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

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a hot water storage type hot water supply apparatus. Such a hot water storage type hot water supply apparatus generally stores hot water heated during time periods when the unit price of electric power is low in a hot water storage tank, and supplies the hot water when necessary. The time period when the unit price of electric power is low is, for example, the nighttime time period.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] For example, in an apartment complex including a plurality of dwelling units, a plurality of the hot water supply apparatuses disclosed in Patent Document 1 may be installed. In such a case, if the plurality of hot water supply apparatuses start heating hot water simultaneously during the nighttime time period, the total power demand of the entire apartment complex at that time may become extremely large.

[0005] Meanwhile, as a contract form for supplying electric power to an apartment complex, there is a form called a high-voltage bulk power reception contract. Under this contract, the management company or management association of the apartment complex concludes a contract with an electric power company, and the user of each dwelling unit concludes a contract with the manager or management association of the apartment complex. In the high-voltage bulk power reception contract, a reference power that is a reference value (upper limit value) for the total power demand of the entire apartment complex is defined. If the reference power is exceeded, a contract with a raised reference power and a high basic charge will be required for the current month and the 11 months starting from the next month.

[0006] Therefore, as described above, if the total power demand of an apartment building containing multiple units becomes very large due to the heating of multiple water heaters, the power demand (more specifically, the maximum power demand) may exceed the standard power, and as a result, the basic charge may increase. In addition, when the power demand increases, problems such as circuit breakers tripping may occur.

[0007] This invention provides a hot water supply system and the like that can suppress the maximum total power demand of multiple houses. [Means for solving the problem]

[0008] A hot water supply system according to one aspect of the present invention includes: an acquisition unit that acquires a plurality of hot water supply pieces of information, including the amount of hot water heated by a hot water supply unit and the start time of use of the hot water supply unit, and a first reference power for a plurality of houses in which the plurality of hot water supply units are installed; a determination unit that, based on the amount of hot water heated included in the plurality of hot water supply pieces of information acquired, determines that if the plurality of hot water supply units start heating simultaneously, the total power demand of the plurality of houses will exceed the acquired first reference power, and determines a schedule in which the hot water supply units start heating in order of the latest start time, which is the latest time at which they start heating so that there is no shortage of hot water at the start time of use included in the hot water supply pieces of information for that hot water supply unit; and a control unit that controls the heating of the plurality of hot water supply units 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 performed by a hot water supply system, comprising: an acquisition step of acquiring a plurality of hot water supply information including the amount of hot 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 of a plurality of houses in which the plurality of hot water supply devices are installed; a determination step of determining a schedule in which, based on the amount of hot water heated included in the plurality of hot water supply information acquired, if it is determined that if the plurality of hot water supply devices start heating simultaneously, the total power demand of the plurality of houses will exceed the acquired first reference power, the hot water supply devices will start heating in the order of the latest hot water supply devices, which is the latest time to start heating so that there is no shortage of hot water 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 plurality of hot water supply devices based on the determined schedule. [Effects of the Invention]

[0010] The hot water supply system and other components of the present invention can suppress the maximum total power demand of multiple residences. [Brief explanation of the drawing]

[0011] [Figure 1A] Figure 1A is a block diagram showing the functional configuration of a hot water supply system according to an embodiment. [Figure 1B] Figure 1B shows an example of the unit price of electricity according to the embodiment. [Figure 2] Figure 2 is a flowchart of Operation Example 1 according to the embodiment. [Figure 3] Figure 3 is a diagram showing the schedule of Operation Example 1 according to the embodiment. [Figure 4] Figure 4 is a more detailed flowchart of step S30 of operation example 1 according to the embodiment. [Figure 5] Figure 5 is another diagram showing the schedule of Operation Example 1 according to the embodiment. [Figure 6] Figure 6 is a flowchart of Operation Example 2 according to the embodiment. [Figure 7]Figure 7 is a diagram showing a schedule of Operation Example 2 according to the embodiment. [Figure 8] Figure 8 is a flowchart of Operation Example 3 according to the embodiment. [Figure 9] Figure 9 is a diagram showing a schedule of Operation Example 3 according to the embodiment. [Figure 10] Figure 10 is a flowchart of Operation Example 4 according to the embodiment. [Figure 11] Figure 11 is a diagram showing a schedule of Operation Example 4 according to the embodiment. [Figure 12] Figure 12 is a flowchart of Operation Example 5 according to the embodiment. [Figure 13] Figure 13 is a diagram showing a schedule of Operation Example 5 according to the embodiment. [Figure 14] Figure 14 is a flowchart of Operation Example 6 according to the embodiment. [Figure 15] Figure 15 is a diagram showing a schedule of Operation Example 6 according to the embodiment. [Figure 16] Figure 16 is a flowchart of Operation Example 7 according to the embodiment. [Figure 17] Figure 17 is a flowchart of Operation Example 8 according to the embodiment. [Figure 18] Figure 18 is a diagram showing a schedule and electricity rate of Operation Example 8 according to the embodiment. [Figure 19] Figure 19 is a flowchart of Operation Example 9 according to the embodiment. [Figure 20] Figure 20 is a diagram showing a schedule of Operation Example 9 according to the embodiment. [Figure 21] Figure 21 is a flowchart of Operation Example 10 according to the embodiment. [Figure 22] Figure 22 is a flowchart of Operation Example 11 according to the embodiment. [Figure 23] Figure 23 is a flowchart of Operation Example 12 according to the embodiment. [Figure 24]Figure 24 is a block diagram showing the functional configuration of a hot water supply system according to a modified example 1 of the embodiment. [Figure 25] Figure 25 is a block diagram showing the functional configuration of a hot water supply system according to a modified example 2 of the embodiment. [Figure 26] Figure 26 is a block diagram showing the functional configuration of a hot water supply system according to a modified example 3 of the embodiment. [Modes for carrying out the invention]

[0012] The embodiments will be described in detail below with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit the present invention. Furthermore, components in the following embodiments that are not described in an independent claim will be described as optional components.

[0013] Please note that each figure is a schematic diagram and not necessarily a strictly accurate representation. Furthermore, in each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

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

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

[0016] The hot water supply system 100 is a system installed in the apartment building 40. Therefore, Figure 1A shows a block diagram that also shows the functional configuration of the apartment building 40 and other components besides the hot water supply system 100. The hot water supply system 100 controls multiple hot water supply devices 11 installed in multiple residences within the apartment building 40 to suppress the maximum value of the total power demand for the apartment building 40.

[0017] In the apartment building 40 according to this embodiment, a high-voltage bulk power supply contract is selected as the contract type for supplying electricity to the apartment building 40. Furthermore, in this contract, two types of time periods with different electricity rates are provided, for example, a first time period and a second time period with a lower electricity rate than the first time period. In addition, the contract may provide three types of time periods with different electricity rates, for example, a first time period, a second time period with a lower electricity rate than the first time period, and a third time period with a higher electricity rate than the first time period. Furthermore, the contract may provide four or more types of time periods with different electricity rates.

[0018] Furthermore, Figure 1B will be used to explain the relationship between electricity unit price and time of day.

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

[0020] For example, the first time zone refers to the time period excluding nighttime, and the second time zone refers to the nighttime period. Unless otherwise specified, the first time zone, where the electricity unit price is higher, is from 7:00 to 23:00, and the second time zone, where the electricity unit price is lower, is from 23:00 to 7:00 the following day. The first and second time zones are consecutive. Generally speaking, the amount and frequency of use of hot water stored in the hot water supply system 11 is higher during the first time zone, which is the time period excluding nighttime, and lower during the second time zone, which is the nighttime period.

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

[0022] The apartment complex 40 is a facility that comprises multiple dwelling units (i.e., multiple residences) and common areas 20, such as a condominium.

[0023] The number of dwelling units in a multi-unit housing complex 40 may be, for example, a dozen or so units, several dozen units, or several hundred units, but is not limited to these. Here, each of the multiple dwelling units is a private area 10 (i.e., a residence) for the resident, and for identification purposes, they may be described as the first private area 10a, the second private area 10b, the third private area 10c, the fourth private area 10d, and the fifth private area 10e. In addition, multiple dwelling units may include other private areas 10 besides the first to fifth private areas 10a to 10e. Furthermore, when there is no particular need for identification, each of the first to fifth private areas 10a to 10e may simply be described as private area 10.

[0024] Each of the multiple dwelling units is equipped with a hot water heater 11, electrical equipment 12, and a control device 13. In other words, each of the multiple hot water heaters 11 installed in the multiple dwellings is a hot water heater equipped in each of the multiple dwelling units, and more specifically, a storage-type hot water heater. For identification purposes, the hot water heaters 11 equipped in each of the 1st to 5th private units 10a to 10e are referred to as the 1st to 5th hot water heaters 11a to 11e. In other words, the multiple hot water heaters 11 include the 1st to 5th hot water heaters 11a to 11e. Also, when there is no particular need for identification, each of the 1st to 5th hot water heaters 11a to 11e may simply be referred to as hot water heater 11. Each of the multiple hot water heaters 11 communicates with each of the multiple control devices 13.

[0025] Since the electrical equipment 12 and control device 13 have similar functions in each of the multiple dwelling units, here we will describe the electrical equipment 12 and control device 13 installed in the first private unit 10a as an example.

[0026] Electrical equipment 12 refers to all electrical equipment in the first private unit 10a, excluding the first hot water supply system 11a. For example, electrical equipment 12 includes household appliances such as lighting fixtures and air conditioners in the first private unit 10a.

[0027] The control device 13 is a device for communicating with and controlling the first hot water supply unit 11a and electrical equipment 12 in the first private unit 10a. More specifically, the control device 13 is a so-called HEMS (Home Energy Management System) controller that communicates with the first hot water supply unit 11a and electrical equipment 12 and monitors or controls the operating status of the first hot water supply unit 11a and electrical equipment 12. For example, through communication, the control device 13 obtains the amount of hot water remaining in the hot water storage tank of the first hot water supply unit 11a (also called the amount of hot water stored). The control device 13 also communicates with the hot water supply system 100.

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

[0029] The target heating amount is the target amount of hot water remaining in the storage tank of the first hot water supply unit 11a when the hot water supply system 100 has finished heating the water in the first hot water supply unit 11a. Alternatively, the target heating amount may be the amount of hot water that the owner of the first private unit 10a plans to use. The control device 13 may determine the heating amount of the first hot water supply unit 11a by subtracting the acquired amount of hot water remaining in the storage tank of the first hot water supply unit 11a (more specifically, the amount of hot water stored before heating) from the target heating amount indicated by the received instruction.

[0030] Furthermore, the reception unit of the control device 13 receives an operation from the owner of the first private unit 10a to instruct the start time of use, which is the time when the hot water stored in the first hot water supply device 11a should be used.

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

[0032] Furthermore, the control device 13 outputs the dedicated power information regarding the power consumption of the electrical equipment 12 to the hot water supply system 100.

[0033] The private area power information includes information indicating the estimated power consumption based on the estimated usage of electrical equipment 12. This information indicating the estimated power consumption is based on the estimated usage of electrical equipment 12 for a predetermined time period on a given day (for example, the second time period). For example, at 22:00, which corresponds to the first time period on that day, the control device 13 predicts and determines the estimated power consumption for the second time period, which starts at 23:00 on that day, based on the past power consumption of electrical equipment 12 for that day. In this case, the control device 13 determines the estimated power consumption for electrical equipment 12 on that day as the average value of the power consumption of electrical equipment 12 in the second time period over a predetermined past period (for example, the period from the day before that day to the past week). The private area power information also includes information indicating the current power consumption of electrical equipment 12 during a predetermined time period on a given day (for example, the second time period). The control device 13 outputs this private area power information to the hot water supply system 100. Note that the predetermined time period on a given day is not limited to the second time period, but may also be the first time period.

[0034] The common areas 20 of the apartment building 40 are, for example, areas other than the multiple dwelling units (houses) of the apartment building 40, and are shared spaces such as corridors, rooftops, gardens, and stairwells.

[0035] The common area 20 is equipped with electrical equipment 21 and a power measuring device 22. For example, lighting, elevators, and water pumps are examples of electrical equipment 21. The power measuring 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 measuring device 22 outputs shared power information regarding the power consumption of electrical equipment 21 to the hot water supply system 100. The shared power information includes information indicating the expected power consumption based on the expected usage amount of electrical equipment 21. This information indicating the expected power consumption is based on the expected usage amount of electrical equipment 21 for a predetermined time period of a day (for example, the second time period). For example, at 22:00, which corresponds to the first time period of the day, the power measuring device 22 predicts and determines the expected power consumption for the second time period, which starts at 23:00 on that day, based on the past power consumption amount of electrical equipment 21 for that day. In this case, the power measuring device 22 determines the average value of the power consumption of electrical equipment 21 in the second time period over a predetermined past period (for example, the period from the day before the day to the past week) as the expected power consumption for electrical equipment 21 on that day. The shared power information also includes information indicating the power consumption of electrical equipment 21 at the present time during a predetermined time period of a day (for example, the second time period). The control device 13 outputs this shared power information to the hot water supply system 100. Note that the specified time period on a given day mentioned above is not limited to the second time period, but may also be the first time period.

[0037] Furthermore, power supply equipment 23 is installed in the common area 20, and for example, solar power generation equipment and charging equipment fall under the category of power supply equipment 23. In other words, in this embodiment, the apartment building 40 is equipped with power supply equipment 23, and power supply equipment 23 includes solar power generation equipment and charging equipment (for example, storage batteries and electric vehicles).

[0038] The electricity output from the power supply equipment 23 is supplied to multiple dwelling units (for example, multiple hot water heaters 11).

[0039] The power supply equipment 23 outputs power supply equipment information, such as the amount of power generated and the amount of charge, to the power measuring device 22, and the power measuring device 22 outputs the acquired power supply equipment information to the hot water supply system 100.

[0040] Here, we will describe the components of the hot water supply system 100.

[0041] As shown in Figure 1A, the hot water supply system 100 comprises a communication unit 110, an acquisition unit 120, a determination unit 130, a control unit 140, and a storage unit 150. The hot water supply system 100 is, for example, a personal computer, but it may also be a server device or the like.

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

[0043] The communication unit 110 acquires hot water supply information for each of the multiple hot water supply devices 11 from the respective control devices 13 of the multiple dwelling units. For example, the communication unit 110 acquires hot water supply information for the first hot water supply device 11a from the control device 13 of the first private unit 10a, and acquires hot water supply information for the second hot water supply device 11b from the control device 13 of the second private unit 10b.

[0044] Furthermore, the acquisition unit 120 is a processing unit that acquires multiple hot water supply information and the first standard power. More specifically, the acquisition unit 120 acquires the hot water supply information for each of the multiple hot water supply devices 11 acquired by the communication unit 110 and acquires the first standard power stored in the storage unit 150. This first standard power is the standard power for multiple residences (in this case, an apartment building 40) where multiple hot water supply devices 11 are installed, and is, for example, the standard power for the second time zone. The first standard power for the second time zone is the standard power stipulated in the high-voltage bulk power receiving contract, and is the first standard power for the apartment building 40 where multiple hot water supply devices 11 are installed. If the total power demand of the apartment building 40 exceeds the first standard power, a contract with a higher basic charge that increases the first standard power will be required for the current month and for 11 months from the following month.

[0045] The decision unit 130 determines a schedule based on the multiple hot water supply information acquired by the acquisition unit 120 and the first reference power acquired by the acquisition unit 120. The schedule shows the scheduled start time and scheduled end time for heating each of the multiple hot water supply devices 11. The schedule is, for example, the schedule for heating each of the multiple hot water supply devices 11 in the second time period. However, it is not limited to this, and the schedule may be, for example, the schedule for heating each of the multiple hot water supply devices 11 in the first, second, and third time periods. Furthermore, the schedule shows the power supply source that supplies the power required for heating each of the multiple hot water supply devices 11, and the power supply source is, for example, a power company and power supply equipment 23.

[0046] The control unit 140 is a processing unit that controls the heating of multiple hot water heaters 11 based on the schedule determined by the decision unit 130. Here, the control unit 140 causes the communication unit 110 to output a control signal to each of the multiple control devices 13 instructing that the heating of the multiple hot water heaters 11 be carried out according to the determined schedule.

[0047] As a result, each of the multiple control devices 13 controls each of the multiple hot water supply devices 11 according to the control signal output from the communication unit 110.

[0048] Each of the acquisition unit 120, the determination unit 130, and the control unit 140 is implemented, for example, by a microcomputer, but may also be implemented by a processor or dedicated circuitry. The functions of each of the acquisition unit 120, the determination unit 130, and the control unit 140 are realized by the execution of software stored in the storage unit 150 by the hardware, such as microcomputers, that constitute each of the acquisition unit 120, the determination unit 130, and the control unit 140.

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

[0050] Next, the operation of the hot water supply system 100 in this embodiment, configured as described above, will be explained.

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

[0052] As shown in Figure 2, steps S10, S20, S30, and S40 are processes performed in the first time zone, and step S90 is a process performed in the second time zone. Note that in the flowcharts shown in subsequent figures, the time zone in which each step is performed may be indicated.

[0053] In this example, the schedule is determined in the first time period and the heating of the multiple hot water heaters 11 is performed in the second time period, but this is not the only example. As described above, the hot water supply system 100 only needs to determine the schedule for heating the multiple hot water heaters 11 before the heating of the multiple hot water heaters 11 begins, and control the heating of the multiple hot water heaters 11 based on this determined schedule. For example, the schedule may be determined in the second time period and the heating of the multiple hot water heaters 11 may be performed in the first time period. Also, for example, in the example shown in Figure 1B(b), the schedule may be determined before a predetermined time period (for example, 12:00 to 14:00) begins, and the heating of the multiple hot water heaters 11 may be performed during that predetermined time period.

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

[0055] Furthermore, in step S10, the acquisition unit 120 may also acquire the target heating amount for each of the multiple hot water supply devices 11 and the remaining amount of hot water in the hot water storage tank, which have been acquired by the communication unit 110.

[0056] Step S10 corresponds to the acquisition step.

[0057] In addition, in the operation example 1, during the processing of step S10, the acquisition unit 120 acquires dedicated power information for the power consumption of electrical equipment 12 and shared power information for the power consumption of electrical equipment 21. More specifically, the communication unit 110 acquires dedicated power information from each of the multiple control devices 13 and shared power information from the power measuring device 22, and the acquisition unit 120 acquires the dedicated power information and shared power information acquired by the communication unit 110.

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

[0059] The second power usage refers to information that integrates the estimated power usage for electrical equipment 12 during the second time period as indicated by the private area power information, and the estimated power usage for electrical equipment 21 during the second time period as indicated by the shared area power information.

[0060] Thus, in Operation Example 1, the acquisition unit 120 acquires, in the process of step S10, the second power consumption corresponding to the expected power consumption of electrical equipment in the apartment building 40, excluding the multiple hot water heaters 11, during the second time period.

[0061] The decision unit 130 determines, based on the heating amounts included in the multiple hot water supply information acquired by the acquisition unit 120, whether the total power demand of the apartment building 40 will exceed the acquired first reference power if the multiple hot water supply devices 11 start heating simultaneously (S20). Here, the decision unit 130 determines whether the total power demand of the apartment building 40 will exceed the acquired first reference power if the multiple hot water supply devices 11 start heating simultaneously in the second time period. More specifically, the decision unit 130 makes the above determination based on the heating amounts included in the multiple hot water supply information and the acquired second power consumption (expected power consumption in the second time period).

[0062] Next, if the decision unit 130 determines that the power demand exceeds the first standard power (Yes in S20), the decision unit 130 determines the following schedule before the second time period, that is, in this case, during the first time period. The decision unit 130 determines a schedule in which the hot water heaters 11 will start heating in order of the hot water heater 11 with the earliest latest heating start time (S30). The latest heating start time is the latest time at which heating will start so that there is no shortage of hot water at the start time of use as indicated in the hot water supply information for that hot water heater 11. For example, if the start time of use for the first hot water heater 11a is 6:00 and the time required for heating is 3 hours, the latest heating start time for the first hot water heater 11a is 3:00. If, in this case, the start time for heating the first hot water supply unit 11a is determined to be 5:50, then there is a high probability that the amount of hot water remaining will not be sufficient at 6:00, the start time of use, and a hot water shortage (running out of hot water) will occur.

[0063] Steps S20 and S30 will be explained in more detail using Figure 3.

[0064] Figure 3 is a diagram showing the schedule for Operation Example 1 according to this embodiment. More specifically, Figure 3(a) shows the schedule when multiple hot water supply devices 11 (first to third hot water supply devices 11a to 11c) start heating simultaneously, and Figure 3(b) shows the schedule when the start of heating for the third hot water supply device 11c is delayed.

[0065] In Figure 3, the time from t0 to t1 corresponds to the second time zone, and the time from t1 onwards corresponds to the first time zone. In step S20, the determination unit 130 determines whether the power demand exceeds the first reference power when the heating of the multiple hot water heaters 11 is started at t0, which is the time when the second time zone begins. Power demand is the total power consumption of all the multiple hot water heaters 11, multiple electrical appliances 12, and electrical appliances 21 in the apartment building 40. The power consumption required to heat the water in the hot water heater 11 is proportional to the amount of water heated by the hot water heater 11. Also, the less water heated, the shorter the time required to heat the water in the hot water heater 11.

[0066] In the schedule shown in Figure 3(a), the power demand exceeds the first reference power, and the decision unit 130 determines that the power demand exceeds the first reference power.

[0067] Furthermore, in the schedule shown in Figure 3, the latest start time for heating the first hot water supply unit 11a is t11, the latest start time for heating the second hot water supply unit 11b is t12, and the latest start time for heating the third hot water supply unit 11c is t13. t11 is earlier than t12 and t13, and t12 is earlier than t13.

[0068] In such cases, the decision unit 130 determines a schedule (shown in Figure 3(b)) that advances the start of heating for the first and second hot water supply units 11a and 11b, which have an earlier latest heating time than the third hot water supply unit 11c, among the first to third hot water supply units 11a to 11c. In other words, the decision unit 130 determines a schedule that delays the start of heating for the third hot water supply unit 11c, which has an even later latest heating time than the first to third hot water supply units 11a to 11c. At this time, the decision unit 130 determines the schedule so that the demand power in the second time period does not exceed the first standard power.

[0069] In Figure 3(b), the heating of the first and second hot water supply units 11a and 11b starts simultaneously at time t0, when the second time period begins, but this is not the only case. Let's consider the case where the power demand exceeds the first standard power when the heating of the first and second hot water supply units 11a and 11b starts simultaneously. In this case, the decision unit 130 determines a schedule that starts heating earlier for the first hot water supply unit 11a, which has an earlier latest heating time than the second hot water supply unit 11b.

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

[0071] Steps S20 and S30 correspond to the decision steps.

[0072] Furthermore, if the decision unit 130 determines that the power demand does not exceed the first standard power (No in S20), the decision unit 130 determines the following schedule before the second time period, that is, in this case, during the first time period. The decision unit 130 determines a schedule in which multiple hot water heaters 11 start heating simultaneously (step S40).

[0073] Furthermore, the control unit 140 controls the heating of the multiple hot water heaters 11 based on the schedule determined by the determination unit 130 in step S30 or S40 (S90). Here, the control unit 140 controls the heating of the multiple hot water heaters 11 in the second time period based on the determined schedule. More specifically, the control unit 140 controls the communication unit 110 to output a control signal to each of the multiple control devices 13 instructing that the heating of the multiple hot water heaters 11 be carried out as indicated by the determined schedule. As a result, each of the multiple control devices 13 controls each of the multiple hot water heaters 11 based on the control signal obtained from the communication unit 110. For example, the control device 13 of the first occupied unit 10a sets the time t0 shown in Figure 3(b) as the start time for heating the first hot water heater 11a and performs heating of the first hot water heater 11a. For example, the control device 13 of the second private unit 10b sets the time t0 shown in Figure 3(b) as the start time for heating the second hot water supply unit 11b and performs heating of the second hot water supply unit 11b. For example, the control device 13 of the third private unit 10c sets the time t13 shown in Figure 3(b) as the start time for heating the third hot water supply unit 11c and performs heating of the third hot water supply unit 11c. Step S90 corresponds to the control step.

[0074] Thus, if the decision unit 130 determines that the power demand exceeds the first standard power during the first time period (Yes in S20), the decision unit 130 determines the following schedule. The decision unit 130 determines a schedule in which the hot water heating will start in order of the hot water heating equipment 11 with the earliest latest heating start time among the multiple hot water heating equipment 11.

[0075] As a result, in Operation Example 1, a hot water supply system 100 is realized that can suppress the overall power demand (more specifically, the maximum power demand) of the apartment building 40. For example, as shown in Figure 3(b), the maximum power demand is prevented from exceeding the first standard power. Therefore, the basic charges for the apartment building 40 are less likely to increase.

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

[0077] In this way, the decision unit 130 prioritizes the hot water supply unit 11 (in this case, the second hot water supply unit 11b) which has a short time window for changing the start time of heating, when determining the heating schedule, making it less likely for the second hot water supply unit 11b to run out of hot water.

[0078] Furthermore, the more detailed processing in step S30 will be explained here using Figures 4 and 5.

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

[0080] In Figures 4 and 5, the latest start time for heating water in the first hot water supply unit 11a is t11, the latest start time for heating water in the second hot water supply unit 11b is t12, and the latest start time for heating water in the third hot water supply unit 11c is t13. t11 is earlier than t12 and t13, while t12 and t13 are the same time.

[0081] As shown in Figure 4, in step S30, the determination unit 130 determines a schedule in which the hot water heating will start in the order of the hot water heating devices 11 with the latest heating start time among the multiple hot water heating devices 11.

[0082] More specifically, the determination unit 130 determines whether there are two hot water heaters 11 among the multiple hot water heaters 11 whose latest heating start times are the same (S30a).

[0083] If there are two hot water heaters 11 with the same latest start time for heating (Yes in step S30a), the determination unit 130 determines the following schedule. In this case, the determination unit 130 determines a schedule in which the two hot water heaters 11 will start heating in the order of the hot water heater 11 whose hot water supply information contains the largest amount of heating (S30b).

[0084] Steps S30a and S30b will be explained in more detail using Figure 5.

[0085] As described above, t11 is earlier than t12 and t13. Therefore, the determination unit 130 first determines a schedule that starts heating earlier for the first hot water supply unit 11a, which has an earlier latest heating time than the second and third hot water supply units 11b and 11c, among the first to third hot water supply units 11a to 11c.

[0086] Then, t12 and t13 are the same time. Here, the amount of water heated, as included in the hot water supply information for the third hot water supply unit 11c, is greater than the amount of water heated, as included in the hot water supply information for the second hot water supply unit 11b. For this reason, the decision unit 130 determines a schedule (shown in Figure 5(b)) that starts heating earlier for the third hot water supply unit 11c, which has a larger amount of water heated than the second hot water supply unit 11b, among the second and third hot water supply units 11b and 11c.

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

[0088] The more a hot water heater 11 has a high heating capacity, the longer it takes to heat the water. In the operation example 1 shown in Figures 4 and 5, the schedule is set so that a hot water heater 11 with a high heating capacity (for example, the third hot water heater 11c) is prioritized for heating, making it less likely for that hot water heater 11 to run out of hot water. In addition, by having the hot water heater 11 with a high heating capacity heat water during a time when the electricity rate is lower (second time zone), the effect of reducing electricity costs is greater compared to when the hot water heater 11 heats water during the first time zone. For this reason, by setting the schedule so that a hot water heater 11 with a high heating capacity is prioritized for heating, the electricity costs paid by the owner of that hot water heater 11 will be lower.

[0089] Alternatively, Example 1 of operation may be as follows:

[0090] The heating amounts of the first to fifth hot water supply units 11a to 11e may differ from each other, and the start times for using the first to fifth hot water supply units 11a to 11e may also differ from each other. In other words, each owner of the first to fifth private units 10a to 10e can set their preferred values ​​by operating the reception unit of the control device 13.

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

[0092] For example, the manager of the hot water supply system 100 may obtain information on the amount of hot water heated and the start time of use by conducting a questionnaire about hot water usage with the owners of each of the first to fifth private units 10a to 10e. The manager can then control an information terminal such as a smartphone, tablet, or personal computer to transmit the information on the amount of hot water heated and the start time of use to the communication unit 110 of the hot water supply system 100. The acquisition unit 120 of the hot water supply system 100 may acquire the information on the amount of hot water heated and the start time of use and determine this as the amount of hot water heated and the start time of use for each of the first to fifth hot water supply devices 11a to 11e. The questionnaire will ask the owners about the type of hot water usage activity (bathing, showering, or other household chores), the amount of hot water used for each type, and the timing of the activity for each season in the first to fifth private units 10a to 10e.

[0093] For example, the hot water supply information for the first to fifth hot water supply devices 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, for example, the amount of water heated and the start time of use for a predetermined period in the past for the first hot water supply device 11a as past usage data. The predetermined period in the past is, for example, the period from the day before the day in question to one week prior, 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 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 times of use over the predetermined period 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 lifestyle schedule information obtained from the information terminals of the owners of the first to fifth private units 10a to 10e. If the owner is using a schedule management app on a smartphone, which is an example of an information terminal, the control device 13 may obtain lifestyle schedule information from the information terminal that shows the owner's daily lifestyle schedule. 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 lifestyle schedule information. In addition, the information terminal may receive an operation from the owner to specify the target amount of water to be heated and the start time of use, and the information terminal may output information specifying the target amount of water to be heated and the start time of use to the control device 13. The hot water supply information may be determined in this way.

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

[0096] In Operation Example 2, three different time zones (1st to 3rd time zones) with varying electricity rates are provided, and an example is described in which the schedule for heating water for one hot water supply unit 11 (here, the 1st hot water supply unit 11a) is determined.

[0097] As shown in Figure 6, first, the process of step S10 is performed, similar to Figure 2.

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

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

[0100] In addition, in Operation Example 2, the second time zone is from 11 PM to 7 AM the following day, the first time zone is from 7 AM to 12 PM, and the third time zone is from 12 PM to 11 PM. The second, first, and third time zones are consecutive time periods.

[0101] The decision unit 130 determines a schedule based on the first and second electricity rates acquired by the acquisition unit 120, so as to reduce the electricity cost for heating water for each of the multiple hot water heaters 11. In this example of operation, the schedule is determined based on the first to third electricity rates acquired by the acquisition unit 120 so as to reduce the electricity cost for heating water for the first hot water heater 11a (S31).

[0102] Step S31 will be explained in more detail using Figure 7.

[0103] As described above, the second electricity rate is cheaper than the first electricity rate, and the first electricity rate is cheaper than the third electricity rate. Therefore, the decision unit 130 determines the schedule so that the first hot water supply unit 11a is heated during the second time period when the electricity rate is cheapest. Furthermore, as shown in Figure 7, if the heating of the first hot water supply unit 11a is not completed within the second time period, the decision unit 130 determines the schedule so that the remaining heating is heated during the first time period when the electricity rate is the second cheapest.

[0104] Then, the process in step S90 is performed, similar to that in Figure 2.

[0105] In Operation Example 2, the water heating of the hot water heater 11 (for example, the first hot water heater 11a) is performed during times when the unit price of electricity is lower, so the electricity charges paid by the owner of the hot water heater 11 can be kept low.

[0106] [Example of operation 3] Figure 8 is a flowchart of operation example 3 according to this embodiment. Figure 9 is a diagram showing the schedule of operation example 3 according to this embodiment. Figure 9(a) shows a schedule in which the first hot water supply device 11a is heated in a second time period that starts earlier, and Figure 9(b) shows a schedule in which the first hot water supply device 11a is heated in a second time period that starts later.

[0107] In Operation Example 3, two time zones (the first and second time zones) with different electricity rates are provided, and an example is described in which the schedule for heating water for one hot water heater 11 (here, the first hot water heater 11a) is determined. In this operation example, two second time zones are provided per day, meaning there are multiple second time zones. For identification purposes, the second time zone that starts earlier as shown in Figure 9 will be referred to as Second Time Zone A, and the second time zone that starts later will be referred to as Second Time Zone B.

[0108] As shown in Figure 8, first, the process in step S10 is performed, similar to Figure 2.

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

[0110] Similar to Operation Example 2, the first electricity unit price is Y yen / kWh, and the second electricity unit price is X yen / kWh. Also, the second electricity unit price is cheaper than the first electricity unit price.

[0111] The decision unit 130 determines the following schedule based on the first and second electricity rates acquired by the acquisition unit 120 and the start time of use included in each of the multiple hot water supply information acquired by the acquisition unit 120. The decision unit 130 determines the schedule so that the electricity cost for heating each of the multiple hot water supply devices 11 is reduced, and so that the time difference between the first scheduled completion time, which is the scheduled time when heating each of the multiple hot water supply devices 11 is expected to be completed, and the start time of use is reduced (S32). In this example of operation, the decision unit 130 determines the schedule based on the first and second electricity rates and the start time of use so that the electricity cost for heating the first hot water supply device 11a is reduced, and so that the time difference between the first scheduled completion time and the start time of use is reduced. In this way, the decision unit 130 determines the schedule so that the time difference between the first scheduled completion time and the start time of use is reduced, but more specifically, it determines the schedule so that the time difference is within a predetermined time. The specified time can be any time between 30 minutes and 8 hours, for example, and may be a time predetermined by the administrator of the hot water supply system 100.

[0112] Step S32 will be explained in more detail using Figure 9.

[0113] As described above, the second electricity rate is lower than the first electricity rate, so the decision unit 130 determines the schedule so that the first hot water supply unit 11a heats up during the second time period when the electricity rate is lowest. Furthermore, if the heating of the first hot water supply unit 11a is not completed within the second time period, the decision unit 130 determines the schedule so that the remaining heating is done during the first time period when the electricity rate is the second lowest. As a result, as shown in Figures 9(a) and 9(b), there are two possible schedules that can be determined.

[0114] Furthermore, in this example, as shown in Figure 9, the time when the owner starts using the hot water is the time when the second time zone B, which starts later, ends. The first scheduled completion time is the time when the water heating of the hot water supply device 11 (in this case, the first hot water supply device 11a) is completed in that schedule. In the example shown in Figure 9(a), the first scheduled completion time is included in the first time zone, and in the example shown in Figure 9(b), the first scheduled completion time is the time when the second time zone B ends and is included in the second time zone B.

[0115] The decision unit 130 then determines a schedule for the first hot water supply unit 11a such that the time difference between the first scheduled completion time and the start time of use is minimized. The time difference between the first scheduled completion time and the start time of use in the schedule shown in Figure 9(b) is shorter than the time difference between the first scheduled completion time and the start time of use in the schedule shown in Figure 9(a). Therefore, the decision unit 130 determines the schedule shown in Figure 9(b) as a schedule that reduces the electricity cost for heating water with the first hot water supply unit 11a and minimizes the time difference between the first scheduled completion time and the start time of use.

[0116] Then, the process in step S90 is performed.

[0117] In Operation Example 3, the water heating of the hot water heater 11 (for example, the first hot water heater 11a) is performed during times when the unit price of electricity is lower, so the electricity charges paid by the owner of the hot water heater 11 can be kept low.

[0118] Furthermore, as shown in Figure 9(a), if the time between the first scheduled completion time and the start time of use is long, the problem arises that the heated water will cool down. However, in operation example 3, as shown in Figure 9(b), the time difference between the first scheduled completion time and the start time of use is short, so the above problem is less likely to occur.

[0119] [Example of operation 4] Figure 10 is a flowchart of operation example 4 according to this embodiment. Figure 11 is a diagram showing the schedule of operation example 4 according to this embodiment.

[0120] Operation Example 4 is an operation that occurs, for example, in step S90 of Operation Example 1, when the control unit 140 controls the heating of multiple hot water supply devices 11 (first and second hot water supply devices 11a and 11b) in the second time period based on the determined schedule. More specifically, it is an operation that occurs while the heating of the first and second hot water supply devices 11a and 11b is in progress.

[0121] As described above, in Operation Example 1, the acquisition unit 120 acquires the second power consumption, which corresponds to the expected power consumption of electrical equipment in the apartment building 40, excluding the multiple hot water heaters 11, during the second time period. However, it is also conceivable that power consumption may exceed the expected amount. Operation Example 4 is an operation that assumes that in step S90, when the multiple hot water heaters 11 are heating water, the power consumption of electrical equipment in the apartment building 40, excluding the multiple hot water heaters 11, exceeds the expected power consumption.

[0122] The acquisition unit 120 acquires the current first power consumption of electrical equipment in the apartment building 40, excluding the multiple 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, the acquisition unit 120 acquires private area power information regarding the power consumption of electrical equipment 12 and shared area power information regarding the power consumption of electrical equipment 21 via the communication unit 110. As described above, in this embodiment, electrical equipment excluding the multiple hot water heaters 11 consists of all of the multiple electrical equipment 12 in multiple dwelling units and the electrical equipment 21 in the shared area 20. The first power consumption is information that integrates the power consumption of electrical equipment 12 at the present time (second time zone) as indicated by the private area power consumption information and the power consumption of electrical equipment 21 at the present time (second time zone) as indicated by the shared area power consumption information.

[0124] In other words, by acquiring power information for private units and power information for shared units, the acquisition unit 120 acquires the current first power consumption of electrical equipment in the apartment building 40, excluding the multiple water heaters 11, during the second time period. Furthermore, the first power consumption can be said to be the measured power consumption of electrical equipment excluding the multiple water heaters 11 at the present time (second time period).

[0125] Next, the decision unit 130 determines, based on the amount of water heated and the acquired first power consumption, whether the total power demand of the apartment building 40 at the present time (second time zone) exceeds the acquired first reference power (S23). In other words, 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 the water heating devices 11 is delayed in step S30 of operation example 1. To put it another way, after the second time zone has started (in step S23), the decision unit 130 predicts and determines whether the power demand will exceed the reference power based on the first power consumption, which is the measured power of electrical equipment excluding the multiple water heating devices 11.

[0126] Furthermore, if it is determined that the power demand in the second time period exceeds the first standard power (Yes in step S23), the decision unit 130 updates the schedule based on the determined schedule as follows: That is, the decision unit 130 updates the schedule determined in step S30 to stop heating the hot water supply unit 11 that has the largest time difference between the second scheduled completion time and the third scheduled completion time (S33). The second scheduled completion time is the scheduled time when heating will be completed as indicated by the schedule determined in step S30. The third scheduled completion time is the scheduled time when heating will be completed if heating is started at the latest scheduled start time.

[0127] The process in step S33 will be explained using Figure 11.

[0128] Figure 11(a) shows the schedule when it is determined that the power demand exceeds the first reference power. For example, as shown in Figure 11(a), at the current time t2 (present time), the first power consumption for electrical equipment excluding the multiple hot water heaters 11 is acquired, and it is determined that the power demand exceeds the first reference power in the second time period (more specifically, from time t2 onwards). In such a case, the decision unit 130 updates the schedule to stop heating the water for the hot water heater 11 among the multiple hot water heaters 11 that has the largest time difference between the second scheduled completion time and the third scheduled completion time.

[0129] Here, we will explain the second and third scheduled completion times in more detail.

[0130] The second scheduled completion time is the scheduled time when the water heating of the hot water supply unit 11 will be completed, as indicated by the schedule determined in step S30, for example. For example, in Figure 11(a), the second scheduled completion time for the first hot water supply unit 11a is t21, and the second scheduled completion time for the second hot water supply unit 11b is t22. t21 and t22 are the same time.

[0131] The third scheduled completion time is the scheduled time when the water heating of the hot water supply unit 11 is scheduled to be completed, assuming that the heating process begins at the latest scheduled start time. For example, in Figure 11(a), the third scheduled completion time for the first hot water supply unit 11a is shown to be t31, and the third scheduled completion time for the second hot water supply unit 11b is shown to be t32. t31 is earlier than t32.

[0132] In step S33, the decision unit 130 updates the schedule to stop heating the water from the hot water heater 11 (here, the first and second hot water heaters 11a and 11b) that has the largest time difference between its second scheduled completion time and its third scheduled completion time. As shown in Figure 11(a), the time difference between the second scheduled completion time and the third scheduled completion time of the second hot water heater 11b is greater than the time difference between the second scheduled completion time and the third scheduled completion time of the first hot water heater 11a. Therefore, the decision unit 130 updates the schedule to stop heating the water from the second hot water heater 11b among the first and second hot water heaters 11a and 11b. More specifically, at the current time t2, the decision unit 130 updates the schedule to stop heating the water from the second hot water heater 11b.

[0133] Figure 11(b) shows a schedule in which the heating of the second hot water supply unit 11b is stopped, that is, a diagram showing the updated schedule. Note that the example shown in Figure 11(b) is not the only example, and in this embodiment, heating of multiple hot water supply units 11 may be stopped. In addition, the first power consumption is acquired at regular intervals (for example, every 5 minutes), and if there is a period after t21 in which the first power consumption decreases, the schedule may be updated so that heating of the second hot water supply unit 11b is started again.

[0134] Compared to a hot water heater 11 with a small time difference between the second scheduled completion time and the third scheduled completion time, a hot water heater 11 with a large time difference has a longer time between the time the heating is stopped and the scheduled time of use, even if the heating is stopped once. Therefore, compared to a hot water heater 11 with a small time difference, a hot water heater 11 with a large time difference is more likely to complete heating by the start time of use, even if the heating is stopped once, as heating will be restarted. For this reason, by updating the schedule so that the heating of the hot water heater 11 with a large time difference (for example, the second hot water heater 11b) is stopped, it becomes less likely that the hot water will run out for both the hot water heater 11 with a small time difference and the hot water heater 11 with a large time difference.

[0135] Furthermore, the control unit 140 controls the heating of the multiple hot water supply units 11 during the second time period based on the schedule updated by the determination unit 130 in step S33 (S53a).

[0136] Furthermore, if it is determined that the power demand in the second time period does not exceed the first standard power (No in step S23), the control unit 140 performs the following processing. In this case, the control unit 140 controls the heating of the multiple hot water supply devices 11 in the second time period based on the schedule determined by the determination unit 130 in step S30 (S53b).

[0137] In operation example 4, if the power demand exceeds the first reference power during the second time period, the hot water supply system 100 updates the schedule to stop heating the hot water supply device 11 (second hot water supply device 11b), thereby preventing the power demand from exceeding the first reference power. In other words, a hot water supply system 100 is realized that can suppress the overall power demand of the apartment building 40 (more specifically, the maximum value of the power demand). Furthermore, as described above, by updating the schedule so that the hot water supply device 11 stops heating the hot water supply device 11 where the time difference between the second scheduled completion time and the third scheduled completion time is large, it becomes less likely for the hot water supply device 11 with a small time difference and the hot water supply device 11 with a large time difference to run out of hot water.

[0138] In example 4, the schedule was updated in the second time zone, but this is not limited to that. For example, the schedule may be updated in the first time zone, and the heating of multiple hot water heaters 11 may be controlled during the first time zone. Also, for example, in the example shown in Figure 1B(b), the schedule may be updated in a predetermined time zone (for example, from 12:00 to 14:00), and the heating of multiple hot water heaters 11 may be controlled during that predetermined time zone.

[0139] [Example of operation 5] Figure 12 is a flowchart of operation example 5 according to this embodiment. Figure 13 is a diagram showing the schedule of operation example 5 according to this embodiment.

[0140] Operation Example 5 is an operation that occurs, for example, in step S90 of Operation Example 1, when the control unit 140 controls the heating of two or more hot water supply devices 11 (first and second hot water supply devices 11a and 11b) in the second time period based on the determined schedule. More specifically, it is an operation that occurs while the heating of the first and second hot water supply devices 11a and 11b is in progress.

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

[0142] The acquisition unit 120 acquires the current first power consumption of electrical equipment in the apartment building 40, excluding the multiple water heaters 11, during the second time period (step S13). As described above, the first power consumption can also be said to be the measured power consumption of electrical equipment excluding the multiple water heaters 11 at the present time (second time period).

[0143] Furthermore, the acquisition unit 120 acquires a boiling instruction that instructs the boiling of a hot water supply unit 11 other than the two or more hot water supply units 11 (first and second hot water supply units 11a and 11b) (S14). Here, the other hot water supply unit 11 is assumed to be the third hot water supply unit 11c. The boiling instruction indicates the boiling amount of the said hot water supply unit 11 (in this case, the third hot water supply unit 11c).

[0144] For example, when the information processing device receives an operation from the owner of the third hot water supply unit 11c (i.e., the owner of the third private unit 10c), the acquisition unit 120 should acquire the instruction to heat the water. 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 the third hot water supply unit 11c wishes to use hot water, they operate the reception unit of the control device 13, which is an example of an information processing device. In other words, the reception unit receives an operation to instruct the third hot water supply unit 11c to heat the water. As a result, the control device 13 outputs a heating instruction to the communication unit 110 according to the received operation. The acquisition unit 120 acquires the heating instruction acquired by the communication unit 110.

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

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

[0148] The decision unit 130 determines whether the total power demand of the apartment building 40 at the present time (second time zone) exceeds the acquired first standard power, based on the amount of water heated included in the hot water supply information for two or more hot water supply devices 11, the acquired first power consumption, and the acquired water heating instructions (S24). In other words, the decision unit 130 makes the above determination based on the amount of water heated by the first and second hot water supply devices 11a and 11b, the first power consumption, and the amount of water heated by the third hot water supply device 11c included in the water heating instructions.

[0149] If it is determined that the power demand exceeds the first reference power during the second time period (Yes in step S24), the decision unit 130 updates the schedule as follows, based on the schedule determined in step S30 and the heating instructions obtained in step S14. Specifically, the decision unit 130 updates the schedule to stop heating the hot water supply unit 11 with the largest time difference between the second scheduled completion time and the third scheduled completion time among the two or more hot water supply units 11, and to start heating the other hot water supply units 11 (S34a). In this example, the decision unit 130 updates the schedule to stop heating the hot water supply unit 11 with the largest time difference between the second scheduled completion time and the third scheduled completion time among the first and second hot water supply units 11a and 11b, and to start heating the third hot water supply unit 11c.

[0150] The processes in steps S24 and S34a will be explained using Figure 13.

[0151] Figure 13(a) shows the schedule determined in step S30. Figure 13(b) shows the schedule in which the first and second hot water supply systems 11a and 11b shown in Figure 13(a) are heated, with the heating of the third hot water supply system 11c added. The schedule shown in Figure 13(b) shows the schedule when it is determined that the power demand exceeds the first standard power. For example, as shown in Figure 13(b), at the current time t2 (current time), the first power consumption for electrical equipment excluding the multiple hot water supply systems 11 and the heating instruction for the third hot water supply system 11c are obtained. At this time, it is determined that the power demand exceeds the first standard power in the second time period (more specifically, from time t2 onwards). In such cases, the decision unit 130 updates the schedule to stop heating the water from the water heater 11 with the largest time difference between the second scheduled completion time and the third scheduled completion time among the two or more water heaters 11, and to start heating the water from the other water heaters 11.

[0152] In step S34a, the decision unit 130 updates the schedule to stop heating the water from the hot water heater 11 (here, the first and second hot water heaters 11a and 11b) that has the largest time difference between the second scheduled completion time and the third scheduled completion time. As shown in Figure 13(b), the time difference between the second scheduled completion time and the third scheduled completion time of the second hot water heater 11b is greater than the time difference between the second scheduled completion time and the third scheduled completion time of the first hot water heater 11a. Therefore, the decision unit 130 updates the schedule to stop heating the water from the second hot water heater 11b (of the first and second hot water heaters 11a and 11b).

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

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

[0155] Furthermore, in step S34a, the decision unit 130 updates the schedule to start heating the other hot water supply unit 11 (third hot water supply unit 11c). More specifically, the decision unit 130 updates the schedule so that heating of the third hot water supply unit 11c starts from time t2 or later. It is preferable for the decision unit 130 to update the schedule so that heating of the third hot water supply unit 11c starts at an earlier time after time t2 (for example, within a few minutes of time t2).

[0156] Figure 13(c) shows a schedule in which the heating of the second hot water supply unit 11b is stopped and the heating of the third hot water supply unit 11c is started; in other words, it shows the updated schedule. As shown in Figure 13(c), the heating of the second hot water supply unit 11b, which has been stopped, may be restarted after the heating of the third hot water supply unit 11c has finished.

[0157] Furthermore, the control unit 140 controls the heating of the multiple hot water supply units 11 during the second time period based on the schedule updated by the determination unit 130 in step S34a (S54a).

[0158] If it is determined that the power demand in the second time period does not exceed the first standard power (No in step S24), the decision unit 130 updates the schedule as follows, based on the schedule determined in step S30 and the heating instructions obtained in step S14. That is, the decision unit 130 updates the schedule to start heating the other hot water supply devices 11 (S34b). The decision unit 130 updates the schedule so that the heating of the third hot water supply device 11c is added to the schedule for heating the first and second hot water supply devices 11a and 11b shown in Figure 13(a).

[0159] Next, the control unit 140 controls the heating of the multiple hot water supply units 11 during the second time period based on the schedule updated by the determination unit 130 in step S34b (S54b).

[0160] In Operation Example 5, if the hot water supply system 100 receives a heating instruction from another hot water supply device 11 (third hot water supply device 11c) during the second time period, it performs the following process: The hot water supply system 100 updates the schedule to start heating the other hot water supply device 11. This allows the hot water supply system 100 to heat the other hot water supply device 11.

[0161] In operation examples 4 and 5, the heating of the second hot water supply unit 11b was stopped because the time difference between the second scheduled completion time and the third scheduled completion time was greater than that of the multiple hot water supply units 11 (first and second hot water supply units 11a and 11b), but this is not limited to this example.

[0162] For example, the administrator of the hot water supply system 100 may obtain information on the stopping of water heating for multiple owners by conducting a questionnaire regarding the stopping of water heating for each owner of the first to fifth private units 10a to 10e. The administrator transmits the information on the stopping of water heating to the communication unit 110 of the hot water supply system 100 by controlling an information terminal such as a smartphone, tablet, or personal computer. The acquisition unit 120 of the hot water supply system 100 acquires the information on the stopping of water heating. As explained in Operation Example 4 and Operation Example 5, the questionnaire asks the owner whether it is permissible to stop the heating of their hot water supply unit 11 when the total power demand of the apartment building 40 exceeds the acquired first standard power. The information on the stopping of water heating for one owner indicates whether it is permissible for that owner to stop the heating of the hot water supply unit 11 they own.

[0163] For example, suppose the information regarding the owner of the first hot water supply unit 11a indicating that it is permissible to stop the heating of the first hot water supply unit 11a. Conversely, suppose the information regarding the owner of the second hot water supply unit 11b indicating that it is not permissible to stop the heating of the second hot water supply unit 11b.

[0164] In such cases, in step S33 of Operation Example 4 and step S34a of Operation Example 5, the decision unit 130 performs the following processing. That is, based on the information of the owners of the first hot water supply unit 11a and the second hot water supply unit 11b regarding the stopping of water heating, the decision unit 130 updates the schedule to stop the water heating of the first hot water supply unit 11a. In other words, if the owner agrees to stop the water heating, the water heating of the owner's hot water supply unit 11 is stopped. If the owner does not agree to stop the water heating, the water heating of the owner's hot water supply unit 11 is not stopped. In other words, the decision unit 130 updates the schedule according to the owner's wishes.

[0165] Furthermore, in operation examples 4 and 5, the stopping of the water heating of the water heater 11 may result in the water heating of the water heater 11 being carried out during a time period with a higher electricity rate (for example, the first time period). As a result, the electricity charges paid by the owner of the water heater 11 will be higher than when the water heating of the water heater 11 is carried out during a time period with a lower electricity rate. In such cases, the display unit of the water heater system 100 will display the difference between the electricity charges when the water heating of the water heater 11 is carried out during a time period with a lower electricity rate and when it is carried out during a time period with a higher electricity rate. By paying the displayed amount to the owner, the manager of the water heater system 100 can increase the owner's willingness to cooperate with the stopping of water heating.

[0166] Furthermore, there are cases where the heating of one hot water heater 11 is stopped and then operated during a period with a higher electricity rate, and this occurs for a predetermined period (for example, two days). This is especially likely to occur during the winter months when hot water demand increases.

[0167] When this case occurs, the following measures should be taken to reduce the electricity bill paid by all owners of the apartment building 40. Specifically, when this case occurs, the hot water system 100 assumes that the water heating of the hot water heater 11 will be performed during the time period with a higher electricity rate for the entire season (e.g., winter) including the specified period. The hot water system 100 compares the amount of the difference if it occurs throughout the entire season with the increase in the electricity bill for the current year if the water heating of the hot water heater 11 is not stopped and the demand power exceeds the first standard power, resulting in a contract with a higher basic charge for the current month and the following 11 months. If the hot water system 100 determines that the increase is lower, it allows the demand power to exceed the first standard power and changes the first standard power from that date onward to a higher first standard power. In other words, from that date onward, the hot water system 100 will determine the schedule based on the changed higher first standard power.

[0168] The specified period is not limited to two days; it could be several days, a week, or a month.

[0169] In example 5, the schedule was updated in the second time zone, but this is not limited to that. For example, the schedule may be updated in the first time zone, and the heating of multiple hot water heaters 11 may be controlled during the first time zone. Also, for example, in the example shown in Figure 1B(b), the schedule may be updated in a predetermined time zone (for example, from 12:00 to 14:00), and the heating of multiple hot water heaters 11 may be controlled during that predetermined time zone.

[0170] [Example of operation 6] Figure 14 is a flowchart of operation example 6 according to this embodiment. Figure 15 is a diagram showing the schedule of operation example 6 according to this embodiment.

[0171] Operation Example 6 is an operation in which, for example, in step S30 of Operation Example 1, after the decision unit 130 has determined the schedule, the decision unit 130 reviews the determined schedule and makes a new decision.

[0172] In Operation Example 6, two time zones (the first and second time zones) with different electricity rates are provided, and an example is described in which the schedule for heating water for one hot water heater 11 (here, the first hot water heater 11a) is determined. In this operation example, two second time zones are provided per day, meaning there are multiple second time zones. For identification purposes, the second time zone that starts earlier as shown in Figure 15 will be referred to as Second Time Zone A, and the second time zone that starts later will be referred to as Second Time Zone B.

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

[0174] The standard time can be any time, such as 30 minutes or more and 8 hours or less, and may be a time predetermined by the administrator of the hot water supply system 100.

[0175] Furthermore, if it is determined that there is a first target hot water supply unit for which the time from the second scheduled completion time to the start time of use exceeds the standard time (Yes in step S60), the decision unit 130 performs the following processing. That is, the decision unit 130 performs heating of the first target hot water supply unit in the second time period, stops it once, and then starts heating again, and then re-determines the schedule so that heating of the first target hot water supply unit is completed by the start time of use (S70).

[0176] The processes in steps S60 and S70 will be explained using Figure 15.

[0177] Figure 15(a) shows the schedule when it is determined that there is a first target hot water supply unit (in this case, the first hot water supply unit 11a) where the time from the second scheduled completion time to the start time of use exceeds the standard time. Also, Figure 15(a) shows the schedule determined in step S30 of operation example 1, for example.

[0178] For example, as shown in Figure 15(a), if the time from the second scheduled completion time to the start of use time exceeds the standard time, that is, if the time from the second scheduled completion time to the start of use time is long, the problem arises that the heated water will cool down. Therefore, the decision unit 130 re-determines the schedule so that the first target hot water supply device is stopped after heating in the second time period (in this case, second time period A), and then heated again in the second time period (in this case, second time period B). At this time, the decision unit 130 re-determines the schedule so that the time from the time when the heating of the first target hot water supply device is completed by heating again to the scheduled time of use is less than the standard time.

[0179] Figure 15(b) shows a schedule in which the heating of the first hot water supply unit 11a is temporarily stopped and then restarted; in other words, it shows the newly determined schedule. Note that the example shown in Figure 15(b) is not the only example, and in this example of operation, if there are multiple first target hot water supply units, the determination unit 130 performs the following process. That is, the determination unit 130 may temporarily stop heating the water of multiple first target hot water supply units and then restart the heating, and then determine the schedule again so that heating of multiple first target hot water supply units is completed by the start time of use.

[0180] Furthermore, the control unit 140 controls the heating of the multiple hot water supply units 11 during the second time period based on the schedule determined again by the determination unit 130 in step S70 (S90).

[0181] Furthermore, if it is determined that there are no first target hot water supply units for which the time from the second scheduled completion time to the start time of use exceeds the standard time (No in step S60), the control unit 140 performs the following processing. In this case, the control unit 140 controls the heating of the multiple hot water supply units 11 during the second time period based on the schedule determined by the determination unit 130 in step S30 (S90).

[0182] Furthermore, as shown in Figure 15, in this example of operation, the schedule determined in step S30 includes the second scheduled completion time in the first time zone. In this schedule, the electricity bill will increase compared to the case where the heating of the first target hot water supply device (first hot water supply device 11a) is completed only in the second time zone.

[0183] Therefore, if the second scheduled completion time is included in the first time zone, the decision unit 130 should re-determine the schedule so that the heating of the first target hot water supply device (first hot water supply device 11a) is completed only in the second time zone. Specifically, as shown in Figure 15(b), if the heating of the first target hot water supply device (first hot water supply device 11a) is not completed only in the second time zone A, the decision unit 130 will re-determine the schedule so that it is also performed in the second time zone B.

[0184] In operation example 6, two second time zones (second time zone A and second time zone B) are provided per day, meaning that multiple second time zones are provided. However, the same processing may be performed even if only one second time zone is provided per day. Specifically, the decision unit 130 performs the following processing when it determines that there is a first target hot water supply device for which the time from the second scheduled completion time to the start time of use exceeds the standard time. The decision unit 130 performs heating of the first target hot water supply device in one second time zone, stops it once, and then re-determines the schedule to perform heating again in that same second time zone.

[0185] In operation example 6, as shown in Figure 15(b), the decision unit 130 restarts the heating of the first target hot water supply unit after it has finished heating, and then re-determines the schedule so that the heating of the first target hot water supply unit is completed by the start time of use. The decision unit 130 re-determines the schedule so that the time from the time when the heating of the first target hot water supply unit is completed to the scheduled time of use is less than the standard time. Therefore, since the time from the time when the heating of the first target hot water supply unit is completed to the scheduled time of use is sufficiently short, the problem of the heated water cooling down due to a long time from the time when the heating is completed (second scheduled completion time) to the start time of use is less likely to occur.

[0186] [Example of operation 7] Figure 16 is a flowchart of operation example 7 according to this embodiment.

[0187] Operation Example 7 is similar to Operation Example 6 in that, for example, in step S30 of Operation Example 1, the decision unit 130 determines the schedule, and then the decision unit 130 reviews the determined schedule and makes a new decision.

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

[0189] The number of heating cycles refers to the number of times the hot water supply device 11 heated water until the target heating amount was reached. For example, in Figure 15(a), the number of heating cycles for the first hot water supply device 11a is 1, and in Figure 15(b), the number of heating cycles for the first hot water supply device 11a is 2. The predetermined number of cycles can be, for example, 3 to 10 times.

[0190] Furthermore, if it is determined that there is a second target hot water supply unit that has heated water more than a predetermined number of times (Yes in step S61), the determination unit 130 re-determines the schedule so that the number of times the second target hot water supply unit heats water is less than the predetermined number (S71).

[0191] Furthermore, the control unit 140 controls the heating of the multiple hot water supply units 11 during the second time period based on the schedule determined again by the determination unit 130 in step S71 (S90).

[0192] Furthermore, if it is determined that there are no second target hot water supply devices that have been heated more than a predetermined number of times (No in step S61), the control unit 140 performs the following processing. In this case, the control unit 140 controls the heating of the multiple hot water supply devices 11 during the second time period based on the schedule determined by the determination unit 130 in step S30 (S90).

[0193] As described above, the predetermined number of times can be, for example, 3 to 10 times. If the number of times the water is heated increases, the heating efficiency of the hot water heater 11 at startup decreases, leading to a problem of increased power consumption. In operation example 7, the number of times the second target hot water heater heats water is less than the predetermined number, so this problem is less likely to occur. In other words, because power consumption is reduced, the hot water heater system 100 can be said to be able to suppress the overall power demand of the apartment building 40 (more specifically, the maximum power demand).

[0194] In example 7, the schedule was re-determined in the first time period, but this is not limited to this. For example, the schedule may be re-determined in the second time period, and the heating of multiple hot water supply devices 11 may be controlled in the first time period. Also, for example, in the example shown in Figure 1B(b), the schedule may be re-determined before the start of a predetermined time period (for example, 12:00 to 14:00), and the heating of multiple hot water supply devices 11 may be controlled during that predetermined time period.

[0195] [Example of operation 8] Figure 17 is a flowchart of operation example 8 according to this embodiment. Figure 18 is a diagram showing the schedule and electricity charges for operation example 8 according to this embodiment.

[0196] Operation Example 8 is similar to Operation Examples 6 and 7 in that, for example, in step S30 of Operation Example 1, the decision unit 130 determines the schedule, and then the decision unit 130 reviews the determined schedule and makes a new decision.

[0197] In operation example 8, step S30 is performed as shown in Figure 17. Then, if the determination unit 130 determines that the second scheduled completion time for heating the third hot water supply unit 11c, whose heating start was delayed in the schedule determined by the determination unit 130 in step S30, falls within the first time zone, the determination unit 130 performs the following processing. That is, the determination unit 130 determines whether the second increase is smaller than the first increase (S62). As explained above, the second time zone is from 23:00 to 7:00 the next day. In other words, the case where the second scheduled completion time for heating the third hot water supply unit 11c falls within the first time zone means that the second scheduled completion time falls within the first time zone of the next day (from 7:00 the next day to 23:00 the next day).

[0198] Here, we will explain the first and second increases using Figure 18.

[0199] Figure 18 shows the schedule determined again by the processing of operation example 8 according to this embodiment. More specifically, Figure 18(a) shows the schedule in which the second scheduled completion time of heating of the third hot water supply device 11c, whose start of heating has been delayed, is included in the first time period. Figure 18(b) shows the schedule when the demand power (charge Pb) exceeds the first standard power (charge Pa).

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

[0201] As mentioned above, the first time zone is when the unit price of electricity is higher, and the second time zone is when the unit price of electricity is lower.

[0202] As shown in Figure 18(a), if the second scheduled completion time for heating the third hot water supply unit 11c falls within the first time zone, the electricity charges paid by the owner of the third hot water supply unit 11c will be higher than if the heating of the third hot water supply unit 11c were completed within the second time zone. The first increase refers to the increase in electricity charges due to the second scheduled completion time for heating the third hot water supply unit 11c falling within the first time zone compared to the electricity charges when the second scheduled completion time falls within the second time zone.

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

[0204] W×(YX)···(1)

[0205] Next, we will explain the second increase using Figure 18(b).

[0206] The second increase is due to the electricity charge being increased because the demand power (charge Pb) exceeded the first standard power (charge Pa) when the third hot water supply unit 11c was heated so that the second scheduled completion time of the heating of the third hot water supply unit 11c falls within the second time period.

[0207] For example, if the charge for demanded electricity is Pb (yen) and the charge for the first standard electricity is Pa (yen), then the second increase for heating the third hot water supply device 11c shown in Figure 18(b) is expressed by equation (2).

[0208] Pb-Pa···(2)

[0209] Pb (yen), which is the charge for electricity demand, is the charge that must be paid to the power company, for example, when the total electricity demand of the apartment building 40 exceeds the first standard electricity. Pa (yen), which is the charge for electricity demand at the first standard electricity, is the charge that must be paid to the power company, for example, when the total electricity demand of the apartment building 40 does not exceed the first standard electricity.

[0210] As shown in Figure 17, if the second increase is smaller than the first increase (yes in S62), the decision unit 130 increases the first reference power and re-determines the schedule so that the second scheduled completion time for heating the third hot water supply device 11c falls within the second time zone (S72). In other words, in this case, the decision unit 130 increases the reference power from the first reference power (rate Pa) to the changed first reference power (rate Pc), and changes the reference power so that the demand power (rate Pb) is smaller than the changed first reference power (rate Pc). As a result, the decision unit 130 re-determines the schedule so that it becomes the schedule shown in Figure 18(b).

[0211] Furthermore, the control unit 140 controls the heating of the multiple hot water supply units 11 during the second time period based on the schedule determined again by the determination unit 130 in step S72 (S90).

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

[0213] In example 8, the hot water supply system 100 can compare the first and second increases and reschedule so that the electricity bill is lower throughout the year.

[0214] [Example of operation 9] Figure 19 is a flowchart of operation example 9 according to this embodiment. Figure 20 is a diagram showing the schedule of operation example 9 according to this embodiment.

[0215] Operation Example 9, like Operation Example 4, is an operation that occurs while the control unit 140 is controlling the heating of multiple hot water supply devices 11 (first to fourth hot water supply devices 11a to 11d) in the second time period based on the schedule determined in step S90 of Operation Example 1. More specifically, it is an operation that occurs while the heating of the first and second hot water supply devices 11a and 11b is in progress, and as will be described later, at the time step S25 related to Operation Example 9 is performed, the heating of the third and fourth hot water supply devices 11c and 11d has not yet begun.

[0216] In Operation Example 9, as shown in Figure 20, we will explain an example where the second time zone includes a portion of the time period. As mentioned above, the second time zone is from 23:00 to 7:00 the following day. The portion of the time period is, for example, from 2:00 to 4:00 the following day within the second time zone, but is not limited to this.

[0217] Further explanation regarding certain time slots follows.

[0218] There are times when the need for energy conservation suddenly increases due to factors such as a tight supply and demand for electricity or a surge in electricity market prices. In such cases, it may be necessary to keep the electricity demand below the first standard power level, or there may be a possibility of lowering electricity rates by keeping it below the first standard power level. In this operational example, the time periods in which the standard power level is below the first standard power level are some of the time periods. It should be noted that it is often difficult to determine whether or not the need for energy conservation will increase before the second time period begins. Therefore, in steps S30 of operational example 1, before operational example 9 is performed, operational example 9 will be explained assuming that such a limited time period does not occur and that the schedule is determined using the first standard power level.

[0219] Furthermore, the acquisition unit 120 acquires the second reference power for a certain 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 (multiple residences). Furthermore, the second reference power is also the reference power for a certain time period included in the second time period.

[0220] Before step S15 is processed, the hot water supply system 100 may perform the following processing. As described above, if the need for power saving suddenly increases, an information terminal such as a smartphone, tablet, or personal computer receives a predetermined operation from the administrator of the hot water supply system 100. The predetermined operation is an operation that instructs the acquisition unit 120 of the hot water supply system 100 to acquire the second standard power. The information terminal transmits information to the communication unit 110 of the hot water supply system 100 instructing the acquisition unit 120 to acquire the second standard power. Upon receiving this information, the communication unit 110 of the hot water supply system 100 may acquire the second standard power in step S15.

[0221] Furthermore, the determination unit 130 determines whether the total power demand of the apartment building 40 (multiple residences) exceeds the second reference power acquired by the acquisition unit 120 during certain time periods 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, so it is possible that the power demand exceeds the second reference power in this schedule. Thus, in operation example 9, it can be said that the reference power is changed from the first reference power to the second reference power.

[0222] Next, if the decision unit 130 determines that the power demand exceeds the second standard power (Yes in S25), the decision unit 130 updates the schedule determined by the decision unit 130 in step S30 before some time periods, that is, in this case, during the second time period. That is, the decision unit 130 updates the schedule so that the hot water heaters 11 start heating in the order of the hot water heaters 11 with the latest heating start time among the multiple hot water heaters 11 (S35). More specifically, the decision unit 130 updates the schedule so that the hot water heaters 11 start heating in the order of the hot water heaters 11 with the latest heating start time among the multiple hot water heaters 11 that have not yet started heating at the time of step S25. As described above, when operation example 9 starts, heating is being performed on two or more hot water heaters 11 (first and second hot water heaters 11a and 11b). Therefore, in step S35, the decision unit 130 updates the schedule so that the water heating starts in the order of the water heating devices 11 that have the earliest latest heating start time, excluding two or more of the multiple water heating devices 11.

[0223] Steps S25 and S35 will be explained in more detail using Figure 20. For example, the time (current time) when the process in step S25 is being performed is time t2 as shown in Figure 20. Also, in the schedule shown in Figure 20, the latest start time for heating the first hot water supply unit 11a is t11, the latest start time for heating the second hot water supply unit 11b is t12, the latest start time for heating the third hot water supply unit 11c is t13, and the latest start time for heating the fourth hot water supply unit 11d is t14. t11 is earlier than t12, t12 is earlier than t13, and t13 is earlier than t14.

[0224] Figure 20(a) shows the schedule determined in step S30. The schedule shown in Figure 20(a) is the schedule when it is determined that the power demand exceeds the second standard power. Figure 20(b) shows a schedule in which, among the multiple hot water heaters 11 (third and fourth hot water heaters 11c and 11d) that have not yet started heating at time t2, the third hot water heater 11c, which has the earliest latest heating start time, starts heating earlier. In other words, Figure 20(b) shows the updated schedule.

[0225] For example, as shown in Figure 20(a), at time t2 (current time), it is determined that the power demand exceeds the second reference power during certain time periods. In such cases, in step S35, the decision unit 130 updates the schedule so that the hot water heaters 11 start heating in order from the one with the latest heating start time among the multiple hot water heaters 11.

[0226] The decision unit 130 updates the schedule so that the third hot water supply unit 11c, which has an earlier latest heating start time, starts heating earlier, and the fourth hot water supply unit 11d, which has a later latest heating start time, starts heating later. Here, the decision unit 130 updates the schedule so that the heating of the third hot water supply unit 11c starts within a certain time period. In addition, to prevent the power demand from exceeding the second standard power during a certain time period, the decision unit 130 updates the schedule so that the heating of the fourth hot water supply unit 11d starts within the second time period after that time period.

[0227] Furthermore, the control unit 140 controls the heating of multiple hot water supply units 11 during a second time period, which includes some time periods, based on the schedule updated by the determination unit 130 in step S35 (S95a).

[0228] Furthermore, if it is determined that the power demand in the second time period does not exceed the second standard power (No in S25), the control unit 140 performs the following processing. In this case, the control unit 140 controls the heating of multiple hot water supply devices 11 in the second time period, including some time periods, based on the schedule determined by the determination unit 130 in step S30 (S95b).

[0229] Example 9 shows an operation in which the baseline power is changed from the first baseline power to the second baseline power when the need for power conservation suddenly increases due to a tight power supply and demand situation or a surge in electricity market prices.

[0230] Then, during certain time periods when the standard power is changed to the second standard power, if the decision unit 130 determines that the demand power exceeds the second standard power (Yes in S25), the decision unit 130 determines the following schedule: The decision unit 130 determines a schedule in which the hot water heating will start in order of the hot water heating equipment 11 with the latest heating start time among the multiple hot water heating equipment 11.

[0231] As a result, in operation example 9, a hot water supply system 100 is realized that can suppress the overall power demand (more specifically, the maximum power demand) of the apartment building 40. For example, as shown in Figure 20(b), the maximum power demand is prevented from exceeding the second standard power. Therefore, the basic charges for the apartment building 40 are less likely to increase.

[0232] Furthermore, as mentioned above, the change in the standard power from the first standard power to the second standard power corresponds to a situation where there is a request for energy conservation due to a tight supply and demand for electricity. Even in such a case, the hot water supply system 100 can suppress the overall power demand of the apartment building 40 (more specifically, the maximum power demand), thereby meeting the societal need for energy conservation.

[0233] [Example of operation 10] Figure 21 is a flowchart of operation example 10 according to this embodiment.

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

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

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

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

[0238] Here, the decision unit 130 re-determines the schedule to supply electricity from the power supply equipment 23 to the apartment building 40 only to the extent that the demand power exceeds the first standard power. The sum of the electricity supplied by the power company and the electricity supplied by the power supply equipment 23 corresponds to the demand power. In other words, since the electricity supplied by the power company corresponds to the first standard power, even if the demand power exceeds the first standard power, the amount of electricity supplied by the power company that exceeds the first standard power is suppressed.

[0239] Furthermore, the control unit 140 controls the heating of the multiple hot water supply units 11 during the second time period based on the schedule determined by the determination unit 130 in step S73 (S90).

[0240] Furthermore, if it is determined that the power demand in the second time period does not exceed the first standard power (No in S63), the control unit 140 performs the following processing. In this case, the control unit 140 controls the heating of the multiple hot water supply devices 11 in the second time period based on the schedule determined by the determination unit 130 in step S30 (S90).

[0241] In operation example 10, if it is determined that the power demand exceeds the first standard power, the schedule is reset so that power is supplied from the power supply equipment 23 to the apartment building 40. This prevents the power supplied by the power company from exceeding the first standard power. Consequently, electricity charges in the apartment building 40 are less likely to increase.

[0242] Furthermore, in operation example 10, if it is determined that the power demand exceeds the first standard power (Yes in S63), the decision unit 130 re-determines the schedule to supply power from the power supply equipment 23 provided by the apartment building 40 to the apartment building 40, but it is not limited to this. In this case, for example, the decision unit 130 may re-determine the schedule to shut off electrical equipment 21 (lighting, elevators, etc.) in the common area 20. As a result, the power demand decreases, and the amount of power supplied by the power company is prevented from exceeding the first standard power.

[0243] [Example of operation 11] Figure 22 is a flowchart of operation example 11 according to this embodiment.

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

[0245] In Operation Example 11, first, step S30 described in Operation Example 1 is performed, and the schedule is determined.

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

[0247] As explained above, the second time zone is from 11 PM to 7 AM the following day. In other words, the case where the second scheduled completion time of the heating of the third hot water supply unit 11c, whose heating start has been delayed, falls within the first time zone means that the said second scheduled completion time falls within the first time zone of the following day (from 7 AM to 11 PM the following day).

[0248] Furthermore, if it is determined that the second scheduled completion time for heating the third hot water supply unit 11c falls within the first time period (Yes in S64), the decision unit 130 re-determines the schedule as follows (S74). In this case, the decision unit 130 re-determines the schedule so that power is supplied from the power supply equipment 23 provided by the apartment building 40 for heating the third hot water supply unit 11c during the first time period. Here, the decision unit 130 re-determines the schedule so that all the power required for heating the third hot water supply unit 11c during the first time period is supplied from the power supply equipment 23. In other words, there is no need for the power company to supply power to the apartment building 40 for heating the third hot water supply unit 11c during the first time period.

[0249] Furthermore, the control unit 140 controls the heating of the multiple hot water supply units 11 during the second time period based on the schedule determined by the determination unit 130 in step S74 (S90).

[0250] Furthermore, if it is determined that the second scheduled completion time for heating the third hot water supply unit 11c is not included in the first time period (No in S64), the control unit 140 performs the following processing. In this case, the control unit 140 controls the heating of the multiple hot water supply units 11 in the second time period based on the schedule determined by the determination unit 130 in step S30 (S90).

[0251] In example 11, if the second scheduled completion time for heating the third hot water supply unit 11c falls within the first time period, the schedule is reset to supply power from the power supply equipment 23 for that heating. Therefore, there is no need for the power company to supply power to the apartment building 40 for that heating. Consequently, electricity costs for the apartment building 40 can be kept low.

[0252] [Example of operation 12] Figure 23 is a flowchart of operation example 12 according to this embodiment.

[0253] In the operation example 12 shown in Figure 23, an example is shown in which the fifth hot water supply device 11e is heated during the first time period.

[0254] For example, when the acquisition unit 120 receives a heating instruction for the fifth hot water supply unit 11e, which is included in the multiple hot water supply units 11, from its owner during the first time period, the processing in operation example 12 begins. In other words, in operation example 12, it is necessary to heat the water for the fifth hot water supply unit 11e during the first time period.

[0255] First, the determination unit 130 determines the lowest of the first, second, and third amounts when the fifth hot water supply device 11e is to be heated during the first time period (S80). The first, second, and third amounts will now be explained.

[0256] The first amount refers to the amount paid when the fifth hot water heater 11e is heated using electricity supplied by the power company. In other words, the first amount is the amount paid to the power company when the fifth hot water heater 11e is heated using electricity supplied by the power company.

[0257] The second amount refers to the amount required to recharge the charging equipment (more specifically, the charging equipment owned by the power supply equipment 23) when the fifth hot water heater 11e is heated using electricity stored in the charging equipment provided by the apartment building 40. In other words, the second amount is the amount required to purchase electricity supplied by the power company to recharge the fifth hot water heater 11e when the electricity stored in the charging equipment is discharged to heat the equipment.

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

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

[0260] Furthermore, 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 to heat the fifth hot water supply device 11e using the power charged in the charging equipment (S82).

[0261] Furthermore, 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 to heat the fifth hot water supply unit 11e using the electricity generated by the solar power generation equipment (S83).

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

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

[0264] (Variation 1) The following describes Modification 1 of the embodiment. In the following description, the differences from the embodiment will be the main focus, and the similarities will be omitted or simplified.

[0265] In this embodiment, the hot water supply system 100 is installed in an apartment building 40, but is not limited to this. In this modified example, the hot water supply system 100 is installed in an area 340 that includes the apartment building 40.

[0266] [composition] Figure 24 is a block diagram showing the functional configuration of a hot water supply system 100 according to a modified example 1 of the embodiment.

[0267] The hot water supply system 100 is installed in area 340, which includes an apartment building 40, multiple detached houses 410, and multiple facilities 520. Accordingly, Figure 24 also shows block diagrams illustrating the functional configurations of each of the apartment building 40, multiple detached houses 410, and multiple facilities 520 included in area 340.

[0268] The hot water supply system 100 controls the plurality of hot water supply apparatuses 411 installed in the plurality of detached houses 410 and the plurality of hot water supply apparatuses 11 installed in the plurality of dwelling units included in the collective housing 40, to suppress the maximum value of the total power demand in the area 340. The plurality of houses according to this modification example includes the plurality of detached houses 410 and the plurality of dwelling units included in the collective housing 40.

[0269] In the area 340 according to this modification example, a high-voltage bulk power receiving contract is selected as the contract form for supplying power to the area 340.

[0270] The hot water supply system 100 according to this modification example determines the schedule for heating water by the plurality of hot water supply apparatuses 411 and the plurality of hot water supply apparatuses 11 before the second time period starts, that is, within the first time period. The hot water supply system 100 controls the plurality of hot water supply apparatuses 411 and the plurality of hot water supply apparatuses 11 based on this determined schedule.

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

[0272] Accordingly, the control apparatus 413 can perform the same information processing as the control apparatus 13. The control apparatus 413 installed in one detached house 410 can output information such as hot water supply information related to the hot water supply apparatus 411 installed in the one detached house 410 to the communication unit 110. In addition, the control apparatus 413 installed in one detached house 410 can output information such as power information (corresponding to the exclusive section power information in the embodiment) related to the electrical device 412 installed in the one detached house 410 to the communication unit 110.

[0273] The facility 520 is a facility installed in the area 340, and is, for example, a commercial facility, an industrial facility, a school, or a public facility. Each of the multiple facilities 520 is equipped with electrical equipment 521, a power measuring device 522, and power supply equipment 523. The electrical equipment 521, the power measuring device 522, and the power supply equipment 523 have the same functions as the electrical equipment 21, the power measuring device 22, and the power supply equipment 23 described in the embodiment, respectively.

[0274] Therefore, the power measuring device 522 can perform the same information processing as the power measuring device 22. A power measuring device 522 installed in one facility 520 can output information such as power information (corresponding to the shared power information in the embodiment) for electrical equipment 521 installed in that facility 520 to the communication unit 110.

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

[0276] (Modification 2) The following describes a modified example 2 of the embodiment. In the following description, the differences from the embodiment will be the main focus, and the similarities will be omitted or simplified.

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

[0278] [composition] Figure 25 is a block diagram showing the functional configuration of the hot water supply system 100 according to a modified example 2 of the embodiment.

[0279] In this modified example, each of the multiple dwelling units is equipped with a hot water supply system 11 and a smart meter 15. Each of the multiple dwelling units is not equipped with a control device 13.

[0280] The hot water supply device 11 in this modified example outputs information such as hot water supply information for the hot water supply device 11 to the hot water supply system 100.

[0281] The smart meter 15 is a device that can measure the amount of electricity used in a dwelling unit at predetermined intervals (for example, every 30 minutes) and has a communication function. In other words, the smart meter 15 can measure the electricity used by electrical equipment 12 (not shown) and can output the electricity usage information for the private unit to the hot water supply system 100.

[0282] Furthermore, in this modified example, a smart meter 25 and power supply equipment 23 are installed in the common area 20. A power measuring device 22 is not installed in the common area 20.

[0283] The power supply equipment 23 in this modified example outputs power supply equipment information, such as the amount of power generated and the amount of charge, to the hot water supply system 100.

[0284] The smart meter 25 is a device that can measure the amount of electricity used in the shared area 20 at predetermined intervals (for example, every 30 minutes) and has a communication function. In other words, the smart meter 25 can measure the electricity used by electrical equipment 21 (not shown) and can output shared area power information to the hot water supply system 100.

[0285] As a result, the hot water supply system 100 according to the modified example 2 can also perform the operation examples 1 to 12 described in the embodiment.

[0286] (Variation 3) The following describes a third modified example of the embodiment. The following description will focus on the differences between this embodiment and modifications 1 and 2, omitting or simplifying the explanation of the commonalities.

[0287] [composition] Figure 26 is a block diagram showing the functional configuration of the hot water supply system 100 according to a modified example 3 of the embodiment.

[0288] In Modification 1, the hot water supply system 100 acquires information from the control devices 13 and 413 and the power measuring devices 22 and 522, but the present invention 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 Modification 3 as described above can also perform the operation examples 1 to 12 described in the embodiment.

[0290] (Effects and the like) Invention 1 is a hot water supply system 100 comprising: an acquisition unit 120 that acquires a plurality of pieces of hot water supply information including a heating amount of a hot water supply device 11 and a use start time of the hot water supply device 11, and first reference power for a plurality of residences in which the plurality of hot water supply devices 11 are installed; a determination unit 130 that, when it is determined based on the heating amounts included in the acquired plurality of pieces of hot water supply information 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 for starting heating in the order of the hot water supply devices 11 having the earliest latest heating start time, which is the latest time at which heating is started so that hot water shortage does not occur at the use start time included in the hot water supply information for the corresponding hot water supply device 11 among the plurality of hot water supply devices 11; and a control unit 140 that controls heating of the plurality of hot water supply devices 11 based on the determined schedule.

[0291] As a result, as shown in Operation Example 1, the hot water supply system 100 capable of suppressing the total power demand (more specifically, the maximum value of the power demand) of the plurality of residences (the collective housing 40 in Operation Example 1) is realized. For example, as shown in (b) of FIG. 3, the maximum value of the power demand is prevented from exceeding the first reference power. Accordingly, the basic charge for the collective housing 40 is less likely to increase.

[0292] Invention 2 is a hot water supply system 100 of Invention 1, wherein the acquisition unit 120 acquires a first reference power for the second time period, which is one of the first time period and the second time period in which the unit price of electricity is lower than the first time period, and the determination unit 130, if it determines that if multiple hot water supply devices 11 start heating simultaneously in the 22nd time period the total power demand of multiple houses will exceed the acquired first reference power, determines a schedule in advance of the second time period for starting to heat water among the multiple hot water supply devices 11 in the order of the hot water supply devices 11 with the latest heating start time, and the control unit 140 controls the heating of the 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 heating of multiple hot water heaters 11 is performed during the second time period when electricity rates are lower, thus reducing the electricity charges paid by the owners of the hot water heaters 11. In other words, a hot water heating system 100 is realized that can reduce the electricity charges paid by the owners of the hot water heaters 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 a plurality of hot water supply devices 11 whose latest heating start times are the same, the determination unit 130 determines a schedule in which the hot water supply devices 11 start heating in order of the hot water supply information for the hot water supply device 11 that contains the largest amount of heating, among the two hot water supply devices 11.

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

[0296] Invention 4 is a hot water supply system 100 of Invention 2, wherein the acquisition unit 120 acquires the first electricity unit price for the first time period and the second electricity unit price for the second time period, and the determination unit 130 determines a schedule based on the acquired first and second electricity unit prices so that the electricity cost for heating each of the multiple hot water supply devices 11 is reduced.

[0297] As a result, as shown in Operation Example 2, the water heating of the hot water heater 11 (for example, the first hot water heater 11a) is performed during times when the unit price of electricity is lower, thus reducing the electricity charges paid by the owner of the hot water heater 11. In other words, a hot water heating system 100 is realized that can reduce the electricity charges paid by the owner of the hot water heater 11.

[0298] Invention 5 is a hot water supply system 100 of Invention 4, in which, when multiple second time zones are provided in a day, the determination unit 130 determines a schedule based on the acquired first and second electricity unit prices and the start time of use included in each of the acquired multiple hot water supply information, so as to reduce the electricity cost for heating each of the multiple hot water supply devices 11 and so as to reduce the time difference between the first scheduled completion time, which is the scheduled time when heating each of the multiple hot water supply devices 11 is scheduled to be completed, and the start time of use.

[0299] As a result, as shown in Operation Example 3, the water heating of the hot water heater 11 (for example, the first hot water heater 11a) is performed during times when the unit price of electricity is lower, thus keeping the electricity charges paid by the owner of the hot water heater 11 low. However, as shown in Figure 9(a), if there is a long time between the first scheduled completion time and the start time of use, the problem arises that the heated water will cool down. However, in Operation Example 3, as shown in Figure 9(b), the time difference between the first scheduled completion time and the start time of use is short, so the above problem is less likely to occur. In other words, a hot water heating system 100 is realized that can keep the electricity charges paid by the owner of the hot water heater 11 low and is less likely to cause the problem of the heated water cooling down.

[0300] Invention 6 is a hot water supply system 100 according to any one of Inventions 1 to 5, wherein when the control unit 140 controls the heating of multiple hot water supply devices 11 based on a determined schedule, the determination unit 130 determines that the total power demand of multiple houses exceeds the first reference power obtained, and updates the schedule to stop heating of the hot water supply device 11 among the multiple hot water supply devices 11 that has the largest time difference between the second scheduled completion time, which is the scheduled time when heating will be completed according to the determined schedule, and the third scheduled completion time, which is the scheduled time when heating will be completed if heating is started at the latest heating start time, and the control unit 140 controls the heating of 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, the hot water supply system 100 updates its schedule to stop heating the water in the hot water supply unit 11 (second hot water supply unit 11b). This prevents the power demand from exceeding the first reference power. In other words, a hot water supply system 100 is realized that can suppress the total power demand (more specifically, the maximum value of power demand) of multiple houses (apartment buildings 40 in Operation Example 4). In addition, by updating the schedule so that the hot water supply unit 11 stops heating the water when the time difference between the second scheduled completion time and the third scheduled completion time is large, it becomes less likely for the hot water supply unit 11 with a small time difference and the hot water supply unit 11 with a large time difference to run out of hot water.

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

[0303] As a result, as shown in Operation Example 5, when the hot water supply system 100 receives a heating instruction from another hot water supply device 11 (third hot water supply device 11c), it performs the following process: The hot water supply system 100 updates the schedule to start heating the other hot water supply device 11. This allows the hot water supply system 100 to heat the other hot water supply device 11.

[0304] Invention 8 is a hot water supply system 100 of Invention 7, wherein 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 outputted boiling instruction.

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

[0306] Invention 9 is a hot water supply system 100 of Invention 7 or 8, in which, when the determination unit 130 determines, based on the acquired heating instructions, that the total power demand of multiple houses exceeds the acquired first reference power, it stops the heating of the hot water supply unit 11 among two or more hot water supply units 11 that has the largest time difference between the second scheduled completion time, which is the scheduled time when heating will be completed as indicated in the determined schedule, and the third scheduled completion time, which is the scheduled time when heating will be completed if heating is started at the latest heating start time, and updates the schedule to start heating of the other hot water supply units 11.

[0307] As a result, as shown in Operation Example 5, when the hot water supply system 100 determines that the power demand exceeds the first reference power based on the heating instruction of another hot water supply device 11 (third hot water supply device 11c), it performs the following processing. That is, the hot water supply system 100 suppresses the power demand from exceeding the first reference power by updating the schedule to stop heating the hot water supply device 11 (second hot water supply device 11b). In other words, a hot water supply system 100 is realized that can suppress the total power demand (more specifically, the maximum value of power demand) of multiple houses (apartment buildings 40 in Operation Example 5). Furthermore, the decision unit 130 updates the schedule to stop heating the hot water supply device 11 (second hot water supply device 11b) where the time difference between the second scheduled completion time and the third scheduled completion time is large. As a result, it becomes less likely for the hot water supply device 11 with a small time difference and the hot water supply device 11 with a large time difference to run out of hot water. In other words, a hot water supply system 100 that is less likely to run out of hot water is realized.

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

[0309] As a result, as shown in Operation Example 6, the decision unit 130 will stop the first target hot water supply unit after it has started heating the water, and then start heating it again, and will re-determine the schedule so that the first target hot water supply unit will be able to heat the water by the start time of use. The decision unit 130 will re-determine the schedule so that the time from the time when the first target hot water supply unit is able to heat the water again to the scheduled time of use will be less than the standard time. Therefore, the time from the time when the first target hot water supply unit is able to heat the water to the scheduled time of use will be sufficiently short, making it less likely for the heated water to cool down. In other words, a hot water supply system 100 that is less prone to the above problem is realized.

[0310] Invention 11 is a hot water supply system 100 according to any one of Inventions 1 to 10, wherein if there is a second target hot water supply unit among a plurality of hot water supply units 11 whose number of boiling cycles indicated by the determined schedule is greater than or equal to a predetermined number, the determination unit 130 re-determines the schedule so that the number of boiling cycles for the second target hot water supply unit becomes less than the predetermined number.

[0311] As a result, as shown in Operation Example 7, the number of times the second target hot water heater heats water will be less than a predetermined number of times, making it less likely for the problem of increased power consumption of the hot water heater 11 due to a high number of heating cycles to occur. In other words, because power consumption is reduced, the hot water heater system 100 can suppress the overall power demand of the apartment building 40 (more specifically, the maximum power demand).

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

[0313] This enables a hot water supply system 100 that can suppress the total power demand (more specifically, the maximum power demand) of multiple residences (in operation example 9, the apartment building 40). For example, as shown in Figure 20(b), the maximum power demand is prevented from exceeding the second standard power. Consequently, the basic charges in the apartment building 40 are less likely to increase.

[0314] Invention 13 is a hot water supply method performed by a hot water supply system 100, comprising: an acquisition step of acquiring a plurality of hot water supply information, including the amount of hot water heated by a hot water supply device 11 and the start time of use of the hot water supply device 11, and a first reference power for a plurality of houses in which the plurality of hot water supply devices 11 are installed; a determination step of determining a schedule in which, based on the amount of hot water heated included in the plurality of hot water supply information, if it is determined that the total power demand of the plurality of houses will exceed the acquired first reference power if the plurality of hot water supply devices 11 start heating simultaneously, the hot water supply method is to start heating in the order of the hot water supply devices 11 with the latest latest start time, which is the time when the hot water supply device 11 starts heating in order so that there is no shortage of hot water 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 plurality of hot water supply devices 11 based on the determined schedule.

[0315] This enables a hot water supply method that can suppress the total power demand (more specifically, the maximum power demand) of multiple residences (in the case of the apartment building 40 in the example of operation 1), as shown in Operation Example 1. For example, as shown in Figure 3(b), the maximum power demand is prevented from exceeding the first standard power. Therefore, the basic charge in the apartment building 40 is less likely to increase.

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

[0317] For example, the first time slot was from 7:00 to 23:00, and the second time slot was from 23:00 to 7:00 the following day, but this is not an exhaustive rule.

[0318] Furthermore, while the amount of water to be heated was determined by the control device 13, it is not limited to this. For example, the hot water supply system 100 may calculate the amount of water to be heated from the target amount of water to be heated and the amount of hot water remaining in the 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 prior was used as the predetermined past period, but is not limited to this. For example, the period from one week before to one day one year prior to the relevant day may be used as the predetermined past period.

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

[0321] In the above embodiments and modifications, the power consumption required for heating the water in the hot water supply device 11 is assumed to be proportional to the amount of water heated by the hot water supply device 11, but this is not limited to this.

[0322] For example, the hot water supply system 100 may calculate the power consumption and time required to heat the water for the hot water supply units 11 based on the specifications of each of the multiple hot water supply units 11, the region where the multiple hot water supply units 11 are installed, and the current season. For example, if the region where the multiple hot water supply units 11 are installed is a colder region, the hot water supply system 100 will calculate that the power consumption and time required to heat the water for the hot water supply units 11 will be higher and longer. Also, if the current season is winter, the hot water supply system 100 will calculate that the power consumption and time required to heat the water for the hot water supply units 11 will be higher and longer. Furthermore, if the hot water supply system 100 cannot obtain information indicating the current season, the hot water supply system 100 may obtain data including the current air temperature and water temperature (data from the Japan Meteorological Agency, etc.) and calculate the power consumption and time required to heat the water for the hot water supply units 11 based on this data.

[0323] Furthermore, for example, the hot water supply system 100 may acquire data including past air temperature and water temperature (data from the Japan Meteorological Agency, etc.) and calculate the power consumption and time required to heat the water using the hot water supply device 11 based on this data.

[0324] Furthermore, if it is determined that the total power demand of multiple residences exceeds the first standard power, the following processing may be carried out. For example, the communication unit 110 of the hot water supply system 100 according to the embodiment sends information (message) requesting cooperation in saving electricity to each control device 13 or owner's information terminal (e.g., smartphone) of the multiple private units 10. This is expected to encourage the owners of the private units 10 to cooperate in saving electricity. The display unit of the hot water supply system 100 displays the difference in charges (amount of charge reduction) between the case where power demand exceeds the first standard power and the case where power demand does not exceed the first standard power. The administrator of the hot water supply system 100 can increase the owner's satisfaction with the cooperation in saving electricity by paying the displayed amount of charge reduction to the owner who cooperated in saving electricity.

[0325] Furthermore, it would be beneficial if the amount of the above-mentioned cost reduction were notified to the owner before the information (message) requesting cooperation in saving electricity is sent. For example, information showing the amount of the above-mentioned cost reduction could be output from the communication unit 110 of the hot water supply system 100 to the control devices 13 of each of the multiple private units 10 or to the owner's information terminal (e.g., smartphone). This would allow the owner to know that there are financial benefits to cooperating in saving electricity.

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

[0327] For example, in this case, it would be beneficial to send the information (message) requesting cooperation in saving electricity before the relevant time period (for example, the day before or a few hours before). This would give the owner time to consider whether or not to cooperate in saving electricity before the relevant time period begins.

[0328] As another example, in this case, the electricity rate per unit of electricity for that particular time period may be increased. In other words, a higher electricity rate per unit of electricity is used compared to the rate per unit of electricity when the total electricity demand of multiple houses does not exceed the first standard power during a given time period. The hot water supply system 100 uses this higher electricity rate to perform the processing described in the above example of operation.

[0329] The administrator of the hot water supply system 100 may obtain information on the cooperation of multiple owners in saving electricity by conducting a questionnaire on electricity saving cooperation with each owner of the first to fifth private units 10a to 10e. The administrator controls an information terminal such as a smartphone, tablet, or personal computer to transmit the information on multiple electricity saving cooperation 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 information on multiple electricity saving cooperation acquired by the communication unit 110. The questionnaire asks whether it is possible for owners to cooperate in saving electricity in their private units 10 when the total electricity demand of the multiple residences exceeds the acquired first standard electricity, and the results of the questionnaire are reflected in the information on electricity saving cooperation. Based on the acquired information on multiple electricity saving cooperation, the hot water supply system 100 determines which equipment (hot water supply device 11, electrical equipment 21) will be stopped when the total electricity demand of the multiple residences exceeds the acquired first standard electricity. The hot water supply system 100 determines a schedule so that the determined equipment is shut down, and controls the equipment based on the determined schedule. For example, if the information regarding cooperation in saving electricity indicates that cooperation in saving electricity is not possible in all of the first to fifth private areas 10a to 10e, the hot water supply system 100 determines a schedule so that the electrical equipment 21 installed in the common area 20 is shut down.

[0330] Furthermore, in the above embodiments and modifications, a process executed by a specific processing unit may be executed by another processing unit. Also, the order of multiple processes may be changed, or multiple processes may be executed in parallel.

[0331] Furthermore, in the above embodiments and modified examples, the 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 also be realized by a program execution unit such as a CPU or 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 implemented 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 they may be separate circuits. Also, these circuits may be general-purpose circuits or dedicated circuits.

[0333] Furthermore, general or specific embodiments of the present invention may be implemented as a system, apparatus, method, integrated circuit, computer program, or recording medium such as a computer-readable CD-ROM. Alternatively, they may be implemented in any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium. For example, the present invention may be implemented as a hot water supply system 100 of the above embodiments and modifications, or as a hot water supply method performed by the hot water supply system 100. The present invention may be implemented as a program for causing a computer to execute such a hot water supply method, or as a non-temporary 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 embodiments and modifications.

[0334] Furthermore, the present invention also includes forms obtained by applying various modifications to each embodiment and modification as conceived by those skilled in the art, or forms realized by arbitrarily combining the components and functions of each embodiment and modification without departing from the spirit of the present invention. [Explanation of Symbols]

[0335] 11,411 Hot water supply equipment 100 Hot water supply system 120 Acquisition Department 130 Decision Section 140 Control Unit

Claims

1. An acquisition unit that acquires multiple pieces of hot water supply information, including the amount of hot water heated by the hot water supply unit and the start time of use of the hot water supply unit, and a first standard power for multiple houses in which the multiple hot water supply units are installed, Based on the amount of hot water to be heated included in the acquired hot water supply information, if it is determined that the total power demand of the multiple houses will exceed the acquired first reference power if the multiple hot water supply devices start heating simultaneously, a determination unit determines a schedule in which the hot water supply devices will start heating in order from the latest hot water supply device, which is the latest time to start heating so that there is no shortage of hot water at the start time of use included in the hot water supply information for that hot water supply device. The system comprises a control unit that controls the heating of the multiple hot water supply units based on the determined schedule, Hot water supply system.

2. The acquisition unit acquires the first reference power for the second time period, which is one of the first time period and the second time period in which the unit price of electricity is lower than that of the first time period. If the determination unit determines that the total power demand of the multiple houses will exceed the acquired first reference power if the multiple hot water heaters start heating simultaneously during the second time period, it determines the schedule for the multiple hot water heaters to start heating in the order of the hot water heater with the earliest latest heating start time, prior to the second time period. The control unit controls the heating of the multiple hot water supply devices during the second time period based on the determined schedule. The hot water supply system according to claim 1.

3. If, among the aforementioned multiple hot water supply devices, there are two hot water supply devices whose latest heating start time is the same, The determination unit determines the schedule for starting the heating process in order of the hot water supply unit that has the largest heating amount included in the hot water supply information for that unit, out of the two hot water supply units. The hot water supply system according to claim 1.

4. The acquisition unit acquires the first electricity unit price for the first time period and the second electricity unit price for the second time period. The determination unit determines the schedule based on the acquired first and second electricity rates so that the electricity cost for heating each of the multiple hot water supply devices is reduced. The hot water supply system according to claim 2.

5. When multiple of the aforementioned second time slots are provided in a single day, The determination unit determines the schedule based on the acquired first and second electricity unit prices and the usage start times included in each of the acquired multiple hot water supply information, such that the electricity cost for heating each of the multiple hot water supply devices is reduced, and the time difference between the first scheduled completion time, which is the scheduled time when heating each of the multiple hot water supply devices is scheduled to be completed, and the usage start time is reduced. The hot water supply system according to claim 4.

6. When the control unit controls the heating of the multiple hot water supply devices based on the determined schedule, When the determination unit determines that the total power demand of the multiple residences exceeds the acquired first reference power, it updates the schedule to stop the heating of the hot water heater among the multiple hot water heaters that has the largest time difference between the second scheduled completion time, which is the scheduled time when heating will be completed as indicated in the determined schedule, and the third scheduled completion time, which is the scheduled time when heating will be completed if heating is started at the latest heating start time. The control unit controls the heating of the multiple hot water supply devices based on the updated schedule. The hot water supply system according to claim 1.

7. When the control unit is heating two or more of the multiple hot water supply devices according to the determined schedule, The acquisition unit acquires a boiling instruction that instructs the boiling of water in the hot water supply equipment other than the two or more hot water supply equipment among the plurality of hot water supply equipment, The decision unit updates the schedule to start heating the other hot water supply equipment based on the acquired heating instruction. The control unit controls the heating of the multiple hot water supply devices based on the updated schedule. The hot water supply system according to claim 1.

8. When the information processing device receives an operation from the owner of the other hot water supply device, The information processing device outputs the boiling instruction indicated by the received operation, The acquisition unit acquires the outputted boiling instruction. The hot water supply system according to claim 7.

9. Based on the acquired heating instruction, the determination unit determines that the total power demand of the multiple residences exceeds the acquired first reference power, and updates the schedule to stop heating the water from the water heater among the two or more water heaters that has the largest time difference between the second scheduled completion time, which is the scheduled time when heating will be completed as indicated in the determined schedule, and the third scheduled completion time, which is the scheduled time when heating will be completed if heating is started at the latest heating start time, and to start heating the water from the other water heaters. The hot water supply system according to claim 7 or 8.

10. The determination unit, based on the start time of use included in each of the acquired multiple hot water supply information, determines that among the multiple hot water supply devices, there is a first target hot water supply device for which the time from the second scheduled completion time (the time when the determined schedule indicates that the heating will be completed) to the start time of use exceeds the standard time, and then determines the schedule again so that the heating of the first target hot water supply device is completed by the start time of use after the heating is performed in the second time period, then stopped and started again. The hot water supply system according to claim 2.

11. If, among the aforementioned multiple hot water supply devices, there is a second target hot water supply device whose number of heating cycles indicated by the determined schedule is greater than or equal to a predetermined number, The determination unit then re-determines the schedule so that the number of times the second target hot water supply device is heated is less than the predetermined number of times. The hot water supply system according to claim 1.

12. When the control unit is controlling the heating of the multiple hot water supply devices according to the determined schedule, The acquisition unit acquires the second reference power of the plurality of houses, which is a reference power lower than the first reference power, and the second reference power for a portion of the time period included in the second time period. If the determination unit determines that the total power demand of the multiple houses exceeds the second reference power obtained during a certain time period in the determined schedule, it updates the schedule so that the hot water heaters among the multiple hot water heaters start heating in the order of the hot water heater with the earliest latest heating start time. The control unit controls the heating of the multiple hot water supply devices during the specified time period based on the updated schedule. The hot water supply system according to claim 2.

13. A method of supplying hot water that is performed by a hot water supply system, An acquisition step of acquiring multiple pieces of hot water supply information, including the amount of hot water heated by the hot water supply equipment and the start time of use of the hot water supply equipment, and a first standard power for multiple houses in which the multiple hot water supply equipment is installed, Based on the amount of water heated, as contained in the acquired hot water supply information, if it is determined that the total power demand of the multiple houses will exceed the acquired first reference power if the multiple hot water supply devices start heating simultaneously, a decision step is made to determine a schedule in which the hot water supply devices will start heating in order from the latest time to start heating, which is the latest time to start heating, so that there is no shortage of hot water at the start time of use as contained in the hot water supply information for that hot water supply device. A control step that controls the heating of the multiple hot water supply devices based on the determined schedule, Hot water supply method.

Images