Control Method, Power Trading System, and Program

Abstract

To provide a control method and the like capable of suppressing fraudulent electricity trading.SOLUTION: The control method includes: a step of receiving a piece of first transaction data including a piece of power transmission amount information and the like representing the amount of the power transmitted to a power storage facility from a first power facility (S104); a step of acquiring a piece of power reception information including a piece of received power amount information, etc. representing the amount of received power received from the first power facility from the power storage facility (S105, 106); a step of verifying the first transaction data by referring to the power reception information (S107); a step of executing a first consensus algorithm together with a second server (S110) when the verification of the first transaction data is successful (Y in S107); and a step of recording a block including the first transaction data on a distributed ledger of a first server when the validity of the first transaction data is verified by the first consensus algorithm.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present disclosure relates to a control method, and particularly to a control method in a system for trading electric power generated in a home or the like.

Background Art

[0002] In recent years, renewable energy such as solar power generation has been spreading. In solar power generation, not only the electric power generated by oneself is used, but also the surplus electric power is sold to an electric power company.

[0003] In the future, it is also assumed that not only electric power companies but also direct sales to neighboring residents will be possible (see, for example, Non-Patent Document 1). In Non-Patent Document 1, a technology for constructing an autonomous distributed system by applying blockchain technology to the personal-to-person trading of electric power in the electric power field is being studied. For example, when a user of a house with solar power generation wants to sell the surplus electric power to other users, a sales contract can be made using blockchain.

[0004] According to Non-Patent Document 1, in the house of a user who wants to sell the surplus electric power, if the generated electric power can be stored, the stored electric power can be directly bought and sold to other users. That is, personal-to-person trading is possible without an intermediary such as an electric power company. On the other hand, in the house of a user who wants to sell the surplus electric power, if the generated electric power cannot be stored, it is necessary to conduct personal-to-person trading of electric power through an intermediary business operator having a power storage facility.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when conducting individual power transactions by entrusting an intermediary with power storage equipment, it is possible that the intermediary may purchase power at an unreasonably low price compared to the average power purchase price desired by the users, or sell the purchased power at an unreasonably high unit price compared to the amount paid for the purchase. That is, when conducting individual power transactions by entrusting an intermediary with power storage equipment, power transactions may also occur due to improper intermediary transactions.

[0007] This disclosure has been made in view of the above circumstances, and an object thereof is to provide a control method and the like that can suppress improper power transactions.

Means for Solving the Problems

[0008] To achieve the above object, the control method of the present disclosure is a control method executed by a first server among the plurality of servers in a power trading system including power equipment used by a user, power storage equipment, and a plurality of servers capable of communicating with the power equipment and the power storage equipment via a network. The method includes obtaining transaction data including power purchase amount information indicating the amount of power to be purchased requested by the user and the electronic signature of the user, obtaining power storage information including power storage amount information indicating the amount of power stored in the power storage equipment from the power storage equipment, determining whether power can be transmitted from the power storage equipment to the power equipment based on the power purchase amount information and the power storage amount information using a smart contract, and transmitting a power transmission request to the power storage equipment when the transmission is possible.

[0009] Note that these general or specific aspects may be implemented in a system, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM, or may be implemented by any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

Advantages of the Invention

[0010] According to the control method and the like of the present disclosure, illegal power trading can be suppressed.

Brief Description of the Drawings

[0011]

Figure 1

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Embodiments for Carrying Out the Invention

[0012] A control method according to an aspect of the present disclosure is a control method executed by a first server among the plurality of servers in a power trading system including power facilities used by a user, power storage facilities, and a plurality of servers capable of communicating with the power facilities and the power storage facilities via a network. The method includes: obtaining transaction data including power purchase amount information indicating the amount of power to be purchased requested by the user and the electronic signature of the user; obtaining power storage information including power storage amount information indicating the amount of power stored in the power storage facilities from the power storage facilities; determining, using a smart contract, whether power can be transmitted from the power storage facilities to the power facilities based on the power purchase amount information and the power storage amount information; and transmitting a power transmission request to the power storage facilities when the power transmission is possible.

[0013] Further, a power trading system is a power trading system including power facilities used by a user, power storage facilities, and a plurality of servers capable of communicating with the power facilities and the power storage facilities via a network. The first server among the plurality of servers obtains transaction data including power purchase amount information indicating the amount of power to be purchased requested by the user and the electronic signature of the user, obtains power storage information including power storage amount information indicating the amount of power stored in the power storage facilities from the power storage facilities, determines, using a smart contract, whether power can be transmitted from the power storage facilities to the power facilities based on the power purchase amount information and the power storage amount information, and transmits a power transmission request to the power storage facilities when the power transmission is possible.

[0014] A control method according to an aspect of the present disclosure is a control method executed by a first server among a plurality of servers in a power trading system including a first power facility used by a first user, a power storage facility connected to the first power facility via a power line, and the plurality of servers capable of communicating with the first power facility and the power storage facility via a network. The method includes receiving, via the network, power transmission amount information indicating an amount of power transmitted from the first power facility to the power storage facility via the power line and first transaction data including an electronic signature of the first user from the first power facility; obtaining, via the network, received power information including received power amount information indicating an amount of power received by the power storage facility from the first power facility from the power storage facility; verifying the first transaction data with reference to the received power information; when verification of the electronic signature of the first user and verification of the validity of the first transaction data are successful in the step of verifying the first transaction data, transferring the first transaction data to a plurality of second servers different from the first server among the plurality of servers; executing a first consensus algorithm for agreeing on the validity of the first transaction data with the second servers; and when the validity of the first transaction data is agreed upon by the first consensus algorithm, recording a block including the first transaction data in a distributed ledger of the first server.

[0015] In this way, the transaction data of the power transaction transmitted to the power storage facility is recorded in the distributed ledger. As a result, the transaction data of the power transaction is made public and it becomes possible to detect forgery, so that it is possible to suppress illegal power transactions by service providers holding storage batteries.

[0016] In addition, in the step of verifying the first transaction data, it may also include a step of comparing the power transmission amount information and the power reception amount information, a step of verifying the electronic signature of the first user, and a step of verifying the validity of the first transaction data.

[0017] Thereby, it is possible to verify the consistency between the power transmitted to the power storage facility and the power received by the power storage facility, as well as the validity of the first transaction data, enabling detection of forgery.

[0018] In addition, the first transaction data further includes a first timestamp indicating the first date and time when the power transmission power was transmitted, the power reception information further includes a second timestamp indicating the second date and time when the power reception power was received, and in the comparing step, it may further compare the first timestamp and the second timestamp.

[0019] In addition, the power trading system further includes a second power facility used by a second user, which is connected to the power storage facility via the power line and can communicate with the plurality of servers via the network. The control method further includes receiving, via the network, second transaction data from the second power facility, the second transaction data including the amount of power purchase information indicating the amount of power to be purchased requested by the second user and the electronic signature of the second user; verifying the received second transaction data; in the step of verifying the second transaction data, when the verification of the electronic signature of the second user and the verification of the validity of the second transaction data are successful, transferring the second transaction data to the second server; executing, together with the second server, a second consensus algorithm for reaching an agreement on the validity of the second transaction data; when the validity of the second transaction data is agreed upon by the second consensus algorithm, recording a block including the second transaction data in the distributed ledger of the first server.

[0020] In this way, the second transaction data of the blockchain indicating the power purchase request is recorded in the distributed ledger. As a result, the transaction data of the power transaction is made public and it becomes possible to detect forgery, so that it is possible to suppress illegal power transactions by service providers holding storage batteries.

[0021] Further, the control method further includes the steps of: obtaining power storage information including power storage amount information indicating the amount of power stored in the power storage facility from the power storage facility via the network; comparing the power purchase amount information with the power storage amount information to determine whether power transmission from the power storage facility to the second power facility is possible; when power transmission from the power storage facility to the second power facility via the power line is possible, requesting the power storage facility to transmit power to the second power facility, and generating third transaction data indicating a matching result of a power transaction in which power stored in the power storage facility is transmitted to the second power facility; transferring the third transaction data to the second server; executing a third consensus algorithm for agreeing on the validity of the third transaction data together with the second server; when the validity of the third transaction data is agreed upon by the third consensus algorithm, recording a block including the third transaction data in the distributed ledger of the first server.

[0022] In this way, the third transaction data of the blockchain indicating the matching result of the power transaction via the storage battery is recorded in the distributed ledger. As a result, the transaction data of the power transaction is made public and tampering can be detected, so that it is possible to suppress unauthorized power transactions by the service provider holding the storage battery.

[0023] Also, when requesting power transmission from the power storage facility to the second power facility, it includes steps of generating fourth transaction data indicating a power trading matching result that power storage power has been requested for power transmission from the power storage facility to the second power facility; transferring the fourth transaction data to the second server; executing a fourth consensus algorithm for reaching an agreement on the validity of the fourth transaction data together with the second server; and when the validity of the fourth transaction data is agreed upon by the fourth consensus algorithm, recording a block including the fourth transaction data in the distributed ledger of the first server. The third transaction data may further include information indicating that power storage power has been transmitted from the power storage facility to the second power facility.

[0024] Also, the first power facility and the second power facility may include at least one of a solar power generation device, a gas power generation device, and a wind power generation device.

[0025] Also, in the step of executing the second consensus algorithm, it may include steps of receiving a second report indicating whether the verification of the validity of the second transaction data has been successful from each of the second servers; determining whether the number of the second reports exceeds a predetermined number; and when the number of the second reports exceeds the predetermined number, determining that it is the case where the validity of the second transaction data is agreed upon by the second consensus algorithm.

[0026] Also, in the step of executing the first consensus algorithm, it may include steps of receiving a first report indicating whether the verification of the validity of the first transaction data has been successful from each of the second servers, determining whether the number of the first reports exceeds a predetermined number, and when the number of the first reports exceeds the predetermined number, determining that the validity of the first transaction data has been agreed upon by the first consensus algorithm.

[0027] Also, after the step of recording the block including the first transaction data in the distributed ledger, the first server may further include a step of notifying the first user that the incentive has been paid after paying the incentive to the first user.

[0028] Also, a controller according to an aspect of the present disclosure is a controller for controlling a first power facility used by a first user in a power trading system including the first power facility, a power storage facility connectable to the first power facility via a power line, and a plurality of servers capable of communicating with the first power facility and the power storage facility via a network. The controller includes a processor and a memory storing a program for causing the processor to execute a predetermined process. The predetermined process includes determining whether an excess power amount of the first power facility is equal to or greater than a predetermined value; when the excess power amount is equal to or greater than the predetermined value, causing at least a part of the excess power amount to be transmitted to the power storage facility via the power line as transmission power; generating first transaction data including transmission amount information indicating the amount of the transmission power and an electronic signature of the first user; transmitting the first transaction data to a first server among the plurality of servers via the network; when the validity of the first transaction data is verified by the plurality of servers and a block including the first transaction data is recorded in a distributed ledger of each of the plurality of servers, causing display on a display of consideration information indicating consideration to be paid to the first user according to the amount of the transmission power; and when the validity of the first transaction data is not verified by the plurality of servers, causing display on the display of failure information indicating that verification has not been performed.

[0029] Moreover, a control method for a controller according to an aspect of the present disclosure is a control method for a display that displays power trading information of a first power facility in a power trading system including a first power facility used by a first user, a power storage facility connected to the first power facility via a power line, and a plurality of servers capable of communicating with the first power facility and the power storage facility via a network. The method includes: displaying, on the display, power transmission information indicating that at least a part of the surplus power amount of the first power facility has been transmitted as power transmission power to the power storage facility via the power line when the surplus power amount of the first power facility is equal to or greater than a predetermined value; displaying, on the display, verification-in-progress information indicating that the validity of the first transaction data is being verified until the validity of the first transaction data including power transmission amount information indicating the amount of the power transmission power and an electronic signature of the first user is verified by the plurality of servers after being transmitted to a first server among the plurality of servers; displaying, on the display, consideration information indicating consideration paid to the first user according to the amount of the power transmission power when the validity of the first transaction data is verified by the plurality of servers; and displaying, on the display, failure information indicating that the agreement has not been reached when the validity of the first transaction data has not been agreed upon by the plurality of servers.

[0030] Also, a data structure according to one aspect of the present disclosure is a data structure used for a block recorded as a blockchain in a power trading system including a first power facility used by a first user, a power storage facility connected to the first power facility via a power line, and a plurality of servers capable of communicating with the first power facility and the power storage facility via a network. The data structure is included in a block of the blockchain and includes a blockchain address that is an identifier for identifying at least one of the first user and the first power facility, generated using a private key of the first user, power transmission amount information indicating the amount of power transmitted from the first power facility to the power storage facility, and an electronic signature of the first user. The power transmission amount information is compared with power purchase amount information indicating the amount of power received by the power storage facility from the first power facility, and is used to verify the legitimacy of the transaction regarding the power transmission.

[0031] Also, a power trading system according to an aspect of the present disclosure includes a first power facility used by a first user, a power storage facility connected to the first power facility via a power line, and a plurality of servers communicably connected to the first power facility and the power storage facility via a network. The first controller included in the first power facility causes at least a part of the surplus power amount of the first power facility to be transmitted to the power storage facility as transmission power via the power line, and generates first transaction data including transmission amount information indicating the amount of the transmission power and an electronic signature of the first user. The first transaction data is transmitted to a first server among the plurality of servers via the network. The second controller included in the power storage facility stores reception information including reception amount information indicating the amount of received power received by the power storage facility from the first power facility in a reception management list. The first server acquires the reception information from the power storage facility via the network, verifies the first transaction data with reference to the reception information, and when the verification of the electronic signature of the first user and the verification of the validity of the first transaction data are successful in the verification of the first transaction data, transfers the first transaction data to a second server which is a plurality of second servers different from the first server among the plurality of servers. The first server and the second server execute a first consensus algorithm for the first transaction data, and when the validity of the first transaction data is verified by the first consensus algorithm, record a block including the first transaction data in a distributed ledger of the first server.

[0032] Hereinafter, embodiments will be described with reference to the drawings. Note that each of the embodiments described below shows a preferred specific example of the present disclosure. That is, the numerical values, shapes, materials, components, arrangements and connection forms of the components, steps, order of steps, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. The present disclosure is defined based on the description of the claims. Therefore, among the components in the following embodiments, the components not described in the independent claims indicating the highest concept of the present disclosure are not necessarily required to achieve the problems of the present disclosure, but are described as components constituting a more preferred form.

[0033] (Embodiment 1) First, the system configuration of the present disclosure will be described.

[0034] [1. System Configuration] The power trading system of the present disclosure suppresses illegal power trading by conducting power trading utilizing blockchain technology such as recording transaction data of power trading with a service provider holding a storage battery as an intermediary in a distributed ledger.

[0035] Hereinafter, the power trading system and the like in the embodiment will be described with reference to the drawings.

[0036] [1.1 Overall Configuration of Power Trading System 10] FIG. 1 is a diagram showing an example of the overall configuration of the power trading system 10 according to the present embodiment.

[0037] As shown in Fig. 1, the power trading system 10 includes, for example, houses 100a, 100b, 100c, authentication servers 200a, 200b, 200c, a storage battery 300, and a management server 350 that manages the storage battery 300. These are connected by a communication network 400. Also, the houses 100a, 100b, 100c and the storage battery 300 are connected by a power network 500. The power network 500 is an example of a power line and is a network through which power can be shared among houses. The power network 500 may be a dedicated line or may use a power grid laid by an electric power company.

[0038] Also, the authentication servers 200a, 200b, 200c (hereinafter also referred to as the authentication servers 200a etc.) are connected to storage devices 201a, 201b, 201c. The authentication servers 200a etc. may be connected to the storage devices 201a etc. via the communication network 400, or may include the storage device 201a internally. The storage device 201a has a distributed ledger in which blockchain transaction data and blocks are electronically recorded.

[0039] Note that Fig. 1 shows an example in which the power trading system 10 includes three houses and three authentication servers, but it is not limited to this. That is, the power trading system 10 may include four or more houses and four or more authentication servers.

[0040] [1.2 Configuration of House 100a] Since houses 100b and 100c have the same configuration, house 100a will be described as an example below.

[0041] Fig. 2 is a diagram showing an example of the overall configuration of house 100a according to the present embodiment.

[0042] As shown in FIG. 2, the house 100a includes a controller 101, a solar power generation unit 102, and a power meter 103. The controller 101, the solar power generation unit 102, and the power meter 103 are connected by a communication network 110. Further, the solar power generation unit 102 and the power meter 103 are connected by a power network 111, and the power meter 103 is connected to a power network 500 outside the house 100a.

[0043] Here, the house 100a and the like are an example of a building having power facilities used by a first user or a second user, and are, for example, a house such as a dwelling house, but are not limited thereto. The house 100a and the like may be a building such as a factory or a building. That is, the house 100a and the like may be in any form as long as it is a building having power facilities used by a user.

[0044] <controller 101> The controller 101 is, for example, a controller of an energy management system, and is an example of a controller that controls a first power facility or a second power facility in the power trading system 10.

[0045] In the present embodiment, the controller 101 displays the solar power generation unit 102, inputs an application for selling or purchasing power, etc. Further, the controller 101 controls the solar power generation unit 102 and transmits power to the power network 111 or the power network 500. Further, the controller 101 manages the amount of transmitted power and notifies an authentication server 200a or the like. Details will be described later.

[0046] <solar power generation unit 102> The solar power generation unit 102 is an example of a solar power generation device included in a first power facility or a second power facility. The solar power generation unit 102 is a device equipped with a power generation method that directly converts sunlight into power using solar cells. The solar power generation unit 102 uses the generated power within the house 100a or transmits the power to the power network 500 via the power network 111.

[0047] Note that the solar power generation 102 may be not only a solar power generation device but also a gas power generation device, a wind power generation device, or the like.

[0048] <Power meter 103> The power meter 103 is included in the first power facility or the second power facility and measures the amount of power transmitted to or received from the power network 500. When the solar power generation 102 transmits power to the power network 500 according to the power transmission instruction of the controller 101, the power meter 103 measures the time and the amount of power at which the power is transmitted and notifies the controller 101. The power meter 103 measures the amount of power received from and used by the power network 500 according to the power utilization instruction from the controller 101. Note that the power meter 103 may be included in the controller 101.

[0049] Hereinafter, an example of the configuration of the controller 101 will be described.

[0050] [1.3 Configuration of Controller 101] FIG. 3 is a block diagram showing the functional configuration of the controller 101 shown in FIG. 2.

[0051] The controller 101 includes a processor and a memory in which a program for causing the processor to execute a predetermined process is stored. That is, the controller 101 is realized by the processor executing a predetermined program using the memory. In the present embodiment, the controller 101 includes an input unit 1011, a transaction data generation unit 1012, a control unit 1013, a recording unit 1014, and a communication unit 1015. Hereinafter, each component will be described.

[0052] <Input unit 1011> The input unit 1011 creates an input screen for the user to input information for selling electricity or purchasing electricity. When selling electricity request information or purchasing electricity request information is input by the user on the created input screen, the input unit 1011 transmits the input selling electricity request information or purchasing electricity request information to the transaction data generation unit 1012.

[0053] FIG. 4 is a diagram showing an example of an input screen for inputting power purchase request information according to the present embodiment. For example, as shown in FIG. 4, in an input screen 1011a for inputting power purchase request information, a date, a power selling amount, and a unit price of power purchase are input by a user. In the example shown in FIG. 4, the power purchase amount is displayed in kWh, but it is not limited thereto. It may be a ratio of the power generated by the solar power generation 102. Further, the power selling amount and the unit price of power purchase are not limited to the case where they are input by the user, and may be determined in advance by the power trading system 10. When the user sets the unit price of power purchase, it is possible to preferentially acquire power by paying more than the market price. Note that the input unit 1011 may present the date, the power purchase amount, and the unit price of power purchase in a state where they are temporarily input on the input screen 1011a, and have the user input whether or not to approve, such as "yes" or "no".

[0054] <Transaction data generation unit 1012> The transaction data generation unit 1012 generates transaction data in the blockchain based on the power selling request information received from the input unit 1011 or the power selling request information. Note that the transaction data generation unit 1012 may determine whether or not the surplus power amount of the solar power generation 102 is equal to or more than a predetermined value, and if it is equal to or more than the predetermined value, generate transaction data. Here, the predetermined value is, for example, the power selling amount included in the power selling request information received from the input unit 1011.

[0055] The transaction data generated by the transaction data generation unit 1012 is an example of first transaction data and second transaction data.

[0056] The first transaction data includes power transmission amount information indicating the amount of power transmitted from the first power facility to the power storage facility via a power line, and the electronic signature of the first user. In addition, the first transaction data further includes a first blockchain address which is an identifier for identifying at least one of the first user and the first power facility, and a first timestamp indicating the first date and time when the power was transmitted. It is not essential for the first transaction data to include the first timestamp. There may be multiple types of the first blockchain address as long as it functions as an identifier for identifying at least one of the first user and the first power facility. And one of them may be included in the first transaction data. The second transaction data includes power purchase amount information indicating the amount of power to be purchased requested by the second user, and the electronic signature of the second user. In addition, the second transaction data further includes a second blockchain address which is an identifier for identifying at least one of the second user and the second power facility. Similarly, there may be multiple types of the second blockchain address as long as it functions as an identifier for identifying at least one of the second user and the second power facility. And one of them may be included in the second transaction data.

[0057] Thus, the transaction data generated by the transaction data generation unit 1012 includes the blockchain address of the user or the controller 101, the power selling request information or the power purchasing request information, and the signature of the user.

[0058] The transaction data generation unit 1012 records the generated transaction data in the recording unit 1014. Also, the transaction data generation unit 1012 transmits the generated transaction data to at least one of the authentication server 200a etc. via the communication unit 1015. Further, when receiving a notification of power transmission from the power meter 103 to the power network 500, the transaction data generation unit 1012 generates transaction data including the time and the amount of power transmitted included in the notification, and records it in the recording unit 1014. The generated transaction data is transmitted to at least one of the authentication server 200a etc. via the communication unit 1015.

[0059] <Control unit 1013> When the surplus power amount of the first power facility is equal to or more than a predetermined value, the control unit 1013 causes at least a part of the surplus power amount to be transmitted as power for power transmission to the power storage facility via the power line. For example, when performing control to transmit power, the control unit 1013 transmits a power transmission instruction indicating that the power generated by the solar power generation 102 is transmitted to the power network 500 to the solar power generation 102. Also, when performing control to use power, the control unit 1013 uses the power purchased via the power network 500.

[0060] Also, the control unit 1013 may control a display built in or connected to the controller 101 to display the power selling request information or power buying request information etc. transmitted to the authentication server 200a etc.

[0061] Also, the control unit 1013 may cause the display to display power transmission information indicating that at least a part of the surplus power amount has been transmitted as power for power transmission to the power storage facility via the power line. The control unit 1013 may cause the display to display verification in progress information indicating that the validity of the first transaction data is being verified from when the first transaction data is transmitted to the first server among the plurality of authentication servers 200a etc. until the validity of the first transaction data is verified by the plurality of authentication servers 200a etc.

[0062] In addition, when the validity of the first transaction data is verified by a plurality of authentication servers 200a or the like, the control unit 1013 may cause the display to display the consideration information indicating the consideration to be paid to the user according to the amount of power transmitted. On the other hand, when the validity of the first transaction data is not verified by a plurality of authentication servers 200a or the like, the control unit 1013 may cause the display to display failure information indicating that the verification has not been performed.

[0063] <Recording unit 1014> The recording unit 1014 records the transaction data generated by the transaction data generation unit 1012. In the present embodiment, the recording unit 1014 records the first transaction data or the second transaction data generated by the transaction data generation unit 1012.

[0064] <Communication unit 1015> The communication unit 1015 communicates with the management server 350 and the authentication servers 200a or the like via the communication network 400. This communication may be performed by TLS (Transport Layer Security). In this case, the encryption key for TLS communication may be held by the communication unit 1015.

[0065] In the present embodiment, the communication unit 1015 transmits the first transaction data or the second transaction data to the first server among the plurality of authentication servers 200a or the like via the communication network 400.

[0066] Next, the authentication servers 200a or the like will be described.

[0067] [1.4 Configuration of Authentication Server 200a] FIG. 5 is a block diagram showing the functional configuration of the authentication server 200a according to the present embodiment. Since the authentication servers 200b and 200c have the same configuration, the authentication server 200a will be described as an example.

[0068] As shown in FIG. 5, the authentication server 200a includes a power storage state acquisition unit 211, a transaction data verification unit 212, a block generation unit 213, a synchronization unit 214, a transaction generation unit 215, a recording unit 216, and a communication unit 217. The authentication server 200a can be realized by a processor executing a predetermined program using a memory. Hereinafter, each component will be described.

[0069] <Power storage state acquisition unit 211> The power storage state acquisition unit 211 acquires, from the power storage facility via the communication network 400, power reception information including power reception amount information indicating the amount of power received by the power storage facility from the first power facility. Further, the power storage state acquisition unit 211 acquires, from the power storage facility via the communication network 400, power storage information including power storage amount information indicating the amount of power stored in the power storage facility. Note that the power storage state acquisition unit 211 may acquire, from the power storage facility via the communication network 400, power reception information including power reception amount information indicating the amount of power received by the power storage facility from the first power facility and a second timestamp indicating the second date and time when the power reception occurred.

[0070] In this way, the power storage state acquisition unit 211 acquires the power reception information and the power storage information as information indicating the power storage state of the storage battery 300, and confirms that the power is indeed stored in the storage battery 300. Then, the power storage state acquisition unit 211 transmits the information indicating the power storage state of the acquired storage battery 300 to the transaction data verification unit 212 and the transaction generation unit 215.

[0071] <Transaction data verification unit 212> When the transaction data verification unit 212 receives the first transaction data, it verifies the validity of the received first transaction data with reference to the power reception information. More specifically, the transaction data verification unit 212 compares the power transmission amount information and the power reception amount information by referring to the power reception information, and confirms that the power transmitted has indeed been stored in the storage battery 300. After that confirmation, the transaction data verification unit 212 verifies the electronic signature of the first user and verifies the validity of the first transaction data. Note that the first transaction data may include a first timestamp, and the power reception information may include a second timestamp. In this case, the transaction data verification unit 212 may compare the power transmission amount information and the power reception amount information by referring to the power reception information, and confirm that the power transmitted has indeed been stored in the storage battery 300. By using the first timestamp and the second stamp, in addition to confirming that power has been transmitted to the storage battery, the transaction data verification unit 212 can confirm that the timing of power transmission and reception is correct.

[0072] Also, when the transaction data verification unit 212 receives the second transaction data, it verifies the received second transaction data. More specifically, the transaction data verification unit 212 verifies the electronic signature of the second user included in the second transaction data and verifies the validity of the second transaction data.

[0073] In this way, the transaction data verification unit 212 verifies the received transaction data. More specifically, when the transaction data verification unit 212 receives transaction data from the house 100a or the like, it verifies whether the blockchain address, the power storage request information or the power purchase request information, and the power information included in the transaction data are correct. If the transaction data verification unit 212 confirms the validity of the transaction data as a result of the verification, it records the transaction data in the recording unit 216.

[0074] Also, the transaction data verification unit 212 refers to the information indicating the state of charge of the storage battery 300 acquired by the state of charge acquisition unit 211 to verify whether the power information is correct, and verifies whether power is being correctly transmitted or used. When the transaction data verification unit 212 confirms the validity of the transaction data as a result of the verification, it notifies the synchronization unit 214 of the transaction data.

[0075] <Block generation unit 213> When the verification of the validity of the transaction data is successful in the transaction data verification unit 212, the block generation unit 213 executes a consensus algorithm for the transaction data together with other authentication servers 200b and 200c, which are second servers different from the first server. The consensus algorithm here means the first consensus algorithm to the third consensus algorithm, and this transaction data means the first transaction data to the third transaction data.

[0076] In this way, the block generation unit 213 executes a consensus algorithm among a plurality of authentication servers. As the consensus algorithm, a consensus algorithm called PBFT (Practical Byzantine Fault Tolerance) may be used, or other known consensus algorithms may be used. When using PBFT, the block generation unit 213 first receives a report from each of the other authentication servers 200b and 200c indicating whether the verification of the transaction has been successful, and determines whether the number of the reports exceeds a predetermined number. Then, when the number of the reports exceeds the predetermined number, the block generation unit 213 may determine that the validity of the transaction data has been verified by the consensus algorithm.

[0077] In addition, when the validity of the transaction data is verified by the consensus algorithm, the block generation unit 213 records the block including the transaction data in the distributed ledger of the storage device 201a of the authentication server 200a.

[0078] As described above, in this embodiment, the block generation unit 213 executes a consensus algorithm among the authentication server 200a, the authentication server 200b, and the authentication server 200c. That is, the block generation unit 213 first generates a block of the blockchain including one or more pieces of transaction data. Next, the block generation unit 213 executes a consensus algorithm. Then, when an agreement is reached by executing the consensus algorithm, the block generation unit 213 records the generated block in the recording unit 216. The block generated by the block generation unit 213 is recorded by being connected to the blockchain recorded in the recording unit 216.

[0079] Here, the data structure of the blockchain and the data structure of the transaction data will be described.

[0080] FIG. 6A is an explanatory diagram showing the data structure of the blockchain.

[0081] The blockchain is one in which blocks, which are its recording units, are connected in a chain (chain) shape. Each block has a plurality of pieces of transaction data and the hash value of the previous block. Specifically, the block B2 includes the hash value of the previous block B1. Then, the hash value calculated from the plurality of pieces of transaction data included in the block B2 and the hash value of the block B1 is included in the block B3 as the hash value of the block B2. In this way, by connecting the blocks in a chain shape while including the content of the previous block as a hash value, it is possible to effectively prevent the falsification of the connected transaction data.

[0082] If the past transaction data is changed, the hash value of the block will become a different value from that before the change. To pass off the tampered block as legitimate, all subsequent blocks would have to be recreated, which is extremely difficult in reality.

[0083] In the present embodiment, each transaction data indicates first transaction data indicating a power selling request, second transaction data indicating a power buying request, and third and / or fourth transaction data indicating a matching result of a power transaction described later.

[0084] FIG. 6B is an explanatory diagram showing the data structure of the transaction data.

[0085] The transaction data D1 shown in FIG. 6B is an example of the first to fifth transaction data. The transaction data D1 includes an address P1 indicating the holder, an address P2 indicating the recipient, and an electronic signature P3 generated by signing the hash values of the addresses P1 and P2 with the signature key of the holder. When new transaction data is generated, the address P1 is blank.

[0086] <Synchronization unit 214> The synchronization unit 214 synchronizes the blocks of the blockchain or the transaction data among a plurality of authentication servers (authentication servers 200a to 200c).

[0087] More specifically, when the verification of the user's electronic signature and the validity of the transaction data included in the transaction data acquired from the house 100a is successful, the synchronization unit 214 transfers a copy of the transaction data to the other authentication servers 200b and 200c. Here, the transaction data means the first to third transaction data, and the user's electronic signature means the electronic signature of the first user or the electronic signature of the second user.

[0088] Among the multiple authentication servers 200a to 200c, peer-to-peer synchronization of blockchain transaction data is performed. Then, the synchronization unit 214 records the synchronized blockchain transaction data in the recording unit 216.

[0089] For example, when the validity of the first transaction data indicating a power selling request or the second transaction data indicating a power buying request is verified, the synchronization unit 214 transfers the content of the first or second transaction data to the other authentication servers 200b and 200c. At the same time, the synchronization unit 214 records the verified transaction data in the recording unit 216.

[0090] In addition, when the synchronization unit 214 receives transaction data from the other authentication servers 200b and 200c, it records the transaction data in the recording unit 216.

[0091] <Transaction generation unit 215> The transaction generation unit 215 compares the power purchase amount information and the power storage amount information to determine whether power transmission from the power storage facility to the second power facility is possible. When power transmission from the power storage facility to the second power facility via the power line is possible, the transaction generation unit 215 requests the power storage facility to transmit power to the second power facility. In addition, the transaction generation unit 215 generates third transaction data indicating the matching result of the power transaction that power stored in the power storage facility is transmitted to the second power facility.

[0092] In the present embodiment, the transaction generation unit 215 matches the power storage list recorded in the recording unit 216 with the power purchase request list to determine whether the house that requested power purchase can purchase power. When the transaction generation unit 215 determines that power purchase is possible, it requests the management server 350 that manages the storage battery 300 to transmit power to the house that requested power purchase, generates transaction data, and records it in the recording unit 216.

[0093] FIG. 7A is a diagram showing an example of a power storage list according to the present embodiment. As shown in FIG. 7A, the power storage list includes a blockchain address, a power storage date, a power storage amount, and a signature, and is recorded in the recording unit 216. For example, in the first row of the power storage list shown in FIG. 7A, it is recorded that the house indicated by the blockchain address "0x03547921" stored 30 kWh of power in the battery 300 by 13:00 on December 14, 2017. In this way, in each row of the power storage list, the stored power amount transmitted and the power storage date are described for the house identified by the blockchain address. As described above, the blockchain address does not have to be uniquely determined by a house or the like, and it is sufficient if the house or the like can be identified. Also, since there is strictly a time lag between the power transmission time and the power reception time, the date does not have to indicate an exact time or the like, and it is sufficient if the date can be correctly identified. Similarly, since there is also power transmission loss, the power storage amount may be treated as the same if it is within a predetermined range that takes into account the power transmission loss and does not exactly match the power transmission amount.

[0094] FIG. 7B is a diagram showing an example of a power purchase request list according to the present embodiment. As shown in FIG. 7B, the power purchase request list includes a blockchain address, a desired power purchase date, a desired power purchase amount, a unit price of power purchase, and a signature. For example, in the first row of the power purchase request list in FIG. 7B, it is recorded that the house indicated by the blockchain address "0x04587463" wants to purchase 10 kWh of power at a unit price of 20 yen around 13:30 on December 15, 2017. In this way, in each row of the power purchase request list, the unit price and the power amount that the house identified by the blockchain address wants to purchase are described at the desired date and time.

[0095] Note that the signature performed by the authentication server 200a shown in FIGS. 7A and 7B is not essential and may be omitted.

[0096] Therefore, the transaction generation unit 215 makes a determination as to whether power transmission to the house that has requested power purchase is possible by referring to and comparing, for example, the date and the amount of power stored in the power storage list shown in FIG. 7A and the date and the amount of power purchased in the power purchase request list shown in FIG. 7B to perform matching.

[0097] When the transaction generation unit 215 determines that power transmission of the power desired by the house that has requested power purchase is possible, the transaction generation unit 215 generates transaction data indicating the matching result of the power transaction, including the blockchain address of the power transmission destination, the date, the amount of power, and the unit price. At the same time, the transaction generation unit 215 requests the management server 350 that manages the storage battery 300 to transmit power to the house that has requested power purchase. Then, the transaction generation unit 215 records the generated transaction data in the recording unit 216. Note that although the transaction generation unit 215 requests the management server 350 to transmit power to the house that has requested power purchase, the unit price may be set higher to preferentially match the house that has requested power purchase.

[0098] FIG. 8 is a diagram showing an example of a power purchase list according to the present embodiment. The power purchase list shown in FIG. 8 is the matching result of the power transaction performed by the transaction generation unit 215, and is an example of a power transaction list indicating who sold how much power at what time. As shown in FIG. 8, the power purchase list is composed of the blockchain address of the power purchase destination, the date, the amount of power, and the unit price. Although the signature of the authentication server is further included in the power purchase list, it is not shown here. Thus, each row of the power purchase list includes the blockchain address of the power purchase source indicating the house that has requested power purchase for which the power transaction matching has been established, the amount of transaction power traded in the power transaction, and the unit price thereof.

[0099] In addition, the transaction generation unit 215 generates transaction data indicating the matching result of the power transaction including the information shown in the rows of the power purchase list in FIG. 8, and records it in the recording unit 216. Then, after generating the power transaction data indicating the matching result of this power transaction, the transaction generation unit 215 notifies the content of the power transaction to the housing 100a or the like where the power transaction is carried out, that is, the power purchase is implemented. Note that the transaction generation unit 215 may broadcast the power transaction result periodically, or may directly notify it if the housing where the power transaction is carried out can be identified by the blockchain address.

[0100] In addition, after the step of recording the block including the first transaction data in the distributed ledger by the transaction generation unit 215, further, after the first authentication server pays the incentive to the first user, it may notify that the incentive has been paid. In the present embodiment, the transaction generation unit 215 pays the incentive to the housing 100a that has transmitted the power. After paying the incentive to the housing 100a that has transmitted the power, the transaction generation unit 215 notifies that fact. In addition, the transaction generation unit 215 may promote the payment of the incentive by notifying the power transaction result indicating the content of the power transaction to the housing 100a or the like where the power purchase is implemented.

[0101] Note that, as a method of paying the incentive, a method of transferring in cash may be used, a method of paying power transaction points may be used, or a method of paying with virtual currency using the blockchain may be used. As a result, the incentive is also paid to the housing 100a or the like that has transmitted the purchased power amount. After the incentive is paid to the housing 100a or the like that has transmitted the purchased power amount, the transaction generation unit 215 may notify that the incentive has been paid to the housing 100a or the like that has transmitted the purchased power amount.

[0102] <Recording unit 216> The recording unit 216 records the transaction data of the blockchain in blocks in the storage device 201a. The storage device 201a may be configured inside the recording unit 216, or may be configured outside the authentication server 200a as shown in FIG. 1. This transaction data means first transaction data indicating a power selling request, second transaction data indicating a power buying request, first transaction data indicating a power selling request, second transaction data indicating a power buying request, and third transaction data indicating a matching result of a power transaction.

[0103] <Communication unit 217> The communication unit 217 communicates with two or more houses 100a, etc., other authentication servers 200b, 200c, and the management server 350. More specifically, the communication unit 217 is a communication interface that communicates with two or more houses 100a, etc., other authentication servers 200b, 200c, and the management server 350. The communication with two or more houses 100a, etc. and the management server 350 may be performed by TLS. In this case, the encryption key for TLS communication may be held by the communication unit 217.

[0104] [1.5 Configuration of the management server 350] FIG. 9 is a block diagram showing the functional configuration of the management server 350 according to the present embodiment. As shown in FIG. 9, the management server 350 includes a power control unit 311, a storage battery control unit 312, a recording unit 313, and a communication unit 314, and manages the storage battery 300. The storage battery 300 and the management server 350 are an example of a power storage facility, and may also be referred to as the storage battery side below.

[0105] <Power control unit 311> The power control unit 311 records, in the recording unit 313, as the received power amount, the amount of power stored in the storage battery 300 by storing the power transmitted from the house 100a, etc. in the storage battery 300 by instructing the storage battery control unit 312. Further, when the power control unit 311 acquires a power transmission request from the authentication server 200a, etc., it instructs the storage battery control unit 312 to control the storage battery 300 to transmit the power stored in the storage battery 300 to the house 100a, etc. which is the power transmission destination included in the power transmission request.

[0106] Further, when the power control unit 311 obtains an inquiry about the state of charge of the storage battery 300 from the authentication server 200a or the like, it transmits the received power information including the received power amount or the stored power information including the stored power amount, which is recorded in the recording unit 313 as information indicating the state of charge of the storage battery 300. Here, as described above, the received power information includes the received power amount information indicating the amount of received power that the power storage facility has received from the first power facility, and the second timestamp indicating the second date and time when the received power was received. That is, the received power information includes the received power amount information indicating the amount of received power received from the house 100a or the like, and the date and time when the received power was received. Further, the stored power information includes the stored power amount information indicating the amount of stored power that the power storage facility holds. That is, the stored power information includes the stored power amount information indicating the current stored power amount in the storage battery 300.

[0107] <Battery control unit 312> When the battery control unit 312 obtains an instruction from the power control unit 311, it controls the storage battery 300. For example, the battery control unit 312 controls the storage battery 300 to transmit the power stored in the storage battery 300 to the house 100a or the like, which is the power transmission destination included in the power transmission request. The battery control unit 312 controls the storage battery 300 to transmit the power stored in the storage battery 300 to the house 100a or the like, which is the power transmission destination included in the power transmission request. Further, the battery control unit 312 obtains the received power information including the received power amount or the stored power information including the stored power amount as information indicating the state of charge of the storage battery 300 from the storage battery 300.

[0108] <Recording unit 313> The recording unit 313 records the information indicating the state of charge of the storage battery 300 obtained from the storage battery 300. In the present embodiment, the recording unit 313 records the received power information or the stored power information obtained from the storage battery 300.

[0109] <Communication unit 314> The communication unit 314 communicates with the house 100a or the like and the authentication server 200a or the like via the communication network 400. This communication may be performed by TLS. In this case, the encryption key for TLS communication may be held by the communication unit 314.

[0110] Note that the management server 350 may not be provided in the power trading system 10. In this case, among the functional configurations of the management server 350 described above, the battery control unit 312 may be configured in the authentication server 200a or the like, and the power control unit 311, the recording unit 313, and the communication unit 314 may be configured in the battery 300. Then, the authentication server 200a or the like and the battery 300 may directly communicate with each other without going through the management server 350. Note that in this case, the battery 300 corresponds to an example of the power storage facility.

[0111] [1.6 Overall Sequence of Power Trading between House and Authentication Server] Next, the sequence of power trading between the house 100a or the like and the authentication server 200a or the like will be described. FIG. 10 is an overall sequence diagram of the power trading according to the present embodiment. Each process will be described later.

[0112] First, in step S100, for example, a power selling process is performed between the house 100a and the authentication servers 200a, 200b, and 200c. Next, in step S200, for example, a power buying process is performed between the house 100c and the authentication servers 200a, 200b, and 200c.

[0113] Note that either the power selling process in step S100 or the power buying process in step S200 may be executed first, and they are performed irregularly.

[0114] [1.6.1 Power Selling Process between House and Authentication Server] Next, the power selling process between the house 100a or the like and the authentication server 200a or the like will be described.

[0115] FIG. 11 is a sequence diagram of the power selling process according to the present embodiment. In FIG. 11, as an example, the house 100a is described as selling power, but it is not limited thereto. The same sequence applies to other houses 100b or the like.

[0116] First, in step S101, when the controller 101 of the house 100a or the user wishes to sell the power generated in excess by the solar power generation 102, they input power selling request information and transmit the power. For example, there may be a case where surplus power is generated, such as when the amount of power used in the house 100a is less than the amount of power generated by the solar power generation 102. In this case, after the user inputs the power selling request information, or when the controller 101 is set to automatically transmit power, the surplus power is automatically transmitted to the battery side. Note that, as described above, the battery side means the management server 350 when there is a management server 350 that manages the battery 300, and means the battery 300 when there is no management server 350.

[0117] Next, in step S103, the controller 101 of the house 100a generates transaction data indicating a power selling request (hereinafter referred to as first transaction data) based on the input power selling request information. As described above, the first transaction data is composed of a blockchain address, a date, a power selling amount, and a signature.

[0118] Next, in step S104, the controller 101 of the house 100a transmits the generated first transaction data to the authentication server 200a. In the example shown in FIG. 11, the controller 101 of the house 100a transmits the generated first transaction data to the authentication server 200a, but it may also be transmitted to other authentication servers 200b, 200c. The same applies when transmitted to other authentication servers 200b, 200c.

[0119] Next, in step S105, when the authentication server 200a receives the first transaction data from the house 100a, it first makes an inquiry about the state of charge of the battery 300.

[0120] Next, in step S106, the battery side transmits power reception information including power reception amount information indicating the amount of power received by the battery 300 from the house 100a as a response to the inquiry about the state of charge of the battery 300.

[0121] Next, in step S107, when the authentication server 200a receives power reception information from the battery side, it verifies the first transaction data received from the house 100a. Note that, as described above, the verification of the first transaction data includes at least verifying the validity of the first transaction data and verifying whether the power information such as power is correctly transmitted and received is correct.

[0122] In step S107, if the verification of the first transaction data fails (N in S107), the authentication server 200a sends a notice to that effect to the house 100a (S108) and ends the process.

[0123] On the other hand, in step S107, if the verification of the first transaction data is successful (Y in S107), the authentication server 200a transfers the first transaction data to the other authentication servers 200b and 200c (S109). Similarly, the other authentication servers 200b and 200c also verify the received first transaction data.

[0124] Next, in step S110, the authentication server 200a, the authentication server 200b, and the authentication server 200c execute a consensus algorithm. When the authentication server 200a, the authentication server 200b, and the authentication server 200c verify that the first transaction data is legitimate transaction data (that is, validity), they each generate a block including the first transaction data. Then, the authentication servers 200a, 200b, and 200c record the blocks including the first transaction data in the distributed ledgers of the storage devices 201a, 201b, and 201c.

[0125] Next, in step S111, the authentication server 200a pays an incentive to the house 100a that transmitted the power. As a method of paying the incentive, a method of transferring cash may be used, a method of paying power trading points may be used, or a method of paying with a virtual currency using blockchain may be used.

[0126] Next, in step S112, the authentication server 200a transmits a notification to the house 100a that transmitted the power, indicating that the incentive has been paid.

[0127] [1.6.2 Power purchase process between house and authentication server] Subsequently, the power purchase process between the house 100a etc. and the authentication server 200a etc. will be described. FIGS. 12 and 13 are sequence diagrams of the power purchase process according to the present embodiment. In FIGS. 12 and 13, as an example, it is described that the house 100c purchases power, but it is not limited to this. The same sequence of power purchase process will apply to other houses 100b etc.

[0128] First, in step S201, when the controller 101 or the user of the house 100c wishes to purchase power, power purchase request information is input. The controller 101 or the user of the house 100c purchases power, for example, when the power consumption in the house 100c is high and it is cheaper to purchase the surplus power stored in the storage battery 300 from a service provider that holds the storage battery 300 than to purchase power from the power company.

[0129] Next, in step S203, the controller 101 of the house 100c generates transaction data indicating a power purchase request (hereinafter referred to as second transaction data) based on the input power purchase request information. As described above, the second transaction data is configured to include a blockchain address, power purchase amount information indicating the amount of power to be purchased for the request, and an electronic signature of the user of the house 100c.

[0130] Next, in step S204, the controller 101 of the house 100c transmits the generated second transaction data to the authentication server 200c. In the example shown in FIG. 12, the controller 101 of the house 100c transmits the generated second transaction data to the authentication server 200c, but it may also be transmitted to other authentication servers 200a and 200b. The same applies when transmitted to other authentication servers 200a and 200b.

[0131] Next, in step S205, the authentication server 200c verifies the second transaction data received from the house 100c.

[0132] In step S205, if the verification of the second transaction data by the authentication server 200c fails (N in S205), the authentication server 200c sends a notice to that effect to the house 100c (S206) and ends the process.

[0133] On the other hand, in step S205, if the verification of the second transaction data by the authentication server 200c is successful (Y in S205), the authentication server 200c transfers the second transaction data to the other authentication servers 200a and 200b (S207). Similarly, the other authentication servers 200b and 200c also verify the received second transaction data.

[0134] Next, in step S208, the authentication servers 200a, 200b, and 200c execute a consensus algorithm. When the authentication servers 200a, 200b, and 200c verify that the second transaction data is legitimate transaction data (i.e., validity), they each generate a block containing the second transaction data. Then, the authentication servers 200a, 200b, and 200c record the blocks containing the second transaction data in the distributed ledgers of the storage devices 201a, 201b, and 201c.

[0135] Next, as shown in FIG. 13, in step S209, the authentication server 200c inquires about the state of charge of the storage battery 300.

[0136] Next, in step S210, the battery side transmits power storage information indicating the amount of power stored in the battery 300 as a response to the inquiry about the state of charge of the battery 300.

[0137] Next, in step S211, when the authentication server 200c acquires the power storage information from the battery side, it determines whether power transmission to the power purchase-requesting house 100c is possible based on the acquired power storage information and the power purchase request list. The power storage information indicates the state of charge of the battery 300. Also, in the power purchase request list, the unit price and the amount of power desired to be purchased are described for the house identified by the blockchain address at the desired date and time.

[0138] In step S211, if the authentication server 200c determines that power transmission is not possible (N in S211), it transmits a notice to that effect to the house 100c (S212) and ends the process.

[0139] On the other hand, in step S211, if the authentication server 200c determines that power transmission is possible (Y in S211), it transmits a power transmission request to the battery side (S213). Note that the authentication server 200c may transmit a reservation confirmation notice indicating that power transmission is possible to the house 100c while transmitting the power transmission request.

[0140] Next, in step S214, when the battery side acquires the power transmission request from the authentication server 200c, it transmits the power stored in the battery 300 to the house 100c, which is the power transmission destination included in the power transmission request.

[0141] Next, in step S215, the authentication server 200c generates transaction data (hereinafter referred to as the third transaction data) indicating the matching result of the power transaction that the power stored in the battery is transmitted to the house 100c from the battery side. Note that the authentication server 200c may generate the third transaction data after confirming that the power has been transmitted from the power storage side to the house 100c.

[0142] Next, in step S216, the authentication server 200c transfers the generated third transaction data to the other authentication servers 200a and 200b. Similarly, the other authentication servers 200a and 200b also verify the received third transaction data.

[0143] Next, in step S217, the authentication servers 200a, 200b, and 200c execute a consensus algorithm. When the authentication servers 200a, 200b, and 200c verify that the third transaction data is legitimate transaction data (i.e., validity), they each generate a block including the third transaction data. Then, the authentication servers 200a, 200b, and 200c record the blocks including the third transaction data in the distributed ledgers of the storage devices 201a, 201b, and 201c.

[0144] Note that in step S213, when the authentication server 200c transmits a power transmission request to the battery side, the authentication server 200c may generate transaction data (hereinafter referred to as fourth transaction data) indicating a power transaction matching result that power storage power has been requested for power transmission from the power storage facility to the second power facility. In this case, the authentication server 200c transfers the generated fourth transaction data to the other authentication servers 200a and 200b. Next, the authentication servers 200a, 200b, and 200c execute a consensus algorithm. When the authentication servers 200a, 200b, and 200c verify that the third transaction data is legitimate transaction data (i.e., validity), they each generate a block including the fourth transaction data. Then, the authentication servers 200a, 200b, and 200c record the blocks including the fourth transaction data in the distributed ledgers of the storage devices 201a, 201b, and 201c.

[0145] In this way, by recording the block including the fourth transaction data, it is possible to indicate that the reservation of power transmission has been completed.

[0146] Also, in this case, as shown in steps S214 to S217 thereafter, when power transmission is completed in step S214, a fourth transaction further including information indicating that the power storage battery side has transmitted power is further generated, and a consensus algorithm may be executed and recorded among the authentication server 200a, the authentication server 200b, and the authentication server 200c.

[0147] Thereby, before generating the third transaction indicating the matching result of the power transaction, a fourth transaction indicating the reservation of power transmission is generated and recorded in the distributed ledger. Thereby, even if there is a time lag between the timing of the matching of the power transaction and the power transmission time, the matching result of the power transaction and the reservation of power transmission can be surely left as evidence.

[0148] [1.7 Effects, etc.] As described above, according to the power trading system 10 and the like according to the embodiment, for example, the transaction data of the power transaction transmitted to the power storage battery 300 is recorded in the distributed ledger. Thereby, the transaction data of the power transaction is made public and it becomes possible to detect falsification, so that it is possible to suppress illegal power transactions by service providers holding the power storage battery. For example, it is possible to verify the matching between the power transmitted to the power storage facility and the power received by the power storage facility, and the validity of the first transaction data, so that it becomes possible to detect falsification.

[0149] Also, the power trading system 10 and the like according to the embodiment may record the transaction data of the second blockchain indicating the power purchase request in the distributed ledger. Also, the power trading system 10 and the like according to the embodiment may record the third transaction data of the blockchain indicating the matching result of the power transaction via the power storage battery in the distributed ledger. Thereby, the transaction data of the power transaction is made public and it becomes possible to detect falsification, so that it is possible to suppress illegal power transactions by service providers holding the power storage battery 300.

[0150] As described above, according to the power trading system 10 and the like according to the embodiment, when conducting personal power trading by entrusting a broker having the storage battery 300, the blockchain technology is utilized to disclose the transaction data of the power trading indicating the power selling process, the power purchase request process, and the power purchase process. Thereby, the broker holding the storage battery 300 cannot sell power at an unduly high unit price compared to the amount paid for purchasing the power, be purchased power at an unduly low price compared to the average desired power purchase price, or reject power purchase despite having stored power. That is, according to the power trading system 10 and the like according to the embodiment, since transparency can be provided to the price at which the power trading is conducted, it is possible to suppress improper price manipulation during power trading by the service provider holding the storage battery 300, and suppress improper power trading.

[0151] In addition, since the broker holds the storage battery 300, each house does not need to hold a storage battery, and the user who purchases power only needs to request the broker. Therefore, the power trading system 10 and the like according to the embodiment also have the effect of being an easily implementable system.

[0152] [2. Other Modification Examples] Although the present disclosure has been described based on the above-described embodiments, it goes without saying that the present disclosure is not limited to the above-described embodiments. The following cases are also included in the present disclosure.

[0153] (1) The authentication server 200a or the like may generate transaction data when paying an incentive and record it in the storage device 201a or the like of the authentication server 200a or the like. The transaction data may include the blockchain address that paid the incentive, information indicating the content of the incentive, and the signature of the authentication server 200a or the like.

[0154] (2) When the power trading with the house that requested power purchase is not established, the authentication server 200a or the like may allow the power purchase request to be made again. Thereby, it becomes possible to reset the time and / or the unit price of the power in the power purchase request, and it is possible to determine again whether the power trading is established.

[0155] (3) When purchasing electricity upon a purchase electricity request, the user who has purchased the electricity may directly pay the payment to the service company for the electricity transaction, or may pay with points or virtual currency obtained from previous electricity sales.

[0156] (4) In the example described in FIG. 11 of the above embodiment, the authentication server 200a pays an incentive to the user of the house 100a that has sold electricity after the electricity has been sold to the battery side, but it is not limited to this. The authentication server 200a may pay an incentive to the user of the house 100a that has sold electricity after the payment process from the user of the house 100c that has purchased electricity. Also, the authentication server 200a may pay the user of the house 100a that has sold electricity not for each electricity sales transaction but in a lump sum for each period.

[0157] (5) In the above embodiment, it is determined whether to transmit power by the authentication server 200a or the like, but it is not limited to this. The authentication server 200a or the like may use the smart contract function of the blockchain to implement a determination program for the establishment of an electricity transaction such as whether power transmission is possible in advance in the authentication server 200a or the like, and automatically determine the electricity transaction.

[0158] (6) In the above embodiment, the user inputs the unit price of purchasing electricity, but it is not limited to this. It is not limited to this, and the authentication server 200a or the like may set the unit price of selling electricity and / or the unit price of purchasing electricity, and the user may select them. Also, the unit price of selling electricity and the unit price of purchasing electricity may be changed according to the time.

[0159] (7) In the above-described embodiment, the authentication server 200a or the like determines whether power transmission is possible using the power storage amount, time, and unit price. However, it may also be determined including the ease of power transmission in the power network. For example, when passing through the power network from the house selling electricity to the house buying electricity, the authentication server 200a or the like may preferentially match power transactions from houses with a shorter distance. Also, the authentication server 200a or the like may preferentially match power transactions from houses with less power loss in the power transmission of the power network. Thereby, the power loss can be reduced in the overall power trading service.

[0160] (8) The authentication server 200a or the like may issue a token for the right to use the power of the storage battery, and the user of the house buying electricity may purchase the token. Thereby, the user buying electricity can purchase the right to use power in advance.

[0161] (9) The management server 350 that manages the storage battery 300 may generate transaction data including the date and the amount of power transmitted and stored when power is transmitted from a house to the storage battery 300. Also, the management server 350 that manages the storage battery 300 may generate transaction data including the date and the amount of power transmitted when power is transmitted from the storage battery 300 to a house. The management server 350 may transmit the generated transaction data to the authentication server 200a or the like so that the generated transaction data is managed by the blockchain.

[0162] (10) In the above-described embodiment, the authentication server 200a or the like determines whether power transmission is possible from the power storage information and the power purchase request information. When the authentication server 200a or the like determines that power transmission is not possible, it may further notify each house of a power selling request. Also, the unit price of power selling may increase in the power selling request after the notification. Thereby, the power storage amount of the storage battery 300 can be increased, and power can be transmitted to the house.

[0163] (11) Further, the management server 350 may transmit the power storage information to the authentication server 200a or the like periodically or when there is a change in the state of charge of the storage battery 300. At this time, the management server 350 may generate transaction data including the state of charge and the date and transmit it to the authentication server 200a or the like.

[0164] (12) Also, the selling electricity price and / or the buying electricity price may be set according to the state of charge of the storage battery 300.

[0165] (13) Furthermore, the present disclosure also includes a data structure used for a block recorded as a blockchain in the power trading system 10 of the above-described embodiment. More specifically, the data structure of the present disclosure is a data structure used for a block recorded as a blockchain in a power trading system including a first power facility used by a first user, a power storage facility connected to the first power facility via a power line, and a plurality of servers capable of communicating with the first power facility and the power storage facility via a network. The data structure is included in a block of the blockchain and includes a blockchain address that is an identifier for identifying at least one of the first user and the first power facility, generated using the private key of the first user, power transmission amount information indicating the amount of power transmitted from the first power facility to the power storage facility, and an electronic signature of the first user. The power transmission amount information included in the data structure of the present disclosure is compared with the power purchase amount information indicating the amount of power received by the power storage facility from the first power facility, and is used to verify the legitimacy of the transaction regarding power transmission. Note that the first transaction data may include a first timestamp, and the power reception information may include a second timestamp. In this case, in addition to being able to confirm that power has been transmitted to the storage battery using the first timestamp and the second stamp, it is possible to confirm that the timing of power transmission and reception is appropriate.

[0166] (14) Each device in the above-described embodiment is specifically a computer system composed of a microprocessor, ROM, RAM, hard disk unit, display unit, keyboard, mouse, etc. A computer program is recorded in the RAM or the hard disk unit. When the microprocessor operates according to the computer program, each device achieves its function. Here, the computer program is composed of a combination of a plurality of instruction codes indicating instructions for the computer in order to achieve a predetermined function.

[0167] (15) Each device in the above-described embodiment may be configured such that some or all of the constituent components are composed of one system LSI (Large Scale Integration). A system LSI is a super multifunctional LSI manufactured by integrating a plurality of components on one chip, and specifically, is a computer system including a microprocessor, ROM, RAM, etc. A computer program is recorded in the RAM. When the microprocessor operates according to the computer program, the system LSI achieves its function.

[0168] Also, each part of the constituent components constituting each of the above devices may be individually formed into one chip, or may be formed into one chip so as to include some or all of them.

[0169] Also, here, although it is a system LSI, depending on the degree of integration, it may also be called an IC, LSI, super LSI, or ultra LSI. Also, the method of integrating into a circuit is not limited to LSI, and it may be realized by a dedicated circuit or a general-purpose processor. After manufacturing the LSI, an FPGA (Field Programmable Gate Array) that can be programmed, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

[0170] Furthermore, if a technology for integrating circuits that replaces LSI emerges due to advancements in semiconductor technology or other derived technologies, it is natural that the integration of functional blocks may be performed using such technology. The application of biotechnology, etc. may be possible.

[0171] (16) Some or all of the components constituting each of the above devices may be configured from an IC card or a single module that is detachable from each device. The IC card or the module is a computer system composed of a microprocessor, ROM, RAM, etc. The IC card or the module may include the above-mentioned super multifunctional LSI. By operating according to a computer program, the microprocessor enables the IC card or the module to achieve its function. This IC card or this module may have tamper resistance.

[0172] (17) The present disclosure may be the method shown above. It may also be a computer program for realizing these methods by a computer, or a digital signal composed of the computer program.

[0173] Moreover, the present disclosure may be the computer program or the digital signal recorded on a computer-readable recording medium, such as a flexible disk, a hard disk, a CD-ROM, an MO, a DVD, a DVD-ROM, a DVD-RAM, a BD (Blu-ray (registered trademark) Disc), a semiconductor memory, etc. It may also be the digital signal recorded on these recording media.

[0174] Furthermore, the present disclosure may be the transmission of the computer program or the digital signal via a telecommunication line, a wireless or wired communication line, a network represented by the Internet, data broadcasting, etc.

[0175] Also, the present disclosure may be a computer system including a microprocessor and a memory, where the memory stores the computer program, and the microprocessor operates according to the computer program.

[0176] Alternatively, it may be implemented by another independent computer system by recording and transferring the program or the digital signal to the recording medium, or by transferring the program or the digital signal via the network or the like.

[0177] (18) It is also possible to combine the above embodiments and the above modification examples respectively.

Industrial Applicability

[0178] In the power trading system, the present disclosure can conduct power trading while eliminating fraud by managing transaction data of power selling, power buying, and power trading information with an authentication server.

Explanation of Signs

[0179] 100a, 100b, 100c Houses 101 Controller 102 Solar Power Generation 103 Power Meter 110, 400 Communication Networks 111, 500 Power Networks 200a, 200b, 200c Authentication Servers 211 Battery State Acquisition Unit 212 Transaction Data Verification Unit 213 Block Generation Unit 214 Synchronization Unit 215 Transaction Generation Unit 216, 313 Recording Units 217, 314 Communication Units 300 Storage Battery 311 Power Control Unit 312 Storage Battery Control Unit 1011 Input Unit 1012 Transaction Data Generation Unit 1013 Control Unit 1014 Recording Unit 1015 Communication Unit

Claims

1. A control method executed by a first server among the plurality of servers in a power trading system including a power facility used by a user, a power storage facility, and a plurality of servers through which the power facility and the power storage facility can communicate via a network, comprising: The power storage facility is a power storage facility used by an intermediary for power trading among a plurality of individuals including the user, and is a power storage facility that temporarily stores the power to be traded. Obtaining transaction data including power purchase amount information indicating the amount of power to be purchased requested by the user and the electronic signature of the user; Obtaining power storage information including power storage amount information indicating the amount of power stored in the power storage facility from the power storage facility; Determining, using a smart contract, whether power can be transmitted from the power storage facility to the power facility based on the power purchase amount information and the power storage amount information; When the power transmission is possible, transmitting a power transmission request to the power storage facility; Control method.

2. Verifying the validity of the transaction data; When the verification of the validity is successful, transferring the transaction data to a plurality of second servers different from the first server among the plurality of servers; Executing a consensus algorithm for reaching an agreement on the validity of the transaction data together with the second server; When the validity of the transaction data is agreed upon by the consensus algorithm, recording a block including the transaction data in the distributed ledger of the first server; The control method according to claim 1.

3. When it is determined that power can be transmitted from the power storage facility to the power facility, generating third transaction data indicating a matching result of a power transaction indicating that power is transmitted from the power storage facility to the power facility; Transferring the third transaction data to a plurality of second servers different from the first server among the plurality of servers; Executing a consensus algorithm for reaching an agreement on the validity of the third transaction data together with the second server; When the validity of the third transaction data is agreed upon by the consensus algorithm, recording a block including the third transaction data in the distributed ledger of the first server, including: The control method according to any one of claims 1 to 2.

4. The stored power held by the energy storage device is renewable energy generated by at least one of a solar power generation device, a gas power generation device, and a wind power generation device. The control method according to any one of claims 1 to 3.

5. A power trading system comprising a power facility used by a user, an energy storage device, and a plurality of servers through which the power facility and the energy storage device can communicate via a network, The energy storage device is an energy storage device used by an intermediary for power trading among a plurality of individuals including the user, and is an energy storage device that temporarily stores the power to be traded. Among the plurality of servers, the first server, Obtains transaction data including power purchase amount information indicating the amount of power purchase requested by the user and the electronic signature of the user, Obtains storage information including storage amount information indicating the amount of stored power held by the energy storage device from the energy storage device, Based on the power purchase amount information and the storage amount information, determines whether power can be transmitted from the energy storage device to the power facility using a smart contract, When the transmission is possible, transmits a power transmission request to the energy storage device. Power trading system.

6. A program for causing a computer to execute the control method according to any one of claims 1 to 4.

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