example, as shown in FIG. 11(a), at the current time t2 (the current time), first power usage data for the electrical appliances excluding the plurality of water heating devices 11 is acquired, and it is determined that the power demand will exceed the first reference power in the second time slot (more specifically, after time t2). In such a case, determination unit 130 updates the schedule to stop heating water for water heating device 11 among the plurality of water heating devices 11 that has the largest time difference between the second estimated completion time and the third estimated completion time.

[0129] Here, the second estimated completion time and the third estimated completion time will be described in more detail.

[0130] The second scheduled completion time is, for example, the scheduled time at which water heating by water heating apparatus 11 is completed, as indicated by the schedule determined in step S30. For example, in FIG. 11(a), the second scheduled completion time for first water heating apparatus 11a is t21, and the second scheduled completion time for second water heating apparatus 11b is t22. t21 and t22 are the same time.

[0131] The third estimated completion time is the estimated time at which water heating of water heating apparatus 11 will be completed if water heating of that apparatus is started at the latest water heating start time. For example, in FIG. 11(a), the third estimated completion time of first water heating apparatus 11a is t31, and the third estimated completion time of second water heating apparatus 11b is t32. t31 is earlier than t32.

[0132] In step S33, determination unit 130 updates the schedule to stop heating of water by water heating device 11, of the plurality of water heating devices 11 (here, first and second water heating devices 11a and 11b), that has the largest time difference between the second and third estimated completion times. As shown in FIG. 11(a), the time difference between the second and third estimated completion times of second water heating device 11b is larger than the time difference between the second and third estimated completion times of first water heating device 11a. Therefore, determination unit 130 updates the schedule to stop heating of water by second water heating device 11b, of first and second water heating devices 11a and 11b. More specifically, determination unit 130 updates the schedule to stop heating of water by second water heating device 11b at current time t2.

[0133] 11(b) is a diagram showing a schedule in which the heating of water by second water heating apparatus 11b is stopped, that is, a diagram showing an updated schedule. Note that this is not limited to the example shown in FIG. 11(b), and in this embodiment, the heating of water by multiple water heating apparatuses 11 may be stopped. In addition, the first power usage may be acquired at regular intervals (e.g., every 5 minutes), and if there is a time period in which the first power usage decreases after t21, the schedule may be updated so that the heating of water by second water heating apparatus 11b is started again.

[0134] Compared with a water heating apparatus 11 with a small time difference between the second and third estimated completion times, a water heating apparatus 11 with a large time difference has a longer time from the time water heating is stopped to the scheduled use time, even if water heating is stopped once. Therefore, compared with a water heating apparatus 11 with a small time difference, a water heating apparatus 11 with a large time difference is more likely to complete water heating by the start time of use by restarting water heating even if water heating is stopped once. Therefore, by having the determination unit 130 update the schedule to stop water heating for the water heating apparatus 11 with a large time difference (e.g., the second water heating apparatus 11b), it becomes less likely that the water heating apparatus 11 with a small time difference and the water heating apparatus 11 with a large time difference will run out of hot water.

[0135] Furthermore, control unit 140 controls the heating of water by a plurality of water heating devices 11 in the second time slot based on the schedule updated by determination unit 130 in step S33 (S53a).

[0136] If it is determined that the power demand in the second time slot does not exceed the first reference power (No in step S23), control unit 140 performs the following process: In this case, control unit 140 controls the heating of water by multiple water heating devices 11 in the second time slot based on the schedule determined by determination unit 130 in step S30 (S53b).

[0137] In operation example 4, when the power demand exceeds the first reference power during the second time slot, hot water supply system 100 updates the schedule to stop heating water by hot water supply apparatus 11 (second hot water supply apparatus 11b), thereby preventing the power demand from exceeding the first reference power. In other words, hot water supply system 100 is realized that can suppress the overall power demand (more specifically, the maximum value of power demand) of apartment building 40. Furthermore, as described above, by determining unit 130 updating the schedule to stop heating water by hot water supply apparatus 11 with a large time difference between the second estimated completion time and the third estimated completion time, hot water shortages are less likely to occur in hot water supply apparatuses 11 with a small time difference and hot water supply apparatuses 11 with a large time difference.

[0138] In operation example 4, the schedule is updated in the second time slot, but this is not limited to this. For example, the schedule may be updated in the first time slot, and the heating of water by multiple water heating devices 11 may be controlled in the first time slot. Furthermore, for example, in the example shown in FIG. 1B (b), the schedule may be updated in a predetermined time slot (e.g., 12:00 to 14:00), and the heating of water by multiple water heating devices 11 may be controlled in the predetermined time slot.

[0139] [Operation Example 5] Fig. 12 is a flowchart of Operation Example 5 according to this embodiment. Fig. 13 is a diagram showing a schedule of Operation Example 5 according to this embodiment.

[0140] Operation example 5 is an operation performed while control unit 140 is controlling the heating of two or more water heating devices 11 (first and second water heating devices 11a and 11b) during the second time slot based on the schedule determined in step S90 in operation example 1. More specifically, this is an operation performed while first and second water heating devices 11a and 11b are heating water.

[0141] Operation example 5, like operation example 4, is an operation that assumes that when two or more water heaters 11 are heating water in step S90, the amount of electricity consumed by electrical equipment in the apartment building 40, excluding multiple water heaters 11, exceeds the expected amount of electricity.

[0142] Acquisition unit 120 acquires the first power consumption at the current time of the electrical appliances in apartment building 40, excluding the plurality of water heating devices 11, during the second time period (step S13). As described above, the first power consumption can also be said to be the actual measured value of the power of the electrical appliances, excluding the plurality of water heating devices 11, at the current time (second time period).

[0143] Furthermore, acquisition unit 120 acquires a water heating instruction instructing water heating of another water heating apparatus 11 other than the two or more water heating apparatuses 11 (first and second water heating apparatuses 11a and 11b) (S14). In this case, the other water heating apparatus 11 is assumed to be third water heating apparatus 11c. The water heating instruction indicates the amount of water to be heated by that water heating apparatus 11 (here, third water heating apparatus 11c).

[0144] For example, when the information processing device receives an operation from the owner of third hot water supply device 11c (i.e., the owner of third exclusive section 10c), acquisition unit 120 may acquire the boiling instruction. The information processing device is the owner's control device 13 or an information terminal such as a smartphone, tablet, or personal computer.

[0145] When the owner of third hot water supply apparatus 11c wishes to use hot water, he or she operates a reception unit of control device 13, which is an example of an information processing device. That is, the reception unit receives an operation to instruct third hot water supply apparatus 11c to heat water. Control device 13 then outputs a heating instruction to communication unit 110 in accordance with the received operation. Acquisition unit 120 acquires the heating instruction acquired by communication unit 110.

[0146] The owner of third hot water supply apparatus 11c may operate an information terminal such as a smartphone, tablet, or personal computer, which is an example of an information processing terminal, to output a boiling instruction from the information terminal to control device 13. Control device 13 thereby acquires the output boiling instruction and outputs the acquired boiling instruction to communication unit 110. Acquisition unit 120 acquires the boiling instruction acquired by communication unit 110.

[0147] In this way, in step S14, acquisition unit 120 acquires a boiling instruction for third hot water supply device 11c.

[0148] Based on the water heating amounts included in the hot water supply information for two or more hot water heaters 11, the acquired first power usage, and the acquired water heating instruction, determination unit 130 determines whether the total power demand of apartment building 40 at the current time (second time period) exceeds the acquired first reference power (S24). That is, determination unit 130 makes the above determination based on the water heating amounts of first and second hot water heaters 11a and 11b, the first power usage, and the water heating amount of third hot water heater 11c included in the water heating instruction.

[0149] If it is determined that the power demand exceeds the first reference power during the second time slot (Yes in step S24), the determination unit 130 updates the schedule as follows based on the schedule determined in step S30 and the heating instruction acquired in step S14. That is, the determination unit 130 updates the schedule so that, among two or more water heating devices 11, the water heating device 11 having the largest time difference between the second estimated completion time and the third estimated completion time stops heating water, and starts heating water for the other water heating devices 11 (S34a). In this operation example, the determination unit 130 updates the schedule so that the water heating device 11 having the largest time difference between the second estimated completion time and the third estimated completion time stops heating water, among the first and second water heating devices 11a and 11b, stops heating water, and starts heating water for the third water heating device 11c.

[0150] The processes in steps S24 and S34a will be described with reference to FIG.

[0151] FIG. 13(a) shows the schedule determined in step S30. FIG. 13(b) shows a schedule in which the heating of water by the third water heating device 11c is added to the schedule in which the heating of water by the first and second water heating devices 11a and 11b is performed as shown in FIG. 13(a). FIG. 13(b) shows a schedule in the case where it is determined that the power demand will exceed the first reference power. For example, as shown in FIG. 13(b), at the current time t2 (current time), the first power usage and the heating instruction for the third water heating device 11c are acquired for the electrical appliances excluding the plurality of water heating devices 11. At this time, it is determined that the power demand will exceed the first reference power during the second time slot (more specifically, after time t2). In such a case, the decision unit 130 stops the heating of the water heating device 11 among the two or more water heating devices 11 that has the largest time difference between the second scheduled completion time and the third scheduled completion time, and updates the schedule so that the heating of the other water heating devices 11 is started.

[0152] In step S34a, determination unit 130 updates the schedule to stop heating water for water heating apparatus 11, of two or more water heating apparatuses 11 (here, first and second water heating apparatuses 11a and 11b), that has the largest time difference between the second and third estimated completion times. As shown in FIG. 13(b), the time difference between the second and third estimated completion times for second water heating apparatus 11b is larger than the time difference between the second and third estimated completion times for first water heating apparatus 11a. Therefore, determination unit 130 updates the schedule to stop heating water for second water heating apparatus 11b, of first and second water heating apparatuses 11a and 11b.

[0153] As in operation example 4, the decision unit 130 updates the schedule to stop the heating of the water heater 11 with the large time difference, making it less likely that the water heater 11 with the small time difference and the water heater 11 with the large time difference will run out of hot water.

[0154] In this way, hot water supply system 100 prevents the power demand from exceeding the first reference power by updating the schedule to stop heating water by hot water supply apparatus 11 (second hot water supply apparatus 11b). In other words, hot water supply system 100 is realized that can suppress the overall power demand (more specifically, the maximum value of power demand) of apartment building 40.

[0155] Furthermore, in step S34a, determination unit 130 updates the schedule so that another water heating apparatus 11 (third water heating apparatus 11c) starts heating water. More specifically, determination unit 130 updates the schedule so that third water heating apparatus 11c starts heating water from time t2 or later. Note that determination unit 130 may update the schedule so that third water heating apparatus 11c starts heating water from an early time after time t2 (for example, within a few minutes of time t2).

[0156] 13(c) is a diagram showing a schedule in which second water heater 11b stops heating water and third water heater 11c starts heating water, i.e., a diagram showing an updated schedule. As shown in FIG. 13(c), second water heater 11b, which was once stopped, may resume heating water after third water heater 11c has finished heating water.

[0157] Furthermore, control unit 140 controls the heating of water by a plurality of water heating devices 11 in the second time slot based on the schedule updated by determination unit 130 in step S34a (S54a).

[0158] If it is determined that the power demand will not exceed the first reference power during the second time slot (No in step S24), the determination unit 130 updates the schedule as follows based on the schedule determined in step S30 and the boiling instruction acquired in step S14. That is, the determination unit 130 updates the schedule so that the other water heating apparatuses 11 start boiling water (S34b). The determination unit 130 updates the schedule so that boiling water by the third water heating apparatus 11c is added to the schedule in which boiling water is performed by the first and second water heating apparatuses 11a and 11b shown in FIG. 13(a).

[0159] Next, control unit 140 controls the heating of water by a plurality of water heating devices 11 in the second time slot based on the schedule updated by determination unit 130 in step S34b (S54b).

[0160] In operation example 5, when hot water supply system 100 receives a heating instruction for another hot water supply apparatus 11 (third hot water supply apparatus 11c) during the second time slot, it performs the following process. That is, hot water supply system 100 updates the schedule to start heating water for the other hot water supply apparatus 11. This allows hot water supply system 100 to heat water for the other hot water supply apparatus 11.

[0161] In operation examples 4 and 5, among the multiple water heating devices 11 (first and second water heating devices 11a and 11b), the heating of the second water heating device 11b, which has a larger time difference between the second scheduled completion time and the third scheduled completion time, is stopped, but this is not limited to this.

[0162] For example, the manager of hot water supply system 100 may obtain information on the stoppage of water heating for each of multiple owners by conducting a survey of the owners of each of first to fifth exclusive units 10a to 10e regarding the stoppage of water heating. The manager controls an information terminal such as a smartphone, tablet, or personal computer, and the information on the stoppage of water heating is transmitted to communication unit 110 of hot water supply system 100. Acquisition unit 120 of hot water supply system 100 acquires the information on the stoppage of water heating. As described in Operational Examples 4 and 5, the survey asks the owners whether it is okay to stop water heating in their own hot water heating apparatus 11 if the total power demand of apartment building 40 exceeds the acquired first reference power. The information on the stoppage of water heating for one owner indicates whether it is okay to stop water heating in the hot water heating apparatus 11 owned by that one owner.

[0163] As an example, suppose that the information about stopping water heating for the owner of first water heating apparatus 11a indicates that it is permissible to stop water heating for first water heating apparatus 11a, and that the information about stopping water heating for the owner of second water heating apparatus 11b indicates that it is not permissible to stop water heating for second water heating apparatus 11b.

[0164] In such a case, in step S33 of Operation Example 4 and step S34a of Operation Example 5, the decision unit 130 performs the following processing. That is, the decision unit 130 updates the schedule so that the first water heating apparatus 11a of the first water heating apparatus 11a and the second water heating apparatus 11b stops heating water based on information about the respective owners of the first water heating apparatus 11a and the second water heating apparatus 11b stopping heating water. In other words, if the owner agrees to stop heating water, the water heating apparatus 11 of the owner stops heating water. If the owner does not agree to stop heating water, the water heating apparatus 11 of the owner does not stop heating water. In other words, the decision unit 130 updates the schedule according to the owner's intentions.

[0165] Furthermore, in operation examples 4 and 5, stopping the heating of water by water heating apparatus 11 may result in water heating by water heating apparatus 11 being performed during a time period with a higher unit price of electricity (e.g., a first time period). As a result, the electricity bill paid by the owner of water heating apparatus 11 is higher than when water heating by water heating apparatus 11 is performed during a time period with a lower unit price of electricity. In such cases, the display unit of water heating system 100 displays the difference in the electricity bill between the time period with the lower unit price of electricity and the time period with the higher unit price of electricity. By paying the displayed amount to the owner, the manager of water heating system 100 can increase the owner's understanding of cooperation in stopping the heating of water.

[0166] Furthermore, there may be cases where the heating of water is stopped for a certain period of time (for example, two days in a row) for one water heater 11 and is instead performed during a time period with a higher electricity unit price. This is particularly likely to occur in winter when demand for hot water increases.

[0167] When this case occurs, the following process may be performed to reduce the electricity bill paid by all owners of the apartment complex 40. That is, when this case occurs, the hot water supply system 100 assumes that the water heater 11 heats water during a time period with a higher unit price for electricity throughout a season (e.g., winter) that includes the specified period. The hot water supply system 100 compares the amount of the difference that would occur throughout the season with the increase in the current year's electricity bill that would occur if the water heater 11 were not stopped and the power demand exceeded the first reference power, resulting in a contract with a higher base price for the current month and the following 11 months. If the hot water supply system 100 determines that the increase is lower, it allows the power demand to exceed the first reference power and changes the first reference power from that date onwards to the higher first reference power. That is, the hot water supply system 100 determines the schedule based on the changed, higher first reference power from that date onwards.

[0168] The predetermined period is not limited to two days, but may be, for example, several days, one week, or one month.

[0169] In Operation Example 5, the schedule is updated in the second time slot, but this is not limited to this. For example, the schedule may be updated in the first time slot, and the heating of water by multiple water heating devices 11 may be controlled in the first time slot. Furthermore, for example, in the example shown in FIG. 1B (b), the schedule may be updated in a predetermined time slot (e.g., 12:00 to 14:00), and the heating of water by multiple water heating devices 11 may be controlled in the predetermined time slot.

[0170] [Operation Example 6] Fig. 14 is a flowchart of Operation Example 6 according to this embodiment. Fig. 15 is a diagram showing a schedule of Operation Example 6 according to this embodiment.

[0171] In the sixth operation example, after the determination unit 130 determines a schedule in step S30 in the first operation example, the determination unit 130 reviews the determined schedule and determines it again.

[0172] In operation example 6, two types of time periods (first and second time periods) with different unit prices of electricity are provided, and an example is described in which a schedule for heating water for one water heating apparatus 11 (here, first water heating apparatus 11a) is determined. Note that in this operation example, two second time periods are provided per day, that is, multiple second time periods are provided. For ease of identification, the second time period starting at an earlier time shown in FIG. 15 will be referred to as second time period A, and the second time period starting at a later time will be referred to as second time period B.

[0173] After step S30 is performed, determination unit 130 makes the following determination based on the use start time included in each of the multiple pieces of hot water supply information acquired by acquisition unit 120. That is, determination unit 130 determines whether or not there is a first target hot water supply device among the multiple hot water supply devices 11 for which the time from the second scheduled completion time to the use start time exceeds the reference time (S60). The second scheduled completion time is the scheduled time at which water heating indicated by the schedule determined by determination unit 130 in step S30 will be completed.

[0174] The reference time may be, for example, a time period between 30 minutes and 8 hours, and may be a time period that is determined in advance by the manager of the hot water supply system 100, for example.

[0175] Furthermore, if it is determined that there is a first target water heating device for which the time from the second scheduled completion time to the usage start time exceeds the reference time (Yes in step S60), determination unit 130 performs the following process: After heating water for the first target water heating device in the second time slot, determination unit 130 stops the water heating and then heats the water again, and re-determines the schedule so that heating of the first target water heating device is completed by the usage start time (S70).

[0176] The processing in steps S60 and S70 will be described with reference to FIG.

[0177] 15A is a diagram showing a schedule when it is determined that there is a first target water heating apparatus (here, first water heating apparatus 11a) for which the time from the second scheduled completion time to the start time of use exceeds the reference time. Also, FIG. 15A is a diagram showing, for example, a schedule determined in step S30 of operation example 1.

[0178] 15A, if the time from the second scheduled completion time to the start time of use exceeds the reference time, that is, if the time from the second scheduled completion time to the start time of use is long, the boiled water will cool down. Therefore, the determination unit 130 re-determines the schedule so that the first target water heating device heats up in the second time slot (second time slot A here), then stops, and then heats up again in the second time slot (second time slot B here). In this case, the determination unit 130 re-determines the schedule so that the time from the time when the first target water heating device finishes heating up to the scheduled time of use is less than the reference time.

[0179] 15(b) is a diagram showing a schedule in which first water heating apparatus 11a is temporarily stopped and then restarted, that is, a diagram showing a re-determined schedule. Note that this is not limited to the example shown in FIG. 15(b), and in this operation example, when there are multiple first target water heating apparatuses, determination unit 130 performs the following processing. That is, determination unit 130 may re-determine a schedule such that water heating for multiple first target water heating apparatuses is stopped once and restarted after the water heating for multiple first target water heating apparatuses is performed, and the water heating for multiple first target water heating apparatuses is completed by the start time of use.

[0180] Furthermore, control unit 140 controls the heating of water by a plurality of water heating devices 11 in the second time slot based on the schedule determined again by determination unit 130 in step S70 (S90).

[0181] If it is determined that there is no first target water heating apparatus for which the time from the second scheduled completion time to the use start time exceeds the reference time (No in step S60), control unit 140 performs the following process: In this case, control unit 140 controls the heating of water by multiple water heating apparatuses 11 during the second time slot based on the schedule determined by determination unit 130 in step S30 (S90).

[0182] 15, in this example, the schedule determined in step S30 includes the second scheduled completion time in the first time slot, which results in a higher electricity bill than if the first target hot water supply device (first hot water supply device 11a) were to complete heating only in the second time slot.

[0183] Therefore, if the second scheduled completion time is included in the first time slot, determination unit 130 may re-determine the schedule so that the heating of water by the first target water heating apparatus (first water heating apparatus 11a) is completed only in the second time slot. Specifically, as shown in (b) of Figure 15, if the heating of water by the first target water heating apparatus (first water heating apparatus 11a) is not completed only in the second time slot A, determination unit 130 re-determines the schedule so that the heating is also performed in the second time slot B.

[0184] In Operation Example 6, two second time slots (second time slot A and second time slot B) are provided in one day, i.e., multiple second time slots are provided, but similar processing may be performed even when one second time slot is provided in one day. That is, when the determination unit 130 determines that there is a first target water heating device for which the time from the second scheduled completion time to the use start time exceeds the reference time, the determination unit 130 performs the following processing. The determination unit 130 re-determines the schedule so that the first target water heating device heats up water during one second time slot, then stops the water heating, and then heats up water again during that one second time slot.

[0185] In operation example 6, as shown in (b) of Figure 15, the determination unit 130 performs heating of the first target hot water supply device, stops the heating, and then performs heating again, re-determining the schedule so that the heating of the first target hot water supply device is completed by the start time of use. Note that the determination unit 130 performs heating again, and re-determines the schedule so that the time from the time when the heating of the first target hot water supply device is completed to the scheduled time of use is less than the reference time. Therefore, because the time from the time when the heating of the first target hot water supply device is completed to the scheduled time of use is sufficiently short, the problem of the boiled water cooling down due to the long time from the time when the heating is completed (second scheduled completion time) to the start time of use is unlikely to occur.

[0186] [Operation Example 7] FIG. 16 is a flowchart of Operation Example 7 according to this embodiment.

[0187] Operation example 7, like operation example 6, is an operation in which, after the determination unit 130 determines a schedule, for example in step S30 in operation example 1, the determination unit 130 reviews the determined schedule and determines it again.

[0188] 16, in operation example 7, after step S30 is performed, determination unit 130 makes the following determination: That is, determination unit 130 determines whether or not there is a second target water heating apparatus among multiple water heating apparatuses 11 for which the number of times water heating is performed indicated by the schedule determined by determination unit 130 in step S30 is equal to or greater than a predetermined number (S61).

[0189] The number of times water is heated refers to the number of times water heating apparatus 11 has heated water until the target amount of water is reached. For example, in Fig. 15(a) , first water heating apparatus 11a has heated water once, and in Fig. 15(b) , first water heating apparatus 11a has heated water twice. The predetermined number of times may be, for example, between 3 and 10 times.

[0190] Furthermore, if it is determined that there is a second target water heating device whose number of boiling operations is greater than or equal to a predetermined number (Yes in step S61), the determination unit 130 re-determines the schedule so that the number of boiling operations of the second target water heating device is less than the above-mentioned predetermined number (S71).

[0191] Furthermore, control unit 140 controls the heating of water by a plurality of water heating devices 11 in the second time slot based on the schedule determined again by determination unit 130 in step S71 (S90).

[0192] If it is determined that there is no second target water heating apparatus that has heated water the predetermined number of times or more (No in step S61), control unit 140 performs the following process: In this case, control unit 140 controls the heating of water by multiple water heating apparatuses 11 during the second time slot based on the schedule determined by determination unit 130 in step S30 (S90).

[0193] As described above, the predetermined number of times may be, for example, between three and ten times. If the number of times water is heated increases, the efficiency of water heating at startup of water heating apparatus 11 decreases, resulting in a problem of increased power consumption. In operation example 7, the number of times water is heated by the second target water heating apparatus is less than the predetermined number of times, making such a problem less likely to occur. In other words, because power consumption is reduced, it can be said that water heating system 100 can suppress the overall power demand (more specifically, the maximum value of power demand) of apartment building 40.

[0194] In Operation Example 7, the schedule is determined again in the first time slot, but this is not limited to this. For example, the schedule may be determined again in the second time slot, and the heating of water by multiple water heating devices 11 may be controlled in the first time slot. Also, for example, in the example shown in FIG. 1B (b), the schedule may be determined again before the start of a predetermined time slot (e.g., 12:00 to 14:00), and the heating of water by multiple water heating devices 11 may be controlled in the predetermined time slot.

[0195] [Operation Example 8] Fig. 17 is a flowchart of Operation Example 8 according to this embodiment. Fig. 18 is a diagram showing a schedule and electricity charges in Operation Example 8 according to this embodiment.

[0196] Operation example 8, like operation examples 6 and 7, is an operation in which, after the determination unit 130 determines a schedule, for example in step S30 in operation example 1, the determination unit 130 reviews the determined schedule and determines it again.

[0197] In operation example 8, step S30 is performed as shown in FIG. 17 . If the determination unit 130 determines in step S30 that the second scheduled completion time of the third water heating apparatus 11c, whose start of water heating has been delayed in the schedule determined by the determination unit 130, falls within the first time slot, the determination unit 130 performs the following process. That is, the determination unit 130 determines whether the second increase is smaller than the first increase (S62). As described above, the second time slot is from 11:00 PM to 7:00 AM the following day. In other words, when the second scheduled completion time of the third water heating apparatus 11c falls within the first time slot, this means that the second scheduled completion time falls within the first time slot of the following day (from 7:00 AM to 11:00 PM the following day).

[0198] Here, the first increase and the second increase will be explained using FIG.

[0199] 18A and 18B are diagrams showing schedules determined again by the processing of operation example 8 according to the present embodiment. More specifically, (a) of Fig. 18A shows a schedule in which the second scheduled completion time of the third hot water supply device 11c, in which the start of the hot water supply device 11c has been delayed, is included in the first time slot. (b) of Fig. 18B shows a schedule in which the demand power (charge Pb) exceeds the first reference power (charge Pa).

[0200] The first increase will be explained using FIG. 18(a).

[0201] As described above, the first time slot is a time slot in which the unit price of power is higher, and the second time slot is a time slot in which the unit price of power is lower.

[0202] 18(a), if the second scheduled completion time of the water heating by the third water heating apparatus 11c falls within the first time slot, the owner of the third water heating apparatus 11c will pay a higher electricity rate than if the water heating by the third water heating apparatus 11c were to finish within the second time slot. The first increase is the increase in the electricity rate due to the second scheduled completion time of the water heating by the third water heating apparatus 11c falling within the first time slot, compared to the electricity rate when the second scheduled completion time falls within the second time slot.

[0203] For example, suppose the unit price of electricity in the second time slot is X (yen / kWh), the unit price of electricity in the first time slot is Y (yen / kWh), and the amount of electricity required to heat water by the third hot water supply apparatus 11c shown in Figure 18(a) during the first time slot is W (kWh). In this case, the first increase is expressed by equation (1).

[0204] W×(Y-X)...(1)

[0205] Next, the second increase will be described with reference to FIG.

[0206] The second increase is an increase in electricity charges due to the demand for electricity (charge Pb) exceeding the first reference power (charge Pa) when the third water heating device 11c is heated so that the second scheduled completion time of the third water heating device 11c falls within the second time zone.

[0207] For example, if the price for the demand power is Pb (yen) and the price for the first reference power is Pa (yen), the second increase for boiling water by the third water heater 11c shown in (b) of Figure 18 is expressed by equation (2).

[0208] Pb-Pa...(2)

[0209] The fee Pb (yen) based on the power demand is the fee that must be paid, for example, to an electric power company when the power demand exceeds the first reference power and the power demand is required for the entire apartment building 40. The fee Pa (yen) based on the first reference power is the fee that must be paid, for example, to an electric power company when the power demand does not exceed the first reference power and the power demand is required for the entire apartment building 40.

[0210] 17, if the second increase is smaller than the first increase (yes in S62), the determination unit 130 increases the first reference power and re-determines the schedule so that the second estimated completion time of the third hot water supply device 11c falls within the second time slot (S72). In other words, in this case, the determination unit 130 increases the reference power from the first reference power (price Pa) to the changed first reference power (price Pc) and changes the reference power so that the demand power (price Pb) is smaller than the changed first reference power (price Pc). As a result, the determination unit 130 re-determines the schedule so as to obtain the schedule shown in FIG. 18(b).

[0211] Furthermore, control unit 140 controls the heating of water by a plurality of water heating devices 11 in the second time slot based on the schedule determined again by determination unit 130 in step S72 (S90).

[0212] If the second increase is equal to or greater than the first increase (No in S62), control unit 140 performs the following process: In this case, control unit 140 controls the heating of water by multiple water heating devices 11 during the second time slot based on the schedule determined by determination unit 130 in step S30 (S90).

[0213] In Operation Example 8, the hot water supply system 100 can compare the first increase with the second increase and re-determine the schedule so that electricity rates are lower throughout the year.

[0214] [Operation Example 9] Fig. 19 is a flowchart of Operation Example 9 according to this embodiment. Fig. 20 is a diagram showing a schedule of Operation Example 9 according to this embodiment.

[0215] Operation example 9, like operation example 4, is an operation performed while control unit 140 is controlling the heating of multiple water heating devices 11 (first to fourth water heating devices 11a to 11d) during the second time slot based on the schedule determined, for example, in step S90 in operation example 1. More specifically, this is an operation performed while first and second water heating devices 11a and 11b are heating water, and as will be described later, when step S25 in operation example 9 is performed, third and fourth water heating devices 11c and 11d have not yet heated water.

[0216] In operation example 9, an example will be described in which the second time period includes a partial time period, as shown in Fig. 20. As described above, the second time period is from 11:00 PM to 7:00 AM the next day. The partial time period is, for example, from 2:00 AM to 4:00 AM the next day within the second time period, but is not limited to this.

[0217] Some time periods will be further explained.

[0218] The need for power saving may suddenly increase due to a tight power supply and demand balance or a rise in the power market price. In such cases, it may be necessary to keep the power demand below the first reference power, or keeping the power demand below the first reference power may result in lower electricity bills. In this operation example, the time period in which the reference power is less than the first reference power is a certain time period. Note that it is often difficult to determine whether the need for power saving will increase before the second time period begins. Therefore, in a stage such as step S30 of operation example 1 before operation example 9 is performed, operation example 9 will be described on the assumption that such a certain time period does not occur and the schedule is determined using the first reference power.

[0219] Furthermore, the acquisition unit 120 acquires a second reference power for the part of the time period (S15). The acquisition unit 120 acquires the second reference power stored in the storage unit 150. The second reference power is a reference power lower than the first reference power and is the reference power for the apartment building 40 (plurality of residences). Furthermore, the second reference power is also the reference power for the part of the time period included in the second time period.

[0220] Before step S15 is processed, hot water supply system 100 may perform the following process. As described above, when there is a sudden increase in the need for power saving, an information terminal such as a smartphone, tablet, or personal computer receives a predetermined operation from the administrator of hot water supply system 100. The predetermined operation is an operation to instruct acquisition unit 120 of hot water supply system 100 to acquire the second reference power. The information terminal transmits information to communication unit 110 of hot water supply system 100 instructing acquisition unit 120 to acquire the second reference power. When communication unit 110 of hot water supply system 100 acquires the information, acquisition unit 120 may acquire the second reference power in step S15.

[0221] Furthermore, the determination unit 130 determines whether the total power demand of the apartment building 40 (plurality of residences) exceeds the second reference power acquired by the acquisition unit 120 during a certain time period in the schedule determined in step S30 (S25). As described above, the schedule determined in step S30 is determined without using the second reference power, and therefore there is a possibility that the second reference power will be exceeded in this schedule. In this way, in operation example 9, it can also be said that the reference power is changed from the first reference power to the second reference power.

[0222] Next, when determination unit 130 determines that the demand power exceeds the second reference power (Yes in S25), determination unit 130 updates the schedule determined by determination unit 130 in step S30 before the certain time period, i.e., in this case, during the second time period. That is, determination unit 130 updates the schedule so that, among the multiple water heating devices 11, water heating starts in the order of the water heating devices 11 with the earliest latest water heating start times (S35). More specifically, determination unit 130 updates the schedule so that, among the multiple water heating devices 11 that have not yet started water heating as of step S25, water heating starts in the order of the water heating devices 11 with the earliest latest water heating start times. As described above, when Operation Example 9 begins, water heating is being performed by two or more water heating devices 11 (first and second water heating devices 11a and 11b). Therefore, in step S35, determination unit 130 updates the schedule so that water heating starts in order of the water heating devices 11 other than two or more of the plurality of water heating devices 11 and having the earliest latest water heating start time.

[0223] Steps S25 and S35 will be described in more detail using Figure 20. For example, the time (current time) when step S25 is being processed is time t2 shown in Figure 20. In addition, in the schedule shown in Figure 20, the latest boil-up start time of first water heater 11a is t11, the latest boil-up start time of second water heater 11b is t12, the latest boil-up start time of third water heater 11c is t13, and the latest boil-up start time of fourth water heater 11d is t14. t11 is earlier than t12, t12 is earlier than t13, and t13 is earlier than t14.

[0224] (a) of Fig. 20 is a diagram showing the schedule determined in step S30. The schedule shown in (a) of Fig. 20 is a diagram showing the schedule when it is determined that the demand power will exceed the second reference power. (b) of Fig. 20 is a diagram showing a schedule in which, among multiple water heating devices 11 (third and fourth water heating devices 11c and 11d) that have not yet started water heating at time t2, third water heating device 11c, which has the earliest latest water heating start time, starts water heating earlier. In other words, (b) of Fig. 20 is a diagram showing an updated schedule.

[0225] 20A, it is determined that the power demand will exceed the second reference power during a certain time period at time t2 (the current time). In such a case, in step S35, determination unit 130 updates the schedule so that water heating starts in order from the water heating apparatus 11 with the earliest latest water heating start time among the plurality of water heating apparatuses 11.

[0226] The determination unit 130 updates the schedule so that, of the third and fourth water heating apparatuses 11c and 11d, the third water heating apparatus 11c, which has the earliest latest water heating start time, starts water heating earlier, and the fourth water heating apparatus 11d, which has the latest latest water heating start time, starts water heating later. Here, the determination unit 130 updates the schedule so that the water heating of the third water heating apparatus 11c starts within a certain time slot. Furthermore, to prevent the demand power from exceeding the second reference power during a certain time slot, the determination unit 130 updates the schedule so that the water heating of the fourth water heating apparatus 11d starts within a second time slot that follows the certain time slot.

[0227] Furthermore, control unit 140 controls the heating of water by a plurality of water heating devices 11 in a second time period that includes some of the time periods, based on the schedule updated by determination unit 130 in step S35 (S95a).

[0228] If it is determined that the demand power does not exceed the second reference power during the second time slot (No in S25), control unit 140 performs the following process: In this case, control unit 140 controls the heating of water by multiple water heating devices 11 during the second time slot, including some of the time slots, based on the schedule determined by determination unit 130 in step S30 (S95b).

[0229] Operation example 9 shows an operation in which the reference power is changed from the first reference power to the second reference power when the need for power saving suddenly increases due to a tight power supply and demand or a sudden rise in the power market price.

[0230] If determination unit 130 determines that the demand power will exceed the second reference power during the part of the time period in which the reference power has been changed to the second reference power (Yes in S25), determination unit 130 determines the following schedule: Determination unit 130 determines a schedule in which water heating starts in order from the water heating device 11 with the earliest latest water heating start time among multiple water heating devices 11.

[0231] As a result, in Operation Example 9, the hot water supply system 100 is realized that can suppress the overall power demand (more specifically, the maximum value of power demand) of the apartment building 40. For example, as shown in (b) of Fig. 20, the maximum value of power demand is suppressed from exceeding the second reference power. Therefore, the basic fee for the apartment building 40 is less likely to become high.

[0232] As described above, the case where the reference power is changed from the first reference power to the second reference power corresponds to a case where a request for power saving is made due to a tight power supply and demand. Even in such a case, the hot water supply system 100 can suppress the overall power demand (more specifically, the maximum value of power demand) of the apartment building 40, thereby satisfying the social need for power saving.

[0233] [Operation Example 10] FIG. 21 is a flowchart of Operation Example 10 according to this embodiment.

[0234] In the operation example 10 shown in FIG. 21, an example is shown in which the schedule is re-determined so that power is supplied from the power supply facility 23 in the second time slot.

[0235] In the operation example 10, first, step S30 described in the operation example 1 is performed, and a schedule is determined.

[0236] Next, based on the schedule determined in step S30 and the acquired first reference power, determination unit 130 determines whether the total power demand of apartment building 40 in the second time slot will exceed the acquired first reference power (S63). That is, in step S63, it is predicted and determined whether the power demand will still exceed the first reference power even if the start of water heating by third hot water supply device 11c is delayed in step S30 of operation example 1.

[0237] Furthermore, if it is determined that the demand power exceeds the first reference power during the second time period (Yes in S63), the determination unit 130 re-determines the schedule so that power is supplied to the apartment building 40 from the power supply equipment 23 provided in the apartment building 40 (S73).

[0238] Here, the determination unit 130 re-determines the schedule so that power is supplied from the power supply facility 23 to the apartment building 40 by the amount of power by which the demand power exceeds the first reference power. The sum of the power supplied from the power company and the power supplied from the power supply facility 23 corresponds to the demand power. In other words, because the power supplied from the power company corresponds to the first reference power, even if the demand power exceeds the first reference power, the power supplied from the power company is prevented from exceeding the first reference power.

[0239] Furthermore, control unit 140 controls the heating of water by a plurality of water heating devices 11 in the second time slot based on the schedule determined by determination unit 130 in step S73 (S90).

[0240] If it is determined that the power demand in the second time slot does not exceed the first reference power (No in S63), control unit 140 performs the following process: In this case, control unit 140 controls the heating of water by multiple water heating devices 11 in the second time slot based on the schedule determined by determination unit 130 in step S30 (S90).

[0241] In operation example 10, when it is determined that the demanded power exceeds the first reference power, the schedule is re-determined so that power is supplied from the power supply facility 23 to the apartment building 40. This prevents the power supplied from the electric power company from exceeding the first reference power. This makes it less likely that the electricity bill for the apartment building 40 will increase.

[0242] Furthermore, in the operation example 10, when it is determined that the power demand exceeds the first reference power (Yes in S63), the determination unit 130 re-determines the schedule so that power is supplied to the apartment building 40 from the power supply facility 23 provided in the apartment building 40, but this is not limited to this. In this case, for example, the determination unit 130 may re-determine the schedule so that the electrical appliances 21 (lights, elevators) in the common area 20 are stopped. This reduces the power demand, thereby preventing the power supplied from the electric power company from exceeding the first reference power.

[0243] [Operation Example 11] FIG. 22 is a flowchart of Operation Example 11 according to this embodiment.

[0244] In the operation example 11 shown in FIG. 22, an example is shown in which the schedule is re-determined so that power is supplied from the power supply facility 23 during the first time slot.

[0245] In the eleventh operational example, first, step S30 described in the first operational example is carried out, and a schedule is determined.

[0246] Next, determination unit 130 determines whether the second scheduled completion time of water heating for at least one water heating apparatus 11 in the schedule determined in step S30 is included in the first time slot (S64). Here, at least one water heating apparatus 11 is third water heating apparatus 11c, which has delayed the start of water heating in the determined schedule.

[0247] As explained above, the second time slot is from 11:00 PM to 7:00 AM the next day. In other words, when the second scheduled completion time of the water heating of third hot water supply device 11c, for which the start of water heating has been delayed, falls within the first time slot, this means that the second scheduled completion time falls within the first time slot of the next day (from 7:00 AM to 11:00 PM the next day).

[0248] Furthermore, if it is determined that the second scheduled completion time of water heating by third water heating apparatus 11c falls within the first time slot (Yes in S64), determination unit 130 redetermines the schedule as follows (S74). In this case, determination unit 130 redetermines the schedule so that power is supplied from power supply facility 23 equipped in apartment building 40 for water heating by third water heating apparatus 11c during the first time slot. Here, determination unit 130 redetermines the schedule so that all of the power required for water heating by third water heating apparatus 11c during the first time slot is supplied from power supply facility 23. In other words, there is no need for the electric power company to supply power to apartment building 40 for water heating by third water heating apparatus 11c during the first time slot.

[0249] Furthermore, control unit 140 controls the heating of water by a plurality of water heating devices 11 during the second time slot based on the schedule determined by determination unit 130 in step S74 (S90).

[0250] If it is determined that the second scheduled completion time of water heating by third water heating apparatus 11c is not included in the first time slot (No in S64), control unit 140 performs the following process: In this case, control unit 140 controls water heating by multiple water heating apparatuses 11 during the second time slot based on the schedule determined by determination unit 130 in step S30 (S90).

[0251] In operation example 11, when the second scheduled completion time of the water heating by third hot water heater 11c falls within the first time slot, the schedule is re-determined to supply power from power supply facility 23 for the water heating. Therefore, there is no need for the power company to supply power to apartment building 40 for the water heating. Therefore, the electricity bill for apartment building 40 can be kept low.

[0252] [Operation Example 12] FIG. 23 is a flowchart of Operation Example 12 according to this embodiment.

[0253] In operation example 12 shown in FIG. 23, an example is shown in which the fifth hot water supply device 11e heats up water in the first time slot.

[0254] As an example, the processing of operation example 12 begins when acquisition unit 120 acquires, during a first time period, an instruction to heat water for fifth water heating apparatus 11e from the owner of fifth water heating apparatus 11e, which is included in multiple water heating apparatuses 11. That is, in operation example 12, it is necessary to heat water for fifth water heating apparatus 11e during the first time period.

[0255] First, determination unit 130 determines the cheapest amount among the first amount, the second amount, and the third amount when fifth hot water supply apparatus 11e heats water in the first time slot (S80). Here, the first amount, the second amount, and the third amount will be described.

[0256] The first amount means the amount when the fifth water heating apparatus 11e is heated using electricity supplied by the electric power company. In other words, the first amount is the amount paid to the electric power company when the fifth water heating apparatus 11e is heated using electricity supplied by the electric power company.

[0257] The second amount means the amount required to recharge a charging facility (more specifically, a charging facility of power supply facility 23) provided in apartment building 40 when fifth water heating apparatus 11e is heated using the electricity stored in the charging facility. In other words, the second amount means the amount required to purchase electricity supplied by the electric power company to recharge the amount of electricity consumed by the discharge of electricity stored in the charging facility when fifth water heating apparatus 11e is heated using the electricity stored in the charging facility.

[0258] The third amount means the amount of electricity sold for the electricity required to heat water by fifth hot water supply apparatus 11e when the electricity is generated by the solar power generation equipment installed in apartment building 40. In other words, the third amount is the amount of electricity sold for the electricity required to heat water by fifth hot water supply apparatus 11e when the solar power generation equipment generates the electricity required to heat water by fifth hot water supply apparatus 11e and the electricity is sold to the electric power company instead of being used for heating water.

[0259] Furthermore, if in step S80 it is determined that the first amount is the cheapest of the first, second, and third amounts, the determination unit 130 determines a control signal to heat the fifth water heater 11e using electricity supplied by the electric power company (S81).

[0260] Also, in step S80, if it is determined that the second amount is the cheapest among the first amount, second amount, and third amount, the determination unit 130 determines a control signal so that the fifth water heating device 11e will heat water using the electricity charged in the charging equipment (S82).

[0261] Also, in step S80, if it is determined that the third amount is the cheapest among the first amount, second amount, and third amount, the determination unit 130 determines a control signal so that the fifth water heating device 11e will heat water using the electricity generated by the solar power generation equipment (S83).

[0262] Furthermore, control unit 140 controls the heating of fifth water heating apparatus 11e based on the control signal determined by determination unit 130 in steps S81, S82, and S83 (S84). More specifically, control unit 140 controls communication unit 110 to output the determined control signal to control device 13 of fifth exclusive unit 10e. As a result, control device 13 controls the heating of fifth water heating apparatus 11e based on the acquired control signal.

[0263] In operation example 12, control unit 140 controls the heating of water by fifth hot water supply apparatus 11e with the least financial loss. Thus, financial loss to the manager of apartment building 40 can be minimized.

[0264] (Modification 1) Modification 1 of the embodiment will be described below. The following description will focus on differences from the embodiment, and descriptions of commonalities will be omitted or simplified.

[0265] In the embodiment, the hot water supply system 100 is installed in the apartment building 40, but the present invention is not limited to this. In this modification, the hot water supply system 100 is installed in an area 340 including the apartment building 40.

[0266] [Configuration] FIG. 24 is a block diagram showing a functional configuration of a hot water supply system 100 according to the first modification of the embodiment.

[0267] The hot water supply system 100 is a system installed in an area 340 that includes an apartment building 40, a plurality of detached houses 410, and a plurality of facilities 520. Therefore, Fig. 24 also shows a block diagram illustrating the functional configuration of each of the apartment building 40, the plurality of detached houses 410, and the plurality of facilities 520 included in the area 340.

[0268] The hot water supply system 100 controls a plurality of hot water supply devices 411 installed in a plurality of detached houses 410 and a plurality of hot water supply devices 11 installed in a plurality of dwelling units included in the apartment building 40, thereby suppressing the maximum value of the overall power demand in the area 340. Note that the plurality of houses according to this modification include a plurality of detached houses 410 and a plurality of dwelling units included in the apartment building 40.

[0269] In the area 340 according to this modification, a high-voltage lump-sum electricity receiving contract is selected as the contract type for supplying electricity to the area 340 .

[0270] Hot water supply system 100 according to this modification determines a schedule for heating water by multiple hot water supply devices 411 and multiple hot water supply devices 11 before the start of the second time slot, that is, during the first time slot. Hot water supply system 100 controls multiple hot water supply devices 411 and multiple hot water supply devices 11 based on this determined schedule.

[0271] Detached house 410 is an example of a house installed in area 340. Each of the plurality of detached houses 410 includes a water heating apparatus 411, an electrical appliance 412, a control device 413, and a power supply facility 423. Water heating apparatus 411, electrical appliance 412, control device 413, and power supply facility 423 have the same functions as water heating apparatus 11, electrical appliance 12, control device 13, and power supply facility 23, respectively, described in the embodiment.

[0272] Therefore, control device 413 can perform information processing similar to that of control device 13. Control device 413 installed in one detached house 410 can output information such as hot water supply information about hot water heater 411 installed in that one detached house 410 to communication unit 110. Control device 413 installed in one detached house 410 can also output information such as power information (equivalent to private area power information in the embodiment) about electrical appliances 412 installed in that one detached house 410 to communication unit 110.

[0273] The facilities 520 are facilities installed in the area 340, such as commercial facilities, industrial facilities, schools, and public facilities. Each of the facilities 520 includes an electric device 521, a power measurement device 522, and a power supply facility 523. The electric device 521, the power measurement device 522, and the power supply facility 523 have the same functions as the electric device 21, the power measurement device 22, and the power supply facility 23 described in the embodiment, respectively.

[0274] Therefore, the power measurement device 522 can perform information processing similar to that of the power measurement device 22. The power measurement device 522 installed in one facility 520 can output information such as power information (corresponding to the shared unit power information in the embodiment) about the electrical devices 521 installed in the one facility 520 to the communication unit 110.

[0275] As a result, the hot water supply system 100 according to the first modification can also perform the operation examples 1 to 12 described in the embodiment.

[0276] (Modification 2) Modification 2 of the embodiment will be described below. The following description will focus on the differences from the embodiment, and the description of the commonalities will be omitted or simplified.

[0277] In the embodiment, hot water supply system 100 acquires information from control device 13 and power measurement device 22, but this is not limited to this. In this modification, hot water supply system 100 acquires information from hot water supply device 11, smart meter 15, power supply facility 23, and smart meter 25.

[0278] [Configuration] FIG. 25 is a block diagram showing the functional configuration of a hot water supply system 100 according to the second modification of the embodiment.

[0279] In this modification, each of the plurality of dwelling units includes a hot water supply device 11 and a smart meter 15. Each of the plurality of dwelling units does not include a control device 13.

[0280] Water heating apparatus 11 according to this modification outputs information such as hot water supply information about water heating apparatus 11 to water heating system 100 .

[0281] The smart meter 15 is a device that can measure the amount of electricity used by the dwelling unit every predetermined time period (e.g., every 30 minutes) and has a communication function. That is, the smart meter 15 can measure the electricity used by the electrical appliances 12 (not shown) and output the private area electricity information to the hot water supply system 100.

[0282] In this modification, the common part 20 is provided with a smart meter 25 and a power supply facility 23. The common part 20 is not provided with a power measurement device 22.

[0283] The power supply facility 23 according to this modification outputs power supply facility information indicating the amount of power generated by the power supply facility 23, the amount of charge, and the like, to the hot water supply system 100.

[0284] The smart meter 25 is a device that can measure the amount of power consumption in the shared part 20 every predetermined time period (for example, every 30 minutes) and has a communication function. That is, the smart meter 25 can measure the power consumption of the electrical appliances 21 (not shown) and output the shared part power information to the hot water supply system 100.

[0285] As a result, the hot water supply system 100 according to the second modification can also perform the operation examples 1 to 12 described in the embodiment.

[0286] (Modification 3) Modification 3 of the embodiment will be described below. The following description will focus on the differences from modifications 1 and 2, and descriptions of commonalities will be omitted or simplified.

[0287] [Configuration] FIG. 26 is a block diagram showing the functional configuration of a hot water supply system 100 according to a third modification of the embodiment.

[0288] In the first modification, the hot water supply system 100 acquires information from the control devices 13 and 413 and the power measurement devices 22 and 522, but is not limited to this. In this modification, the hot water supply system 100 acquires information from the hot water supply devices 11 and 411, the smart meters 15, 25, 415, and 525, and the power supply facilities 23, 423, and 523.

[0289] The hot water supply system 100 according to the third modification can also perform the first to twelfth operational examples described in the embodiment.

[0290] (Effects, etc.) Invention 1 is a hot water supply system 100 comprising: an acquisition unit 120 that acquires a plurality of pieces of hot water information including the amount of water heated by the hot water supply device 11 and the start time of use of the hot water supply device 11, and a first reference power of a plurality of residences in which the plurality of hot water supply devices 11 are installed; a decision unit 130 that, when it is determined based on the amount of water heated included in the plurality of pieces of hot water information acquired, that if the plurality of hot water supply devices 11 start heating at the same time, the total power demand of the plurality of residences will exceed the acquired first reference power, determines a schedule to start heating among the plurality of hot water supply devices 11 in order of the hot water supply device 11 with the earliest latest start time of heating, which is the latest time to start heating so that hot water does not run out at the start time of use included in the hot water supply information for that hot water supply device 11; and a control unit 140 that controls the heating of the plurality of hot water supply devices 11 based on the determined schedule.

[0291] This realizes the hot water supply system 100 that can suppress the overall power demand (more specifically, the maximum value of the power demand) of multiple residences (in the case of the operation example 1, the apartment building 40), as shown in the operation example 1. For example, as shown in (b) of Fig. 3, the maximum value of the power demand is suppressed from exceeding the first reference power. Therefore, the basic charge for the apartment building 40 is less likely to become high.

[0292] Invention 2 is hot water supply system 100 of Invention 1, in which acquisition unit 120 acquires a first reference power for the second time period from among the first time period and a second time period in which the unit price of electricity is lower than that of the first time period, and when determination unit 130 determines that if multiple hot water supply devices 11 start heating water simultaneously in a 22nd time period, the total power demand of multiple homes will exceed the acquired first reference power, determine a schedule to start heating water in order of the hot water supply device 11 with the earliest latest heating start time, before the second time period, and control unit 140 controls the heating of water by multiple hot water supply devices 11 in the second time period based on the determined schedule.

[0293] As a result, as shown in Operation Example 1, the water heating of the plurality of water heating devices 11 is performed during the second time slot when the unit price of electricity is lower, thereby reducing the electricity bill paid by the owners of the water heating devices 11. In other words, water heating system 100 is realized that can reduce the electricity bill paid by the owners of water heating devices 11.

[0294] Invention 3 is a hot water supply system 100 of Invention 1 or 2, in which, when there are two hot water supply devices 11 among multiple hot water supply devices 11 that have the same latest start time of heating, the determination unit 130 determines a schedule to start heating in order of the hot water supply device 11 that has the largest amount of heating contained in the hot water supply information for that hot water supply device 11.

[0295] As a result, as shown in Operation Example 1, a schedule is determined such that water heating apparatus 11 with a large amount of water being heated (for example, third water heating apparatus 11c) is given priority for heating, making it less likely that water heating apparatus 11 will run out of hot water. In other words, hot water supply system 100 is realized in which water heating apparatus 11 is less likely to run out of hot water.

[0296] Invention 4 is the hot water supply system 100 of Invention 2, in which the acquisition unit 120 acquires a first unit price of electricity for a first time period and a second unit price of electricity for a second time period, and the determination unit 130 determines a schedule based on the acquired first unit price of electricity and second unit price of electricity so as to reduce the electricity charges for heating water for each of the multiple hot water supply devices 11.

[0297] As a result, as shown in Operation Example 2, water heating by water heating apparatus 11 (for example, first water heating apparatus 11a) is performed during a time period when the unit price of electricity is cheaper, thereby reducing the electricity bill paid by the owner of water heating apparatus 11. In other words, water heating system 100 is realized that can reduce the electricity bill paid by the owner of water heating apparatus 11.

[0298] Invention 5 is a hot water supply system 100 of Invention 4, in which, when multiple second time periods are set in a day, the determination unit 130 determines a schedule based on the acquired first and second unit prices of electricity and the start time of use included in each of the acquired multiple pieces of hot water supply information so that the electricity bill for heating water from each of the multiple hot water supply devices 11 is low and so that the time difference between the first scheduled completion time, which is the scheduled time when heating water from each of the multiple hot water supply devices 11 will be completed, and the start time of use is short.

[0299] As a result, as shown in Operation Example 3, water heating apparatus 11 (e.g., first water heating apparatus 11a) heats water during a time period when the unit price of electricity is lower, thereby reducing the electricity bill paid by the owner of water heating apparatus 11. Incidentally, as shown in FIG. 9A, if the time between the first estimated completion time and the start time of use is long, the problem of the boiled water cooling down can occur. However, in Operation Example 3, as shown in FIG. 9B, the time difference between the first estimated completion time and the start time of use is short, making this problem less likely to occur. In other words, a water heating system 100 is realized that can reduce the electricity bill paid by the owner of water heating apparatus 11 and is less likely to cause the problem of the boiled water cooling down.

[0300] Invention 6 is a hot water supply system 100 of any one of Inventions 1 to 5, in which, when the control unit 140 is controlling the heating of water by multiple hot water supply devices 11 based on a determined schedule, the decision unit 130, when determining that the total power demand of the multiple homes will exceed the acquired first reference power, updates the schedule to stop the heating of water by the hot water supply device 11 among the multiple hot water supply devices 11 that has the largest time difference between the second estimated completion time, which is the estimated time for the heating to be completed as indicated by the determined schedule, and the third estimated completion time, which is the estimated time for the heating to be completed when the heating is started at the latest heating start time, and the control unit 140 controls the heating of water by the multiple hot water supply devices 11 based on the updated schedule.

[0301] As a result, as shown in Operation Example 4, when the power demand exceeds the first reference power, hot water supply system 100 updates the schedule so that hot water supply device 11 (second hot water supply device 11b) stops heating water. This prevents the power demand from exceeding the first reference power. In other words, hot water supply system 100 is realized that can suppress the overall power demand (more specifically, the maximum value of power demand) of multiple residences (in Operation Example 4, apartment building 40). Furthermore, by determining unit 130 updating the schedule so that hot water supply device 11 with a large time difference between the second estimated completion time and the third estimated completion time stops heating water, hot water supply devices 11 with a small time difference and hot water supply devices 11 with a large time difference are less likely to run out of hot water.

[0302] Invention 7 is a hot water supply system 100 of any one of Inventions 1 to 6, in which, when the control unit 140 is heating water for two or more of the multiple hot water supply devices 11 according to a determined schedule, the acquisition unit 120 acquires a heating instruction instructing the heating of water for other hot water supply devices 11 than the two or more of the multiple hot water supply devices 11, the determination unit 130 updates the schedule based on the acquired heating instruction to start heating water for the other hot water supply devices 11, and the control unit 140 controls the heating of water for the multiple hot water supply devices 11 based on the updated schedule.

[0303] As a result, as shown in Operation Example 5, when hot water supply system 100 receives a heating instruction for another hot water supply apparatus 11 (third hot water supply apparatus 11c), it performs the following process. That is, hot water supply system 100 updates the schedule to start heating water for the other hot water supply apparatus 11. As a result, hot water supply system 100 can heat water for the other hot water supply apparatus 11.

[0304] Invention 8 is a hot water supply system 100 of Invention 7, in which, when the information processing device receives an operation from the owner of another hot water supply device 11, the information processing device outputs a boiling instruction indicated by the received operation, and the acquisition unit 120 acquires the output boiling instruction.

[0305] As a result, as shown in Operation Example 5, the hot water supply system 100 can update the schedule through the owner's operation.

[0306] Invention 9 is a hot water supply system 100 of Invention 7 or 8, in which, when the decision unit 130 determines based on the acquired heating instructions that the total power demand of multiple homes will exceed the acquired first reference power, it stops heating of the hot water supply device 11 among two or more hot water supply devices 11 that has the largest time difference between the second estimated completion time, which is the estimated time for completion of heating indicated by the determined schedule, and the third estimated completion time, which is the estimated time for completion of heating when heating is started at the latest heating start time, and updates the schedule to start heating of the other hot water supply devices 11.

[0307] As a result, as shown in Operation Example 5, when hot water supply system 100 determines that the power demand will exceed the first reference power based on a heating instruction from another hot water supply apparatus 11 (third hot water supply apparatus 11c), it performs the following processing. Specifically, hot water supply system 100 updates the schedule to stop heating water from hot water supply apparatus 11 (second hot water supply apparatus 11b), thereby preventing the power demand from exceeding the first reference power. In other words, hot water supply system 100 is realized that can reduce the overall power demand (more specifically, the maximum power demand) of multiple residences (in Operation Example 5, apartment building 40). Furthermore, determination unit 130 updates the schedule to stop heating water from hot water supply apparatus 11 (second hot water supply apparatus 11b) with a large time difference between the second and third estimated completion times. This reduces the likelihood of hot water shortages in hot water supply apparatuses 11 with a small time difference and hot water supply apparatuses 11 with a large time difference. In other words, hot water supply system 100 is realized that is less likely to run out of hot water.

[0308] Invention 10 is a hot water supply system 100 of Invention 2, in which the determination unit 130, when determining based on the start of use times included in each of the acquired hot water supply information that there is a first target hot water supply device among the multiple hot water supply devices 11 for which the time from the second scheduled completion time, which is the scheduled time for completion of heating indicated in the determined schedule, to the start of use time exceeds a reference time, determines again the schedule so that heating of the first target hot water supply device is completed by the start of use time after heating during the second time period, and then stops and heats up again.

[0309] As a result, as shown in Operation Example 6, the determination unit 130 performs heating of the first target hot water supply device, stops the heating, and then performs heating again, re-determining the schedule so that heating of the first target hot water supply device is completed by the start time of use. Note that the determination unit 130 performs heating again, and re-determines the schedule so that the time from the time when heating of the first target hot water supply device is completed to the scheduled time of use is less than the reference time. Therefore, the time from the time when heating of the first target hot water supply device is completed to the scheduled time of use is sufficiently short, making it less likely that the problem of the boiled water cooling down will occur. In other words, a hot water supply system 100 that is less likely to cause the above problem is realized.

[0310] Invention 11 is a hot water supply system 100 of any one of Inventions 1 to 10, in which, when there is a second target hot water supply device among the multiple hot water supply devices 11 whose determined schedule indicates a number of times that the number of times that the water is boiled is greater than a predetermined number, the determination unit 130 re-determines the schedule so that the number of times that the second target hot water supply device boils is less than the predetermined number.

[0311] As a result, as shown in Operation Example 7, the number of times that the second target hot water supply apparatus heats up is less than the predetermined number of times, which makes it less likely that a problem will occur in which the amount of power consumed by hot water supply apparatus 11 increases due to a large number of times that the water is heated up. In other words, because the amount of power consumed is reduced, hot water supply system 100 can reduce the overall power demand (more specifically, the maximum value of power demand) of apartment building 40.

[0312] Invention 12 is hot water supply system 100 of Invention 2, in which, when control unit 140 controls the heating of water by multiple water heating devices 11 according to a determined schedule, acquisition unit 120 acquires second reference powers for multiple residences that are lower than the first reference power, the second reference powers being for a portion of a time period that is included in the second time period, and when determination unit 130 determines that the total power demand of the multiple residences exceeds the acquired second reference power during a portion of the time period in the determined schedule, it updates the schedule so that the water heating of the multiple water heating devices 11 starts in order of the water heating device 11 with the earliest latest heating start time, and control unit 140 controls the heating of water by multiple water heating devices 11 during a portion of the time period based on the updated schedule.

[0313] As a result, as shown in Operation Example 9, the hot water supply system 100 is realized that can suppress the overall power demand (more specifically, the maximum value of power demand) of multiple residences (in Operation Example 9, the apartment building 40). For example, as shown in (b) of Fig. 20, the maximum value of power demand is suppressed from exceeding the second reference power. Therefore, the basic charge for the apartment building 40 is less likely to become high.

[0314] Invention 13 is a hot water supply method executed by hot water supply system 100, including an acquisition step of acquiring multiple pieces of hot water information including the amount of water heated by hot water supply device 11 and the start time of use of hot water supply device 11, and a first reference power of multiple residences in which multiple hot water supply devices 11 are installed; a determination step of, when it is determined based on the amount of water heated by the multiple pieces of hot water information acquired that if multiple hot water supply devices 11 start heating at the same time, the total power demand of the multiple residences will exceed the acquired first reference power, determining a schedule for starting heating among the multiple hot water supply devices 11 in order of the hot water supply device 11 with the earliest latest start time of heating, which is the latest time for starting heating so that hot water does not run out at the start time of use included in the hot water supply information for that hot water supply device 11; and a control step of controlling the heating of the multiple hot water supply devices 11 based on the determined schedule.

[0315] This realizes a hot water supply method that can reduce the overall power demand (more specifically, the maximum power demand) of multiple residences (in Operation Example 1, apartment building 40), as shown in Operation Example 1. For example, as shown in Fig. 3(b), the maximum power demand is prevented from exceeding the first reference power. Therefore, the basic charge for apartment building 40 is less likely to increase.

[0316] (Other Embodiments) Although the embodiments have been described above, the present invention is not limited to the above-described embodiments and modifications.

[0317] As an example, the first time period is from 7:00 to 23:00, and the second time period is from 23:00 to 7:00 the next day, but the present invention is not limited to this.

[0318] Furthermore, although the amount of water to be boiled is determined by the control device 13, this is not limiting. For example, the hot water supply system 100 may calculate the amount of water to be boiled from the target amount of water to be boiled and the amount of hot water remaining in the hot water storage tank.

[0319] In order to determine the amount of water to be heated and the start time of use, the period from the day before the relevant day to one week ago is used as the predetermined past period, but this is not limited to this. For example, the period from one week before to one day one year ago of the relevant day may be used as the predetermined past period.

[0320] Furthermore, the communication method between devices described in the above embodiment and modifications is merely an example, and the communication method between devices is not particularly limited.

[0321] In the above embodiment and modified example, the amount of electric power used (power consumption) required to heat water by water heater 11 is proportional to the amount of water heated by water heater 11, but this is not limiting.

[0322] For example, hot water heating system 100 may calculate the amount of power required to heat water by hot water heating device 11 and the time required for heating water based on the specifications of each of multiple hot water heating devices 11, the region in which multiple hot water heating devices 11 are installed, the current season, etc. For example, if the region in which multiple hot water heating devices 11 are installed is a colder region, hot water heating system 100 calculates the amount of power required to heat water by hot water heating device 11 to be greater and the time required for heating water to be longer. Furthermore, if the current season is winter, hot water heating system 100 calculates the amount of power required to heat water by hot water heating device 11 to be greater and the time required for heating water to be longer. Furthermore, for example, if hot water heating system 100 cannot acquire information indicating the current season, hot water heating system 100 may acquire data including the current air temperature and water temperature (data from the Japan Meteorological Agency, etc.) and calculate the amount of power required to heat water by hot water heating device 11 and the time required for heating water based on this data.

[0323] Furthermore, for example, the hot water supply system 100 may acquire data including past air and water temperatures (data from the Japan Meteorological Agency, etc.), and based on this data, calculate the amount of electricity used and the time required for heating the water by the hot water supply device 11.

[0324] Furthermore, if it is determined that the total power demand of multiple residences exceeds the first reference power, the following process may be performed. For example, the communication unit 110 of the hot water supply system 100 according to the embodiment transmits information (messages) requesting cooperation in saving power to the control devices 13 of the multiple private units 10 or to the information terminals (e.g., smartphones) of the owners. This is expected to encourage the owners of the private units 10 to cooperate in saving power. The display unit of the hot water supply system 100 displays the difference in charges (amount of charge reduction) between when the power demand exceeds the first reference power and when the power demand does not exceed the first reference power. The manager of the hot water supply system 100 can pay the displayed amount of charge reduction to the owners who cooperate in saving power, thereby increasing the owners' understanding of their cooperation in saving power.

[0325] The owner may be notified of the amount of the fee reduction before the information (message) requesting cooperation in saving electricity is sent. For example, information indicating the amount of the fee reduction may be output from the communication unit 110 of the hot water supply system 100 to the control device 13 of each of the multiple private units 10 or to the owner's information terminal (e.g., a smartphone). This allows the owner to know that there will be a financial benefit to cooperating in saving electricity.

[0326] Furthermore, there are cases where it is known in advance (for example, one hour or one week in advance) that the total power demand of a plurality of residences will exceed the first reference power during a certain time period.

[0327] As an example, in this case, the information (message) requesting cooperation in saving electricity may be transmitted before the certain time period (for example, the day before or several hours before the certain time period), thereby giving the owner time to consider whether or not to cooperate in saving electricity before the start of the certain time period.

[0328] As another example, in this case, the unit price of electricity for the certain time period may be increased. That is, a higher unit price of electricity is used compared to the unit price of electricity when the total power demand of the multiple homes does not exceed the first reference power during the certain time period. The hot water supply system 100 performs the processing of the above-described operation example using this higher unit price of electricity.

[0329] The manager of the hot water supply system 100 may acquire information on the power-saving cooperation of multiple owners by conducting a survey on power-saving cooperation among the owners of the first to fifth private units 10a to 10e. The manager controls an information terminal, such as a smartphone, tablet, or personal computer, to transmit the plurality of pieces of power-saving cooperation information to the communication unit 110 of the hot water supply system 100. The acquisition unit 120 of the hot water supply system 100 acquires the plurality of pieces of power-saving cooperation information acquired by the communication unit 110. The survey asks whether the owners will be able to cooperate in power-saving in their private units 10 if the total power demand of the multiple homes exceeds the acquired first reference power, and the power-saving cooperation information reflects the results of the survey. Based on the plurality of pieces of power-saving cooperation information acquired, the hot water supply system 100 determines which appliances (hot water supply apparatus 11, electrical appliances 21) to shut down if the total power demand of the multiple homes exceeds the acquired first reference power. The hot water supply system 100 determines a schedule so that the determined appliances are stopped, and controls the appliances based on the determined schedule. For example, if the power saving cooperation information indicates that power saving cooperation is not possible in all of the first to fifth exclusive use units 10a to 10e, the hot water supply system 100 determines a schedule so that the electrical appliances 21 installed in the common unit 20 are stopped.

[0330] In the above-described embodiment and modifications, the processing performed by a specific processing unit may be performed by another processing unit. The order of multiple processing operations may be changed, or multiple processing operations may be performed in parallel.

[0331] In the above-described embodiment and modified examples, components such as the acquisition unit 120, the determination unit 130, and the control unit 140 may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0332] Furthermore, components such as the acquisition unit 120, the determination unit 130, and the control unit 140 may be realized by hardware. For example, components such as the control unit 140 may be circuits (or integrated circuits). These circuits may form a single circuit as a whole, or may be separate circuits. Furthermore, each of these circuits may be a general-purpose circuit or a dedicated circuit.

[0333] Furthermore, the general or specific aspects of the present invention may be realized as a system, device, method, integrated circuit, computer program, or computer-readable recording medium such as a CD-ROM. Furthermore, the present invention may be realized as any combination of a system, device, method, integrated circuit, computer program, and recording medium. For example, the present invention may be realized as the hot water supply system 100 of the above-described embodiment and modified examples, or as a hot water supply method executed by the hot water supply system 100. The present invention may be realized as a program for causing a computer to execute such a hot water supply method, or as a non-transitory recording medium on which such a program is recorded. Such a program includes an application program for causing a computer, such as a general-purpose information terminal, to function as the hot water supply system 100 of the above-described embodiment and modified examples.

[0334] In addition, the present invention also includes forms obtained by applying various modifications that a person skilled in the art would think of to each embodiment and variant, or forms realized by arbitrarily combining the components and functions of each embodiment and variant within the scope that does not deviate from the intent of the present invention.

[0335] 11, 411 water heating device 100 water heating system 120 acquisition unit 130 determination unit 140 control unit

Claims

1. A hot water supply system comprising: an acquisition unit that acquires multiple hot water supply information including the amount of water heated by a hot water supply device and the start time of use of the hot water supply device, and a first reference power for multiple residences in which multiple hot water supply devices are installed; a determination unit that, when it is determined based on the amount of water heated included in the multiple acquired hot water supply information that the total power demand of the multiple residences would exceed the acquired first reference power if the multiple hot water supply devices were to start heating at the same time, determines a schedule for starting water heating among the multiple hot water supply devices in order of the hot water supply device with the earliest latest start time of heating, which is the latest time to start heating so that hot water does not run out at the start time of use included in the hot water supply information for that hot water supply device; and a control unit that controls the heating of the multiple hot water supply devices based on the determined schedule.

2. The hot water supply system of claim 1, wherein the acquisition unit acquires the first reference power for the second time period from among the first time period and a second time period having a lower unit price for electricity than the first time period, and the determination unit, when it determines that the total power demand of the multiple homes would exceed the acquired first reference power if the multiple hot water supply devices start boiling water simultaneously in the second time period, determines the schedule in which the multiple hot water supply devices start boiling water in order of the hot water supply device with the earliest latest boiling start time, prior to the second time period, and the control unit controls the boiling water of the multiple hot water supply devices during the second time period based on the determined schedule.

3. The hot water supply system of claim 1, wherein, when there are two hot water supply devices among the plurality of hot water supply devices whose latest heating start time is the same, the determination unit determines the schedule for starting heating of the hot water supply device among the two hot water supply devices in order of the hot water supply amount contained in the hot water supply information for that hot water supply device.

4. The hot water supply system of claim 2, wherein the acquisition unit acquires a first unit price of electricity for the first time period and a second unit price of electricity for the second time period, and the determination unit determines the schedule based on the acquired first unit price of electricity and second unit price of electricity so as to reduce the electricity bill for boiling water for each of the multiple hot water supply devices.

5. The hot water supply system of claim 4, wherein, when a plurality of the second time periods are provided in a day, the determination unit determines the schedule based on the acquired first and second unit prices of electricity and the start time of use included in each of the acquired hot water supply information, so that the electricity bill for heating water from each of the plurality of hot water supply devices is low and so that the time difference between the first scheduled completion time, which is the scheduled time when heating water from each of the plurality of hot water supply devices is completed, and the start time of use is short.

6. The hot water heating system of claim 1, wherein when the control unit controls the heating of water by the multiple hot water heating devices based on the determined schedule, the determination unit, when it determines that the total power demand of the multiple homes exceeds the acquired first reference power, updates the schedule so as to stop heating of water by the hot water heating device among the multiple hot water heating devices which has the largest time difference between a second estimated completion time, which is the estimated time for completion of heating indicated by the determined schedule, and a third estimated completion time, which is the estimated time for completion of heating when heating is started at the latest heating start time, and the control unit controls the heating of water by the multiple hot water heating devices based on the updated schedule.

7. The hot water supply system of claim 1, wherein, when the control unit is heating water up for two or more of the multiple hot water supply devices in accordance with the determined schedule, the acquisition unit acquires a heating instruction instructing the heating of water up for other hot water supply devices other than the two or more hot water supply devices among the multiple hot water supply devices, the determination unit updates the schedule based on the acquired heating instruction to start heating water up for the other hot water supply devices, and the control unit controls the heating of water up for the multiple hot water supply devices based on the updated schedule.

8. The hot water supply system of claim 7, wherein when the information processing device receives an operation from an owner of the other hot water supply device, the information processing device outputs the boiling instruction indicated by the received operation, and the acquisition unit acquires the output boiling instruction.

9. The hot water supply system of claim 7 or 8, wherein when the decision unit determines based on the acquired boiling instructions that the total power demand of the plurality of houses will exceed the acquired first reference power, it stops boiling water of the hot water supply device among the two or more hot water supply devices which has the largest time difference between a second scheduled completion time, which is the scheduled time for completion of boiling water indicated in the determined schedule, and a third scheduled completion time, which is the scheduled time for completion of boiling water when boiling water is started at the latest boiling start time, and updates the schedule to start boiling water of the other hot water supply devices.

10. The hot water supply system of claim 2, wherein when the determination unit determines, based on the use start time contained in each of the acquired hot water supply information, that there is a first target hot water supply device among the multiple hot water supply devices for which the time from a second scheduled completion time, which is the scheduled time for completion of water heating indicated in the determined schedule, to the use start time exceeds a reference time, the determination unit re-determines the schedule so that after water heating of the first target hot water supply device during the second time period, it stops the water heating and then heats it again, so that water heating of the first target hot water supply device is completed by the use start time.

11. The hot water supply system of claim 1, wherein, when there is a second target hot water supply device among the plurality of hot water supply devices, the determined schedule indicates a number of times that the number of times that the water is boiled is equal to or greater than a predetermined number, the determination unit re-determines the schedule so that the number of times that the second target hot water supply device boils is less than the predetermined number.

12. The hot water system of claim 2, wherein when the control unit is controlling the heating of water by the multiple water heating devices in accordance with the determined schedule, the acquisition unit acquires second reference powers for the multiple residences which are lower than the first reference power, the second reference powers being for a portion of a time period included in the second time period; when the determination unit determines that the total power demand of the multiple residences exceeds the acquired second reference power during the portion of the time period in the determined schedule, the determination unit updates the schedule so that the multiple water heating devices start heating water in order of the water heating device having the earliest latest heating start time; and the control unit controls the heating of water by the multiple water heating devices during the portion of the time period based on the updated schedule.

13. A hot water supply method executed by a hot water supply system, comprising: an acquisition step of acquiring multiple pieces of hot water supply information including the amount of water heated by a hot water supply device and the start time of use of the hot water supply device, and a first reference power for multiple residences in which multiple hot water supply devices are installed; a determination step of, when it is determined based on the amount of water heated by the multiple pieces of hot water supply information acquired, that the total power demand of the multiple residences would exceed the acquired first reference power if the multiple hot water supply devices were to start heating at the same time, determining a schedule for starting heating among the multiple hot water supply devices in order of the hot water supply device with the earliest latest heating start time, which is the latest time to start heating so that hot water does not run out at the start time of use included in the hot water supply information for that hot water supply device; and a control step of controlling the heating of the multiple hot water supply devices based on the determined schedule.

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