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

Abstract

To provide a technology which can suppress an increase in procurement cost of a shortage of power when the suppliable power of a power generation unit is reduced more than 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, and belongs to one of a plurality of groups. The heat supply management server performs scheduling processing for setting an operation permission time band with respect to each of the plurality of groups on the basis of determination reference power data indicating a secular change in determination reference power which is obtained by subtracting correction power from the suppliable power. The correction power data is set so that the correction power becomes large in a time zone in which a power market price is high, and that the correction power becomes small in a time zone in which the power market price is low.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 is configured to execute a scheduling process of setting a time period for executing the heat storage operation for each of the plurality of heat supply devices based on the supplyable power data.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The amount of electricity generated by a power generation facility may decrease compared to the initial assumptions, resulting in a decrease in the amount of electricity that can be supplied. In such cases, if the amount of electricity that can be supplied is insufficient to cover the total power consumption of multiple heat supply devices operating in thermal storage mode, the shortage must be procured from the electricity market. Therefore, if the shortage of electricity that can be supplied occurs during periods when electricity market prices are high, the cost of procuring electricity may increase. This specification provides a technology that can suppress the increase in the cost of procuring electricity to cover the shortage when the amount of electricity that can be supplied by a power generation facility decreases compared to the initial assumptions. [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 power that can be supplied from the power generation facility to the plurality of heat supply devices; set correction power data showing the change over time of correction power; calculate judgment criterion power data showing the change over time of judgment criterion power obtained by subtracting the correction power from the supplyable power; and, based on the judgment criterion power data, execute a scheduling process to set an operating permission time period, which is the time period during which the heat storage operation is permitted to be performed for each of the plurality of groups. The correction power data may be set so that the correction power is large during times when the electricity market price is high and small during times when the electricity market price is low.

[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 power that can be supplied from the power generation facility to the plurality of heat supply devices; set correction power data showing the change over time of correction power; calculate judgment criterion power data showing the change over time of judgment criterion power obtained by subtracting the correction power from the supplyable power; and, based on the judgment criterion power data, execute a scheduling process to set an operating permission time period, which is the time period during which the heat storage operation is permitted to be performed for each of the plurality of groups. The correction power data may be set so that the correction power is large during times when the electricity market price is high and small during times when the electricity market price is low.

[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 operation method described above may include: acquiring supplyable power data showing the change over time of supplyable power, which is the power that can be supplied from the power generation equipment to the plurality of heat supply devices; setting correction power data showing the change over time of correction power; calculating judgment criterion power data showing the change over time of judgment criterion power obtained by subtracting the correction power from the supplyable power; and performing a scheduling process 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 judgment criterion power data. The correction power data may be set such that the correction power is large during times when the electricity market price is high and small during times when the electricity market price is low.

[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 following steps: acquire available power data showing the change over time of available power, which is the power that can be supplied from the power generation equipment to the plurality of heat supply devices; set corrected power data showing the change over time of corrected power; calculate judgment criterion power data showing the change over time of judgment criterion power obtained by subtracting the corrected power from the available power; and perform scheduling processing to set an operating permission time period, which is a time period during which the heat storage operation is permitted, for each of the plurality of groups based on the judgment criterion power data. The corrected power data may be set so that the corrected power is large during times when the electricity market price is high and small during times when the electricity market price is low.

[0009] In the above configuration, the permitted operating hours for each group are set based on the time-dependent change in the judgment criterion power, which is obtained by subtracting correction power from the available power. In this case, the correction power is a large value when the electricity market price is high and a small value when the electricity market price is low. Therefore, the judgment criterion power is significantly smaller than the available power when the electricity market price is high, and is the same as or slightly smaller than the available power when the electricity market price is low. In the above configuration, the permitted operating hours for each group are set based on this judgment criterion power data. As a result, scheduling is achieved such that, when the electricity market price is high, there is a relatively large margin of available power relative to the sum of the power consumption of the thermal storage operation of multiple heat supply units, and when the electricity market price is low, there is a relatively small margin of available power relative to the sum of the power consumption of the thermal storage operation of multiple heat supply units. Therefore, even if the power generated by the power generation equipment decreases more than initially expected, and the available power decreases more than initially expected, it is possible to make it less likely for a shortage of available power to occur when the electricity market price is high. This configuration helps to suppress the increase in procurement costs for the power shortage if the amount of power that can be supplied by the power generation facility decreases more than initially expected.

[0010] In a second embodiment, in the heat supply system of the first embodiment, the corrected power data may be set such that the corrected power becomes zero during the time period when the electricity market price is below a first predetermined value, and the corrected power becomes a positive value during the time period when the electricity market price is above the first predetermined value.

[0011] With the above configuration, during periods when the electricity market price is lower than the first predetermined value, the judgment criterion power can be matched with the available power. This enables scheduling that is more aligned with the expected available power data.

[0012] In a third embodiment, in the heat supply system of the first or second embodiment, the heat supply management server may be configured in the scheduling process to set the permitted operating time period for each of the plurality of groups such that the permitted operating time period does not include a time period in which the electricity market price is equal to or greater than a second predetermined value.

[0013] According to the above configuration, during periods when the electricity market price is above the second predetermined value, no operating hours are set (in other words, thermal storage operation is prohibited for all groups during periods when the electricity market price is above the second predetermined value). Therefore, even if the amount of electricity generated by the power generation equipment decreases compared to the initial assumption, and the amount of available electricity decreases compared to the initial assumption, it is possible to reliably prevent a shortage of available electricity during periods when the electricity market price is above the second predetermined value.

[0014] In a fourth embodiment, in the heat supply system of any one of the first to third embodiments, each of the plurality of heat supply devices may further include an auxiliary heat source unit that uses fuel to heat the heat medium. The heat supply management server may, after executing the scheduling process, determine whether there is an excess period in which the available power, obtained by subtracting the planned power usage from the available power, falls below a predetermined threshold. If such an excess period exists, it may identify a group whose permitted operating time includes the excess period as a cancellation candidate group. The server may calculate the heat supply cost if the heat supply device belonging to the cancellation candidate group performs the heat storage operation during the permitted operating time as a first cost, and the heat supply cost if the heat supply device belonging to the cancellation candidate group does not perform the heat storage operation during the permitted operating time but instead uses the auxiliary heat source unit as a second cost. If the first cost is higher than the second cost, the server may cancel the permitted operating time set for the cancellation candidate group.

[0015] According to the above configuration, when there is an excess period, the heat supply cost when heat is supplied by the auxiliary heat source unit is compared with the heat supply cost when heat is supplied after thermal storage operation by the heat source unit, and a decision is made on whether or not to cancel the operating period of the group of candidates for cancellation in order to reduce the heat supply cost. By adopting such a configuration, the heat supply cost in the heat supply system can be reduced.

[0016] In a fifth embodiment, in the heat supply system of any one of the first to third embodiments, each of the plurality of heat supply devices may further include an auxiliary heat source unit that uses fuel to heat the heat medium. After executing the scheduling process, the heat supply management server determines whether there is an excess period in which the available power, obtained by subtracting the planned power usage from the available power, falls below a predetermined threshold. If such an excess period exists, the server identifies a group whose permitted operating time includes the excess period as a candidate shortening group. The server calculates the heat supply cost when the heat supply devices belonging to the candidate shortening group perform the heat storage operation during the permitted operating time as a first cost. The server calculates the heat supply cost when the heat supply devices belonging to the candidate shortening group do not perform the heat storage operation during the permitted operating time and instead use the auxiliary heat source unit as a second cost. If the first cost is higher than the second cost, the server may be configured to shorten the permitted operating time set for the candidate shortening group so as not to include the excess period.

[0017] According to the above configuration, when there is an excess period, the heat supply cost when heat is supplied by the auxiliary heat source unit is compared with the heat supply cost when heat is supplied after thermal storage operation by the heat source unit, and a decision is made as to whether or not to shorten the operating period of the candidate shortening group so that the heat supply cost is lower. By adopting such a configuration, the heat supply cost in the heat supply system can be reduced.

[0018] In the sixth aspect, in the heat supply system according to the fourth or fifth aspect, the first cost may be based on a value obtained by dividing the electricity market price by the thermal efficiency of the heat source unit. The second cost may be based on a value obtained by dividing the fuel gas market price by the thermal efficiency of the auxiliary heat source unit.

[0019] According to the above configuration, the first cost and the second cost can be calculated respectively by simple calculations.

[0020] In the seventh aspect, in the heat supply system according to the sixth aspect, the heat source unit may include a heat pump heat source that absorbs heat from the outside air to heat the heat medium. The thermal efficiency of the heat source unit may be set based on the outside air temperature in the operation permission time zone.

[0021] The thermal efficiency of the heat pump heat source that absorbs heat from the outside air to heat the heat medium varies according to the outside air temperature. According to the above configuration, the first cost can be calculated more accurately.

Brief Description of Drawings

[0022] [[ID=I9]] [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 water heater 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 diagram showing an example of the relationship between the scheduling result by the hot water supply management server 116 of the comparative example and the assumed surplus power. [Figure 5] It is a diagram showing an example of the relationship between the scheduling result by the hot water supply management server 116 of the comparative example and the actual surplus power. [Figure 6] It is a diagram showing an example of the relationship between the scheduling result by the hot water supply management server 116 of the embodiment and the assumed surplus power. [Figure 7]This figure shows an example of the relationship between the scheduling results from the hot water supply management server 116 in the embodiment and the actual surplus power. [Figure 8] This figure shows another example of the relationship between the scheduling results from the hot water supply management server 116 in the embodiment and the expected surplus power. [Figure 9] This is a flowchart of the scheduling process for another permitted operating time period executed by the hot water supply management server 116 in the embodiment. [Figure 10] This figure shows yet another example of the relationship between the scheduling results from the hot water supply management server 116 in the embodiment and the expected surplus power. [Modes for carrying out the invention]

[0023] (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 an energy 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.

[0024] 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.

[0025] (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.

[0026] (HP Unit 4) HP Unit 4 is a heat source that uses electricity to heat 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 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.

[0027] (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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] (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 (e.g., city 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.

[0032] 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.

[0033] 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.

[0034] (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.

[0035] (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.

[0036] 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.

[0037] 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.

[0038] 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 due to the closing of a tap or the completion of filling a bathtub, and will terminate the hot water supply operation.

[0039] (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.

[0040] (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 energy provider 108 supplies the electricity generated by the power generation facility 110 to multiple residences 102a, 102b, ... and other consumers. In addition, the energy provider 108 can also procure electricity from other power generation facilities other than the power generation facility 110 through the electricity market and supply electricity to multiple residences 102a, 102b, ..., but will prioritize the supply of electricity generated by the power generation facility 110 when it is available. Furthermore, the energy provider 108 can procure fuel gas through the fuel gas market and supply fuel gas to multiple residences 102a, 102b, ...

[0041] (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.

[0042] (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.

[0043] The hot water supply management server 116 has pre-stored the average thermal efficiency of the HP unit 4 and the average thermal efficiency of the burner unit 8 for each of the multiple storage-type hot water heaters 104a, 104b, ... The thermal efficiency of the HP unit 4 is calculated by dividing the amount of heat added to the water (e.g., in kWh equivalent) when the HP unit 4 heats the water by the amount of electricity consumed by the HP unit 4 (e.g., in kWh equivalent). The thermal efficiency of the burner unit 8 is calculated by dividing the amount of heat added to the water (e.g., in kWh equivalent) when the burner unit 8 heats the water by the amount of fuel gas consumed by the burner unit 8 (e.g., in kWh equivalent).

[0044] The hot water supply management server 116 can obtain electricity market price data via the internet 118, which shows the changes over time in the electricity market price when the energy company 108 procures electricity from the electricity market on a given day. In addition, the hot water supply management server 116 can obtain fuel gas market price data via the internet 118, which shows the changes over time in the fuel gas market price when the energy company 108 procures fuel gas from the fuel gas market on a given day.

[0045] (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).

[0046] 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.

[0047] In S4, the hot water supply management server 116 sets correction power data that shows the change in correction power over time, based on electricity market price data. For example, the hot water supply management server 116 may set the correction power data by calculating a value obtained by multiplying the electricity market price by a predetermined coefficient for all time periods. Alternatively, the hot water supply management server 116 may set the correction power data by setting the correction power to zero during time periods when the electricity market price is below a first predetermined value, and by calculating a value obtained by multiplying the electricity market price by a predetermined coefficient for time periods when the electricity market price is above the first predetermined value.

[0048] In S6, the hot water supply management server 116 sets an operating prohibition period, which is a period during which the operating permission period is prohibited, based on electricity market price data. For example, the hot water supply management server 116 determines whether there is a period during which the electricity market price is equal to or greater than a second predetermined value, and if such a period exists, it sets that period as an operating prohibition period. Here, the second predetermined value is set to a value higher than the first predetermined value.

[0049] In S8, the hot water supply management server 116 identifies the groups that will be subject to setting the permitted operating time periods from among the groups for which operating time periods have not yet been set.

[0050] In S10, the hot water supply management server 116 calculates available power data based on the surplus power data acquired in S2, the correction power data set in S4, 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 correction power and the planned power usage from the surplus power.

[0051] In S12, the hot water supply management server 116 sets the permitted operating time periods for the target group based on the no-operation time periods set in S6 and the available power data calculated in S10. For example, the hot water supply management server 116 corrects the available power during the no-operation time periods to zero and sets the permitted operating time periods for the target group so that they are allocated to the time period with the most available power. For example, the hot water supply management server 116 may set the permitted operating time periods for the target group so that the time with the highest available power is included in the permitted operating time period.

[0052] In S14, the hot water supply management server 116 updates the planned power usage data based on the power consumption of the storage-type water heaters 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.

[0053] 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.

[0054] By repeatedly executing processes S8 to S16, the operating time periods permitted for each group are set. In this case, if the available power data is calculated using only surplus power data and planned power usage data, without considering the correction power data, scheduling may occur with little margin between surplus power and planned power usage during periods of high electricity market prices, as shown in Figure 4. In this case, as shown in Figure 5, if the actual surplus power is less than the expected surplus power, there is a risk of a surplus power shortage during periods of high electricity market prices. If a surplus power shortage occurs during such periods, the energy business operator 108 will have to procure electricity from the electricity market at a high price, leading to increased procurement costs.

[0055] In contrast, the hot water supply system 100 of this embodiment calculates usable power data by considering not only surplus power data and planned power usage data, but also correction power data. As a result, as shown in Figure 6, scheduling can be achieved that leaves little margin between surplus power and planned power usage during periods when electricity market prices are low, and leaves sufficient margin between surplus power and planned power usage during periods when electricity market prices are high. In this case, as shown in Figure 7, even if the actual surplus power is less than the expected surplus power, the shortage of surplus power will not occur during periods when electricity market prices are high, but rather during periods when electricity market prices are low. If a shortage of surplus power occurs during such periods, the energy business operator 108 can procure electricity from the electricity market at a low price, so it will not lead to a significant increase in procurement costs.

[0056] In Figure 3, at S16, if scheduling is completed for all groups (resulting in YES), the process proceeds to S18. In S18, the hot water supply management server 116 determines whether or not there are excess time periods based on the surplus power data and the planned power usage data. In this embodiment, an excess time period is a period in which the value of available power, obtained by subtracting the planned power usage from the surplus power, falls below a predetermined threshold (e.g., zero). Note that the predetermined threshold may be a value other than zero. If there are no excess time periods (resulting in NO), the process proceeds to S30. If there are excess time periods (resulting in YES), the process proceeds to S20.

[0057] In S20, the hot water supply management server 116 identifies groups that are candidates for cancellation of the permitted operating time period as cancellation candidate groups. In this embodiment, the hot water supply management server 116 identifies cancellation candidate groups from among groups whose permitted operating time period includes an overtime period. For example, as shown in Figure 8, if there is an overtime period T1 and an overtime period T2, the hot water supply management server 116 identifies one of groups C and G (for example, group G) whose permitted operating time period includes the overtime period T1 as a cancellation candidate group for the overtime period T1, and identifies one of groups E, F and H (for example, group H) whose permitted operating time period includes the overtime period T2 as a cancellation candidate group for the overtime period T2.

[0058] In S22 of Figure 3, the hot water supply management server 116 calculates the hot water supply cost as the first cost when a storage-type water heater 104 belonging to the cancellation candidate group performs boiling operation during the permitted operating time period. For example, the first cost is calculated using the following formula. (First cost) = (Electricity market price) ÷ (Thermal efficiency of HP unit 4) Here, the electricity market price is, for example, the price per kWh.

[0059] Generally, the thermal efficiency of the HP unit 4 changes depending on the outside temperature. For this reason, the hot water supply management server 116 may obtain weather data for the day via the internet 118, identify the outside temperature during the permitted operating time period at the residence 102 where the storage-type hot water heater 104 belonging to the cancellation candidate group is installed, and then determine the thermal efficiency of the HP unit 4 to be used in calculating the first cost based on the average thermal efficiency of the HP unit 4 stored in advance and the identified outside temperature.

[0060] In S24, the hot water supply management server 116 calculates the hot water supply cost as a second cost when a storage-type water heater 104 belonging to the cancellation candidate group does not perform boiling operation during the permitted operating time period, but instead heats water using the burner unit 8. For example, the second cost is calculated using the following formula. (Second cost) = (Fuel gas market price) ÷ (Thermal efficiency of burner unit 8) Generally speaking, the market price for fuel gases such as city gas is 1m³ 3 While the price is traded per unit, in this embodiment, in order to compare with the first cost, the fuel gas market price is converted to a price per kWh. However, as long as the units of the first cost and the second cost are the same, various units can be used, not limited to the price per kWh, such as the price per MJ or the price per kcal.

[0061] In S26, the hot water supply management server 116 determines whether there are any cancellation candidate groups where the first cost calculated in S22 exceeds the second cost calculated in S24. If there are no cancellation candidate groups where the first cost exceeds the second cost (NO), the process proceeds to S30. If there are cancellation candidate groups where the first cost exceeds the second cost (YES), the process proceeds to S28.

[0062] In S28, the hot water supply management server 116 cancels the set operating permission time for groups of cancellation candidates where the first cost exceeds the second cost. Storage-type water heaters 104 belonging to groups whose operating permission time has been canceled are prohibited from performing boiling operations on that day. After S28, the process proceeds to S30.

[0063] As shown in Figure 8, the electricity market price fluctuates throughout the day. In contrast, although not shown in the figure, the fuel gas market price does not fluctuate throughout the day. For example, for group G, a candidate for cancellation regarding the excess time period T1, the electricity market price during the permitted operating time period is low, so the first cost is less than or equal to the second cost. In this case, the permitted operating time period for group G is not cancelled, and the storage-type water heater 104 belonging to group G performs boiling operation during the permitted operating time period. In contrast, for example, for group H, a candidate for cancellation regarding the excess time period T2, the electricity market price during the permitted operating time period is high, so the first cost exceeds the second cost. In this case, the permitted operating time period for group H is cancelled, and the storage-type water heater 104 belonging to group H is prohibited from performing boiling operation during the excess time period. Note that in this case, the storage-type water heater 104 belonging to group H may be configured to allow boiling operation during other time periods.

[0064] In S30 of Figure 3, 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 S30, the process in Figure 3 ends.

[0065] The hot water supply management server 116 may perform the process shown in Figure 9 instead of the process shown in Figure 3. For example, the hot water supply management server 116 performs the process shown in Figure 9 every day at a predetermined time (for example, 2:00).

[0066] The processes from S2 to S18 and the process in S30 in Figure 9 are the same as the processes from S2 to S18 and the process in S30 in Figure 3. In the process of S18 in Figure 9, if there is no excess time period (NO), the process proceeds to S30. If there is an excess time period (YES), the process proceeds to S32.

[0067] In S32, the hot water supply management server 116 identifies groups that are candidates for shortening the permitted operating time period as shortening candidate groups. In this embodiment, the hot water supply management server 116 identifies the group that was last scheduled among the groups whose permitted operating time period includes an excess time period as a shortening candidate group. For example, as shown in Figure 8, if there is an excess time period T1 and an excess time period T2, the hot water supply management server 116 identifies the group that was last scheduled among groups C and G whose permitted operating time period includes an excess time period T1 (for example, group G) as a shortening candidate group for excess time period T1, and the group that was last scheduled among groups E, F and H whose permitted operating time period includes an excess time period T2 (for example, group H) as a shortening candidate group for excess time period T2.

[0068] In S34, the hot water supply management server 116 divides the excess time period into time slots of a predetermined length (e.g., 30 minutes), and calculates the hot water supply cost as the first cost for each time slot when the storage-type water heater 104 belonging to the shortening candidate group performs boiling operation. The calculation of the first cost in S34 is the same as the calculation of the first cost in S22 in Figure 3, so a detailed explanation is omitted.

[0069] In S36, the hot water supply management server 116 calculates the hot water supply cost as a second cost for each of the above-mentioned time slots, assuming that the storage-type water heater 104 belonging to the shortened candidate group does not perform boiling operation, but instead heats water using the burner unit 8. The calculation of the second cost in S36 is the same as the calculation of the second cost in S24 in Figure 3, so a detailed explanation is omitted.

[0070] In S38, the hot water supply management server 116 determines whether there is a time frame in which the first cost calculated in S34 exceeds the second cost calculated in S36. If there is no time frame in which the first cost exceeds the second cost (NO), the process proceeds to S30. If there is a time frame in which the first cost exceeds the second cost (YES), the process proceeds to S40.

[0071] In S40, the hot water supply management server 116 shortens the operating permission period for the shortened candidate group by removing time slots where the first cost exceeds the second cost from the operating permission period set for the shortened candidate group. After S40, the process proceeds to S30.

[0072] In the example shown in Figure 10, for Group G, a candidate for cancellation regarding the excess time period T1, the electricity market price during the permitted operating hours is low, so the first cost is less than or equal to the second cost in every time slot of the excess period. In this case, the permitted operating hours for Group G are not shortened. On the other hand, for Group H, a candidate for cancellation regarding the excess time period T2, the electricity market price during the permitted operating hours is high, so the first cost exceeds the second cost in every time slot of the excess period. In this case, the permitted operating hours for Group H are shortened so as not to include the excess period.

[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, a configuration was described in which each of the multiple storage-type water heaters 104a, 104b, ... is equipped with an HP unit 4, a tank unit 6, and a burner unit 8. Alternatively, among the multiple storage-type water heaters 104a, 104b, ..., some storage-type water heaters 104' are equipped with an HP unit 4, a tank unit 6, and a burner unit 8, while the remaining storage-type water heaters 104'' are equipped with an HP unit 4 and a tank unit 6 but do not have a burner unit 8. In this case, the storage-type water heaters 104' equipped with a burner unit 8 and the storage-type water heaters 104'' without a burner unit 8 are classified into separate groups, and the processes S20-S28 in Figure 3 and S32-S40 in Figure 9 are performed only on the group to which the storage-type water heaters 104' equipped with a burner unit 8 belong.

[0076] 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).

[0077] 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 (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, set correction power data that shows the change over time of correction power, calculate judgment criterion power data that shows the change over time of judgment criterion power by subtracting correction power from surplus power, and, based on the judgment criterion power data, execute scheduling processing to set the permitted operating time period, which is the time period during which the boiling operation is permitted for each of the multiple groups. The correction power data is set so that the correction power is large during times when the electricity market price is high and small during times when the electricity market price is low.

[0078] In the above configuration, the permitted operating time periods for each group are set based on the time-dependent change in the judgment criterion power, which is obtained by subtracting correction power from surplus power. In this case, the correction power is a large value when the electricity market price is high and a small value when the electricity market price is low. Therefore, the judgment criterion power is significantly smaller than the surplus power when the electricity market price is high, and is the same as or slightly smaller than the surplus power when the electricity market price is low. In the above configuration, the permitted operating time periods for each group are set based on this judgment criterion power data. As a result, scheduling is achieved such that, when the electricity market price is high, there is a relatively large margin of surplus power relative to the sum of the power consumption of the boiling operations of the multiple storage-type water heaters 104, and when the electricity market price is low, there is a relatively small margin of surplus power relative to the sum of the power consumption of the boiling operations of the multiple storage-type water heaters 104. Therefore, even if the power generated by the power generation equipment 110 decreases more than initially expected, and the surplus power decreases more than initially expected, it is possible to make it less likely for a shortage of surplus power to occur when the electricity market price is high. By adopting this configuration, if the surplus power from the power generation facility 110 decreases more than initially expected, it is possible to suppress the increase in procurement costs for the power shortage.

[0079] In one or more embodiments, the corrected power data is set such that the corrected power is zero during periods when the electricity market price is below a first predetermined value, and a positive value during periods when the electricity market price is above the first predetermined value.

[0080] With the above configuration, during periods when the electricity market price is lower than the first predetermined value, the judgment criterion power can be matched with the surplus power. This enables scheduling that is more aligned with the expected surplus power data.

[0081] In one or more embodiments, the hot water supply management server 116 is configured in scheduling processing to set the permitted operating time periods for each of the multiple groups such that the permitted operating time periods do not include time periods in which the electricity market price is equal to or greater than a second predetermined value.

[0082] According to the above configuration, during the time periods when the electricity market price is above the second predetermined value, no operating hours are set (in other words, boiling operation is prohibited for all groups during the time periods when the electricity market price is above the second predetermined value). Therefore, even if the amount of electricity generated by the power generation equipment 110 decreases compared to the initial assumption, and the amount of surplus electricity decreases compared to the initial assumption, it is possible to reliably prevent a shortage of surplus electricity during the time periods when the electricity market price is above the second predetermined value.

[0083] In one or more embodiments, each of the multiple storage-type water heaters 104 further comprises a burner unit 8 (an example of an auxiliary heat source unit) that uses fuel to heat water. After performing scheduling processing, the hot water management server 116 determines whether there are excess time periods T1 and T2, which are time periods in which the available power obtained by subtracting the planned power usage from the available power is less than a predetermined threshold. If excess time periods T1 and T2 exist, the server identifies groups that include excess time periods T1 and T2 in their permitted operating time periods as cancellation candidate groups. The server calculates the hot water cost (an example of a heat supply cost) when a storage-type water heater 104 belonging to the cancellation candidate group performs boiling operation during the permitted operating time period as the first cost, and calculates the hot water cost when a storage-type water heater 104 belonging to the cancellation candidate group does not perform boiling operation during the permitted operating time period and instead uses the burner unit 8 as the second cost. If the first cost is higher than the second cost, the server is configured to cancel the permitted operating time period set for the cancellation candidate group.

[0084] According to the above configuration, when there are excess time periods T1 and T2, the hot water supply cost when hot water is supplied by the burner unit 8 is compared with the hot water supply cost when hot water is supplied after boiling operation by the HP unit 4, and a decision is made on whether or not to cancel the operating permission time period of the cancellation candidate group in order to reduce the hot water supply cost. By adopting this configuration, the hot water supply cost in the hot water supply system 100 can be reduced.

[0085] 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 unit) that uses fuel to heat water. After performing scheduling processing, the hot water management server 116 determines whether there are excess time periods T1 and T2, which are time periods in which the available power obtained by subtracting the planned power usage from the available power is less than a predetermined threshold. If excess time periods T1 and T2 exist, the server identifies groups that include excess time periods T1 and T2 in their permitted operating time periods as shortened candidate groups. The server calculates the hot water cost (example of heat supply cost) when a storage-type water heater 104 belonging to the shortened candidate group performs boiling operation during the permitted operating time period as the first cost, and calculates the hot water cost when a storage-type water heater 104 belonging to the shortened candidate group does not perform boiling operation during the permitted operating time period and instead uses the burner unit 8 as the second cost. If the first cost is higher than the second cost, the server is configured to shorten the permitted operating time period set for the shortened candidate group so as not to include the excess time periods.

[0086] According to the above configuration, when there are excess time periods T1 and T2, the hot water supply cost when hot water is supplied by the burner unit 8 is compared with the hot water supply cost when hot water is supplied after boiling operation by the HP unit 4, and it is decided whether or not to shorten the permitted operating time period of the shortened candidate group so that the hot water supply cost is lower. By adopting this configuration, the hot water supply cost in the hot water supply system 100 can be reduced.

[0087] In one or more embodiments, the first cost is based on the electricity market price divided by the thermal efficiency of the HP unit 4. The second cost is based on the fuel gas market price divided by the thermal efficiency of the burner unit 8.

[0088] With the above configuration, the first cost and the second cost can be calculated using a simple calculation.

[0089] In one or more embodiments, the HP unit 4 includes a heat pump heat source that absorbs heat from the outside air to heat water. The thermal efficiency of the HP unit 4 is set based on the outside air temperature during the permitted operating hours.

[0090] The thermal efficiency of a heat pump heat source, which absorbs heat from the outside air to heat a heat transfer medium, changes depending on the outside air temperature. With the above configuration, the first cost can be calculated more accurately.

[0091] 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]

[0092] 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 104': Storage-type water heater 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 aforementioned 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. Set correction power data that shows the change in correction power over time, The judgment criterion power data is calculated, showing the change over time of the judgment criterion power obtained by subtracting the correction power from the available power supply. Based on the aforementioned determination criteria power 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. A heat supply system in which the corrected power data is set such that the corrected power is large during periods when electricity market prices are high and small during periods when electricity market prices are low.

2. The heat supply system according to claim 1, wherein the corrected power data is set such that the corrected power becomes zero during the time period when the electricity market price is below a first predetermined value, and the corrected power becomes a positive value during the time period when the electricity market price is above the first predetermined value.

3. The heat supply management server is configured in the scheduling process to set the permitted operating time period for each of the plurality of groups such that the permitted operating time period does not include a time period in which the electricity market price is equal to or greater than a second predetermined value.

4. Each of the aforementioned plurality of heat supply devices further comprises an auxiliary heat source unit that uses fuel to heat the heat transfer medium, After executing the scheduling process, the heat supply management server determines whether there is an excess period in which the available power, obtained by subtracting the planned power usage from the available power supply, falls below a predetermined threshold. If the aforementioned excess time period exists, Groups whose operating permit period includes the aforementioned excess period are identified as groups for cancellation. The first cost is calculated as the heat supply cost when the heat supply device belonging to the group of cancellation candidates performs the heat storage operation during the permitted operating time period. The second cost is calculated for the heat supply when the heat supply device belonging to the group of cancellation candidates does not perform the heat storage operation during the permitted operating time period, but instead uses the auxiliary heat source unit. The heat supply system according to claim 1, configured to cancel the operating permit time period set for the cancellation candidate group if the first cost is higher than the second cost.

5. Each of the aforementioned plurality of heat supply devices further comprises an auxiliary heat source unit that uses fuel to heat the heat transfer medium, After executing the scheduling process, the heat supply management server determines whether there is an excess period in which the available power, obtained by subtracting the planned power usage from the available power supply, falls below a predetermined threshold. If the aforementioned excess time period exists, Groups whose operating permit time period includes the aforementioned excess time period are identified as candidate groups for shortening the operating period. The first cost is calculated as the heat supply cost when the heat supply device belonging to the shortened candidate group performs the heat storage operation during the permitted operating time period. The heat supply cost is calculated as a second cost when the heat supply device belonging to the shortened candidate group does not perform the heat storage operation during the permitted operating time period, but instead uses the auxiliary heat source unit. The heat supply system according to claim 1, wherein, if the first cost is higher than the second cost, the operating permission period set for the shortening candidate group is shortened so as not to include the excess period.

6. The first cost is based on the value obtained by dividing the electricity market price by the thermal efficiency of the heat source unit. The heat supply system according to claim 4 or 5, wherein the second cost is based on the value obtained by dividing the fuel gas market price by the thermal efficiency of the auxiliary heat source unit.

7. The heat source unit includes a heat pump heat source that absorbs heat from the outside air to heat the heat transfer medium. The heat supply system according to claim 6, wherein the thermal efficiency of the heat source unit is set based on the outside air temperature during the permitted operating time period.

8. 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 aforementioned 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. Set correction power data that shows the change in correction power over time, The judgment criterion power data is calculated, showing the change over time of the judgment criterion power obtained by subtracting the correction power from the available power supply. Based on the aforementioned determination criteria power 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. The heat supply management server is configured such that the corrected power data is large during periods when electricity market prices are high, and small during periods when electricity market prices are low.

9. 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 aforementioned 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, Setting correction power data that shows the change in correction power over time, To calculate judgment criterion power data showing the change over time of the judgment criterion power obtained by subtracting the correction power from the available power supply, 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 aforementioned determination criterion power data. The correction power data is set to be large during periods when electricity market prices are high, and small during periods when electricity market prices are low.

10. 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 aforementioned 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; The steps include setting correction power data that shows the change in correction power over time, The steps include: calculating judgment criterion power data that shows the change over time of the judgment criterion power obtained by subtracting the correction power from the available power supply; Based on the aforementioned determination criteria power data, the system executes 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 program sets the corrected power data such that the corrected power is large during periods when electricity market prices are high and small during periods when electricity market prices are low.

Images