Power service system

Abstract

This invention provides a power service system that can reduce electricity costs for consumers while eliminating risks for both retail electricity providers and consumers. [Solution] The power service system 1 according to the present invention comprises a customer facility 50 equipped with a first power load 504 and a second power load 503, a variable power load power analysis unit 15 that determines a correlation formula between the daily maximum temperature forecast value and the amount of electricity that the first power load 504 receives on the day on which the maximum temperature forecast value is determined, an operation planning unit 17 that calculates an operation plan for the first power load 504 and calculates the expected power cost reduction value in the operation plan, and a transmitting / receiving unit 18 that transmits the operation plan and the expected power cost reduction value to the customer facility 50 and receives the judgment result regarding the operation plan from the customer facility 50. The operation planning unit 17 estimates the amount of electricity of the first power load 504 using the maximum temperature forecast value obtained from weather forecast information and the correlation formula, and calculates an operation plan for the first power load 504 using the estimated amount of electricity.

Description

Technical Field

[0001] The present invention relates to a power service system for supplying power to consumers.

Background Art

[0002] In recent years, due to the increasing introduction costs of renewable energy such as solar power generation and soaring fuel prices, electricity rates have been rising. In addition, due to the output fluctuations of renewable energy, the market value of electricity in the wholesale power market, that is, the spot price of electricity, has come to vary greatly throughout the day. These factors pose business risks for retail electricity providers.

[0003] For this reason, in addition to the conventional fixed-rate plan, retail electricity providers have come to propose a market-linked rate plan in which the rate changes in linkage with the spot price. In the market-linked rate plan, consumers have the advantage of being able to reduce their electricity costs by using electricity during time periods when the spot price is low, but there is a risk that the electricity cost will increase if electricity is consumed during time periods when the spot price is high. On the other hand, for retail electricity providers, since the price of electricity is determined by the common information of the market value, it may be difficult to differentiate from other companies.

[0004] In the fixed-rate plan, risks arise for retail electricity providers due to fluctuations in the procurement price. In order to eliminate this risk, retail electricity providers will set a high electricity rate in the fixed-rate plan. Then, a risk of higher electricity rates will arise for consumers.

[0005] An example of a technology to reduce such risks for retail electricity providers and consumers is described in Patent Document 1. The information provision system described in Patent Document 1 comprises a meter data management server that receives electricity usage data of consumers measured by smart meters, a web server that provides an information menu to the consumer terminal, and an information management server that creates and provides materials corresponding to the information menu selected by the consumer terminal. The information menu includes electricity usage, electricity utilization messages, and pricing plans. The information management server creates the requested information using electricity usage data of consumers that it manages the consumer terminal. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-188965 [Overview of the project] [Problems that the invention aims to solve]

[0007] Consumer loads often consist of a mix of variable power loads, which can be adjusted to match fluctuating electricity prices, and fixed power loads, which cannot be adjusted. In such situations, even if consumers use electricity in a way that aligns with market-linked pricing plans, they cannot change the power consumption of their fixed power loads, and therefore often do not fully enjoy the benefits of market-linked pricing plans. As a result, retail electricity providers are unable to fully elicit behavioral changes from consumers in line with spot prices, making it difficult to provide attractive electricity services to consumers.

[0008] The objective of this invention is to provide a power service system that can reduce electricity costs for consumers while eliminating risks for both retail electricity providers and consumers. [Means for solving the problem]

[0009] The power service system according to the present invention comprises a customer facility equipped with a first power load and a second power load with different operation from the first power load, a variable power load power analysis unit that determines a correlation formula representing the correlation between the daily maximum temperature forecast value in the area where the customer facility is located and the amount of electricity received by the first power load on the day on which the maximum temperature forecast value is determined, an operation planning unit that calculates an operation plan for the first power load and calculates the reduction in electricity charges if the operation plan is followed as an expected power cost reduction value, and a transmitting / receiving unit that transmits the operation plan and the expected power cost reduction value to the customer facility and receives the judgment result regarding the operation plan from the customer facility. The operation planning unit estimates the amount of electricity of the first power load using the maximum temperature forecast value obtained from weather forecast information and the correlation formula obtained by the variable power load power analysis unit, and calculates the operation plan for the first power load using the estimated amount of electricity of the first power load. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a power service system that can reduce electricity costs for consumers while eliminating risks for both retail electricity providers and consumers. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows a power service system according to Embodiment 1 of the present invention and customer equipment, which is equipment owned by a customer. [Figure 2] This diagram shows the configuration of the power service system according to Example 1. [Figure 3A] This figure shows an example of the operation of the power service system on a normal day in Example 1. [Figure 3B] This figure shows an example of the operation of the power service system on an extremely hot day in Example 1. [Figure 4] This figure shows a power service system according to Embodiment 2 of the present invention and customer equipment, which is equipment owned by a customer. [Figure 5]This figure shows the configuration of the power service system according to Example 2. [Figure 6] This figure shows an example of the operation of the power service system on a normal day in Example 2. [Modes for carrying out the invention]

[0012] The electricity service system according to the present invention can reduce electricity costs while maintaining the convenience of electricity use for consumers, while eliminating risks for both retail electricity providers and consumers.

[0013] The customer's equipment has two power loads connected to an interconnection point that splits the received power into two. The received power (power consumption) of each power load is measured by a power meter, with a market-linked pricing plan applied to one power meter and a fixed-rate pricing plan applied to the other power meter.

[0014] In this invention, for power consumption of power loads with fixed-rate plans, it is possible to avoid increased electricity costs when spot prices surge, thus allowing consumers to reduce overall electricity costs while eliminating risk. This enables consumers to control their electricity costs by operating equipment in accordance with spot electricity prices.

[0015] Retail electricity providers can reduce electricity procurement costs by stimulating electricity demand linked to the spot price of electricity while reducing risk for consumers.

[0016] Hereinafter, a power service system according to an embodiment of the present invention will be described with reference to the drawings. In the drawings referred to herein, the same or corresponding components are denoted by the same reference numerals, and repeated descriptions of these components may be omitted. [Examples]

[0017] A power service system according to Embodiment 1 of the present invention will be described with reference to Figures 1 to 3B.

[0018] FIG. 1 is a diagram showing a power service system 1 according to the present embodiment and customer equipment 50 which is equipment possessed by a customer.

[0019] The power service system 1 according to the present embodiment is connected to the customer equipment 50 via the Internet 20. The customer equipment 50 is linked to the power grid 10, and power is supplied from the power grid 10. Power is supplied to the power grid 10 by a retail electricity business operator.

[0020] The customer equipment 50 includes a variable power load 504, a non-variable power load 503, a power meter 502, and a power meter 501. The variable power load 504 is linked to the power grid 10 via the power meter 502. The non-variable power load 503 is linked to the power grid 10 via the power meter 501. The non-variable power load 503 may be a non-variable power load group composed of a plurality of non-variable power loads. The power meter 502 measures the power received by the variable power load 504 (the power consumption of the variable power load 504). The power meter 501 measures the power received by the non-variable power load 503 (the power consumption of the non-variable power load 503).

[0021] The variable power load 504 is a first power load whose operation can be adjusted according to a fluctuating power charge. The variable power load 504 includes, for example, a water heater, a storage battery, a compressor, and an electric heating device. The non-variable power load 503 is a load whose operation is different from that of the variable power load 504, that is, a second power load whose operation cannot be adjusted according to a fluctuating power charge. The non-variable power load 503 includes, for example, an air conditioner, lighting fixtures, and OA equipment.

[0022] The customer equipment 50 further includes an energy management terminal 550 and a communication interface 505. The energy management terminal 550 is connected via communication to a power meter 501, a power meter 502, and a variable power load 504. The communication interface 505 is a human interface terminal for the energy manager / operator among the customers to communicate with the power service system 1. The energy management terminal 550 and the communication interface 505 are connected to the power service system 1 via the internet 20.

[0023] The power service system 1 receives power reception information from power meters 501 and 502 from the energy management terminal 550. The power service system 1 also receives spot price information Cmkt and weather forecast information Wfd for the area where the customer equipment 50 is located via the internet 20. The spot price information Cmkt is received, for example, from a server (not shown) that discloses the spot price of electricity in the wholesale electricity market. This spot price of electricity is, for example, the fixed price for the following day. The weather forecast information Wfd is received, for example, from a server (not shown) that provides weather forecast information.

[0024] The power service system 1 receives power reception information from power meters 501 and 502, spot price information Cmkt, and weather forecast information Wfd. Based on this information, it calculates the operation plan for the variable power load 504 for the following day and the expected reduction in power costs if this operation plan is applied. It then transmits the calculated operation plan and the expected reduction in power costs to the communication interface 505. If the power service system 1 does not receive a rejection of the transmitted operation plan from the energy manager / operator (the consumer) via the communication interface 505 by a predetermined time, it transmits an equipment operation command to execute this operation plan to the variable power load 504 via the energy management terminal 550. This predetermined time can be arbitrarily set in advance.

[0025] The communication interface 505 comprises a display unit and an input unit. The display unit displays the operational plan and expected reduction in power costs transmitted from the power service system 1. The input unit is a component for the energy manager / operator to communicate to the power service system 1 whether they accept or reject the application of the operational plan transmitted from the power service system 1.

[0026] In this embodiment, as an example, we will describe a case where the variable power load 504 is a water heater with a built-in hot water storage tank, and the operational plan for the variable power load 504 required by the power service system 1 is a hot water storage plan.

[0027] Figure 2 shows the configuration of the power service system 1 according to this embodiment. The power service system 1 includes an addition unit 11, a power reception analysis unit 12, a data storage unit 13, a variable power load power analysis unit 15, a data storage unit 16, a heatwave estimation unit 14, an operation planning unit 17, a transmission / reception unit 18, and an equipment operation command transmission unit 19.

[0028] The power service system 1 receives power reception information P1 from power meter 502, power reception information P2 from power meter 501, spot price information Cmkt, weather forecast information Wfd, and calendar information Calendar via the internet 20. Power reception information P1 includes the amount of electricity received by the variable power load 504 (power received by the variable power load 504). Power reception information P2 includes the power received by the non-variable power load 503. Calendar information Calendar contains information about the month, day, and day of the week, including information on weekdays, weekends (Saturday and Sunday), and public holidays.

[0029] Furthermore, the power service system 1 transmits and receives the following information to and from the customer equipment 50 (Figure 1) via the internet 20. The power service system 1 transmits the requested operation plan Plan for the variable power load 504 to the communication interface 505 and receives a rejection signal Ans from the communication interface 505, which is a signal indicating that the energy management / operator has rejected the transmitted operation plan Plan. Then, the power service system 1 transmits an equipment operation command Com for the variable power load 504 to the variable power load 504 via the energy management terminal 550.

[0030] The summing unit 11 receives power reception information P1 and power reception information P2 and calculates the power reception power P at the interconnection point of the customer equipment 50, which is the sum of the power reception power of the variable power load 504 and the power reception power of the non-variable power load 503.

[0031] The power reception analysis unit 12 receives the power reception P calculated by the summing unit 11, weather forecast information Wfd, and calendar information Calendar. The power reception analysis unit 12 refers to the calendar information Calendar and separates the power reception P into weekday power reception and weekend and holiday power reception for each month, and saves the separated power reception data to the data storage 13.

[0032] Furthermore, the power reception analysis unit 12 refers to the weather forecast information Wfd and determines the predicted maximum temperature value for the day in the area where the customer equipment 50 is located. Then, based on the data stored in the data storage 13, the power reception analysis unit 12 calculates a correlation equation that represents the correlation between the calculated maximum temperature forecast value and the maximum value of the power reception P for each day, separated into weekdays and weekends / holidays for each month. The power reception analysis unit 12 outputs the calculated correlation equation to the extreme heat day estimation unit 14. For example, this correlation equation can be approximated by a linear function, and the power reception analysis unit 12 outputs information about the coefficients of this correlation equation (e.g., proportionality constant and intercept) to the extreme heat day estimation unit 14.

[0033] The variable power load power analysis unit 15 receives power reception information P1, weather forecast information Wfd, and calendar information Calendar. The variable power load power analysis unit 15 refers to the calendar information Calendar and separates the power received by the variable power load 504 included in the power reception information P1 into weekday power received and weekend and holiday power received on a monthly basis, and saves the separated power received data (power reception information P1) to the data storage 16.

[0034] Furthermore, the variable power load power analysis unit 15 refers to the weather forecast information Wfd and determines the predicted maximum temperature value for the day in the area where the customer equipment 50 is located. Then, based on the data stored in the data storage 16, the variable power load power analysis unit 15 calculates a correlation equation that represents the correlation between the calculated maximum temperature forecast value and the amount of electricity received by the variable power load 504 on the day on which this maximum temperature forecast value was calculated, for each of the received power (receiving information P1) separated into weekdays and weekends / holidays for each month. The variable power load power analysis unit 15 outputs the calculated correlation equation to the operation planning unit 17. For example, this correlation equation can be approximated by a linear function, and the variable power load power analysis unit 15 outputs information about the coefficients of this correlation equation (e.g., proportionality constant and intercept) to the operation planning unit 17.

[0035] The extreme heat day estimation unit 14 takes the weather forecast information Wfd, calendar information Calendar, data stored in the data storage 13, and the correlation formula (for example, the coefficient of the correlation formula) obtained by the power reception analysis unit 12 as input and determines whether the following day is a day (for example, an extreme heat day) in which the maximum daily value of the power reception P of the customer equipment 50 is large throughout the year. An extreme heat day is a specific day with high power demand. The extreme heat day estimation unit 14 then outputs the result of its determination to the operation planning unit 17.

[0036] Let's explain a specific example of how the extreme heat day estimation unit 14 makes its judgment. For example, the extreme heat day estimation unit 14 uses the data stored in the data storage 13 to determine the maximum daily power received for each day of the year, and uses the day with the 10th largest maximum value in the year as the reference day to determine the maximum power received on this reference day. The extreme heat day estimation unit 14 also obtains the forecast maximum temperature for the next day from the weather forecast information Wfd and the calendar information Calendar, and uses this forecast maximum temperature and the correlation formula obtained by the power received analysis unit 12 (a correlation formula that represents the correlation between the forecast maximum temperature and the maximum daily power received P) to estimate the maximum power demand for the next day. Then, if the estimated maximum power demand for the next day is greater than the maximum power received on the reference day, the extreme heat day estimation unit 14 determines that the next day is an extreme heat day, and if it is less than or equal to the maximum value, it determines that the next day is a normal day. The extreme heat day estimation unit 14 outputs these judgment results to the operation planning unit 17.

[0037] The operation planning unit 17 inputs calendar information (Calendar), weather forecast information (Wfd), the results of the extreme heat day estimation unit 14, the correlation formula obtained by the variable power load power analysis unit 15, and spot price information (Cmkt) to calculate the operation plan (Plan) for the variable power load 504.

[0038] Specifically, the operation planning unit 17 obtains the forecast maximum temperature for the next day from the weather forecast information Wfd and calendar information Calendar, and uses this forecast maximum temperature and the correlation formula (a correlation formula that represents the correlation between the forecast maximum temperature and the amount of electricity received by the variable power load 504) obtained by the variable power load power analysis unit 15 to estimate the amount of electricity for the variable power load 504 the next day. Then, the operation planning unit 17 refers to the spot price information Cmkt and calculates the operation plan Plan for the variable power load 504 the next day so that the estimated amount of electricity for the variable power load 504 is consumed during the time when spot prices are low.

[0039] However, on extremely hot days, the power demand from air conditioners, which represent a fixed power load 503, increases, resulting in a large peak in received power P during the year. The peak of received power P occurs during the daytime when the outside temperature is high. Since the basic charge for commercial electricity is determined by the maximum power demand, even if the spot price during the day is low, increasing daytime electricity demand will lead to an increase in the basic charge. In other words, increasing daytime electricity demand on extremely hot days may ultimately increase annual electricity costs, even if the spot price during the day is low.

[0040] Therefore, in this embodiment, if the extreme heat day estimation unit 14 determines that the following day will be an extreme heat day, the operation planning unit 17 calculates an operation plan Plan for the variable power load 504 so that the amount of electricity from the variable power load 504 is consumed at night, when the spot price is not low, even if the spot price for the following day is lowest during the daytime. Then, the operation planning unit 17 sets the operation plan for the variable power load 504 to the default operation plan according to the calculated operation plan Plan, rather than an operation plan that consumes electricity during the time when the spot price is low. The default operation plan is, for example, an operation plan that consumes the amount of electricity from the variable power load 504 at night in order to avoid the concentration of electricity demand during the daytime. For example, if the variable power load 504 is a water heater, the default operation plan is to store hot water and consume electricity at night.

[0041] Furthermore, the operations planning unit 17 calculates the expected reduction in electricity cost based on the calculated operations plan, which would result in a reduction in the electricity usage charge for the following day. For example, the operations planning unit 17 calculates: Expected reduction in electricity costs = (Spot price during the time period when electricity is consumed in the previous operational plan × Estimated amount of electricity for variable power load 504) - (Spot price during the time period when electricity is consumed in the revised operational plan × Estimated amount of electricity for variable power load 504) The expected reduction in electricity costs is calculated according to the following formula. In the example above, the time of day when electricity is consumed under the original operational plan is during the day, and the time of day when electricity is consumed under the revised operational plan is at night. On extremely hot days, the expected reduction in electricity costs may be a negative value.

[0042] The operation planning unit 17 outputs the calculated operation plan (Plan) and the expected power cost reduction value to the transmission / reception unit 18.

[0043] The transmitting / receiving unit 18 transmits the operation plan Plan and the expected power cost reduction value to the communication interface 505 of the customer equipment 50 (Figure 1) via the internet 20. The communication interface 505 displays the operation plan Plan and the expected power cost reduction value and waits for the energy management / operator, which is the customer, to input a decision result regarding whether to accept or reject the operation plan Plan. The transmitting / receiving unit 18 receives the decision result regarding the operation plan Plan from the customer equipment 50. For example, if the energy management / operator rejects the operation plan Plan, the transmitting / receiving unit 18 receives a rejection signal Ans from the communication interface 505.

[0044] If, after the transmitting / receiving unit 18 transmits the operation plan Plan and the expected power cost reduction, it does not receive a rejection signal Ans indicating rejection of the operation plan Plan within a predetermined time, the operation planning unit 17 determines that the operation plan Plan has been accepted and sets the calculated operation plan Plan as the operation plan for the variable power load 504 for the following day in the equipment operation command transmitting unit 19. The variable power load 504 is operated according to this operation plan Plan.

[0045] If the transmitting / receiving unit 18 receives a rejection signal Ans within a predetermined time, the operation planning unit 17 determines that the operation plan Plan has been rejected and sets the default operation plan as the operation plan for the variable power load 504 for the following day in the equipment operation command transmission unit 19. The variable power load 504 is then operated according to the default operation plan.

[0046] The equipment operation command transmission unit 19 transmits the operation plan set in the operation plan unit 17 as equipment operation command Com to the variable power load 504 via the internet 20 and the energy management terminal 550.

[0047] The variable power load 504 is operated according to the transmitted equipment operation command Com.

[0048] An example of the operation of the power service system 1 according to this embodiment will be explained using Figures 3A and 3B. In this embodiment, an example of operation will be explained in two cases: a normal day and a hot day. As mentioned above, a hot day is a day when the maximum power demand is greater than the maximum value of the received power on the reference day, and a normal day is a day when the maximum power demand is less than or equal to the maximum value of the received power on the reference day.

[0049] Figure 3A shows an example of the operation of the power service system 1 on a normal day. Figure 3B shows an example of the operation of the power service system 1 on an extremely hot day. In Figures 3A and 3B, the upper graph shows the time change of the spot price over a day, and the lower graph shows the time change of the received power P over a day.

[0050] In the graphs of received power P in Figures 3A and 3B, the hatched bars represent the received power of the variable power load 504 obtained from the power meter 502's power receiving information P1, while the unhatched white bars represent the received power of the non-variable power load 503 obtained from the power meter 501's power receiving information P2.

[0051] The electricity rate plan for the non-variable power load 503 to which the power meter 501 is connected will be a fixed rate plan with a constant rate. The electricity rate plan for the variable power load 504 to which the power meter 502 is connected will be a market-linked rate plan with a rate that changes in conjunction with the spot price.

[0052] First, we will explain the operation of the power service system 1 on a normal day, as shown in Figure 3A.

[0053] Figure 3A shows the spot price on a typical sunny day as an example. The spot price remains almost constant at night and rises from around 5 AM when people begin their activities. Subsequently, the spot price drops sharply when there is an excess of electricity supply from solar power generation facilities, and rises again in the evening when solar power output decreases, partly due to increased household electricity consumption. Finally, the spot price falls from around 7 PM due to the decrease in electricity demand following the end of business activities.

[0054] In response to such fluctuations in spot prices on normal days, the power service system 1 according to this embodiment calculates an operation plan in which the water heater, which is a variable power load 504, stores hot water during the daytime when spot prices are low, rather than storing hot water at night according to the default operation plan.

[0055] In the example shown in Figure 3A, the default operation plan stores hot water from 2:00 AM to 4:00 AM, but an operation plan is calculated in which the variable power load 504 stores hot water from 11:00 AM to 1:00 PM. By having the variable power load 504 store hot water according to this operation plan, electricity costs (electricity charges) can be reduced.

[0056] The variable power load 503 includes, for example, air conditioners, lighting fixtures, and office automation equipment, and it is difficult to operate them in accordance with spot prices. For this reason, for the variable power load 503 to which the power meter 501 is connected, the electricity rate plan is a fixed rate plan with a constant rate, so that consumers can avoid the risk of rising electricity costs due to soaring spot prices.

[0057] Next, we will explain the operation of the power service system 1 on a day of extreme heat as shown in Figure 3B.

[0058] On extremely hot days, daytime electricity demand for air conditioners increases, and daytime spot prices decrease less than on normal days, even on sunny days. Also, the increased electricity demand for air conditioners increases the received power (received power obtained from received power information P2) of the variable power load 503 of the customer equipment 50. The basic charge for electricity for the customer equipment 50 is determined by the peak of the received power P. In other words, on extremely hot days when daytime electricity demand is high due to air conditioners, storing hot water during the day will increase the basic charge for electricity and thus increase electricity costs.

[0059] Therefore, in this embodiment, the power service system 1 calculates an operation plan such that, on extremely hot days, the water heater, which is a variable power load 504, stores hot water from 2:00 AM to 4:00 AM according to the default operation plan, as shown in Figure 3B, in order to avoid an increase in the maximum annual power demand.

[0060] As explained above, in the power service system 1 according to this embodiment, the power meter 502 connected to the variable power load 504 measures power according to a market-linked pricing plan, and the power meter 501 connected to the non-variable power load 503 measures power according to a fixed pricing plan. Since the variable power load 504 is operated according to the spot price, the electricity costs for consumers can be reduced.

[0061] Furthermore, in the power service system 1 according to this embodiment, the risk of high electricity costs during periods of high spot prices for the power consumption of the non-variable power load 503 can be avoided, so consumers can reduce overall electricity costs while taking such risks into consideration. In addition, consumers can refuse or permit changes to the operation of the variable power load 504 before operation, thus reducing the risk of inconvenience being impaired due to changes in the operating hours of the variable power load 504.

[0062] In this embodiment, an example was described in which the variable power load 504 is a water heater. However, the variable power load 504 is not limited to a water heater and may be any device such as a storage battery, a compressor with a tank for storing compressed air, or an electric heating device equipped with a heat storage device. For example, the variable power load 504 may be equipment equipped with an energy storage element.

[0063] Furthermore, in this embodiment, if the transmitting / receiving unit 18 does not receive a rejection signal Ans from the communication interface 505 within a predetermined time, the operation planning unit 17 sets the calculated operation plan Plan in the equipment operation command transmission unit 19, and the variable power load 504 is operated according to this operation plan Plan. Instead of receiving the rejection signal Ans, the transmitting / receiving unit 18 may receive an agreement signal that accepts the operation plan Plan.

[0064] In this case, if the transmitting / receiving unit 18 does not receive an agreement signal from the communication interface 505 within a predetermined time, the operation planning unit 17 determines that the operation plan has been rejected and sets the default operation plan as the operation plan for the variable power load 504 for the following day in the equipment operation command transmission unit 19. The variable power load 504 is operated according to the default operation plan. If the transmitting / receiving unit 18 receives an agreement signal within a predetermined time, the operation planning unit 17 determines that the operation plan has been accepted and sets the calculated operation plan as the operation plan for the variable power load 504 for the following day in the equipment operation command transmission unit 19. The variable power load 504 is operated according to this operation plan.

[0065] Furthermore, in this embodiment, an example was described in which the power reception analysis unit 12 expresses the correlation equation representing the correlation between the maximum temperature forecast value and the maximum value of power reception in a day as a linear function. This correlation equation may be expressed as a higher-order polynomial of degree two or higher, rather than a linear function. The power reception analysis unit 12 outputs information about the coefficients of this correlation equation to the extreme heat day estimation unit 14.

[0066] Furthermore, in this embodiment, an example was described in which the variable power load power analysis unit 15 expresses the correlation equation, which represents the correlation between the maximum temperature forecast value and the amount of electricity received by the variable power load 504 on the day on which the maximum temperature forecast value was obtained, as a linear function. This correlation equation may be expressed as a higher-order polynomial of degree two or higher, rather than as a linear function. The variable power load power analysis unit 15 outputs information about the coefficients of this correlation equation to the operation planning unit 17.

[0067] As explained above, in the power service system 1 according to this embodiment, retail electricity providers can eliminate the risk of fluctuations in spot prices associated with fixed-rate plans by introducing market-linked pricing plans, thereby reducing electricity procurement costs. Consumers can eliminate the risk of being charged high electricity rates with fixed-rate plans, thereby reducing their electricity costs. [Examples]

[0068] A power service system 1 according to Embodiment 2 of the present invention will be described with reference to Figures 4 to 6. Below, the differences between the power service system 1 according to Embodiment 1 and the power service system 1 according to Embodiment 1 will be mainly described.

[0069] Figure 4 shows the power service system 1 according to this embodiment and the customer equipment 50, which is equipment owned by the customer. The customer equipment 50 includes a variable power load 504 equipped with an energy storage element 504a. The energy storage element 504a is capable of storing energy.

[0070] In the power service system 1 according to this embodiment, the variable power load 504 is equipped with an energy storage element 504a. The power service system 1 receives information about the amount of energy stored in the energy storage element 504a and calculates an operational plan for the variable power load 504 by reflecting this energy storage information. As a result, the variable power load 504 can store the necessary energy in the energy storage element 504a by the time it is time to consume the received power and perform its own functions. Therefore, in the power service system 1 according to this embodiment, it is possible to reduce the electricity costs for consumers while reducing the risk of impairing the convenience of the variable power load 504.

[0071] The power service system 1 according to this embodiment receives information about the amount of energy stored by the energy storage element 504a as energy quantity information THS. The power service system 1 according to this embodiment receives the energy quantity information THS from the variable power load 504 via the energy management terminal 550 and the internet 20.

[0072] In this embodiment, as an example, we describe a case where the variable power load 504 is a water heater, the energy storage element 504a is a hot water storage tank, and the energy quantity information THS is information about the amount of hot water remaining in the hot water storage tank. The energy storage element 504a stores energy by storing hot water. The amount of hot water remaining, which is the amount of stored energy, is transmitted to the power service system 1 from the variable power load 504 as energy quantity information THS.

[0073] Figure 5 shows the configuration of the power service system 1 according to this embodiment.

[0074] The difference between the power service system 1 according to this embodiment and the power service system 1 according to Embodiment 1 is that the power service system 1 according to this embodiment determines the amount of electricity to be received by the variable power load 504 from calendar information (e.g., information on weekdays, weekends, and holidays) and weather forecast information Wfd (predicted maximum temperature value for the day), inputs energy quantity information THS, statistically determines the time period when hot water demand occurs, calculates the hot water storage completion time t1 so that the amount of hot water remaining in the hot water storage tank does not fall below a predetermined lower limit, and reflects this hot water storage completion time t1 in the operation plan of the variable power load 504. As a result, the power service system 1 according to this embodiment can reduce electricity costs while reducing the risk of insufficient energy storage (running out of hot water) in the energy storage element 504a (hot water storage tank) of the customer equipment 50.

[0075] Statistically determining the time periods when hot water demand occurs means calculating statistics on the time periods when hot water demand occurs from data collected in the past. At this time, the amount of hot water demanded is also calculated for each time period. This makes it possible to probabilistically determine how much hot water demand occurs at each time period. The hot water storage completion time t1 can be calculated from the data obtained through this statistical processing. For example, the hot water storage completion time t1 is defined as the time when the amount of hot water required by the hot water demand is completed to be stored in the hot water storage tank.

[0076] The power service system 1 according to this embodiment will be explained using Figure 5, focusing on the processing of energy quantity information THS (the amount of remaining hot water, which is the amount of stored energy).

[0077] The variable power load power analysis unit 15 receives energy quantity information THS as input, refers to calendar information Calendar, separates the energy quantity information THS into weekday energy quantity information THS and weekend and holiday energy quantity information THS for each month, and saves the separated energy quantity information THS data to the data storage 16.

[0078] Furthermore, the variable power load power analysis unit 15 calculates, by statistical processing, the time t1 for hot water storage completion so that the amount of hot water in the hot water storage tank does not fall below the lower limit of the remaining amount with a predetermined probability, based on the energy amount information THS data stored in the data storage 16. The variable power load power analysis unit 15 outputs the calculated hot water storage completion time t1 to the operation planning unit 17.

[0079] This predetermined probability can be arbitrarily set in advance, for example, to 95%. The lower limit of the remaining hot water volume can also be arbitrarily set in advance, for example, to 10% of the maximum amount of hot water stored in the hot water storage tank, which is the energy storage element 504a of the variable power load 504. By setting the predetermined probability and the lower limit of the remaining hot water volume as described above, it is possible to prevent the hot water storage completion time t1 from being excessively early.

[0080] Furthermore, as described in Example 1, the variable power load power analysis unit 15 separates the power received by the variable power load 504 included in the power receiving information P1 into weekday power received and weekend and holiday power received on a monthly basis, and stores the separated power received data (power receiving information P1) in the data storage 16.

[0081] Furthermore, as described in Example 1, the variable power load power analysis unit 15 uses the data stored in the data storage 16 to determine a correlation equation that represents the correlation between the calculated maximum temperature forecast value and the amount of electricity received by the variable power load 504 on the day on which the maximum temperature forecast value was calculated, for each of the received power (receiving information P1) separated into weekdays and weekends / holidays for each month. The variable power load power analysis unit 15 outputs the calculated correlation equation, along with the calculated hot water storage completion time t1, to the operation planning unit 17.

[0082] The operation planning unit 17 calculates an operation plan Plan in which the energy storage element 504a of the variable power load 504 stores energy (in this embodiment, the hot water storage tank of the water heater stores hot water). The operation planning unit 17 inputs the hot water storage completion time t1 obtained by the variable power load power analysis unit 15, and, as explained in Example 1, inputs calendar information Calendar, weather forecast information Wfd, the judgment result of the extreme heat day estimation unit 14, the correlation formula obtained by the variable power load power analysis unit 15, and spot price information Cmkt, and calculates an operation plan Plan for the variable power load 504.

[0083] In this embodiment, the operation planning unit 17 calculates the operation plan Plan for the variable power load 504 as described in Embodiment 1, with the constraint that hot water storage in the storage tank is completed by the storage completion time t1. This constraint limits, for example, the time at which hot water storage can be started. For example, on normal days, the operation planning unit 17 calculates an operation plan that minimizes the electricity usage charge, and on extremely hot days, it calculates an operation plan that follows the default operation plan.

[0084] The operation planning unit 17 outputs the calculated operation plan (Plan) and the expected power cost reduction value to the transmission / reception unit 18.

[0085] Similar to Embodiment 1, if the transmitting / receiving unit 18 does not receive a rejection signal Ans indicating rejection of the operation plan Plan within a predetermined time after transmitting the operation plan Plan and the expected power cost reduction, the operation planning unit 17 sets the calculated operation plan Plan in the equipment operation command transmission unit 19. If the transmitting / receiving unit 18 receives a rejection signal Ans within the predetermined time, the operation planning unit 17 sets the default operation plan in the equipment operation command transmission unit 19.

[0086] An example of the operation of the power service system 1 according to this embodiment will be explained using Figure 6. In this embodiment, an example of operation on a normal day will be described.

[0087] Figure 6 shows an example of the operation of the power service system 1 on a normal day. From top to bottom, Figure 6 shows a graph showing the time change of the spot price over a day, a graph showing the time change of the energy quantity information THS (amount of remaining hot water, which is the amount of energy stored) over a day, and a graph showing the time change of the received power P over a day. In the graph of energy quantity information THS, the time change of hot water demand is also shown with a dashed line.

[0088] In the graph of received power P in Figure 6, the hatched bars represent the received power of the variable power load 504 obtained from the power meter 502's power receiving information P1, while the unhatched white bars represent the received power of the non-variable power load 503 obtained from the power meter 501's power receiving information P2.

[0089] Figure 6 shows an example of the operation of the power service system 1 when the transmitting / receiving unit 18 does not receive a rejection signal Ans, that is, when the operation plan calculated by the operation planning unit 17 is not rejected. The hot water storage completion time t1 calculated by the variable power load power analysis unit 15 is assumed to be 12:00.

[0090] The operation planning unit 17 calculates an operation plan such that the variable power load 504 receives power during times when spot prices are low, and that the variable power load 504 receives the amount of power necessary for hot water storage by the time the hot water storage is completed t1. For example, the operation planning unit 17 calculates an operation plan in which the variable power load 504 receives power and stores hot water between 9:00 and 11:00.

[0091] The power received P shown in Figure 6 increases earlier, starting around 9:00 AM, due to hot water storage, compared to the graph of power received P shown in Figure 3A in Example 1. It can also be seen that hot water storage in the storage tank is completed by the storage completion time t1.

[0092] Thus, in the power service system 1 according to this embodiment, by completing hot water storage before the time when hot water demand is expected to occur (hot water storage completion time t1), it is possible to prevent running out of hot water in the hot water storage tank and reduce the electricity usage charges for the variable power load 504.

[0093] As explained above, in the power service system 1 according to this embodiment, the power meter 502 connected to the variable power load 504 measures power according to a market-linked pricing plan, and the power meter 501 connected to the non-variable power load 503 measures power according to a fixed pricing plan. Since the variable power load 504 is operated according to the spot price, the electricity costs for consumers can be reduced.

[0094] Furthermore, in the power service system 1 according to this embodiment, the risk of high electricity costs during periods of high spot prices for the power consumption of the non-variable power load 503 can be avoided, so consumers can control their overall electricity costs while taking such risks into consideration. In addition, consumers can refuse or permit changes to the operation of the variable power load 504 in advance, thus reducing the risk of inconvenience being impaired due to changes in the operating hours of the variable power load 504.

[0095] Furthermore, the power service system 1 according to this embodiment can reduce the risk of impairing customer convenience due to insufficient energy storage capacity in the energy storage element 504a of the variable power load 504 by inputting energy quantity information THS from the variable power load 504.

[0096] In this embodiment, as an example, the variable power load 504 is a water heater, the energy storage element 504a is a hot water storage tank, and the energy quantity information THS is information about the amount of hot water remaining in the hot water storage tank. In this embodiment, the variable power load 504 may be a cooling and heating supply system, the energy storage element 504a may be an ice thermal storage tank, and the energy quantity information THS may be information about the thickness of the ice inside the ice thermal storage tank. In this case, the cooling and heating demand corresponds to the hot water supply demand from the water heater.

[0097] If the energy storage element 504a is an ice thermal storage tank, restarting ice making while ice remains inside the ice thermal storage tank may result in the ice being formed in an irregular shape. Therefore, the power service system 1 according to this embodiment stores information about the power received by the cooling equipment, which is a variable power load 504, during the day (the power received by the variable power load 504 obtained from the power receiving information P1 of the power meter 502), and uses this data to calculate an ice making plan, which is the operational plan for the variable power load 504. This makes it possible to avoid starting ice making while ice remains inside the ice thermal storage tank.

[0098] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible. For example, the embodiments described above are explained in detail to make the present invention easier to understand, and the present invention is not necessarily limited to embodiments having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add configurations from other embodiments to the configuration of one embodiment. Furthermore, it is possible to delete parts of the configuration of each embodiment, or to add or replace other configurations. [Explanation of Symbols]

[0099] 1...Power service system, 10...Power grid, 11...Adding unit, 12...Received power analysis, 13...Data storage, 14...Extreme heat day estimation unit, 15...Variable power load power analysis unit, 16...Data storage, 17...Operation planning unit, 18...Transmitting / receiving unit, 19...Equipment operation command transmission unit, 20...Internet, 50...Customer equipment, 501...Power meter, 502...Power meter, 503...Non-variable power load, 504...Variable power load, 504a...Energy storage element, 505...Communication interface, 550...Energy management terminal, Ans...Rejection signal, Calendar...Calendar information, Cmkt...Spot price information, Com...Equipment operation command, P...Received power, Plan...Operation plan, P1...Received power information, P2...Received power information, THS...Energy amount information, Wfd...Weather forecast information.

Claims

1. The customer's equipment includes a first power load and a second power load that operates differently from the first power load. A variable power load power analysis unit that determines a correlation formula representing the correlation between the daily maximum temperature forecast value in the area where the customer equipment is located and the amount of electricity received by the first power load on the day on which the maximum temperature forecast value was determined. An operation planning unit calculates the operation plan for the first power load and calculates the reduction in electricity charges when following the operation plan as the expected reduction in electricity costs, A transmitting and receiving unit that transmits the operation plan and the expected power cost reduction to the customer equipment and receives the judgment result regarding the operation plan from the customer equipment, Equipped with, The operation planning unit estimates the amount of energy of the first power load using the maximum temperature forecast value obtained from weather forecast information and the correlation formula obtained by the variable power load power analysis unit, and calculates the operation plan for the first power load using the estimated amount of energy of the first power load. A power service system characterized by the following features.

2. The aforementioned first power load is equipped with an energy storage element, The operation planning unit calculates the operation plan for which the energy storage element stores energy. The power service system according to claim 1.

3. The aforementioned first power load is a variable power load whose operation can be adjusted in accordance with fluctuating electricity rates. The aforementioned second power load is a non-variable power load whose operation cannot be adjusted in accordance with fluctuating electricity rates. The operation planning unit calculates the operation plan for the first power load using the estimated amount of electricity for the first power load and the spot price of electricity. The power service system according to claim 1.

4. A power reception analysis unit inputs the sum of the power received by the first power load and the power received by the second power load, and calculates a correlation formula that represents the correlation between the daily maximum temperature forecast value in the area where the customer equipment is located and the daily maximum value of the sum. The system includes a heatwave estimation unit that estimates electricity demand using the maximum temperature forecast value obtained from the weather forecast information and the correlation formula obtained by the power reception analysis unit, and determines whether the following day will be a heatwave day based on the estimated electricity demand. The operation planning unit calculates the operation plan for the first power load using the judgment result of the extreme heat day estimation unit. The power service system according to claim 1.

5. The variable power load power analysis unit refers to calendar information and separates the amount of electricity received by the first power load into weekday power and weekend and holiday power for each month, and calculates the correlation formula for each of the separated received powers. The power service system according to claim 1.

6. The transmitting / receiving unit transmits the operation plan and the expected power cost reduction to the communication interface provided by the customer equipment. The operation planning unit determines that the operation plan has been accepted if the transmitting / receiving unit does not receive a rejection signal from the communication interface that rejects the operation plan. The power service system according to claim 1.

7. The transmitting / receiving unit transmits the operation plan and the expected power cost reduction to the communication interface provided by the customer equipment. The operation planning unit determines that the operation plan has been rejected if the transmitting / receiving unit does not receive an agreement signal from the communication interface to accept the operation plan. The power service system according to claim 1.

8. The variable power load power analysis unit receives information from the first power load regarding the amount of energy stored by the energy storage element as energy quantity information. The operation planning unit calculates the operation plan using the energy quantity information. The power service system according to claim 2.

9. The first power load is a water heater, The aforementioned energy storage element is a hot water storage tank. The aforementioned energy quantity information is information about the amount of hot water remaining in the hot water storage tank. The power service system according to claim 8.

10. The aforementioned first power load is a cooling and heating supply facility. The aforementioned energy storage element is an ice thermal storage tank. The aforementioned energy quantity information is information about the thickness of the ice inside the ice thermal storage tank. The power service system according to claim 8.

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