Power control system, power control method, and charge control program

Abstract

To realize reverse power flow transmission without causing any disadvantages to consumers. [Solution] A reverse flow control unit executes reverse flow transmission, transmitting power stored in a storage battery used by a consumer to the power grid during a reverse flow period that satisfies a predetermined reverse flow activation condition; and a compensation processing unit performs compensation processing to waive the cost of the consumer purchasing power transmitted from the power grid during a compensation period, which is the period during which power is transmitted from the power grid to the consumer after the reverse flow transmission is executed and until the amount of transmitted power becomes equal to the amount of power transmitted to the power grid during the reverse flow period, and to provide the consumer with a predetermined incentive. The power control system is configured to include the following.

Description

[Technical Field]

[0001] The present invention relates to a power control system, a power control method, and a charge control program. [Background technology]

[0002] Conventionally, when purchasing electricity transmitted from a power grid, the purchase price may be set so that the purchase price varies depending on the time period. For example, Patent Document 1 discloses a technology for creating a charging and discharging plan for a storage battery by calculating a demand forecast value for each hour based on a forecast value of generated power, a forecast error determined based on actual values ​​of past generated power, and a forecast value of the amount of power demand for each hour, and performing an optimization calculation to reduce the power procurement fee in a time-of-day electricity rate system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2024-68782 Summary of the Invention [Problem to be solved by the invention]

[0004] A business that supplies electricity to a consumer and the consumer may enter into an electricity purchase and sale contract. For example, a contract may be concluded in which the business purchases electricity stored in a storage battery from the consumer when market prices rise, and the consumer pays an electricity fee to purchase electricity from the business when the consumer demands electricity. In such a configuration, if electricity rates are time-of-day rates, the consumer may incur disadvantages depending on the timing of the purchase and sale. For example, if a consumer sells electricity to a business when electricity rates are low and purchases electricity from a business when electricity rates are high, a situation may arise in which the consumer would have been better off holding the electricity until electricity rates rise and consuming it for themselves rather than selling it. In a configuration that determines the timing of the purchase and sale while predicting power generation and electricity demand, it is difficult to always make accurate predictions, and therefore, if the predictions are incorrect, the consumer may incur disadvantages. The present invention has been made in consideration of the above-mentioned problems, and aims to prevent disadvantages from occurring to consumers. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, the power control system includes a reverse flow control unit that executes reverse flow transmission, in which power stored in a storage battery used by a consumer is transmitted to the power grid during a reverse flow period that satisfies a predetermined reverse flow activation condition, and a compensation processing unit that performs compensation processing to waive the cost of the consumer purchasing power transmitted from the power grid during a compensation period that is a period during which power is transmitted from the power grid to the consumer after the reverse flow transmission is executed and until the amount of power of the transmitted power becomes equal to the amount of power transmitted to the power grid during the reverse flow period, and to provide the consumer with a predetermined incentive.

[0006] That is, in a power control system, if power is purchased from a consumer during a reverse flow period, even if the consumer purchases power after the reverse flow period, the purchase of the same amount of power as the amount of power transmitted in reverse flow is free of charge. Therefore, even if a consumer needs to purchase power after selling it, no loss occurs. Therefore, there is no disadvantage to the consumer. Furthermore, providing incentives to consumers when reverse flow transmission is performed can encourage the use of the power control system. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 illustrates a power control system. [Figure 2] FIG. 2 is a diagram illustrating a schematic diagram of power transfer. [Figure 3] 1 is a graph showing electricity prices and the like. [Figure 4] 1 is a graph showing electricity prices and the like. [Figure 5] 10 is a flowchart of a power control process. [Figure 6] FIG. 10 is a diagram showing examples of market prices, etc. [Figure 7] FIG. 10 is a diagram showing an example of difference values ​​obtained for each frame. [Figure 8] FIG. 10 is a diagram showing an example of a frame during a reverse power flow period. [Figure 9] 10 is a flowchart of a compensation process. DETAILED DESCRIPTION OF THE INVENTION

[0008] Here, the embodiments of the present invention will be described in the following order. (1) Power control system configuration: (2) Power control processing: (3) Compensation process: (4) Other embodiments:

[0009] (1) Power control system configuration: FIG. 1 is a diagram showing the configuration of a power control system 10. In FIG. 1, the exchange of signals and information is indicated by solid lines or solid arrows, and the exchange of power is indicated by dashed lines. In this embodiment, power can be supplied from a power grid 70 to facilities 50, such as homes owned by multiple consumers. The facility 50 is also equipped with a storage battery 50a and a solar power generation unit 50b. The solar power generation unit 50b includes a solar panel (not shown) and is capable of generating power using sunlight. The storage battery 50a is a secondary battery capable of storing power.

[0010] The power control system 10 is a computer used by an administrator who manages the charging and discharging of multiple storage batteries 50a. In this embodiment, the administrator is a business operator who procures power from various facilities connected to the power grid 70 and sells it to others. The business operator may be any entity that supplies power to consumers, and may be a retail electricity supplier or a specified wholesale supplier, and various entities can be the business operator. In this embodiment, the business operator supplies power to consumers from the power grid 70 and also purchases power from consumers. When the business operator purchases power from consumers, the power stored in the storage batteries 50a is transmitted to the power grid 70. In this specification, power transmission from the storage batteries 50a to the power grid 70 is referred to as reverse power flow transmission.

[0011] Each consumer consumes the power supplied from at least one of the power grid 70, the solar power generation unit 50b, and the storage battery 50a. Therefore, when the consumer receives power from the power grid 70 and consumes it himself, he purchases the power from the business. On the other hand, when the amount of power generated by the solar power generation unit 50b is greater than the consumer's own power consumption, the power is stored in the storage battery 50a. When the surplus power stored in the storage battery 50a is transmitted to the power grid 70 via reverse power flow, the consumer sells the power to the business.

[0012] When a consumer purchases electricity from a utility, the price of the electricity transmitted from the power grid 70 to the consumer is determined by a contract between the utility and the consumer, and various prices are possible. In this specification, it is assumed that the consumer has a contract to purchase electricity at a price that varies depending on the time of day (time-of-day rate). This price is what is known as the electricity fee. Figure 2 is a diagram that schematically shows the exchange of electricity. As shown in Figure 2, the time-of-day rate is the price at which the consumer purchases electricity from the utility, and also the price at which the utility sells electricity from the power grid 70 to the consumer.

[0013] FIG. 3 is a graph showing electricity prices, etc., with the horizontal axis representing time and the vertical axis representing price or energy consumption. The time on the horizontal axis is shown in blocks obtained by dividing 24 hours into time slots of multiple unit time lengths. In this example, the block is assumed to be divided into blocks of 30 minutes each. The first block 1 shown is the block from 0:00 to 0:30, and the 48th block 48 is the block from 23:30 to 24:00. In FIG. 3, the time-of-day rates, which are prices that change depending on the time slot, are shown by dashed lines.

[0014] The time-of-use charge is a price per unit of electricity (yen / kWh), and the billing amount is determined according to the amount of electricity consumed by the consumer in each time slot. In this example, the lowest fixed price is applied to multiple time slots from night to early morning, and the highest fixed price is applied to multiple time slots during the day, with time slots having intermediate fixed prices between the two. Of course, this price is just an example, and the relationship between time and price may be different.

[0015] In this embodiment, the electricity supplied by the utility to the consumer includes electricity traded on the energy trading market and electricity transmitted via reverse power flow from the consumer. Of course, it may also include electricity supplied from other sources, such as electricity supplied based on a contract with a power generation company. While the energy trading market is not limited, this specification assumes that it is the spot market provided by JEPX (Japan Electric Power Exchange). Therefore, the price of electricity procured by the utility from the energy trading market in any given time slot is determined by the market price on the energy trading market. In Figure 3, the market price is indicated by a dashed line.

[0016] When a business sells electricity to a consumer, the business procures electricity from the energy trading market at the market price as shown in Figure 2, or purchases electricity in advance from a consumer and stores it in a power storage facility (not shown) and provides it to the consumer at a time-of-use rate. The market price at which a business procures electricity from the energy trading market fluctuates from one frame to another as shown in Figure 3. Generally, market prices rise in frames where the supply and demand of electricity is tight. For example, in the example shown in Figure 3, the market price exceeds 40 yen / kWh in frames 11 to 16, indicating a sharp rise.

[0017] In such a situation where market prices are soaring, if a utility were to procure electricity from the electricity trading market, it would be costly. Therefore, in such a situation where market prices are soaring, it is preferable for a utility to procure electricity from a supplier other than the electricity trading market, i.e., from a consumer's storage battery 50a, through reverse power flow transmission.

[0018] When a consumer and a utility enter into a contract to transmit power from the consumer in a situation where market prices are rising, the utility purchases power from the consumer and transmits it back. When this power transmission is performed, the consumer sells the power to the utility at a predetermined price, as shown in Figure 2. Conventionally, this price has been calculated by adding a certain amount to the time-of-day rate at which the utility sells the power to the consumer.

[0019] However, with such a sales price, there may be disadvantages for the consumer depending on the timing of the sale of electricity from the consumer to the utility. For example, consider a case where the time-of-day rate is low (i.e., the sales price is low) during a period when market prices are rising, and then the time-of-day rate becomes high after that. In this case, the sales price at which the consumer sells electricity to the utility during the period when market prices are rising is low, but the time-of-day rate at which the consumer purchases electricity from the utility when the remaining energy in the storage battery 50a runs out is high. For this reason, depending on the amount of reverse flow power transmission, a situation may arise in which the consumer transmits reverse flow power even though not transmitting reverse flow power would have reduced the total cost.

[0020] A more specific example will be described with reference to Fig. 3. In Fig. 3, the change in the consumer's own power consumption is indicated by a solid line. Furthermore, in Fig. 3, the amount of solar power generation, which is the amount of power generated by the solar power generation unit 50b, the amount of reverse power transmission from the storage battery 50a, and the amount of purchased power, which is the amount of power purchased from the power grid 70, are indicated by bar graphs for each frame.

[0021] FIG. 3 shows an example in which reverse power transmission is performed intensively during periods when market prices are rising. In order to perform reverse power transmission during periods when market prices are rising, it is necessary to retain as much of the power stored in the storage battery 50a as possible without using it during periods when market prices are not rising. FIG. 3 shows such an example, and in frames 1 to 11 and the frames before them, it is assumed that the amount of self-consumption power is covered by the amount of power purchased from the power grid 70 in order to retain the power stored in the storage battery 50a. In frames 12 to 16, reverse power transmission is performed because market prices are rising. It is assumed that the amount of self-consumption power in frames 12 to 16 is supplied from the storage battery 50a, but it may also be supplied from the power grid 70.

[0022] In the example shown in Fig. 3, it is assumed that the remaining energy amount in the storage battery 50a will be 0 from frame 17 onwards, and in this case, the self-consumption amount will be covered by the power purchased from the power grid 70. Note that from frame 17 onwards, if the remaining energy amount in the storage battery 50a is not 0, the remaining energy amount in the storage battery 50a may be maintained in preparation for the next market price spike, and reverse power transmission may not be performed. From frame 24 onwards, the amount of solar power generated by the solar power generation unit 50b becomes greater than 0 kWh, so the power generated by the solar power generation unit 50b is preferentially consumed in the home, and if there is still surplus power after self-consumption, that power is charged into the storage battery 50a.

[0023] In this example, assume that the selling price of electricity (Figure 2) when reverse flow transmission is performed is the time-of-day rate plus a fixed amount α (for example, 3 yen) per unit of power. The time-of-day rate in frames 12 to 16 is 20 yen, so the selling price is 20 yen + α yen. On the other hand, the time-of-day rate in frames 17 to 20 is 30 yen, and 40 yen from frame 21 onwards. Therefore, the price at which consumers purchase electricity from the power grid 70 from frame 17 onwards is higher than the price at which electricity is sold from frames 12 to 6. For this reason, depending on the amount of electricity sold by consumers in frames 12 to 16 and the amount of electricity purchased by consumers from frame 17 onwards, the former amount may be less than the latter amount, which could result in a loss for the consumer.

[0024] On the other hand, if a utility company uses a time-of-day rate plus a certain amount as the sales price when selling electricity to consumers, it may incur disadvantages to the utility company. For example, consider a situation where the time-of-day rate is high (i.e., the sales price) during a period when market prices are rising, and then the time-of-day rate drops, but the market price remains higher than the time-of-day rate. In this case, the sales price (Figure 2), which is the price at which the utility company purchases electricity from consumers during the period when market prices are rising, is high, but the time-of-day rate at which consumers purchase electricity from the utility when the remaining energy in storage battery 50a runs out, is low. However, the utility company must procure this electricity from the market and supply it to consumers. If the market price is higher than the time-of-day rate, the utility company's procurement costs will increase depending on the amount of electricity. This could lead to a situation where the utility company transmits reverse power flow, even though not transmitting reverse power flow would have reduced total costs.

[0025] A more specific example will be described with reference to Figure 4. Figure 4 is a diagram showing the same amount of power, prices, etc. as Figure 3 in the same format. In Figure 4, the time-of-day rates are the same as in Figure 3, but the amount of solar power generation, amount of reverse power transmission, amount of purchased power, amount of self-consumption power, and market price are different.

[0026] In FIG. 4, market prices rise sharply in frames 34 to 38. In order to perform reverse power flow transmission during this period, it is assumed that the power stored in the storage battery 50a is retained without being used before frame 33. In frames 34 to 38, reverse power flow transmission is performed because market prices are rising sharply. From frame 39 onwards, the remaining power in the storage battery 50a runs out, so the private consumption power from frame 39 onwards is covered by power purchased from the power grid 70.

[0027] In this example, assume that the selling price of electricity when reverse flow transmission is performed (Figure 2) is a time-of-day charge plus a fixed amount α (e.g., 3 yen) per unit of power. The time-of-day charge in frames 34 to 36 is 40 yen, and the time-of-day charge in frames 37 and 38 is 30 yen, so the respective selling prices are 40 + α yen and 30 + α yen. On the other hand, the time-of-day charge in frames 39 to 44 is 30 yen, and 20 yen from frame 45 onwards. Therefore, the time-of-day charge, which is the price at which the utility sells electricity to consumers from frame 39 onwards, is lower than the selling price, which is the price at which the utility purchases electricity from consumers from frames 34 to 36. Therefore, depending on the amount of electricity purchased by the utility in frames 34 to 38 and the amount of electricity purchased by consumers from frame 39 onwards, the former amount may be greater than the latter amount, potentially resulting in a loss for the utility.

[0028] The power control system 10 according to this embodiment is a system that completes a transaction so that neither the consumer nor the business operator suffers any disadvantages. The power control system 10 is capable of communicating with a cloud server 60 via the Internet. The cloud server 60 is capable of communicating with devices within a facility 50 to which each of a plurality of consumers belongs via the Internet. The cloud server 60 is only required to be able to control the charging and discharging of at least the storage battery 50a via communication, but may also control other devices, such as a solar power generation unit 50b. In this embodiment, communication and control are performed by a smart meter (not shown) installed in the facility 50, but control may also be performed in other ways, such as by various computers capable of communicating with the cloud server 60.

[0029] The cloud server 60 can also communicate with a weather information management server 80 and a payment server 90. The weather information management server 80 is a server that manages weather information for each region, and defines information indicating the weather for a predetermined period from the present onwards for each region, and stores this information in a storage medium (not shown). In this embodiment, the weather information includes a weather forecast and solar radiation forecast for a predetermined period from the present onwards. The weather forecast and solar radiation forecast may be any information that can be used to obtain an estimated charge amount of the storage battery. In this embodiment, the weather forecast is a weather category (sunny, cloudy, rainfall, snowfall, etc.), and the solar radiation forecast is the amount of radiant energy that a unit area of ​​an object on the ground surface will receive from the sun per unit time.

[0030] The payment server 90 is a server for electronically executing payments between consumers and businesses. Payments may be made by exchanging money or a value equivalent to money between consumers and businesses, and the form of payment is not limited. In this embodiment, the payment server 90 can electronically deposit money into bank accounts registered in advance by the business and consumers, respectively, and withdraw money from those bank accounts.

[0031] The power control system 10 is capable of communicating with a smart meter (not shown) provided in the facility 50, a weather information management server 80, and a payment server 90 via a cloud server 60. In this embodiment, the power control system 10 is capable of issuing instructions via the cloud server 60 to each of the storage batteries 50a used by multiple consumers to perform reverse power flow transmission, supplying power from each storage battery 50a to the power grid 70.

[0032] The power control system 10 can acquire weather information via the cloud server 60. That is, the power control system 10 specifies the area and time for which weather information is to be acquired, and sends a request for weather information to the cloud server 60. When the request is made, the cloud server 60 communicates with the weather information management server 80, acquires weather information for the specified area and time, and sends it to the power control system 10. The power control system 10 acquires the weather information sent from the cloud server 60.

[0033] The power control system 10 can cause the payment server 90 to perform payment processing via the cloud server 60. That is, the power control system 10 can instruct the payment server 90 to make deposits and withdrawals between the bank account of the business operator and the bank account of the consumer. The cloud server 60 instructs the payment server 90 to make payments based on the instructions. The payment server 90 then executes the deposits and withdrawals between the specified bank accounts in accordance with the instructions.

[0034] The power control system 10 includes a control unit 20 including a CPU, RAM, ROM, etc., a storage medium 30, and a communication unit 40. The communication unit 40 is a device for communicating with a cloud server 60.

[0035] The storage medium 30 records various programs and various data. In this embodiment, the storage medium 30 stores price information 30a, an estimated photovoltaic power generation amount 30b, an estimated private power consumption amount 30c, and an estimated remaining energy amount 30d. The price information 30a includes a market price for each time slot and an hourly rate for each time slot. The market price indicates the price that a business operator must pay when procuring electricity from the energy trading market, and in this embodiment, is defined for each 30-minute time slot. In this embodiment, the market price is determined at a predetermined time. In this embodiment, the market prices for 48 time slots per day are determined at 10:00 a.m. the day before. Once the market prices are determined, information indicating the market prices is saved in the storage medium 30 as price information 30a.

[0036] The time-based rate indicates the price that a consumer must pay to a business when electricity is provided to the consumer from the power grid 70, and in this embodiment is defined in 30-minute intervals. In this embodiment, the time-based rate is a price that fluctuates depending on the time of day. In this embodiment, both the market price and the time-based rate are defined as the price per unit of electricity, i.e., yen / kWh.

[0037] The estimated solar power generation amount 30b is an estimated value of the solar power generation amount for each frame. The solar power generation amount is a value corresponding to the weather information output by the weather information management server 80, and is predicted based on the weather information for each location where the solar power generation unit 50b used by the consumer is installed. The estimated solar power generation amount is an estimated value for any frame from the current frame onwards, and is assumed to be, for example, a value as shown by the open bar graphs in Figures 3 and 4. The estimated solar power generation amount 30b is obtained for each facility 50, and is stored in the storage medium 30 in association with the identification information of the facility 50.

[0038] The self-power consumption estimated value 30c is an estimate of the amount of self-power consumption for each frame. The self-power consumption is the total amount of power used by consumers in the facility 50, and is estimated based on the history of the amount of self-power consumption in the facility 50. That is, the history of past self-power consumption for any frame is stored in a storage medium (not shown) of the facility 50 or in the storage medium 30, and the statistical value of this history is used as the self-power consumption estimated value 30c. For example, the self-power consumption estimated value 30c is assumed to be a value like the solid line shown in Figures 3 and 4. The self-power consumption estimated value 30c is obtained for each facility 50, and is stored in the storage medium 30 in association with identification information of the facility 50. Of course, the self-power consumption may be estimated based on various information, for example, the season or weather.

[0039] The remaining energy estimate 30d is an estimate of the remaining energy of the storage battery 50a. In this embodiment, the remaining energy estimate 30d indicates the amount of energy that can be discharged from the storage battery 50a, and is estimated based on the solar power generation estimate 30b and the self-power consumption estimate 30c. The power control system 10 can acquire the current remaining energy of each storage battery 50a via the cloud server 60. The remaining energy estimate of any frame from the present onward can be estimated by adding surplus power obtained by subtracting the self-power consumption from the solar power generation amount of each frame to the remaining energy in the current frame. The remaining energy estimate 30d is acquired for each facility 50, and is stored in the storage medium 30 in association with the identification information of the facility 50.

[0040] In this embodiment, it is assumed that reverse flow power transmission is performed during periods when market prices are high, and the system is configured to prevent self-consumption from the storage battery 50a during periods other than periods when market prices are high so that reverse flow power transmission can be concentrated during periods when market prices are high. Therefore, it is assumed that the remaining energy amount does not decrease during periods other than periods when market prices are high. However, if the amount of power generated by the solar power generation unit 50b is large and exceeds the capacity of the storage battery 50a, the surplus may be transmitted through reverse flow power transmission. Note that the above control is an example, and control may be adopted in which the remaining energy amount of the storage battery 50a is self-consumed while reverse flow power transmission is performed during periods when market prices are high.

[0041] The control unit 20 executes various programs stored in the storage medium 30 or ROM. As an example of such programs, the control unit 20 can execute a charge control program. When the charge control program is executed, the control unit 20 functions as a reverse power flow control unit 20a and a compensation processing unit 20b.

[0042] The reverse flow control unit 20a has a function of executing reverse flow transmission during the reverse flow period, in which the power stored in the storage battery 50a used by the consumer is transmitted to the power grid 70. Furthermore, the compensation processing unit 20b has a function of performing compensation processing to waive the cost of the consumer purchasing the power transmitted from the power grid 70 during the compensation period after the reverse flow transmission has been executed, and to provide the consumer with a predetermined incentive.

[0043] Here, the reverse flow period is a period during which a predetermined reverse flow activation condition is satisfied, and the compensation period is a period during which power is transmitted from the power grid 70 to the consumer after the reverse flow period, and is a period until the amount of transmitted power becomes equal to the amount of power transmitted to the power grid during the reverse flow period.

[0044] That is, the control unit 20 identifies the reverse flow period using the function of the reverse flow control unit 20a, and controls the storage battery 50a during the reverse flow period to transmit power to the power grid 70. Furthermore, the control unit 20 performs compensation processing using the function of the compensation processing unit 20b when a consumer purchases power from the power grid 70, waiving the cost until the amount of power becomes equal to the amount of reverse flow power transmission, and providing an incentive.

[0045] The reverse flow activation condition is a condition for determining whether or not to execute reverse flow power transmission. In this embodiment, the reverse flow activation condition is a condition under which no disadvantage occurs to the business operator. In this embodiment, the control unit 20 performs compensation processing using the compensation processing unit 20b, so that consumers who perform reverse flow power transmission do not suffer any disadvantages and instead receive benefits. Therefore, consumers are always guaranteed not to suffer any disadvantages.

[0046] Therefore, if the reverse flow activation condition is set to a condition that does not cause any disadvantages to the business operator, discharge control can be operated in a way that does not cause any disadvantages to either the consumer or the business operator. Specifically, the reverse flow activation condition is set to be that the difference obtained by subtracting the amount of electricity to be transmitted to the consumer during the compensation period from the amount of electricity to be procured at market price during the reverse flow period is greater than the incentive.

[0047] The amount of electricity procured at market prices for the amount of electricity transmitted in reverse flow during the reverse flow period is the amount that the utility would have to pay to procure that amount of electricity in the market if reverse flow transmission were not implemented during the reverse flow period. Therefore, this amount can be considered as the cost that the utility would incur if reverse flow transmission were not implemented.

[0048] On the other hand, the amount of electricity to be transmitted to consumers during the compensation period when it is procured at market prices is the amount that the utility would have to pay if it procured that amount of electricity on the market during the compensation period when consumers need electricity. Because the compensation period occurs when reverse power flow transmission is implemented, this amount can be considered as the cost that the utility incurs when it implements reverse power flow transmission.

[0049] Therefore, the difference value obtained by subtracting the latter from the former is the difference value between the cost when reverse flow transmission is not performed and the cost when reverse flow transmission is performed. Therefore, if this difference value is larger than the incentive, the total cost when reverse flow transmission is not performed will be larger than the total cost when reverse flow transmission is performed (power procurement cost + incentive). Such a reverse flow activation condition is met when market prices are rising during the reverse flow period. Therefore, when the reverse flow activation condition is met, it can be assumed that market prices are rising. It can be assumed that performing reverse flow transmission during a reverse flow period when the above reverse flow activation condition is met will be beneficial to the business operator and will not be disadvantageous. With this configuration, discharge control can be operated in a way that does not disadvantage either the consumer or the business operator.

[0050] The control unit 20 executes reverse power transmission during the reverse power flow period using the function of the reverse power flow control unit 20a. The process for executing the reverse power transmission will be described in detail later. When reverse power transmission is executed, the control unit 20 executes compensation processing using the function of the compensation processing unit 20b. The compensation processing includes a process of freeing up the cost for the consumer to purchase power transmitted from the power grid 70 that is equal to the amount of reverse power transmission.

[0051] The process of making the cost free can be implemented in various ways, but in this embodiment, when power is transmitted from the power grid 70 to a consumer, the control unit 20 charges the consumer an amount acquired based on the time-based rate and the amount of power, regardless of whether the period is a compensation period or not. That is, the control unit 20 instructs the payment server 90 to charge the electricity fee via the cloud server 60. As a result, the payment server 90 performs the instructed payment process and transfers the electricity fee from the consumer's bank account to the business's bank account.

[0052] Thereafter, the control unit 20 calculates the amount required to purchase the same amount of power as the reverse flow transmission during the compensation period, and performs a process of refunding this amount plus the incentive. That is, the control unit 20 instructs the payment server 90 via the cloud server 60 to refund the refund amount. As a result, the payment server 90 performs the instructed payment process and transfers the refund amount from the business operator's bank account to the consumer's bank account. Details of the compensation process will be described later. Of course, this compensation process is just one example, and a process may be performed in which the amount required to purchase the same amount of power as the reverse flow transmission during the compensation period is not charged to the consumer, thereby making this amount free of charge.

[0053] According to the present embodiment as described above, when reverse power transmission is performed during a reverse power flow period when market prices are soaring, it is possible to prevent disadvantages from occurring to consumers and also to businesses.

[0054] (2) Power control processing: Next, the power control process will be described in detail. Fig. 5 is a flowchart showing the power control process. Here, the power control process will be described focusing on a facility 50 of a certain customer, but the power control system 10 executes similar processes for each facility 50. Furthermore, in this embodiment, the control unit 20 repeatedly executes the power control process at regular intervals.

[0055] When the power control process starts, the control unit 20 acquires price information 30a using the function of the reverse power flow control unit 20a (step S100). That is, the control unit 20 references the price information 30a stored in the storage medium 30 and acquires the market price and time-of-day charges for each frame from the present onwards. The control unit 20 acquires and updates the price information 30a every time the market price in the electricity trading market is determined. Therefore, the market prices acquired in step S100 include market prices for all frames that can currently be acquired. Figure 6 is a diagram showing examples of market prices, etc. for some frames.

[0056] Next, the control unit 20 acquires the solar power generation amount estimate 30b and the self-power consumption amount estimate 30c using the function of the reverse power flow control unit 20a (step S105). Specifically, the control unit 20 acquires, via the communication unit 40, weather information for the region to which the consumer facility 50 belongs, for each time period in each frame for which the market price is known. The control unit 20 then acquires the solar power generation amount estimate 30b for each frame by identifying the solar power generation amount that is previously associated with the weather information. Fig. 6 also shows an example of the solar power generation amount estimate 30b.

[0057] Furthermore, the control unit 20 acquires a history of past private power consumption for any frame and performs statistics to acquire a private power consumption estimated value 30c. Figure 6 also shows an example of the private power consumption estimated value 30c.

[0058] Next, the control unit 20, using the function of the reverse flow control unit 20a, acquires the remaining energy estimate value 30d in the case where reverse flow power transmission due to the market price hike is not performed (step S110). Specifically, the control unit 20 acquires the current remaining energy of the storage battery 50a of the facility 50 via the cloud server 60. The control unit 20 also identifies power sources that cover the private consumption amount acquired in step S105 in frames from the current frame onwards, and determines whether surplus power will be generated if the private consumption amount is covered by each power source. Here, the power sources that cover the private consumption amount can be the storage battery 50a, the solar power generation unit 50b, and the power grid 70, but in this embodiment, a priority order is set for the power sources to be used.

[0059] Specifically, when the amount of solar power generated by the solar power generation unit 50b is greater than 0 kWh, the solar power generation unit 50b has a higher priority than the power grid 70. Therefore, in a frame where solar power is generated by the solar power generation unit 50b, the power generated by the solar power generation is used preferentially for self-consumption. Therefore, in a frame where the amount of solar power generation is greater than the amount of self-consumption, all of the self-consumption is covered by solar power generation, and the surplus power is stored in the storage battery 50a. In a frame where the amount of solar power generation is less than the amount of self-consumption, all of the solar power generation is used for self-consumption, and the shortfall is purchased from the power grid 70.

[0060] On the other hand, when the amount of solar power generated by the solar power generation unit 50b is 0 kWh, either the storage battery 50a or the power grid 70 has a higher priority. In this embodiment, the storage battery 50a has a higher priority after a predetermined time (for example, 17:00), and the power grid 70 has a higher priority before the predetermined time. Therefore, when the amount of solar power generated is 0 kWh and before the predetermined time, the private power consumption is covered by the power transmitted from the power grid 70. When the amount of solar power generated is 0 kWh and after the predetermined time, the private power consumption is covered by the remaining power of the storage battery 50a. If the remaining power is insufficient, the private power consumption is covered by the power transmitted from the power grid 70. Note that this control is an example, and for example, the storage battery 50a may have a higher priority than the power grid 70 regardless of the time or the remaining power.

[0061] The control unit 20 identifies the power source that covers the self-power consumption of each frame according to the above priority order, and identifies the amount of power supplied from each power source. If the amount of solar power generation in each frame is greater than the self-power consumption, the control unit 20 assumes that the surplus power is stored in the storage battery 50a and increases the estimated remaining power value of the storage battery 50a in each frame. Note that because there is an upper limit to the amount of power that can be charged to the storage battery 50a, the control unit 20 does not set the estimated remaining power value to a value greater than the upper limit. If there is surplus power that exceeds the upper limit, the surplus power may be transmitted as reverse power flow.

[0062] Furthermore, when the remaining amount of energy stored in the storage battery 50a decreases as a result of covering the self-consumption amount of each unit according to the above priority order, the control unit 20 subtracts that amount of energy from the remaining energy estimate. Note that, at the stage of acquiring the remaining energy estimate, the control unit 20 acquires the remaining energy estimate assuming that reverse power flow transmission will not be performed due to a market price hike.

[0063] FIG. 6 illustrates an example of an estimated remaining energy value. In this example, the estimated remaining energy value in frame 27 (13:00) is 5 kWh, which is assumed to be the upper limit. That is, the remaining energy of storage battery 50a reaches the upper limit before 13:00. In this embodiment, the remaining energy of storage battery 50a is not used for self-consumption before the predetermined time of 17:00. Therefore, the control unit 20 estimates the estimated remaining energy value in frames 27 to 34 to be constant at 5 kWh. Of course, if the remaining energy does not reach the upper limit, the remaining energy may increase according to the surplus power in each frame. Note that in frames 27 to 34, while solar power generation is used preferentially for self-consumption, if the solar power generation is insufficient, the shortage is covered by power transmitted from the power grid 70.

[0064] On the other hand, from frame 35 (17:00) onwards, the remaining energy of the storage battery 50a is used preferentially for private consumption. Therefore, for example, since the private consumption amount estimated value 30c in frame 35 is 0.36, the remaining energy amount estimated value 30d is 4.64 kWh. The control unit 20 performs similar calculations from frame 36 onwards to obtain the remaining energy amount estimated value 30d. In the example shown in FIG. 6, the remaining energy amount is 0 kWh in frame 46. Therefore, the power grid 70 is used to cover the private consumption amount from frame 46 onwards.

[0065] Next, in steps S115 to S150, the control unit 20 performs processing to set the reverse flow period and the compensation period. First, in steps S115 to S135, the control unit 20 extracts one frame from all frames for which the market price has been determined from the present onward as a processing target, and estimates the benefit to the business operator if reverse flow transmission is performed for each frame.

[0066] Specifically, the control unit 20 selects one frame that has not been the processing target of steps S115 to S135 from among all frames whose market prices have been determined from now on, and sets it as the processing target. Then, the control unit 20 acquires the backward flow transmittable amount of the frame to be processed using the function of the backward flow control unit 20a (step S115). That is, the control unit 20 acquires the backward flow transmittable amount based on the remaining energy amount estimate acquired in step S110.

[0067] Specifically, since there is an upper limit to the amount of power that can be discharged from the storage battery 50a per unit time, there is also an upper limit to the amount of power that can be discharged in one frame. The control unit 20 determines the possible amount of reverse flow power transmission as the value obtained by subtracting the amount of power that is diverted from the storage battery 50a for self-consumption from the maximum amount of power that is within the upper limit of the amount of power that can be discharged in one frame and within the remaining power amount.

[0068] For example, in the example shown in FIG. 6, assume that the upper limit of the amount of energy that can be discharged in one frame is 1 kWh. In this case, if the frame to be processed is frame 27, the remaining energy estimate 30d for frame 27 is 5 kWh, which is smaller than the upper limit of the amount of energy that can be discharged in one frame (1 kWh). Furthermore, the amount of energy diverted from storage battery 50a for self-consumption is 0 kWh, so the amount of reverse flow transmittable energy is 1 - 0 = 1 kWh. If the frame to be processed is frame 35, the remaining energy estimate 30d for frame 35 is 4.64 kWh, which is smaller than the upper limit of the amount of energy that can be discharged in one frame (1 kWh). Furthermore, the amount of energy diverted from storage battery 50a for self-consumption is 0.36 kWh, so the amount of reverse flow transmittable energy is 1 - 0.36 = 0.64 kWh.

[0069] Next, the control unit 20, using the function of the reverse flow control unit 20a, acquires the reverse flow transmittable amount x the market price of the frame to be processed (step S120). That is, the control unit 20 refers to the market price acquired in step S100 and acquires the market price of the frame to be processed. Then, the control unit 20 acquires the product of the market price and the reverse flow transmittable amount acquired in step S115.

[0070] 6, if the frame to be processed is frame 27 and the available reverse flow power transmission capacity is 1 kWh, the market price is 22 yen / kWh, so the product is 1 x 22 = 22 yen. If the frame to be processed is frame 35 and the available reverse flow power transmission capacity is 0.64 kWh, the market price is 80 yen / kWh, so the product is 0.64 x 80 = 14.08 yen. The value acquired in step S120 in this way indicates the cost required when a business operator procures power from the market for the frame to be processed.

[0071] Next, the control unit 20, using the function of the reverse flow control unit 20a, acquires the market price of the frame of the compensation period times the reverse flow transmittable amount (step S125). That is, based on the remaining energy estimate acquired in step S110, the control unit 20 identifies the frame in which the remaining energy of the storage battery 50a will first become 0 if reverse flow power transmission of the reverse flow transmittable amount is performed in the frame to be processed. Furthermore, the control unit 20 sets the frame from this frame onwards as the compensation period, and acquires the market price of the frame in the compensation period by referring to the market price acquired in step S100. Then, the control unit 20 acquires the product of the market price and the reverse flow transmittable amount acquired in step S115.

[0072] 6, if the frame to be processed is frame 27 and the possible amount of reverse flow power transmission is 1 kWh, the control unit 20 assumes that frame 27 is a reverse flow period and that reverse flow power transmission will be performed in frame 27. In this case, the remaining energy amount estimate obtained from frame 27 onwards is 1 kWh, and therefore the remaining energy amount of the storage battery 50a in frame 43 is 0.12. Therefore, the control unit 20 regards frame 43 onwards as a compensation period and obtains the cost of purchasing 1 kWh of power from the market, which is the possible amount of reverse flow power transmission from frame 43 onwards.

[0073] If the reverse flow transmittable capacity is less than the self-consumption capacity for one frame, the control unit 20 calculates the reverse flow transmittable capacity multiplied by the market price of the frames for the compensation period across multiple frames, and regards this as the cost of procuring the same amount of power as the reverse flow transmittable capacity. Specifically, if we consider the self-consumption amounts of 0.34 (= 0.46 - 0.12) kWh, 0.44 kWh, and 0.22 kWh (= 1 - 0.34 - 0.44) for frames 43, 44, and 45, respectively, to be procured, the total would be 1 kWh. Therefore, based on the market price of each frame, the control unit 20 calculates 0.34 x 37.6 + 0.44 x 24.6 + 0.22 x 29.5 = 30.1 yen, and uses this as the market price for the reverse flow transmittable capacity multiplied by the compensation period.

[0074] Next, the control unit 20 acquires the difference value using the function of the reverse power flow control unit 20a (step S130). That is, the control unit 20 acquires the difference value by subtracting the amount acquired in step S125 from the amount acquired in step S120. In the example shown in FIG. 6 above, if frame 27 is the processing target and the compensation period is from frame 43 onwards, the control unit 20 acquires 22-30.1=-8.1 yen as the difference value.

[0075] Next, the control unit 20 determines whether trial calculations have been completed for all frames (step S135). That is, the control unit 20 determines that trial calculations have been completed for all frames if the processing of steps S115 to S135 has been completed for all frames whose market prices have been determined from the present onwards.

[0076] If it is determined in step S135 that trial calculations have not been completed for all frames, the control unit 20 selects a frame that has not yet been processed from among the frames whose market prices have been determined from now on, sets it as a new processing target, and repeats the processing from step S115 onwards.If it is determined in step S135 that trial calculations have been completed for all frames, the control unit 20, using the function of the reverse power flow control unit 20a, obtains a combination of frames that maximizes the sum of the difference values ​​(step S140).

[0077] That is, the difference value acquired for each frame by the processing of steps S115 to S135 is a difference value obtained by subtracting the cost required for the business operator to procure the same amount of power as the reverse flow transmittable amount during the compensation period from the cost required for the business operator to procure power from the market in the frame being processed. The former is the cost that the business operator must pay if procuring power in the frame being processed without performing reverse flow transmission, and the latter is the cost that the business operator must pay if procuring the power required by consumers during the compensation period after performing reverse flow transmission. Therefore, it can be said that the higher the former is compared to the latter, the more advantageous it is for the business operator to perform reverse flow transmission. This is because the higher the former is compared to the latter, the greater the difference value between performing and not performing reverse flow transmission in the frame being processed.

[0078] Fig. 7 is a diagram showing an example of the difference value obtained for each frame after steps S115 to S135 are executed. When step S140 is executed after steps S115 to S135, the benefit (the difference value described above) that the business operator will gain when reverse power flow transmission is performed is quantified, as shown in Fig. 7. Therefore, the control unit 20 obtains a combination of frames that maximizes the sum of these difference values.

[0079] Various methods may be used to obtain a combination of frames that maximizes the sum of the difference values. In this embodiment, the control unit 20 sorts the frames in descending order of the difference values. According to the above process, by selecting the sorted frames from the top down, it becomes possible to obtain a combination of frames that maximizes the sum of the difference values. For example, in the example shown in FIG. 7 , the frames are sorted as follows: frames 36, 37, 34, 35, 38, 41, and 42. After sorting, for example, when selecting two frames, the control unit 20 selects frames 36 and 37 to maximize the sum of the difference values, and when selecting five frames, the control unit 20 selects frames 36, 37, 34, 35, and 38 to maximize the sum of the difference values.

[0080] Next, the control unit 20 determines whether the reverse flow activation condition is met using the function of the reverse flow control unit 20a (step S145). As described above, the reverse flow activation condition is that the difference obtained by subtracting the amount of power to be transmitted to consumers in the compensation period from the amount of power to be transmitted in the reverse flow period at market price is greater than the incentive.

[0081] Therefore, the control unit 20 selects N pieces (N is an integer greater than or equal to 1) from the combinations (sorted pieces) acquired in step S140, assumes them to be reverse flow periods, and performs a process to identify the compensation period for when reverse power is generated during the reverse flow period. In this case, the control unit 20 selects pieces so that N is maximized. That is, the control unit 20 selects the top N pieces from the pieces sorted in step S140, assumes that the N pieces are reverse flow periods, and performs the same process as steps S115 to S130 to obtain the costs for the reverse flow period and the compensation period, and obtains the difference value. Then, if the difference value is greater than the incentive (reverse flow power amount (kWh) × fixed price (yen / kWh)), it is deemed that the reverse flow activation condition is met. If the difference value is met, the control unit 20 adds 1 to N and repeats the same process. As a result, the longest number of pieces that meets the reverse flow activation condition is identified. If N that satisfies the reverse flow initiation condition is found, the control unit 20 determines that the reverse flow initiation condition is satisfied.

[0082] If it is not determined in step S145 that the reverse flow activation condition is satisfied, the control unit 20 repeats the processes from step S100 onwards. That is, the control unit 20 waits until the next trial calculation timing (for example, the end timing of the current frame) and repeats the processes from step S100 onwards.

[0083] If it is determined in step S145 that the reverse flow activation condition is met, the control unit 20 sets a reverse flow period and a compensation period using the functions of the reverse flow control unit 20a and the compensation processing unit 20b (step S150). That is, the control unit 20 sets each frame for which it is determined in step S145 that the reverse flow activation condition is met as a reverse flow period. Furthermore, the control unit 20 regards the period that was assumed to be the compensation period for that frame in the same processing as in step S125 as the compensation period.

[0084] Next, the control unit 20 determines whether the current period is a reverse flow period using the function of the reverse flow control unit 20a (step S155). That is, the control unit 20 identifies the time using a timing circuit (not shown) and determines whether the current frame is a frame in a reverse flow period. FIG. 8 is a diagram showing an example in which frames 34 to 38, out of frames 33 to 48, are in a reverse flow period. In this example, if the current frame is 33, 39 to 48, the control unit 20 does not determine that the current period is a reverse flow period. If the current frame is 34 to 38, the control unit 20 determines that the current period is a reverse flow period.

[0085] If it is determined in step S155 that the current period is a reverse flow period, the control unit 20 executes reverse flow power transmission using the function of the reverse flow control unit 20a (step S160). That is, the control unit 20 controls the storage battery 50a via the cloud server 60 to execute reverse flow power transmission, in which power other than power used for self-consumption is transmitted to the power grid 70. Here, it is assumed that the maximum amount of power that can be transmitted in reverse flow power is transmitted in reverse flow power transmission, but reverse flow power transmission of a predetermined amount of power may also be performed. Note that if the remaining power in the storage battery 50a is depleted, reverse flow power transmission is not performed. If it is not determined in step S155 that the current period is a reverse flow period, the control unit 20 skips step S160.

[0086] If step S160 has been executed, or if it is not determined in step S155 that the current period is a reverse flow period, the control unit 20 determines whether all reverse flow periods have elapsed using the function of the reverse flow control unit 20a (step S165). That is, the control unit 20 determines whether all reverse flow periods set in step S150 have elapsed. If it is not determined in step S165 that all reverse flow periods have elapsed, the control unit 20 repeats the processing from step S155 onwards. If it is determined in step S165 that all reverse flow periods have elapsed, the control unit 20 repeats the processing from step S100 onwards. That is, the control unit 20 executes the processing from step S100 onwards again after a certain period has elapsed.

[0087] (3) Compensation process: In this embodiment, the control unit 20 executes compensation processing at regular intervals (for example, once a month). FIG. 9 is a flowchart showing the compensation processing. When the compensation processing starts, the control unit 20 acquires the power purchase cost for the compensation period using the function of the compensation processing unit 20b (step S200). Specifically, the control unit 20 acquires the power purchase cost by multiplying the purchase price of the power transmitted from the power grid 70 to the consumer during all compensation periods set since the last compensation processing was executed up to the present (i.e., all compensation periods for which compensation processing has not been executed).

[0088] The compensation period is the period set in step S150. That is, it is the period from when reverse flow transmission is performed until the integrated value of the amount of power transmitted from the power grid 70 to the consumer during a period other than the reverse flow period reaches the amount of power transmitted to the power grid 70 during the reverse flow period. For example, in the example shown in FIG. 8 , frames 34 to 38 are the reverse flow period, and the integrated value of the amount of reverse flow power during the reverse flow period is 3.07 kWh (= 0.68 + 0.64 + 0.6 + 0.58 + 0.57). The compensation period starts from frame 39, and it is at frame 45 that the integrated value of the amount of power transmitted from the power grid 70 during the compensation period reaches 3.07 kWh (0.44 + 0.45 + 0.46 + 0.46 + 0.44 + 0.36 = 3.07). Therefore, in this example, frames 39 to 45 are set as the compensation period.

[0089] In this embodiment, the purchase price of electricity transmitted from the power grid 70 to the consumer is the time-based rate described above. Therefore, the control unit 20 references the time-based rate obtained in step S100 and obtains the electricity purchase cost by multiplying the amount of electricity consumed by the consumer in each frame by the time-based rate. For example, in the example shown in FIG. 8, frames 39 to 45 are the compensation period, and the electricity purchase cost for each frame is obtained, and the sum of these amounts becomes the consumer's electricity purchase cost. For frame 39, the electricity purchase cost is 30 x 0.44 = 13.2, and for frame 40, the electricity purchase cost is 30 x 0.45 = 13.5. The total electricity purchase cost for frames 39 to 45 is 88.5 yen.

[0090] Next, the control unit 20 executes compensation processing using the function of the compensation processing unit 20b (step S205). That is, the control unit 20 outputs an instruction to deposit the amount obtained in step S200, which is the consumer's electricity purchase cost plus the incentive, into the consumer's bank account. The instruction is sent to the payment server 90 via the cloud server 60, and the payment server 90 deposits the amount obtained in step S200, which is the consumer's electricity purchase cost plus the incentive, into the consumer's bank account based on the instruction.

[0091] The incentive is calculated by multiplying the amount of reverse flow power (kWh) by a fixed price (yen / kWh). In the example shown in FIG. 8, the fixed price is 3 yen / kWh. For example, in frame 34, the amount of reverse flow power is 0.68 kWh, so the incentive is 2.04 yen (= 0.68 × 3). The control unit 20 performs similar processing for frames 35 to 38. As a result, the total incentive is 9.21 yen (= 2.04 + 1.92 + 1.8 + 1.74 + 1.71).

[0092] According to the above process, when power is transmitted from the power grid 70 during the compensation period, the consumer pays an electricity fee based on the time-of-use rate. However, since the consumer's electricity purchase cost is credited in step S205, the transmission is essentially free of charge. Therefore, there is no disadvantage for the consumer when reverse power flow transmission is performed. On the other hand, since an incentive is paid to the consumer, there is an advantage to the consumer when reverse power flow transmission is performed compared to when reverse power flow transmission is not performed.

[0093] Furthermore, if reverse power flow transmission is not implemented, the business operator will need to procure electricity from the energy trading market. The cost of procuring this electricity from the market is the market price (yen / kWh) x the amount of electricity (kWh). If reverse power flow transmission is implemented, these costs required for market procurement will be unnecessary. On the other hand, the power to be supplied to consumers during the compensation period will need to be procured from the market. The cost of procuring this electricity from the market is the market price (yen / kWh) x the amount of electricity (kWh). Therefore, if the value obtained by subtracting the latter cost from the former cost is greater than the incentive, the difference will be a benefit to the business operator.

[0094] For example, in the example shown in FIG. 8 , the market price for block 34 is 78 yen, and the amount of reverse flow power is 0.68 kWh, so the market procurement cost is 53.04 yen (= 78 × 0.68). The total market procurement cost for blocks 34 to 38 is 244.23 yen. The market price for block 39 is 53.9 yen, and the amount of power transmitted from the power grid 70 is 0.44 kWh, so the market procurement cost is 23.7 yen (= 53.9 × 0.44). The total market procurement cost for blocks 39 to 45 is 111.80 yen. As described above, the total incentive is 9.21 yen, so the business operator benefits by 123.22 yen (= 224.23 - 111.80 - 9.21). In this embodiment, the reverse flow activation conditions are set to derive these benefits to the business operator, so there are no disadvantages to the business operator when reverse flow transmission is performed.

[0095] (4) Other embodiments: The above embodiment is one example for implementing the present invention, and various other embodiments are also possible. For example, the power control system 10 may be realized by multiple devices, or may be configured to be realized by a cloud server or the like. Furthermore, the power control system 10 may be capable of communicating with a weather information management server 80, a payment server 90, multiple storage batteries, etc., without going through the cloud server 60. Furthermore, the power control system 10 may be realized by a device within the facility 50, such as a smart meter.

[0096] Furthermore, at least some of the reverse power flow control unit 20a and the compensation processing unit 20b may be separated into multiple devices. Of course, some of the configurations of the above-described embodiment may be omitted, the order of processing may be changed or omitted, or the processing content may be different. For example, in steps S115 to S140, the process of acquiring the combination of frames that maximizes the sum of the difference values ​​may be various processes. More specifically, any number of combinations of frames may be acquired from the frames acquired in step S130, and the combination that provides the greatest benefit to the utility may be acquired assuming that each combination is in a reverse power flow period.

[0097] Furthermore, the storage battery 50a is not limited to a battery that charges with power generated by a solar power generation device. For example, it may be a storage battery mounted on a vehicle. Furthermore, the private power generation is not limited to solar power generation, but may be wind power generation, small hydroelectric power generation, biomass power generation, geothermal power generation, etc. Furthermore, when calculating the incentive, the fixed price is not limited to 3 yen and may be another value. Furthermore, the time-of-use charge may be a charge that varies for each time slot or a charge that is linked to the market price. Furthermore, the method for obtaining the solar power generation amount estimate 30b and the private power consumption amount estimate 30c is not limited, and various methods may be used.

[0098] The reverse flow control unit is only required to be able to execute reverse flow transmission, in which power stored in a storage battery used by a consumer is transmitted to the power grid during a reverse flow period in which a predetermined reverse flow activation condition is satisfied. In other words, the reverse flow control unit is only required to identify a period in which the reverse flow activation condition is satisfied and execute reverse flow transmission from the storage battery to the power grid during that period. Therefore, the reverse flow control unit is only required to be able to control the storage battery used by the consumer.

[0099] The reverse flow activation condition may be a condition for determining whether or not reverse flow should be performed. The reverse flow activation condition may be various conditions and is not limited to the configuration set so as not to incur any disadvantages to the utility in each frame, as in the above-described embodiment. For example, if the total cost of the utility procuring power from the market during a reverse flow period spanning multiple frames is greater than the total cost of the utility procuring power from the market during a compensation period spanning multiple frames and the total cost required for incentives, the utility will not incur any disadvantages and will benefit. The reverse flow activation condition may be determined to satisfy such a condition. Furthermore, in cases where the source of power procurement is not limited to a market such as JEPX, whether or not the reverse flow activation condition is satisfied may be determined based on the prices at which power is purchased from multiple power suppliers. The reverse flow period may be a period during which reverse power transmission is performed, and may be a discrete period or a continuous period.

[0100] The storage battery may be a secondary battery used by a consumer, and there are no limitations on the type, capacity, etc. of the battery. The power grid may be a facility that can transmit power to consumers and also transmit power from the storage battery, and there are no limitations on the form, scale, etc. Of course, various facilities, such as power storage facilities and power plants, may be connected to the power grid.

[0101] The compensation processing unit may perform compensation processing to waive the cost of purchasing power transmitted from the power grid to a consumer during a compensation period, which is a period during which power is transmitted from the power grid to a consumer after reverse flow transmission is performed and until the amount of transmitted power becomes equal to the amount of power transmitted to the power grid during the reverse flow period, and to provide a predetermined incentive to the consumer. That is, the compensation processing unit waives the cost of purchasing power transmitted from the power grid to a consumer during the compensation period, to a consumer who performed reverse flow transmission during the reverse flow period, so as to prevent a situation in which it would have been less costly to not perform reverse flow transmission and instead self-consumer the power stored in the storage battery. The compensation period may be set as a period for compensating for the power transmitted through reverse flow transmission, and may be a discrete period or a continuous period.

[0102] The compensation process may be a process for freeing the cost of purchasing electricity transmitted from the power grid to the consumer during the compensation period and providing a predetermined incentive to the consumer. That is, the compensation processing unit calculates the cost of purchasing electricity transmitted from the power grid to the consumer during the compensation period and performs a process for providing the cost to the consumer. The process may be realized by various processes, such as a transfer process to the consumer's account or a process of associating points or the like having the same value as the cost with an account associated with the consumer, as long as the transfer process can be performed electronically. The incentive may be realized in various ways, such as payment in the form of money or points, or a future discount or the like.

[0103] Furthermore, embodiments of the invention may be programs or methods. The above-described systems, programs, and methods may be realized as a single device or multiple devices, and include various aspects. They may also be modified as appropriate, such as being partly software and partly hardware. Furthermore, the invention may also be realized as a recording medium for a program that controls the system. Of course, the recording medium for the software may be a magnetic recording medium or a semiconductor memory, and any recording medium developed in the future may be considered in the same way. [Explanation of symbols]

[0104] 10...power control system, 20...control unit, 20a...reverse power flow control unit, 20b...compensation processing unit, 30...storage medium, 30a...price information, 30b...estimated photovoltaic power generation amount, 30c...estimated self-power consumption amount, 30d...estimated remaining power amount, 40...communication unit, 50...facility, 50a...storage battery, 50b...photovoltaic power generation unit, 60...cloud server, 70...power system, 80...weather information management server, 90...payment server

Claims

1. a reverse flow control unit that executes reverse flow transmission to transmit power stored in a storage battery used by the consumer to the power grid during a reverse flow period in which a predetermined reverse flow activation condition is satisfied; a compensation processing unit that performs compensation processing to waive the cost of the consumer purchasing the power transmitted from the power grid during a compensation period, which is a period during which power is transmitted from the power grid to the consumer after the reverse flow transmission is performed and until the amount of power of the transmitted power becomes equal to the amount of power transmitted to the power grid during the reverse flow period, and to provide the consumer with a predetermined incentive; A power control system comprising:

2. The reverse power flow activation condition is: a difference value obtained by subtracting the amount of electricity to be transmitted to the consumer during the compensation period from the amount of electricity to be transmitted during the reverse flow period at the market price is greater than the incentive; The power control system of claim 1 .

3. The reverse flow control unit is acquiring an estimate of the remaining energy of the storage battery on the assumption that each time period of a unit time length is not the reverse flow period based on an estimate of the amount of energy generated by photovoltaic power generation and an estimate of the amount of energy consumed by the consumer; identifying the compensation period based on the estimated value of the remaining energy when each of the time periods is assumed to be the reverse flow period, and determining the time period that satisfies the reverse flow activation condition as the reverse flow period; The power control system of claim 2 .

4. The reverse flow control unit is When there are a plurality of time periods that satisfy the reverse flow activation condition, the combination of time periods that maximizes the sum of the difference values ​​is determined as the reverse flow period. The power control system of claim 3 .

5. The compensation processing unit The compensation period is defined as a period until an integrated value of the amount of power transmitted from the power system to the consumer reaches the amount of power transmitted to the power system during the reverse flow period, and the cost is obtained by multiplying the purchase price of the power transmitted from the power system to the consumer during the compensation period by the amount of power transmitted from the power system to the consumer. The power control system according to claim 1 or 2.

6. the market price is a spot market price; The price of the electricity transmitted from the power grid to the consumer is a price that varies depending on the time period determined by a contract between the consumer and a supplier that supplies electricity from the power grid. The power control system of claim 2 .

7. a reverse flow control step of executing reverse flow transmission in which power stored in a storage battery used by the consumer is transmitted to the power grid during a reverse flow period in which a predetermined reverse flow activation condition is satisfied; a compensation processing step of performing compensation processing to waive the cost of the consumer purchasing the power transmitted from the power grid during a compensation period, which is a period during which power is transmitted from the power grid to the consumer after the reverse flow transmission is performed and until the amount of power of the transmitted power becomes equal to the amount of power transmitted to the power grid during the reverse flow period, and to provide the consumer with a predetermined incentive; A power control method comprising:

8. Computer, a reverse flow control unit that executes reverse flow transmission to transmit power stored in a storage battery used by the consumer to the power grid during a reverse flow period in which a predetermined reverse flow activation condition is satisfied; a compensation processing unit that performs compensation processing to waive the cost of the consumer purchasing the power transmitted from the power grid during a compensation period, which is a period during which power is transmitted from the power grid to the consumer after the reverse flow transmission is performed and until the amount of power of the transmitted power becomes equal to the amount of power transmitted to the power grid during the reverse flow period, and to provide the consumer with a predetermined incentive; A charging control program that functions as a

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