Heat supply system, heat supply management server, operating method and program

Abstract

To provide a technology which can utilize increased suppliable power to a heat storage operation of a heat supply device when the suppliable power of a power generation unit is increased exceeding an initial assumption.SOLUTION: A heat supply system comprises: a plurality of heat supply devices; a power generation unit which can supply power generated by using renewable energy to the plurality of heat supply devices; and a heat supply management server. Each of the plurality of heat supply devices can perform a heat storage operation. The heat supply server performs scheduling processing for setting an operation permission time band with respect to each of a plurality of groups on the basis of suppliable power data. The heat supply management server repeatedly performs, in the scheduling processing, serial processing of: specifying a setting-objective group; specifying usable power data; specifying determination reference power data; setting the operation permission time band of the setting-objective group so as to include a time at which determination reference power becomes the highest; and updating the usable power data.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed in this specification relates to a heat supply system, a heat supply management server, an operation method, and a program.

Background Art

[0002] Patent Document 1 discloses a heat supply system including a plurality of heat supply devices, a power generation facility capable of supplying power generated using renewable energy to the plurality of heat supply devices, and a heat supply management server. Each of the plurality of heat supply devices includes a heat storage unit that stores a heat medium and a heat source unit that heats the heat medium using power. Each of the plurality of heat supply devices is capable of executing a heat storage operation of heating the heat medium by the heat source unit and storing the heated heat medium in the heat storage unit. The heat supply management server acquires supplyable power data indicating a change over time of supplyable power, which is power that can be supplied from the power generation facility to the plurality of heat supply devices, and based on the supplyable power data, executes a scheduling process of setting an execution time zone, which is a time zone for executing the heat storage operation, for each of the plurality of heat supply devices. In the scheduling process, the heat supply management server identifies a heat supply device to be set, identifies usable power data, based on the usable power data, identifies a time zone in which the heat storage operation can be executed, within the range of the identified time zone, sets the execution time zone of the heat storage operation of the heat supply device to be set, and repeatedly executes a series of processes of updating the usable power data by subtracting power planned to be used by the heat supply device to be set from the usable power in the set execution time zone.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] In the heat supply system described in Patent Document 1, scheduling is not performed such that the sum of the power consumption of the heat storage operation of multiple heat supply devices exceeds the assumed available power supply. Therefore, if the power generated by the power generation equipment increases more than initially assumed, and the available power supply increases more than initially assumed, the increased available power supply cannot be used for the heat storage operation of the heat supply devices. This specification provides a technology that enables the use of the increased available power supply for the heat storage operation of the heat supply devices when the available power supply of the power generation equipment increases more than initially assumed. [Means for solving the problem]

[0005] This specification discloses a heat supply system. In a first embodiment, the heat supply system may include a plurality of heat supply devices, a power generation facility capable of supplying electricity generated using renewable energy to the plurality of heat supply devices, and a heat supply management server. Each of the plurality of heat supply devices may include a heat storage unit for storing a heat medium and a heat source unit for heating the heat medium using electricity. Each of the plurality of heat supply devices may be capable of performing a heat storage operation in which the heat source unit heats the heat medium and stores the heated heat medium in the heat storage unit. Each of the plurality of heat supply devices may belong to any one of a plurality of groups. The heat supply management server may be configured to acquire supplyable power data showing the change over time of supplyable power, which is the electricity that can be supplied from the power generation facility to the plurality of heat supply devices, and to perform scheduling processing to set an operating permission time period, which is the time period during which the heat storage operation is permitted, for each of the plurality of groups based on the supplyable power data. The heat supply management server may be configured to repeatedly perform a series of processes in the scheduling process, including identifying the group to be set as the target group, identifying usable power data showing the change in usable power over time, identifying judgment criterion power data showing the change in judgment criterion power over time based on the usable power data, setting the permitted operating time period for the target group so that it includes the time when the judgment criterion power is highest, and updating the usable power data by subtracting the power to be used by the target group from the usable power during the set permitted operating time period.

[0006] This specification also discloses a heat supply management server. The heat supply management server may be used in a heat supply system comprising a plurality of heat supply devices, a power generation facility capable of supplying electricity generated using renewable energy to the plurality of heat supply devices, and the heat supply management server. Each of the plurality of heat supply devices may include a heat storage unit for storing a heat medium and a heat source unit for heating the heat medium using electricity. Each of the plurality of heat supply devices may be capable of performing a heat storage operation in which the heat source unit heats the heat medium and stores the heated heat medium in the heat storage unit. Each of the plurality of heat supply devices may belong to any one of a plurality of groups. The heat supply management server may be configured to acquire supplyable power data showing the change over time of supplyable power, which is the electricity that can be supplied from the power generation facility to the plurality of heat supply devices, and to perform scheduling processing to set an operating permission time period, which is the time period in which the heat storage operation is permitted, for each of the plurality of groups based on the supplyable power data. The heat supply management server may be configured to repeatedly perform a series of processes in the scheduling process, including identifying the group to be set as the target group, identifying usable power data showing the change in usable power over time, identifying judgment criterion power data showing the change in judgment criterion power over time based on the usable power data, setting the permitted operating time period for the target group so that it includes the time when the judgment criterion power is highest, and updating the usable power data by subtracting the power to be used by the target group from the usable power during the set permitted operating time period.

[0007] This specification also discloses a method for operating a heat supply management server. The heat supply management server may be used in a heat supply system comprising a plurality of heat supply devices, a power generation facility capable of supplying electricity generated using renewable energy to the plurality of heat supply devices, and the heat supply management server. Each of the plurality of heat supply devices may include a heat storage unit for storing a heat medium and a heat source unit for heating the heat medium using electricity. Each of the plurality of heat supply devices may be capable of performing a heat storage operation in which the heat source unit heats the heat medium and stores the heated heat medium in the heat storage unit. Each of the plurality of heat supply devices may belong to any one of a plurality of groups. The operating method may include acquiring supplyable power data that shows the change over time of supplyable power, which is the electricity that can be supplied from the power generation facility to the plurality of heat supply devices, and performing a scheduling process to set an operating permission time period, which is a time period during which the execution of the heat storage operation is permitted, for each of the plurality of groups based on the supplyable power data. Executing the scheduling process may include repeatedly performing a series of processes: identifying the group to be scheduled as the target group; identifying available power data showing the change in available power over time; identifying judgment criterion power data showing the change in judgment criterion power over time based on the available power data; setting the permitted operating time period for the target group so that it includes the time when the judgment criterion power is highest; and updating the available power data by subtracting the power to be used by the target group from the available power during the set permitted operating time period.

[0008] This specification also discloses a program for a heat supply management server. The heat supply management server may be used in a heat supply system comprising a plurality of heat supply devices, a power generation facility capable of supplying electricity generated using renewable energy to the plurality of heat supply devices, and the heat supply management server. Each of the plurality of heat supply devices may include a heat storage unit for storing a heat medium and a heat source unit for heating the heat medium using electricity. Each of the plurality of heat supply devices may be capable of performing a heat storage operation in which the heat source unit heats the heat medium and stores the heated heat medium in the heat storage unit. Each of the plurality of heat supply devices may belong to any one of a plurality of groups. The program may cause the heat supply management server to perform the steps of acquiring supplyable power data showing the change over time of supplyable power, which is the electricity that can be supplied from the power generation facility to the plurality of heat supply devices, and performing a scheduling process to set an operating permission time period, which is the time period in which the heat storage operation is permitted, for each of the plurality of groups based on the supplyable power data. The step of executing the scheduling process may include repeatedly performing a series of processes: identifying the group to be scheduled as the target group; identifying available power data showing the change in available power over time; identifying judgment criterion power data showing the change in judgment criterion power over time based on the available power data; setting the permitted operating time period for the target group so that it includes the time when the judgment criterion power is highest; and updating the available power data by subtracting the power to be used by the target group from the available power during the set permitted operating time period.

[0009] In the above configuration, scheduling can be achieved such that the sum of the power consumption of the thermal storage operations of multiple heat supply units exceeds the assumed available power. Therefore, if the power generated by the power generation equipment increases more than initially expected, and the available power increases more than initially expected, the increased available power can be used for the thermal storage operations of the heat supply units. In addition, in the above configuration, the operating permission time period for the target group is set so as to include the time when the judgment criterion power is highest, so scheduling can be achieved that matches the trend of increase or decrease in available power over time. Therefore, even if the power generated by the power generation equipment decreases uniformly from the initial expectations at all times, and the available power decreases uniformly from the initial expectations at all times, it is possible to suppress a significant decrease in the proportion of available power used in the thermal storage operations of each heat supply unit.

[0010] In a second embodiment, in the heat supply system of the first embodiment, the heat supply management server may be configured to shorten the duration of the permitted operating time period and then execute the scheduling process again if, after executing the scheduling process, the predetermined scheduling completion conditions are not met.

[0011] In the scheduling process, the shorter the duration of the permitted operating time slot for each group, the more accurately scheduling can be achieved that is aligned with the temporal increase or decrease trend of available power. With the above configuration, if the scheduling completion conditions are not met after the scheduling process is executed and the scheduling process is executed again, scheduling can be achieved that is aligned with the temporal increase or decrease trend of available power.

[0012] In a third embodiment, the heat supply system of the second embodiment may include the scheduling completion condition that the available power exceeds a predetermined threshold at all times.

[0013] With the above configuration, if, at the stage when scheduling has been performed for all groups, the available power does not exceed a predetermined threshold at any given time, the scheduling completion condition is not met, and the scheduling process is executed again. With this configuration, if the predetermined threshold is set to zero or a positive value, scheduling can be achieved so that the sum of the power consumption when multiple heat supply devices are actually performing thermal storage operation does not exceed the actual available power supply as much as possible. Furthermore, if the predetermined threshold is set to a negative value, scheduling can be achieved so that the power consumption when multiple heat supply devices are actually performing thermal storage operation uses up as much of the actual available power supply as possible.

[0014] In a fourth embodiment, in the heat supply system of the second or third embodiment, each of the plurality of heat supply devices may further include an auxiliary heat source that uses fuel to heat the heat transfer medium.

[0015] If the operating time period for each group is shortened, there is a risk that each heat supply unit will not be able to secure the necessary amount of heat when performing thermal storage operation. With the above configuration, since each heat supply unit is equipped with an auxiliary heat source, even if shortening the operating time period for each group results in each heat supply unit being unable to secure the necessary amount of heat storage, the heat transfer medium can be heated by the auxiliary heat source. Convenience for the users of each heat supply unit can be ensured.

[0016] In the fifth embodiment, in the heat supply system of any one of the second to fourth embodiments, the initial value of the duration of the permitted operating period may be set based on the maximum duration of the heat storage operation in each of the plurality of heat supply devices.

[0017] With the above configuration, scheduling can be achieved such that the length of the permitted operating time for each group is close to the maximum operating time for the thermal storage operation of each heat supply unit.

[0018] In the sixth embodiment, in the heat supply system of any one of the first to fifth embodiments, the criterion power may be specified as the minimum value of the usable power over a predetermined time interval.

[0019] When setting the operating permission time period for a target group so that it includes the time when the judgment criterion power is highest, if there is a steep peak in the judgment criterion power, the scheduling will result in many groups' operating permission time periods being concentrated at the time of that peak. In this case, the sum of the power consumption of the heat storage operation of the heat supply equipment in the time periods before and after that peak may exceed the expected available power. With the above configuration, since the judgment criterion power is identified as the minimum value of usable power within a predetermined time range, scheduling that eliminates the impact of a steep peak in usable power can be achieved.

[0020] In the seventh embodiment, in the heat supply system of any one of the first to fifth embodiments, the criterion power may be specified as the average value of the available power over a predetermined time period.

[0021] When setting the operating permission time period for a target group so that it includes the time when the judgment criterion power is highest, if there is a steep peak in the judgment criterion power, the scheduling will result in many groups' operating permission time periods being concentrated at the time of that peak. In this case, the sum of the power consumption of the heat supply equipment's thermal storage operation in the time periods before and after that peak may exceed the expected available power. With the above configuration, since the judgment criterion power is identified as the average value of the available power over a predetermined time range, scheduling can be achieved that eliminates the impact of a steep peak in the available power.

[0022] In the eighth aspect, in the heat supply system according to any one of the first to seventh aspects, the set target group may be specified according to a group order list. The heat supply management server may be configured to change the group order list at predetermined intervals.

[0023] When performing scheduling processing based on available power data, since the daily fluctuations of the available power data are not so large, it is considered that the results of daily scheduling do not change so much. Therefore, when the set target group is specified according to the group order list, if the group order list is not changed regularly, the operation permission time zones of each group may become the same time zones every day. According to the above configuration, since the group order list is changed regularly, it is possible to suppress the occurrence of bias in the operation permission time zones of each group.

[0024] In the ninth aspect, in the heat supply system according to any one of the first to seventh aspects, each of the plurality of heat supply devices may be configured to change the group to which it belongs among the plurality of groups at predetermined intervals.

[0025] According to the above configuration, even when the operation permission time zones of each group become the same time zones every day, it is possible to suppress the occurrence of bias in the operation permission time zones of each heat supply device.

[0026] In the tenth aspect, in the heat supply system according to any one of the first to ninth aspects, each of the plurality of heat supply devices may hold an alternative time table including at least one time zone. Each of the plurality of heat supply devices may be configured to set, as its own operation permission time zone, one time zone selected from the at least one time zone of the alternative time table when communication with the heat supply management server becomes unavailable.

[0027] According to the above configuration, even when each heat supply device becomes unable to communicate with the heat supply management server and cannot obtain the scheduling result from the heat supply management server, it can execute the heat storage operation at an appropriate time zone.

[0028] In the eleventh aspect, in the heat supply system of the tenth aspect, the alternative time table may include a plurality of time zones. Each of the plurality of heat supply devices may be configured to change the time zone selected as the operation permission time zone from the plurality of time zones of the alternative time table at predetermined intervals.

[0029] According to the above configuration, it is possible to suppress the occurrence of bias in the operation permission time zone of the heat supply device that has become unable to communicate with the heat supply management server.

Brief Description of the Drawings

[0030] [Figure 1] It is a diagram schematically showing the configuration of the hot water supply system 100 of the embodiment. [Figure 2] It is a diagram schematically showing the configuration of the storage type hot water supply device 104 of the embodiment. [Figure 3] It is a flowchart of the scheduling process of the operation permission time zone executed by the hot water supply management server 116 of the embodiment. [Figure 4] It is a graph showing an example of surplus power data in the embodiment. [Figure 5] It is a graph showing examples of available power data and determination reference power data in the embodiment. [Figure 6] It is a diagram showing a state where the operation time zone of group A is specified in the embodiment. [Figure 7] It is a graph showing an example of available power data after the operation time zone of group A is specified in the embodiment. [Figure 8] It is a graph showing examples of available power data and determination reference power data after the operation time zone of group A is specified in the embodiment. [Figure 9]This figure shows how the operating time period for group B is determined in the example. [Figure 10] This figure shows examples of surplus power data and planned power usage data after scheduling processing has been performed in the embodiment. [Figure 11] This figure shows another example of surplus power data and planned power usage data after scheduling processing has been performed in the embodiment. [Figure 12] This figure shows yet another example of surplus power data and planned power usage data after scheduling processing has been performed in the embodiment. [Figure 13] This figure shows an example of an alternative timetable maintained by the storage-type water heater 104 in the embodiment. [Figure 14] This figure shows an example of the time period during which hot water is supplied in a residence 102 where the storage-type water heater 104 of the embodiment is installed. [Modes for carrying out the invention]

[0031] (Examples) As shown in Figure 1, the hot water supply system 100 according to this embodiment includes multiple storage-type water heaters 104a, 104b, ... and multiple home gateways 106a, 106b, ... installed in each of multiple residences 102a, 102b, ..., as well as power generation equipment 110 and a power management server 112 managed by the power company 108, and a hot water supply management server 116 managed by the manufacturer 114 of the storage-type water heaters 104a, 104b, .... The multiple home gateways 106a, 106b, ..., the power management server 112, and the hot water supply management server 116 are each connected to the Internet 118.

[0032] In the following explanation, each of the multiple residences 102a, 102b, ..., each of the multiple storage-type water heaters 104a, 104b, ..., and each of the multiple home gateways 106a, 106b, ... may be simply referred to as residence 102, storage-type water heater 104, and home gateway 106.

[0033] (Storage-type water heater 104) As shown in Figure 2, the storage-type water heater 104 according to this embodiment includes an HP (heat pump) unit 4, a tank unit 6, and a burner unit 8.

[0034] (HP Unit 4) HP Unit 4 is a heat source that heats water by absorbing heat from the outside air. HP Unit 4 is equipped with an HP heat source 17 consisting of a compressor 10, a condenser 12, an expansion valve 14, and an evaporator 16. HP Unit 4 heats water by absorbing heat from the outside air by circulating a refrigerant (e.g., a fluorocarbon refrigerant) in the order of compressor 10, condenser 12, expansion valve 14, and evaporator 16. The compressor 10 pressurizes the refrigerant to high temperature and high pressure. The condenser 12 cools the refrigerant by heat exchange with water. HP supply path 19 and HP return path 21 are connected to both ends of the water flow path of the condenser 12, respectively. The expansion valve 14 reduces the pressure of the refrigerant to low temperature and low pressure. The evaporator 16 heats the refrigerant by heat exchange with the outside air. The HP unit 4 further includes a circulation pump 18 for circulating water to the condenser 12, a supply thermistor 20 for detecting the temperature of the water flowing into the condenser 12, a return thermistor 22 for detecting the temperature of the water flowing out of the condenser 12, an ambient temperature thermistor 23 for detecting the ambient temperature, and an HP controller 24 for controlling the operation of each component of the HP unit 4.

[0035] (Tank Unit 6) The tank unit 6 comprises a tank 30, a mixing valve 32, and a bypass control valve 34. The tank 30 is a sealed container that stores water inside, with its exterior covered in insulating material. The capacity of the tank 30 in this embodiment is, for example, 100 liters. When the circulation pump 18 of the HP unit 4 is driven, the water at the bottom of the tank 30 is sent to the condenser 12 via the tank supply path 31 and the HP supply path 19. The water, heated to a high temperature in the condenser 12, is returned to the tank 30 from the top of the tank 30 via the HP return path 21 and the tank return path 33. When the water heated by the HP unit 4 flows into the tank 30, a temperature stratification is formed inside the tank 30, in which a layer of high-temperature water is stacked on top of a layer of low-temperature water. The tank 30 is equipped with an upper thermistor 36 for detecting the temperature of the water at the top, an intermediate thermistor 37 for detecting the temperature of the water in the middle, and a lower thermistor 38 for detecting the temperature of the water at the bottom.

[0036] The tank unit 6 is supplied with tap water via a water supply path 40. The water supply path 40 is equipped with a pressure reducing valve 42 for reducing the water supply pressure and an inlet thermistor 44 for detecting the water supply temperature. The water supply path 40 branches into a tank water supply path 46 that communicates with the bottom of the tank 30 and a tank bypass path 48 that communicates with the mixing valve 32. Check valves 50 and 52 are installed in the tank water supply path 46 and the tank bypass path 48, respectively. The tank bypass path 48 is also equipped with a water-side water flow sensor 54 for detecting the flow rate of tap water flowing into the mixing valve 32. The top of the tank 30 and the mixing valve 32 are connected via a tank hot water outlet path 56. The tank hot water outlet path 56 is equipped with a check valve 58 and a hot water-side water flow sensor 60 for detecting the flow rate of water from the tank 30 flowing into the mixing valve 32.

[0037] The mixing valve 32 mixes tap water flowing in from the tank bypass path 48 with water from the tank 30 flowing in from the tank hot water outlet path 56 and sends the mixture to the first hot water supply path 62. The mixing valve 32 is driven by a stepping motor (not shown) to adjust the opening degree on the tank bypass path 48 side (opening degree on the cold water side) and the opening degree on the tank hot water outlet path 56 side (opening degree on the hot water side). A mixing thermistor 64 is installed in the first hot water supply path 62 to detect the temperature of the water sent out from the mixing valve 32.

[0038] Hot water is supplied from the tank unit 6 to hot water outlets such as kitchens, showers, and faucets via a second hot water supply route 66. The second hot water supply route 66 is equipped with a hot water outlet thermistor 68 for detecting the temperature of the water supplied to the hot water outlets, and a check valve 70. The first hot water supply route 62 and the second hot water supply route 66 are connected by a hot water bypass route 72. A bypass control valve 34 is installed in the hot water bypass route 72. The tank unit 6 is further equipped with a tank controller 74 that controls the operation of each component of the tank unit 6.

[0039] (Burner unit 8) The burner unit 8 includes a burner 80, a heat exchanger 82, a bypass servo 84, a water flow servo 86, and a hot water supply valve 88. The burner 80 is an auxiliary heat source that heats the water flowing through the heat exchanger 82 by burning fuel gas. Fuel gas is supplied to the burner 80 via a gas supply pipe (not shown). Water from the first hot water supply path 62 of the tank unit 6 flows into the heat exchanger 82 via the burner forward path 90. The water that has passed through the heat exchanger 82 flows out to the second hot water supply path 66 of the tank unit 6 via the burner return path 92. The burner forward path 90 is equipped with a water flow servo 86 that adjusts the flow rate of water flowing through the burner forward path 90, and a water flow sensor 91 that detects the flow rate of water flowing through the burner forward path 90. The burner forward path 90 and the burner return path 92 are connected via a burner bypass path 94. A bypass servo 84 is installed at the connection point between the burner supply path 90 and the burner bypass path 94. The bypass servo 84 adjusts the flow rate of water from the burner supply path 90 to the burner bypass path 94. A burner hot water thermistor 96 is installed on the burner return path 92 to detect the temperature of the water flowing out of the heat exchanger 82. A hot water filling path 98 branches off from the burner return path 92. A hot water filling valve 88 is installed on the hot water filling path 98. Hot water is supplied from the burner unit 8 to the bathtub, which is the hot water supply point, via the hot water filling path 98.

[0040] The burner unit 8 further includes a burner controller 97 and a remote control 99 that can communicate with the burner controller 97. The burner controller 97 controls the operation of each component of the burner unit 8. The remote control 99 accepts various operation inputs from the user via switches, buttons, etc. The remote control 99 also notifies the user of various information regarding the settings and operation of the storage-type water heater 104 through displays and voice.

[0041] The HP controller 24, tank controller 74, burner controller 97, and remote control 99 are all equipped with a control unit such as a CPU, ROM, and RAM, and a storage unit such as an EEPROM. The control unit executes various processes according to the program stored in the storage unit. The HP controller 24 and the tank controller 74 can communicate with each other. The tank controller 74 and the burner controller 97 can communicate with each other. Therefore, by the coordinated control of the HP controller 24, the tank controller 74, and the burner controller 97, the storage-type water heater 104 can perform various operations such as boiling operation and hot water supply operation. Hereafter, the HP controller 24, the tank controller 74, and the burner controller 97 will be collectively referred to simply as controllers.

[0042] (Boiling operation) During boiling operation, the storage-type water heater 104 drives the HP unit 4 to heat the water in the tank 30. When boiling operation begins, the controller drives the compressor 10 of the HP heat source 17 to circulate the refrigerant in the order of compressor 10, condenser 12, expansion valve 14, and evaporator 16, and also drives the circulation pump 18 to circulate water between the tank 30 and the condenser 12. As a result, the water drawn from the bottom of the tank 30 is heated to the target boiling temperature in the condenser 12 and returned to the top of the tank 30. When the temperature detected by the supply thermistor 20 reaches the target boiling temperature, the controller determines that all the water in the tank 30 has been replaced with water heated to the target boiling temperature and terminates the boiling operation.

[0043] (Hot water supply operation) During hot water supply operation, water at the set hot water temperature is supplied to the hot water supply location. The set hot water temperature is set by the user. When the controller determines that the hot water supply has started due to opening a faucet or filling a bathtub, etc., when the sum of the flow rate detected by the water-side water flow sensor 54 and the flow rate detected by the hot water-side water flow sensor 60 (also called the hot water supply flow rate) is equal to or greater than the minimum operating flow rate, the controller determines that hot water supply has started to the hot water supply location. The controller then performs either non-combustion hot water supply operation or combustion hot water supply operation according to the temperature detected by the upper thermistor 36.

[0044] The controller performs non-combustion hot water supply operation if the temperature detected by the upper thermistor 36 is equal to or above the hot water supply set temperature. In non-combustion hot water supply operation, the controller prohibits combustion operation of the burner 80 and adjusts the opening of the mixing valve 32 so that the temperature detected by the mixing thermistor 64 becomes the hot water supply set temperature. As a result, water that has been temperature-adjusted to the hot water supply set temperature is supplied to the hot water supply location.

[0045] Furthermore, the controller executes combustion hot water supply operation if the temperature detected by the upper thermistor 36 is below the hot water supply set temperature. In combustion hot water supply operation, the controller permits combustion operation of the burner 80 and adjusts the opening of the mixing valve 32 so that the temperature detected by the mixing thermistor 64 is lower than the hot water supply set temperature by the minimum heating capacity of the burner 80. In this case, the high-temperature water supplied from the top of the tank 30 and the low-temperature water supplied from the water supply path 40 are mixed in the mixing valve 32, then heated to the hot water supply set temperature by the burner 80 and supplied to the hot water supply location. Note that combustion hot water supply operation also includes the case where the mixing valve 32 is fixed in a fully closed position on the tank 30 side. In this case, the controller adjusts the heating capacity of the burner 80 so that the water heated by the burner 80 reaches the hot water supply set temperature.

[0046] If the hot water flow rate falls below the minimum operating flow rate while the above-mentioned non-combustion or combustion hot water supply operation is being performed, the controller will determine that the hot water supply to the hot water source has ended, such as by closing the tap or finishing filling the bathtub, and will terminate the hot water supply operation.

[0047] (Home Gateway 106) As shown in Figure 1, the home gateway 106 can communicate with the controller of the storage-type water heater 104, for example, via a wireless LAN. The controller of the storage-type water heater 104 can connect to the internet 118 via the home gateway 106.

[0048] (Power generation equipment 110) The power generation facility 110 is a facility that generates electricity using renewable energy sources such as solar power, wind power, wave power / tidal power, and flowing water / tides. The power company 108 supplies the electricity generated by the power generation facility 110 to multiple residences 102a, 102b, ... and other consumers. In addition, the power company 108 can also procure electricity from other power generation facilities other than the power generation facility 110 and supply it to multiple residences 102a, 102b, ... but if the electricity generated by the power generation facility 110 is available, the power company 108 will prioritize supplying the electricity generated by the power generation facility 110.

[0049] (Power management server 112) The power management server 112 includes a control unit such as a CPU, ROM, and RAM, and a storage unit such as an HDD or SSD. The control unit executes various processes according to the programs stored in the storage unit. Based on the actual power generated by the power generation equipment 110 over a predetermined past period (for example, one year), the power management server 112 estimates power generation data that shows the change over time of the power generated by the power generation equipment 110 on the current day. Alternatively, the power management server 11 may estimate power generation data that shows the change over time of the power generated by the power generation equipment 110 on the current day based on weather data over a predetermined past period, the actual power generated by the power generation equipment 110, and the weather forecast data for the current day. Furthermore, the power management server 112 estimates planned power supply data showing the time-series changes in the planned power supply to be supplied from the power generation facility 110 to multiple customers other than residences 102a, 102b, ... on a given day, based on the actual power supply data supplied from the power generation facility 110 to multiple customers other than residences 102a, 102b, ... over a predetermined past period (for example, one year). Alternatively, the power management server 11 may estimate planned power supply data showing the time-series changes in the planned power supply to be supplied from the power generation facility 110 to multiple customers other than residences 102a, 102b, ... on a given day, based on weather data from a predetermined past period, the actual power supply data supplied from the power generation facility 110 to multiple customers other than residences 102a, 102b, ... and the weather forecast data for the day. The power management server 112 estimates surplus power data, which shows the time-dependent changes in the surplus power that can be supplied from the power generation facility 110 to multiple residences 102a, 102b, ... on that day, at a predetermined time each day (for example, 0:00), based on the power generation data and the planned power supply data.

[0050] (Hot water supply management server 116) The hot water supply management server 116 is equipped with a control unit such as a CPU, ROM, and RAM, and a storage unit such as an HDD or SSD. The control unit executes various processes according to the programs stored in the storage unit. The hot water supply management server 116 can communicate with the power management server 112 via the internet 118. The hot water supply management server 116 can also communicate with each of the controllers of the multiple storage-type water heaters 104a, 104b, ... via the internet 118. The hot water supply management server 116 classifies each of the multiple storage-type water heaters 104a, 104b, ... into one of several groups and manages them. Each of the multiple groups contains one or more of the multiple storage-type water heaters 104a, 104b, ... For example, storage-type water heater 104a belongs to group A, storage-type water heater 104b belongs to group B, and the other storage-type water heaters 104 each belong to their respective groups.

[0051] (Scheduling of permitted driving hours) The hot water supply management server 116 performs scheduling for the operating permission time period for each of the multiple groups of storage-type water heaters 104a, 104b, ..., in order to maximize the proportion of electricity used by electricity generated by the power generation equipment 110. The multiple storage-type water heaters 104a, 104b, ... will perform heating operation as needed if the current time falls within the operating permission time period, and will not perform heating operation if the current time falls outside the operating permission time period. The hot water supply management server 116 performs the processing shown in Figure 3 every day at a predetermined time (for example, 2 o'clock).

[0052] In S2, the hot water supply management server 116 obtains surplus power data from the power management server 112. In this embodiment, the hot water supply management server 116 queries the power management server 112 for surplus power data, and the power management server 112 sends the surplus power data to the hot water supply management server 116 as a response to the query. Alternatively, the surplus power data may be sent periodically (for example, once a day) from the power management server 112 to the hot water supply management server 116. Through the processing in S2, surplus power data as shown in Figure 4 is obtained.

[0053] As shown in Figure 3, in S4, the hot water supply management server 116 identifies the group order list. The group order list indicates the order in which scheduling is performed for each group, for example, group A as the first, group B as the second, and so on.

[0054] In S6, the hot water supply management server 116 sets the initial value of the time length ΔT for the permitted operating time period. The initial value of the time length ΔT is set to, for example, the maximum time required for the boiling operation of the storage-type water heater 104 (e.g., 3 hours).

[0055] In S8, the hot water supply management server 116 identifies the groups to be set as target groups for setting the permitted operating time period, based on the group sequence list identified in S4.

[0056] In S10, the hot water supply management server 116 calculates available power data based on the surplus power data acquired in S2 and the planned power usage data. In this embodiment, the planned power usage data shows the change over time of the planned power usage, which is the power that will be used for the boiling operation of the storage-type water heater 104 belonging to a group for which operating permission time periods have already been set. For each time of day, the hot water supply management server 116 calculates available power data that shows the change over time of available power by calculating the available power by subtracting the planned power usage from the surplus power.

[0057] In S12, the hot water supply management server 116 sets the permitted operating time for the target group so that the permitted operating time for the target group is allocated to the time when there is the greatest surplus of available power. In this embodiment, the hot water supply management server 116 calculates the minimum value of available power within a time range of ±ΔT / 2 centered on that time for all times of the day as the criterion power. Based on the criterion power data showing the change in the criterion power over time, the server sets the permitted operating time for the target group so that the center time of the permitted operating time for the target group (the time exactly halfway between the start and end times of the permitted operating time) coincides with the time when the criterion power is at its maximum. Alternatively, the hot water supply management server 116 may calculate the average value of available power within a time range of ±ΔT / 2 centered on that time for all times of the day as the criterion power. Alternatively, the hot water supply management server 116 may calculate the minimum or average value of available power over a time interval of +ΔT following each time of day as the criterion power, and based on the criterion power data showing the change in criterion power over time, set the permitted operating time for the target group so that the start time of the permitted operating time for the target group coincides with the time when the criterion power is at its maximum. Alternatively, the hot water supply management server 116 may calculate the minimum or average value of available power over a time interval of -ΔT preceding each time of day as the criterion power, and based on the criterion power data showing the change in criterion power over time, set the permitted operating time for the target group so that the end time of the permitted operating time for the target group coincides with the time when the criterion power is at its maximum.

[0058] In S14, the hot water supply management server 116 updates the planned power usage data based on the power consumption ΔW of the storage-type water heater 104 belonging to the target group for which the permitted operating time period was set in S12, and the permitted operating time period set in S12.

[0059] In S16, the hot water supply management server 116 determines whether scheduling has been completed for all groups. If scheduling has not been completed for all groups (NO), the process returns to S8.

[0060] By repeatedly executing the processes from S8 to S16, the permitted operating time zones for each group are sequentially set according to the group sequence list identified in S4. For example, when setting the permitted operating time zone for the first group A in the group sequence list, the planned power usage data is zero at all times, so the available power data is equal to the surplus power data. Then, as shown in Figure 5, the judgment criterion power data is calculated based on the available power data, and as shown in Figure 6, the permitted operating time zone for group A is set so that the center time of the permitted operating time zone coincides with the time when the judgment criterion power data is at its maximum. Subsequently, when setting the permitted operating time zone for the second group B in the group sequence list, the power to be used in the boiling operation performed by the storage-type water heater 104 belonging to group A is reflected in the planned power usage data, so as shown in Figure 7, the available power data is obtained by subtracting the planned power usage data from the surplus power data. Then, as shown in Figure 8, the judgment criterion power data is calculated based on the available power data, and as shown in Figure 9, the permitted operating time zone for group B is set so that the center time of the permitted operating time zone coincides with the time when the judgment criterion power data is at its maximum. This process of setting permitted driving time slots for each group will be implemented for all groups.

[0061] In Figure 3, at S16, once scheduling is complete for all groups (resulting in a YES response), the process proceeds to S18.

[0062] In S18, the hot water supply management server 116 determines whether the scheduling completion conditions are met. In this embodiment, the hot water supply management server 116 determines that the scheduling completion conditions are met if, at all times on the day, the available power obtained by subtracting the power to be used from the surplus power exceeds a predetermined threshold, and determines that the scheduling completion conditions are not met otherwise. If the scheduling completion conditions are not met in S18 (NO), the process proceeds to S20.

[0063] The predetermined threshold used in S18 is set based on the power company 108's surplus power usage policy. For example, as shown in Figure 10, when scheduling is performed for all groups, there may be times during a certain period of the day when the planned power usage exceeds the surplus power. In this case, the power company 108 may have to procure power from other power generation facilities other than the power generation facility 110 for the amount of power usage that exceeds the surplus power. For this reason, if the power company 108 wants to ensure that the power actually consumed by the multiple storage-type water heaters 104a, 104b, ... does not exceed the surplus power as much as possible, the predetermined threshold used in S18 in Figure 3 is set to zero or a positive value. This makes it possible to achieve scheduling that ensures the power actually consumed by the multiple storage-type water heaters 104a, 104b, ... does not exceed the surplus power as much as possible. In contrast, if the power company 108 wants to avoid wasting surplus power even if the actual power consumed by multiple storage-type water heaters 104a, 104b, ... exceeds the surplus power, it sets the predetermined threshold used in S18 to a negative value (a value that allows for an amount exceeding the surplus power). This makes it possible to achieve scheduling that uses up as much of the surplus power as possible based on the actual power consumed by the multiple storage-type water heaters 104a, 104b, ...

[0064] In S20, the hot water supply management server 116 determines whether the duration ΔT of the permitted operating time period is less than or equal to the minimum duration (e.g., 0.5 hours). The minimum duration is set based on, for example, the minimum amount of hot water required in the tank 30 for the residence 102 (e.g., the amount of hot water used for showering). If the duration ΔT exceeds the minimum duration (i.e., NO), the process proceeds to S22.

[0065] In S22, the hot water supply management server 116 reduces the duration ΔT of the permitted operating time period by a predetermined time range (for example, 0.1 hours).

[0066] In S24, the hot water supply management server 116 resets all schedules set by the processes from S8 to S22. After S24, the process returns to S8. Then, with the duration ΔT of the permitted operating time period shortened, the permitted operating time periods are set again, starting from the first group in the group order list. This configuration allows for more effective use of surplus power, and the permitted operating time periods for each group are rescheduled accordingly.

[0067] If the scheduling completion condition is met in S18 (YES), rescheduling is not necessary, and the process proceeds to S26. Also, if the time length ΔT in S20 is less than or equal to the lower limit time length (YES), the time length ΔT of the permitted operating time period cannot be reduced any further, and effective rescheduling cannot be performed, so in this case the process also proceeds to S26.

[0068] In S26, the hot water supply management server 116 sends the scheduled operating permission time slots for each group to the controllers of the storage-type water heaters 104 belonging to each group. The hot water supply management server 116 may also store the scheduled operating permission time slots for each group in a scheduling table, and the storage-type water heaters 104 may query the hot water supply management server 116 for the operating permission time slots of the group to which they belong, as needed. After S26, the process shown in Figure 3 is completed.

[0069] (Rotation of group order list) By executing scheduling using the process shown in Figure 3, the permitted operating time slots for the first group A, the second group B, ..., and the eighth group H are set, for example, as shown in Figure 11. In the process shown in Figure 3, if the surplus power data acquired in S2 is similar for the current day and the previous day, similar scheduling results will be obtained for the current day and the previous day. Therefore, if the same group order list is used every day when identifying the group order list in S4 of Figure 3, the permitted operating time slots for each group will be similar every day, which may lead to a bias in the permitted operating time slots for each group. Therefore, by changing the order of the groups every predetermined period (for example, one week) when identifying the group order list in S4, the permitted operating time slots assigned to each group can be changed, as shown in Figure 12, and a bias in the permitted operating time slots for each group can be suppressed.

[0070] (Rotation of the group to which storage-type water heater 104 belongs) Alternatively, when identifying the group order list in S4 of Figure 3, even if the same group order list is used every day and the permitted operating time periods for each group are similar every day, it is possible to prevent bias in the permitted operating time periods for each of the multiple storage-type water heaters 104a, 104b, ... by changing the group to which each of the multiple groups belongs, for example, every predetermined period (for example, one week).

[0071] (Scheduling of the storage-type water heater 104 when communication with the hot water supply management server 116 is not possible) In some cases, one or more of the storage-type water heaters 104a, 104b, ... may lose communication with the water supply management server 116. In this embodiment, in such a case, the storage-type water heater 104' that has lost communication with the water supply management server 116 sets its permitted operating time for the day based on an alternative timetable stored in the controller. The alternative timetable may be set by the manufacturer 114 before the storage-type water heater 104' is shipped from the factory, or it may be set by the user when the storage-type water heater 104' is in use.

[0072] For example, as shown in Figure 13, the alternative timetable includes five time slots (a: 9:00-11:00, b: 10:00-12:00, c: 11:00-13:00, d: 12:00-14:00, e: 13:00-15:00). When the controller of the storage-type water heater 104' detects that communication with the hot water supply management server 116 is impossible, it selects one time slot from the alternative timetable and sets that time slot as an permitted operating time slot. In this case, the controller of the storage-type water heater 104' can change the time slot selected from the alternative timetable every predetermined period (for example, every day) to prevent an imbalance in the permitted operating time slots of the storage-type water heater 104'.

[0073] (modified version) In the above embodiment, a hot water supply system 100 was described as an example of a heat supply system, and a storage-type water heater 104 was described as an example of a heat supply device. However, the heat supply system and heat supply device may supply heat for other purposes such as heating. In this case, the heat transfer medium may be a heat transfer medium other than water, such as antifreeze. Also, in the above embodiment, a tank unit 6 was described as an example of a heat storage unit, but the heat storage unit may store the heat transfer medium in other forms. Furthermore, in the above embodiment, an HP unit 4 was described as an example of a heat source unit, but the heat source unit may heat the heat transfer medium in other forms such as an electric heater.

[0074] In the above embodiment, a configuration was described in which the power management server 112 transmits surplus power data, which shows the change over time of surplus power of the power generation equipment 110, to the hot water supply management server 116 as data showing the change over time of the amount of power that can be supplied from the power generation equipment 110 to multiple storage-type water heaters 104a, 104b, ... on a given day. Alternatively, the power management server 112 may transmit power generation data, which shows the change over time of power generated by the power generation equipment 110, to the hot water supply management server 116 as data showing the change over time of the amount of power that can be supplied from the power generation equipment 110 to multiple storage-type water heaters 104a, 104b, ... on a given day.

[0075] In the above embodiment, the hot water supply management server 116 was configured to set permitted operating time periods for each group for all time periods (for example, from 2:00 AM to 2:00 AM the following day), permit boiling operation if the current time falls within the permitted operating time period, and prohibit boiling operation if the current time falls outside of the permitted operating time period. Alternatively, the hot water supply management server 116 may be configured to set permitted operating time periods for each group only for specific time periods when there is a large surplus of power (for example, from 6:00 AM to 6:00 PM the following day), permit boiling operation if the current time falls within the permitted operating time period, and prohibit boiling operation if the current time falls outside of the permitted operating time period. In this case, boiling operation may be permitted for all groups during time periods other than those mentioned above (for example, from 2:00 AM to 6:00 AM the following day, and from 6:00 PM the following day to 2:00 AM the following day). Alternatively, the hot water supply management server 116 may be configured to allow all groups to perform boiling operations during times other than those mentioned above (for example, from 2:00 to 6:00 on the same day, and from 18:00 on the same day to 2:00 the following day) when the electricity market price at which the power company 108 procures electricity from the electricity market is below a predetermined price, and to prohibit all groups from performing boiling operations during times when the electricity market price is above the predetermined price.

[0076] The controller of the storage-type water heater 104 may set the boiling operation time for the day based on past hot water usage records in the residence 102. The setting process by which the boiling operation time is set by the storage-type water heater 104 through learning control will be explained below with reference to Figure 14.

[0077] The controller stores, each time hot water is supplied to residence 102, hot water supply time information indicating the time when hot water supply started and ended, and hot water supply volume information indicating the amount of hot water supplied. The controller also stores, each time the storage-type water heater 104 performs a boiling operation, boiling time information indicating the time when the boiling operation started and ended, and boiled water volume information indicating the amount of hot water heated during the boiling operation. The controller stores the hot water supply time information, hot water supply volume information, boiling time information, and boiled water volume information for one day as the daily operation history of residence 102. In this embodiment, the controller stores the operation history of residence 102 for the past seven days. Therefore, every 24 hours, the controller erases the operation history from eight days prior and stores the operation history for the previous day.

[0078] Next, the controller identifies the earliest time the first hot water supply was started during the past seven days, based on the operating history of residence 102 for the past seven days. Hereafter, this time will be referred to as the "first scheduled hot water supply start time S1". For example, the controller identifies 6:00 as the first scheduled hot water supply start time S1 (see Figure 14). In the initial hot water supply, approximately 5 to 20 liters of water are usually supplied. In this case, the controller sets the target water volume to be heated up to the first scheduled hot water supply start time S1 to 30 liters.

[0079] Furthermore, the controller identifies the earliest time the hot water filling operation started during the past seven days, based on the operating history of residence 102 for the past seven days. Hereafter, this time will be referred to as the "second scheduled hot water start time B1". In this embodiment, residence 102 is pre-set to start the hot water filling operation at 20:00 every day. For example, the controller identifies 20:00 as the second scheduled hot water start time B1 (see Figure 14). Note that approximately 150L to 180L of water is supplied during the hot water filling operation. In this case, the controller sets the target amount of water to be heated up until the second scheduled hot water start time B1 to 100L, which is the maximum capacity of the tank 30.

[0080] Furthermore, the controller identifies the latest time during which hot water service ended in the past seven days, based on the operating history of residence 102 for the past seven days. Hereafter, this time will be referred to as "hot water service end time G1". For example, the controller identifies 0:00 as hot water service end time G1 (see Figure 14).

[0081] Furthermore, the controller determines a first predetermined time α, a second predetermined time β, and a third predetermined time γ based on the target boiling temperature and the target water volume to be boiled. The first predetermined time α is the time required for the boiling operation performed before the first hot water supply to heat the target water volume (e.g., 30 L) to the target boiling temperature (e.g., 45 °C). The second predetermined time β is the time required for the boiling operation performed before the bath filling operation to heat the target water volume (e.g., 100 L) to the target boiling temperature (e.g., 45 °C). The third predetermined time γ is the time after the HP unit 4 is stopped, during which it is assumed that water at the set hot water temperature can be supplied to the hot water supply location until the hot water supply end time G1, using only the high-temperature water stored in the tank 30.

[0082] Next, as shown in Figure 14, the controller identifies the time α before the first scheduled hot water supply start time S1 as the first scheduled boiling start time S0, and the time β before the second scheduled hot water supply start time B1 as the second scheduled boiling start time B0. The controller also identifies the time γ before the third scheduled hot water supply end time G1 as the heat pump stop time G0. When the scheduled boiling start times S0 and B0 arrive, the controller starts the boiling operation. When the heat pump stop time G0 arrives, the controller prohibits the boiling operation. Note that the first scheduled hot water supply start time S1 can also be called the first scheduled boiling end time S1, and the second scheduled hot water supply start time B1 can also be called the second scheduled boiling end time B1.

[0083] Furthermore, if the time period for the boiling operation performed before the hot water filling operation on the day (from the second scheduled boiling start time B0 to the second scheduled boiling end time B1), which is set by the learning control described above, does not fall within the permitted operating time period scheduled by the hot water management server 116, the controller is configured to start the boiling operation when the start time of the permitted operating time period scheduled by the hot water management server 116 arrives, rather than when the second scheduled boiling start time B0 set by the learning control arrives. Alternatively, the controller may be configured to start the boiling operation performed before the first hot water supply on the day when the first scheduled boiling start time S0, set by the learning control, arrives, regardless of the permitted operating time period scheduled by the hot water management server 116. Furthermore, if the time period for the boiling operation performed before the first hot water supply of the day (from the first scheduled boiling start time S0 to the first scheduled boiling end time S1), which is set by the learning control described above, overlaps at least partially with the time period during which boiling operation is prohibited due to the electricity market price being above a predetermined price, the controller may be configured to reset the first scheduled boiling end time S1 to a time earlier than the start time of the time period during which boiling operation is prohibited, and to reset the first scheduled boiling start time S0 accordingly, and to start boiling operation when the reset first scheduled boiling start time S0 arrives.

[0084] As described above, in one or more embodiments, the hot water supply system 100 (an example of a heat supply system) comprises a plurality of storage-type water heaters 104 (an example of a heat supply device), a power generation facility 110 capable of supplying electricity generated using renewable energy to the plurality of storage-type water heaters 104, and a hot water supply management server 116 (an example of a heat supply management server). Each of the plurality of storage-type water heaters 104 comprises a tank unit 6 (an example of a heat storage unit) for storing water (an example of a heat transfer medium) and an HP unit 4 (an example of a heat source unit) for heating water using electricity. Each of the plurality of storage-type water heaters 104 is capable of performing a boiling operation (an example of a heat storage operation) in which the HP unit 4 heats water and stores the heated water in the tank unit 6. Each of the plurality of storage-type water heaters 104 belongs to one of a plurality of groups. The hot water supply management server 116 is configured to acquire surplus power data (example of supplyable power data) that shows the change over time of surplus power (example of supplyable power), which is the power that can be supplied from the power generation equipment 110 to multiple storage-type hot water heaters 104, and to perform scheduling processing to set an operating permission time period, which is the time period during which boiling operation is permitted for each of the multiple groups, based on the surplus power data. In the scheduling processing, the hot water supply management server 116 is configured to repeatedly perform a series of processes, which include identifying the group to be set as the target group, identifying the supplyable power data that shows the change over time of the supplyable power, identifying the judgment criterion power data that shows the change over time of the judgment criterion power based on the supplyable power data, setting the operating permission time period for the target group to include the time when the judgment criterion power is highest, and updating the supplyable power data by subtracting the power that the target group is scheduled to use from the supplyable power during the set operating permission time period.

[0085] In the above configuration, scheduling can be achieved such that the sum of the power consumption of the boiling operations of the multiple storage-type water heaters 104 exceeds the expected surplus power. Therefore, if the power generated by the power generation equipment 110 increases more than initially expected, and the surplus power increases more than initially expected, the increased surplus power can be used for the boiling operations of the storage-type water heaters 104. In addition, in the above configuration, the operating permission time period for the target group is set so as to include the time when the judgment criterion power is highest, so scheduling can be achieved that matches the trend of increase or decrease in surplus power over time. Therefore, even if the power generated by the power generation equipment 110 decreases uniformly from the initially expected level at all times, and the surplus power decreases uniformly from the initially expected level at all times, it is possible to suppress a significant decrease in the utilization rate of surplus power in the boiling operations of each storage-type water heater 104.

[0086] In one or more embodiments, the hot water supply management server 116 is configured to shorten the duration of the permitted operating time period and then re-execute the scheduling process if, after executing the scheduling process, the predetermined scheduling completion conditions are not met.

[0087] In the scheduling process, the shorter the duration of the permitted operating time slot for each group, the more accurate the scheduling becomes in relation to the temporal increase or decrease in surplus power. With the above configuration, if the scheduling completion conditions are not met after the scheduling process is executed and the scheduling process is executed again, scheduling can be achieved that is more accurate in relation to the temporal increase or decrease in surplus power.

[0088] In one or more embodiments, the scheduling completion condition includes the availability of power exceeding a predetermined threshold at all times.

[0089] With the above configuration, if, at the stage when scheduling has been performed for all groups, the available power does not exceed a predetermined threshold at any given time, the scheduling completion condition is not met, and the scheduling process is executed again. With this configuration, if the predetermined threshold is set to zero or a positive value, scheduling can be achieved so that the sum of the power consumption when multiple storage-type water heaters 104 actually perform boiling operations does not exceed the actual surplus power as much as possible. Furthermore, if the predetermined threshold is set to a negative value, scheduling can be achieved so that the power consumption when multiple storage-type water heaters 104 actually perform boiling operations makes use of the actual surplus power as much as possible.

[0090] In one or more embodiments, each of the multiple storage-type water heaters 104 further comprises a burner unit 8 (example of an auxiliary heat source) that uses fuel to heat water.

[0091] If the operating time period for each group is shortened, there is a risk that each storage-type water heater 104 will not be able to secure the necessary amount of heat when it performs boiling operation. With the above configuration, since each storage-type water heater 104 is equipped with a burner unit 8, even if shortening the operating time period for each group results in each storage-type water heater 104 being unable to secure the necessary amount of heat, the water can still be heated by the burner unit 8. This ensures the convenience of each user of the storage-type water heater 104.

[0092] In one or more embodiments, the initial value of the permitted operating time period is set based on the maximum boiling time for each of the multiple storage-type water heaters 104.

[0093] According to the above configuration, scheduling can be achieved such that the length of the permitted operating time for each group is close to the maximum operating time for the boiling operation of each storage-type water heater 104.

[0094] In one or more embodiments, the criterion power is defined as the minimum available power over a predetermined time interval. In one or more embodiments, the criterion power is defined as the average value of available power over a predetermined time interval.

[0095] If the operating permission time period for a target group is set so that it includes the time when the judgment criterion power is highest, then if there is a steep peak in the judgment criterion power, the scheduling will result in many groups' operating permission time periods being concentrated at the time of that peak. In this case, the total power consumption of the boiling operation of the storage-type water heater 104 in the time periods before and after that peak may exceed the expected surplus power. With the above configuration, since the judgment criterion power is identified as the minimum value of usable power within a predetermined time range, even if there is a steep peak in usable power, scheduling that eliminates the influence of that peak can be achieved.

[0096] In one or more embodiments, the target group is identified according to a group sequence list. The hot water supply management server 116 is configured to change the group sequence list at predetermined intervals.

[0097] When scheduling is performed based on surplus power data, the daily fluctuations in surplus power data are not very large, so the results of daily scheduling are not expected to vary significantly. For this reason, if the target groups are identified according to a group sequence list, there is a risk that the operating hours permitted for each group will be similar every day unless the group sequence list is changed periodically. With the above configuration, the group sequence list is changed periodically, which helps to prevent bias in the operating hours permitted for each group.

[0098] In one or more embodiments, each of the multiple storage-type water heaters 104 is configured to change the group to which it belongs from among multiple groups at predetermined intervals.

[0099] According to the above configuration, even if the permitted operating hours for each group are similar every day, it is possible to prevent bias in the permitted operating hours for each storage-type water heater 104.

[0100] In one or more embodiments, each of the multiple storage-type water heaters 104 maintains an alternative timetable that includes at least one time period. Each of the multiple storage-type water heaters 104 is configured to set one time period selected from at least one time period in the alternative timetable as its permitted operating time period if communication with the water supply management server 116 becomes impossible.

[0101] According to the above configuration, even if each storage-type water heater 104 becomes unable to communicate with the hot water supply management server 116 and is unable to obtain scheduling results from the hot water supply management server 116, it can still perform a water heating operation at an appropriate time.

[0102] In one or more embodiments, the alternative timetable includes multiple time zones. Each of the multiple storage-type water heaters 104 is configured to change the time zone selected as the permitted operating time zone from the multiple time zones of the alternative timetable at predetermined intervals.

[0103] According to the above configuration, it is possible to suppress the imbalance in the operating time periods of the storage-type water heater 104 that has lost communication with the hot water supply management server 116.

[0104] Although each embodiment has been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness. [Explanation of Symbols]

[0105] 4: HP Unit 6: Tank Unit 8: Burner Unit 10: Compressor 12: Condenser 14: Expansion valve 16: Evaporator 17:HP heat source 18: Circulation pump 19: Route to HP 20: Outbound thermistor 21: HP return route 22: Return thermistor 23: Outdoor temperature thermistor 24: HP Controller 30: Tank 31: Route to the tank 32: Mixing valve 33: Tank return route 34: Bypass control valve 36: Upper thermistor 37: Intermediate thermistor 38: Lower thermistor 40: Water supply route 42: Pressure Reducing Valve 44: Inlet thermistor 46: Tank water supply route 48: Tank bypass route 50: Check valve 52: Check valve 54: Water side water volume sensor 56: Tank hot water outlet route 58: Check valve 60: Hot water flow sensor 62: First hot water supply route 64: Mixed Thermistor 66: Second hot water supply route 68: Hot water outlet thermistor 70: Check valve 72: Hot water bypass route 74: Tank Controller 80: Burner 82: Heat exchanger 84: Bypass Servo 86: Water volume servo 88: Hot water valve 90: Outbound journey to Burna 91: Water volume sensor 92: Return trip to Burna 94: Burner Bypass Route 96: Burner hot water thermistor 97: Burner Controller 98: Bathtub filling route 99: Remote control 100: Hot water supply system 102: Residence 102a: Residence 102b: Residence 104: Storage-type water heater 104a: Storage-type water heater 104b: Storage-type water heater 106: Home Gateway 106a: Home Gateway 106b: Home Gateway 108:Electric power company 110: Power generation equipment 112: Power management server 114: Manufacturer 116: Hot water supply management server 118: Internet

Claims

1. A heat supply system comprising multiple heat supply devices, a power generation facility capable of supplying electricity generated using renewable energy to the multiple heat supply devices, and a heat supply management server, Each of the aforementioned heat supply devices is A heat storage unit that stores a heat transfer medium, It is equipped with a heat source unit that uses electricity to heat the heat transfer medium, Each of the plurality of heat supply devices is capable of performing a heat storage operation in which the heat source unit heats the heat medium and stores the heated heat medium in the heat storage unit. Each of the aforementioned heat supply devices belongs to one of the groups, The aforementioned heat supply management server, The power generation equipment acquires power supply data that shows the change over time of the available power supply, which is the power that can be supplied from the power generation equipment to the plurality of heat supply devices. Based on the available power supply data, the system is configured to perform a scheduling process to set an operating permission period, which is a period of time during which the heat storage operation is permitted, for each of the multiple groups. In the scheduling process, the heat supply management server, Identify the group to be configured as the target group. Identify available power data that shows the change in available power over time, Based on the aforementioned usable power data, the judgment criterion power data showing the change in judgment criterion power over time is identified. The operating permission time period for the target group is set so that it includes the time when the judgment criterion power is highest. A heat supply system configured to repeatedly perform a series of processes to update the available power data by subtracting the power usage planned by the designated target group from the available power during the set operating permission period.

2. The heat supply management server is configured to shorten the duration of the permitted operating time period and then execute the scheduling process again if, after executing the scheduling process, the predetermined scheduling completion conditions are not met.

3. The heat supply system according to claim 2, wherein the scheduling completion condition includes the available power exceeding a predetermined threshold at all times.

4. The heat supply system according to claim 2, wherein each of the plurality of heat supply devices further comprises an auxiliary heat source that uses fuel to heat the heat transfer medium.

5. The heat supply system according to claim 2, wherein the initial value of the duration of the permitted operating period is set based on the maximum duration of the heat storage operation in each of the plurality of heat supply devices.

6. The heat supply system according to claim 1, wherein the criterion power is identified as the minimum value of the usable power within a predetermined time interval.

7. The heat supply system according to claim 1, wherein the criterion power is identified as the average value of the usable power over a predetermined time period.

8. The aforementioned target group is identified according to the group order list, The heat supply system according to claim 1, wherein the heat supply management server is configured to change the group sequence list at predetermined intervals.

9. The heat supply system according to claim 1, wherein each of the plurality of heat supply devices is configured to change the group to which it belongs among the plurality of groups at predetermined intervals.

10. Each of the aforementioned heat supply devices maintains an alternative timetable that includes at least one time period. The heat supply system according to claim 1, wherein each of the plurality of heat supply devices is configured to set one time period selected from the at least one time period of the alternative timetable as its own permitted operating time period when communication with the heat supply management server becomes impossible.

11. The aforementioned alternative timetable includes multiple time slots, The heat supply system of claim 10, wherein each of the plurality of heat supply devices is configured to change the time period selected as the permitted operating time period from the plurality of time periods in the alternative timetable at predetermined intervals.

12. It is a heat supply management server, The heat supply management server is used in a heat supply system comprising a plurality of heat supply devices, a power generation facility capable of supplying electricity generated using renewable energy to the plurality of heat supply devices, and the heat supply management server. Each of the aforementioned heat supply devices is A heat storage unit that stores a heat transfer medium, It is equipped with a heat source unit that uses electricity to heat the heat transfer medium, Each of the plurality of heat supply devices is capable of performing a heat storage operation in which the heat source unit heats the heat medium and stores the heated heat medium in the heat storage unit. Each of the aforementioned heat supply devices belongs to one of the groups, The aforementioned heat supply management server, The power generation equipment acquires power supply data that shows the change over time of the available power supply, which is the power that can be supplied from the power generation equipment to the plurality of heat supply devices. Based on the available power supply data, the system is configured to perform a scheduling process to set an operating permission period, which is a period of time during which the heat storage operation is permitted, for each of the multiple groups. In the scheduling process, the heat supply management server, Identify the group to be configured as the target group. Identify available power data that shows the change in available power over time, Based on the aforementioned usable power data, the judgment criterion power data showing the change in judgment criterion power over time is identified. The operating permission time period for the target group is set so that it includes the time when the judgment criterion power is highest. A heat supply management server is configured to repeatedly perform a series of processes to update the available power data by subtracting the power usage planned by the designated target group from the available power during the set operating permission period.

13. A method for operating a heat supply management server, The heat supply management server is used in a heat supply system comprising a plurality of heat supply devices, a power generation facility capable of supplying electricity generated using renewable energy to the plurality of heat supply devices, and the heat supply management server. Each of the aforementioned heat supply devices is A heat storage unit that stores a heat transfer medium, It is equipped with a heat source unit that uses electricity to heat the heat transfer medium, Each of the plurality of heat supply devices is capable of performing a heat storage operation in which the heat source unit heats the heat medium and stores the heated heat medium in the heat storage unit. Each of the aforementioned heat supply devices belongs to one of the groups, The aforementioned operation method is, To acquire supplyable power data that shows the change over time of supplyable power, which is the power that can be supplied from the power generation facility to the plurality of heat supply devices, The system includes performing a scheduling process to set an operating permission period, which is a period of time during which the heat storage operation is permitted, for each of the multiple groups based on the available power supply data. Executing the aforementioned scheduling process means Identify the group to be configured as the target group. Identify available power data that shows the change in available power over time, Based on the aforementioned usable power data, the judgment criterion power data showing the change in judgment criterion power over time is identified. The operating permission time period for the target group is set so that it includes the time when the judgment criterion power is highest. An operating method that includes repeatedly executing a series of processes to update the available power data by subtracting the power usage planned by the designated target group from the available power during the set operating permission period.

14. A program for a heat supply management server, The heat supply management server is used in a heat supply system comprising a plurality of heat supply devices, a power generation facility capable of supplying electricity generated using renewable energy to the plurality of heat supply devices, and the heat supply management server. Each of the aforementioned heat supply devices is A heat storage unit that stores a heat transfer medium, It is equipped with a heat source unit that uses electricity to heat the heat transfer medium, Each of the plurality of heat supply devices is capable of performing a heat storage operation in which the heat source unit heats the heat medium and stores the heated heat medium in the heat storage unit. Each of the aforementioned heat supply devices belongs to one of the groups, The program is transmitted to the heat supply management server. The steps include: acquiring supplyable power data that shows the change over time of supplyable power, which is the power that can be supplied from the power generation facility to the plurality of heat supply devices; Based on the available power supply data, the system performs a scheduling process to set an operating permission period, which is a period of time during which the heat storage operation is permitted, for each of the multiple groups. The step of executing the aforementioned scheduling process is: Identify the group to be configured as the target group. Identify available power data that shows the change in available power over time, Based on the aforementioned usable power data, the judgment criterion power data showing the change in judgment criterion power over time is identified. The operating permission time period for the target group is set so that it includes the time when the judgment criterion power is highest. A program that includes the step of repeatedly performing a series of processes to update the available power data by subtracting the power to be used by the designated target group from the available power during the set operating permission period.

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