communication systems

Abstract

To facilitate proving that electricity consumed is derived from renewable energy.SOLUTION: A communication system 800 comprises: a certification system 700 that accumulates signature data obtained by encrypting detailed data indicating the time and amount of power supplied and received between multiple elements including a power generating installation that generates power from renewable energy, a charging installation that charges a vehicle 410, and the vehicle 410 by a power supplying element or power receiving element using a secret key of the power supplying element or power receiving element and a public key of the certification system 700; and an energy management system 200 that receives, from a low-order system, power data indicating the supply or use amount of power generated at least by renewable energy for each element included in the multiple elements, accumulates the received power data, and when receiving an inquiry about the supply or use state of power generated at least by renewable energy, refers to the accumulated power data and returns an answer to the inquiry.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to communication systems. [Background technology]

[0002] Patent Document 1 discloses a power management system that supplies surplus power generated by solar power generation at a user's home to a power grid, while managing the system so that when a vehicle is charged using power supplied from the power grid at a location other than the user's home, the power used for charging is covered by the surplus power generated at the user's home. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-061429 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional systems cannot prove that the electricity consumed is derived from renewable energy sources, i.e., that the electricity was used without generating greenhouse gases such as carbon dioxide.

[0005] The purpose of this disclosure is to make it easier to prove that the electricity consumed comes from renewable sources. [Means for solving the problem]

[0006] The communication system according to the present disclosure includes: a certification system that stores signature data obtained by encrypting detailed data indicating the time and amount of power supplied and received between a plurality of elements including a power generation facility that generates power using renewable energy, a charging facility that charges a vehicle, and the vehicle, by the power supplying element or the power receiving element using a private key of the power supplying element or the power receiving element and a public key of the certification system; For each element included in the plurality of elements, an energy management system is provided that receives from a lower-level system power data indicating the supply or usage amount of at least the power generated by the renewable energy, stores the received power data, and, upon receiving an inquiry about the supply or usage status of at least the power generated by the renewable energy, refers to the stored power data and returns a response to the inquiry. [Effects of the Invention]

[0007] According to the present disclosure, it becomes easier to prove that consumed electricity comes from renewable energy sources. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a configuration of a communication system according to an embodiment of the present disclosure. [Figure 2] 1 is a block diagram illustrating a configuration of an energy management system according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a block diagram illustrating a configuration of a vehicle management server according to an embodiment of the present disclosure. [Figure 4] FIG. 10 is a sequence diagram illustrating an operation of a communication system according to an embodiment of the present disclosure. [Figure 5] FIG. 10 is a sequence diagram illustrating an operation of a communication system according to an embodiment of the present disclosure. [Figure 6] FIG. 10 is a sequence diagram illustrating an operation of a communication system according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0010] In each drawing, the same or corresponding parts are denoted by the same reference numerals. In the description of this embodiment, the description of the same or corresponding parts will be omitted or simplified as appropriate.

[0011] The configuration of a communication system 800 according to this embodiment will be described with reference to FIG.

[0012] The communication system 800 includes a HEMS 100, which is an example of a lower system, an energy management system 200, a BEMS 300, which is another example of a lower system, a vehicle management server 400, a communication network 500, a power network 600, and a certification system 700. "HEMS" is an abbreviation for home energy management system. "BEMS" is an abbreviation for building energy management system. The energy management system 200 can communicate with the HEMS 100, the BEMS 300, the vehicle management server 400, and the certification system 700 via the communication network 500. The energy management system 200 can also communicate with a database 220 via the communication network 500. The vehicle management server 400 can communicate with the energy management system 200, multiple vehicles 410, and the certification system 700 via the communication network 500. The vehicle management server 400 can also communicate with the database 420 via the communication network 500.

[0013] The HEMS 100 is one or more devices that manage energy such as power in a home 120 in which a charging facility 110 that charges a vehicle 410 such as a BEV and a power generation facility 130 that generates power using renewable energy are installed. "BEV" is an abbreviation for battery electric vehicle. The home 120 is a residence or facility belonging to a user. The charging facility 110 may exchange power with the vehicle 410 connected to the HEMS 100. That is, the charging facility 110 may not only charge the vehicle 410 but also receive power from the vehicle 410. The charging facility 110 includes, for example, a home charging stand. The power generation facility 130 includes, for example, a solar panel and a power conditioner.

[0014] The energy management system 200 is installed in a facility such as a data center and operated by a business operator that provides energy-related services such as electricity. The energy management system 200 is one or more computers such as servers that belong to a cloud computing system or other computing system.

[0015] The BEMS 300 is one or more devices that manage energy such as power in a large-scale facility 320 in which charging equipment 310 that charges vehicles 410 such as BEVs and power generation equipment 330 that generates power using renewable energy are installed. The large-scale facility 320 is a facility that is larger than the residence 120, such as an office or a store. The charging equipment 310 may exchange power with the vehicle 410 connected to the BEMS 300. That is, the charging equipment 310 may not only charge the vehicle 410, but also receive power from the vehicle 410. The charging equipment 310 includes, for example, an office charging stand or a store charging stand. The power generation equipment 330 includes, for example, a solar panel and a power conditioner.

[0016] The vehicle management server 400 is installed in a facility such as a data center and is operated by a business that provides services related to multiple vehicles 410. The vehicle management server 400 is a computer that belongs to a cloud computing system or other computing system.

[0017] The communication network 500 includes the Internet, at least one WAN, at least one MAN, or any combination thereof. "WAN" is an abbreviation for wide area network. "MAN" is an abbreviation for metropolitan area network. The communication network 500 may include at least one wireless network, at least one optical network, or any combination thereof. The wireless network may be, for example, an ad hoc network, a cellular network, a wireless LAN, a satellite communication network, or a terrestrial microwave network. "LAN" is an abbreviation for local area network.

[0018] The power grid 600 is a system, i.e., a power system, that purchases power from a power plant 610 and supplies the purchased power to consumers such as homes 120 or large-scale facilities 320. The power plant 610 is equipped with power generation equipment 620 such as solar panels.

[0019] The attestation system 700 is installed in a facility such as a data center and operated by a public institution such as a government agency. The attestation system 700 is one or more computers such as servers belonging to a cloud computing system or other computing system.

[0020] An overview of this embodiment will be described with reference to FIG.

[0021] The certification system 700 receives the signature data Gi from a lower-level system such as the HEMS 100 or the BEMS 300 via the communication network 500. Alternatively, when the signature data Gi is transferred from the lower-level system to the energy management system 200, the certification system 700 may receive the signature data Gi from the energy management system 200 via the communication network 500. The signature data Gi is data obtained by the power supply element encrypting the detailed data Di using the private key of the power supply element and the public key of the certification system 700. The detailed data Di is data indicating the time and amount of power supply and reception between multiple elements including the power generation facilities 130 and 330, the charging facilities 110 and 310, and the vehicle 410. The power supply element is an element among the multiple elements that supplies power to other elements. The certification system 700 stores the received signature data Gi.

[0022] The energy management system 200 receives power data Pi from a lower-level system via the communication network 500. The power data Pi is data indicating the amount of power supplied that is generated at least by renewable energy for each element included in the multiple elements. The energy management system 200 stores the received power data Pi in the database 220. When the energy management system 200 receives an inquiry about the supply status of power generated at least by renewable energy, the energy management system 200 returns a response to the inquiry by referring to the power data Pi stored in the database 220. For example, assume that the power data Pi indicates that the amount of power supplied from the power generation facility 130 to the charging facility 110 is 10 kWh and that the amount of power supplied from the charging facility 110 to the vehicle 410 is 30 kWh. In this case, in response to an inquiry about the amount of power supplied from the charging facility 110 to the vehicle 410 that is generated by renewable energy, the response "10 kWh" is returned.

[0023] According to this embodiment, it becomes easier to prove that electricity supplied from any element and consumed is derived from renewable energy, i.e., it becomes easier to prove that electricity was used without generating greenhouse gases such as carbon dioxide.

[0024] The certification system 700 further receives the signature data Gj from the lower system via the communication network 500. Alternatively, when the signature data Gj is transferred from the lower system to the energy management system 200, the certification system 700 may receive the signature data Gj from the energy management system 200 via the communication network 500. The signature data Gj is data obtained by the power receiving element encrypting the detailed data Dj using the private key of the power receiving element and the public key of the certification system 700. The detailed data Dj is data indicating the time and amount of power supply and reception between multiple elements. The power receiving element is an element among the multiple elements that receives power supply from other elements. The certification system 700 stores the received signature data Gj.

[0025] The energy management system 200 further receives power data Pj from the lower system via the communication network 500. The power data Pj is data indicating the usage amount of power generated at least by renewable energy for each element included in the multiple elements. The energy management system 200 stores the received power data Pj in the database 220. When the energy management system 200 receives an inquiry about the usage status of power generated at least by renewable energy, the energy management system 200 refers to the power data Pj stored in the database 220 and returns a response to the inquiry. For example, assume that the power data Pj indicates that the usage amount of power generated by renewable energy for charging the vehicle 410 at the charging facility 110 is 10 kWh. In this case, in response to an inquiry about the usage amount of power generated by renewable energy for charging the vehicle 410 at the charging facility 110, the response "10 kWh" is returned.

[0026] According to this embodiment, it becomes easier to prove that the electricity consumed by any element is derived from renewable energy, that is, it becomes easier to prove that the electricity was used without generating greenhouse gases such as carbon dioxide.

[0027] The energy management system 200 generates report data Rx by referencing the power data Pi and Pj stored in the database 220. The report data Rx is data that indicates at least the supply status and usage status of power generated by renewable energy. For example, suppose the power data Pi indicates that the amount of power supplied from the power generation facility 130 to the charging facility 110 is 10 kWh, and the amount of power supplied from the charging facility 110 to the vehicle 410 is 30 kWh. Assume that the power data Pj indicates that the amount of power generated by renewable energy used by the charging facility 110 to charge the vehicle 410 is 10 kWh. In this case, the report data Rx indicates that the amount of power generated by renewable energy used by the charging facility 110 to charge the vehicle 410 is 10 kWh, and that the amount of power generated by renewable energy used by the charging facility 110 to charge the vehicle 410 is 10 kWh. The energy management system 200 transmits the generated report data Rx to the certification system 700 via the communication network 500 .

[0028] The certification system 700 receives the report data Rx from the energy management system 200 via the communication network 500. When the certification system 700 detects an inconsistency between the supply status and the usage status indicated in the report data Rx, the certification system 700 obtains the detailed data Di and Dj by decrypting the stored signature data Gi and Gj, respectively. The certification system 700 identifies the source of the inconsistency by analyzing the obtained detailed data Di and Dj.

[0029] According to this embodiment, if any doubt arises as to whether the consumed electricity is derived from renewable energy, the doubt can be easily resolved.

[0030] The vehicle management server 400 monitors the power usage status of the vehicle 410. Specifically, the vehicle management server 400 receives encrypted data Ek from the vehicle 410 via the communication network 500. The encrypted data Ek is data obtained by the vehicle 410 encrypting the detailed data Dk using the private key of the vehicle 410 and the public key of the vehicle management server 400. The detailed data Dk is data indicating the time and amount of power consumption in the vehicle 410. The vehicle management server 400 stores the data obtained by decrypting the received encrypted data Ek in the database 420 as detailed data Dk.

[0031] The vehicle management server 400 receives the signature data Gk from the vehicle 410 via the communication network 500. The signature data Gk is data obtained by the vehicle 410 encrypting the detailed data Dk using the private key of the vehicle 410 and the public key of the certification system 700. The vehicle management server 400 transmits the received signature data Gk to the certification system 700 via the communication network 500.

[0032] The certification system 700 receives the signature data Gk from the vehicle management server 400 via the communication network 500. The certification system 700 stores the received signature data Gk.

[0033] The energy management system 200 generates report data Ry by referencing the power data Pi stored in the database 220. The report data Ry is data that indicates the supply status of at least power generated by renewable energy. For example, assume that the power data Pi indicates that the amount of power supplied from the power generation facility 130 to the charging facility 110 is 10 kWh, and that the amount of power supplied from the charging facility 110 to the vehicle 410 is 30 kWh. In this case, the report data Ry indicates that the amount of power generated by renewable energy supplied from the charging facility 110 to the vehicle 410 is 10 kWh. The energy management system 200 transmits the generated report data Ry to the vehicle management server 400 and the certification system 700 via the communication network 500.

[0034] The vehicle management server 400 receives the report data Ry from the energy management system 200 via the communication network 500. The vehicle management server 400 identifies the usage status of at least the electricity generated by renewable energy in the vehicle 410 based on the supply status indicated by the report data Ry and the electricity usage status in the vehicle 410. For example, assume that the report data Ry indicates that the amount of electricity generated by renewable energy supplied from the charging facility 110 to the vehicle 410 is 10 kWh. Assume that the detailed data Dk stored in the database 420 indicates that the amount of electricity used by the vehicle 410 is 20 kWh. In this case, it is determined that the amount of electricity generated by renewable energy used by the vehicle 410 is 10 kWh. The vehicle management server 400 generates report data Rz. The report data Rz is data indicating the usage status identified by the vehicle management server 400. The vehicle management server 400 transmits the generated report data Rz to the certification system 700 via the communication network 500.

[0035] The certification system 700 receives report data Ry from the energy management system 200 via the communication network 500. The certification system 700 receives report data Rz from the vehicle management server 400 via the communication network 500. When the certification system 700 detects an inconsistency between the supply status indicated by the received report data Ry and the usage status indicated by the received report data Rz, the certification system 700 obtains detailed data Di and Dk by decrypting the accumulated signature data Gi and Gk, respectively. The certification system 700 identifies the source of the inconsistency by analyzing the obtained detailed data Di and Dk.

[0036] According to this embodiment, if any doubt arises as to whether the consumed electricity is derived from renewable energy, the doubt can be easily resolved.

[0037] When the vehicle management server 400 receives an inquiry about the usage status of at least electricity generated by renewable energy in the vehicle 410, it identifies the usage status of at least electricity generated by renewable energy in the vehicle 410 based on the supply status indicated by the report data Ry and the usage status of electricity in the vehicle 410. The vehicle management server 400 returns a response about the identified usage status. For example, if it is identified that the usage amount of electricity generated by renewable energy in the vehicle 410 is 10 kWh, the response "10 kWh" is returned in response to the inquiry about the usage amount of electricity generated by renewable energy in the vehicle 410.

[0038] According to this embodiment, it becomes easier to prove that the electricity consumed by the vehicle 410 is derived from renewable energy. In other words, it becomes easier to prove that the electricity was used without generating greenhouse gases such as carbon dioxide.

[0039] In this embodiment, the energy management system 200 receives encrypted data Ei from a lower-level system via the communication network 500. The encrypted data Ei is data obtained by the lower-level system encrypting the power data Pi using the private key of the lower-level system and the public key of the energy management system 200. The energy management system 200 stores the data obtained by decrypting the received encrypted data Ei in the database 220 as the power data Pi.

[0040] In this embodiment, the energy management system 200 further receives encrypted data Ej from the lower system via the communication network 500. The encrypted data Ej is data obtained by the lower system encrypting the power data Pj using the private key of the lower system and the public key of the energy management system 200. The energy management system 200 stores the data obtained by decrypting the received encrypted data Ej in the database 220 as the power data Pj.

[0041] According to this embodiment, security is improved.

[0042] The configuration of an energy management system 200 according to this embodiment will be described with reference to FIG.

[0043] The energy management system 200 includes a control unit 201 , a storage unit 202 , and a communication unit 203 .

[0044] The control unit 201 includes at least one processor, at least one programmable circuit, at least one dedicated circuit, or any combination thereof. The processor is a general-purpose processor such as a CPU or GPU, or a dedicated processor specialized for specific processing. "CPU" is an abbreviation for central processing unit. "GPU" is an abbreviation for graphics processing unit. An example of the programmable circuit is an FPGA. "FPGA" is an abbreviation for field-programmable gate array. An example of the dedicated circuit is an ASIC. "ASIC" is an abbreviation for application specific integrated circuit. The control unit 201 executes processing related to the operation of the energy management system 200 while controlling each unit of the energy management system 200.

[0045] The storage unit 202 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or any combination thereof. The semiconductor memory is, for example, a RAM, a ROM, or a flash memory. "RAM" is an abbreviation for random access memory. "ROM" is an abbreviation for read only memory. RAM is, for example, an SRAM or a DRAM. "SRAM" is an abbreviation for static random access memory. "DRAM" is an abbreviation for dynamic random access memory. ROM is, for example, an EEPROM. "EEPROM" is an abbreviation for electrically erasable programmable read only memory. Flash memory is, for example, an SSD. "SSD" is an abbreviation for solid-state drive. Magnetic memory is, for example, an HDD. "HDD" is an abbreviation for hard disk drive. The storage unit 202 functions, for example, as a main storage device, an auxiliary storage device, or a cache memory. The storage unit 202 stores data used in the operation of the energy management system 200 and data obtained by the operation of the energy management system 200. In this embodiment, the database 220 is constructed in an external storage to which the communication unit 203 can be connected, but may also be constructed in the storage unit 202.

[0046] The communication unit 203 includes at least one communication interface. The communication interface is, for example, an interface that complies with a wired LAN communication standard such as Ethernet (registered trademark) or a wireless LAN communication standard such as IEEE802.11. "IEEE" is an abbreviation for Institute of Electrical and Electronics Engineers. The communication unit 203 communicates with the HEMS 100, the BEMS 300, the vehicle management server 400, and the certification system 700. The communication unit 203 receives data used in the operation of the energy management system 200 and transmits data obtained by the operation of the energy management system 200.

[0047] The functions of the energy management system 200 are realized by executing an energy management program according to this embodiment on a processor serving as the control unit 201. That is, the functions of the energy management system 200 are realized by software. The energy management program causes a computer to execute the operations of the energy management system 200, thereby causing the computer to function as the energy management system 200. That is, the computer functions as the energy management system 200 by executing the operations of the energy management system 200 in accordance with the energy management program.

[0048] The program can be stored on a non-transitory computer-readable medium. Examples of non-transitory computer-readable media include flash memory, magnetic recording devices, optical disks, magneto-optical recording media, and ROMs. The program can be distributed by selling, transferring, or lending portable media such as SD cards, DVDs, or CD-ROMs that store the program. "SD" is an abbreviation for Secure Digital. "DVD" is an abbreviation for digital versatile disc. "CD-ROM" is an abbreviation for compact disc read only memory. The program can also be distributed by storing it in the storage of a server and transferring it from the server to another computer. The program can also be provided as a program product.

[0049] A computer temporarily stores a program stored on a portable medium or transferred from a server in its main storage device. The computer then reads the program stored in the main storage device using a processor and executes processing in accordance with the read program. The computer may also read the program directly from a portable medium and execute processing in accordance with the program. The computer may also execute processing in accordance with the received program each time a program is transferred from a server to the computer. Processing may also be executed through a so-called ASP-type service that achieves its functions by issuing execution instructions and obtaining results without transferring the program from the server to the computer. "ASP" is an abbreviation for application service provider. A program is information used for processing by a computer and includes something equivalent to a program. For example, data that is not a direct instruction to a computer but has properties that specify computer processing falls under the category of "something equivalent to a program."

[0050] Some or all of the functions of the energy management system 200 may be implemented by a programmable circuit or a dedicated circuit as the control unit 201. In other words, some or all of the functions of the energy management system 200 may be implemented by hardware.

[0051] The configuration of the vehicle management server 400 according to this embodiment will be described with reference to FIG.

[0052] The vehicle management server 400 includes a control unit 401 , a storage unit 402 , and a communication unit 403 .

[0053] The control unit 401 includes at least one processor, at least one programmable circuit, at least one dedicated circuit, or any combination thereof. The processor is a general-purpose processor such as a CPU or GPU, or a dedicated processor specialized for a specific process. The programmable circuit is, for example, an FPGA. The dedicated circuit is, for example, an ASIC. The control unit 401 controls each unit of the vehicle management server 400 and executes processes related to the operation of the vehicle management server 400.

[0054] The storage unit 402 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or any combination thereof. The semiconductor memory is, for example, RAM, ROM, or flash memory. The RAM is, for example, SRAM or DRAM. The ROM is, for example, EEPROM. The flash memory is, for example, SSD. The magnetic memory is, for example, HDD. The storage unit 402 functions as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit 402 stores data used in the operation of the vehicle management server 400 and data obtained by the operation of the vehicle management server 400. In this embodiment, the database 420 is constructed in external storage to which the communication unit 403 can be connected, but it may also be constructed in the storage unit 402.

[0055] The communication unit 403 includes at least one communication interface. The communication interface is, for example, an interface that complies with a wired LAN communication standard such as Ethernet (registered trademark) or a wireless LAN communication standard such as IEEE802.11. The communication unit 403 communicates with the energy management system 200, the multiple vehicles 410, and the certification system 700. The communication unit 403 receives data used in the operation of the vehicle management server 400, and transmits data obtained by the operation of the vehicle management server 400.

[0056] The functions of the vehicle management server 400 are realized by executing a vehicle management program according to this embodiment on a processor serving as the control unit 401. That is, the functions of the vehicle management server 400 are realized by software. The vehicle management program causes a computer to execute the operations of the vehicle management server 400, thereby causing the computer to function as the vehicle management server 400. That is, the computer functions as the vehicle management server 400 by executing the operations of the vehicle management server 400 in accordance with the vehicle management program.

[0057] Some or all of the functions of the vehicle management server 400 may be realized by a programmable circuit or a dedicated circuit as the control unit 401. In other words, some or all of the functions of the vehicle management server 400 may be realized by hardware.

[0058] The operation of the communication system 800 according to this embodiment will be described with reference to Figures 4 to 6. This operation corresponds to the communication method according to this embodiment.

[0059] Of the operations of communication system 800, the operations related to BEMS 300 are similar to the operations related to HEMS 100, and therefore a description thereof will be omitted. The operations related to charging equipment 310, power generation equipment 330, and other equipment in large-scale facility 320, and vehicle 410 charged by charging equipment 310 are similar to the operations related to charging equipment 110, power generation equipment 130, and other equipment in residence 120, and vehicle 410 charged by charging equipment 110, and therefore a description thereof will be omitted.

[0060] In each step shown in FIG. 4, each element registers a public key corresponding to its own private key for signing in the certification system 700 together with an ID identifying the element. "ID" is an abbreviation for "identifier." The certification system 700 can verify the signature using the public key shared by each element. Each element obtains from the certification system 700 a public key corresponding to the private key that can be verified only by the certification system 700. The specific processing of each step is described below.

[0061] In step S01, the control unit 401 of the vehicle management server 400 registers the public key of the vehicle management server 400 together with the ID of the vehicle management server 400 in the certification system 700 by transmitting the ID and public key of the vehicle management server 400 to the certification system 700 via the communication unit 403. The control unit 401 of the vehicle management server 400 receives the public key of the certification system 700 from the certification system 700 via the communication unit 403. The control unit 401 of the vehicle management server 400 stores the received public key in the memory unit 402.

[0062] In step S02, the control unit 201 of the energy management system 200 registers the public key of the energy management system 200 together with the ID of the energy management system 200 in the certification system 700 by transmitting the ID and public key of the energy management system 200 to the certification system 700 via the communication unit 203. The control unit 201 of the energy management system 200 receives the public key of the certification system 700 from the certification system 700 via the communication unit 203. The control unit 201 of the energy management system 200 stores the received public key in the memory unit 202.

[0063] In step S03, the HEMS 100 registers the public key of the HEMS 100 in the certification system 700 together with the ID of the HEMS 100. The HEMS 100 acquires the public key of the certification system 700 from the certification system 700.

[0064] In steps S04, S06, and S07, the power consuming equipment other than charging equipment 110 in home 120, charging equipment 110, and power generation equipment 130 each register the public key of the equipment together with the ID of the equipment in certification system 700. The power consuming equipment other than charging equipment 110 in home 120, charging equipment 110, and power generation equipment 130 each obtain the public key of certification system 700 from certification system 700.

[0065] In step S05, the vehicle 410 registers the public key of the vehicle 410 in the certification system 700 together with the ID of the vehicle 410. The vehicle 410 obtains the public key of the certification system 700 from the certification system 700.

[0066] In step S11, the control unit 201 of the energy management system 200 transmits the public key of the energy management system 200 to the vehicle management server 400 via the communication unit 203. The control unit 401 of the vehicle management server 400 receives the public key of the energy management system 200 from the energy management system 200 via the communication unit 403. The control unit 401 of the vehicle management server 400 stores the received public key in the memory unit 402. The control unit 401 of the vehicle management server 400 transmits the public key of the vehicle management server 400 to the energy management system 200 via the communication unit 403. The control unit 201 of the energy management system 200 receives the public key of the vehicle management server 400 from the vehicle management server 400 via the communication unit 203. The control unit 201 of the energy management system 200 stores the received public key in the memory unit 202.

[0067] In step S12, the vehicle 410 transmits the ID and public key of the vehicle 410 to the vehicle management server 400. The control unit 401 of the vehicle management server 400 receives the ID and public key of the vehicle 410 from the vehicle 410 via the communication unit 403. The control unit 401 of the vehicle management server 400 stores the received ID and public key in the memory unit 402. The control unit 401 of the vehicle management server 400 transmits the public key of the vehicle management server 400 to the vehicle 410 via the communication unit 403. The vehicle 410 acquires the public key of the vehicle management server 400 from the vehicle management server 400.

[0068] In step S13, the HEMS 100 transmits the ID and public key of the HEMS 100 to the energy management system 200. The control unit 201 of the energy management system 200 receives the ID and public key of the HEMS 100 from the HEMS 100 via the communication unit 203. The control unit 201 of the energy management system 200 stores the received ID and public key in the memory unit 202. The control unit 201 of the energy management system 200 transmits the public key of the energy management system 200 to the HEMS 100 via the communication unit 203. The HEMS 100 acquires the public key of the energy management system 200 from the energy management system 200.

[0069] In steps S14, S16, and S17, the power consuming equipment other than charging equipment 110 in residence 120, charging equipment 110, and power generation equipment 130 each register the public key of that equipment together with the ID of that equipment in HEMS 100. The power consuming equipment other than charging equipment 110 in residence 120, charging equipment 110, and power generation equipment 130 each acquire the public key of HEMS 100 from HEMS 100.

[0070] In step S15, the vehicle 410 registers the public key of the vehicle 410 together with the ID of the vehicle 410 in the HEMS 100. The vehicle 410 acquires the public key of the HEMS 100 from the HEMS 100.

[0071] The specific processing of each step shown in FIG. 5 is described below.

[0072] In step S21, the power generation equipment 130 of the residence 120 tallyes the amount of power generated by renewable energy. The power generation equipment 130 generates encrypted data E0 by signing the tally result with the private key of the power generation equipment 130 and the public key of the HEMS 100. Similarly, the power generation equipment 130 generates signature data G0 by signing the tally result with the private key of the power generation equipment 130 and the public key of the certification system 700. The power generation equipment 130 passes the encrypted data E0 and the signature data G0 to the HEMS 100. When the power generation equipment 130 transfers power to the charging equipment 110 of the residence 120, the power generation equipment 130 generates detailed data D1 indicating the ID of the power generation equipment 130, the ID of the charging equipment 110, the amount of power transferred to the charging equipment 110, and the time. The power generation equipment 130 generates encrypted data E1 by signing the detailed data D1 with the private key of the power generation equipment 130 and the public key of the HEMS 100. Similarly, the power generation facility 130 generates signature data G1 by signing the detailed data D1 with the private key of the power generation facility 130 and the public key of the certification system 700. The power generation facility 130 passes the encrypted data E1 and the signature data G1 to the HEMS 100.

[0073] In step S22, the charging equipment 110 of the residence 120 generates detailed data D2 indicating the ID of the charging equipment 110, the ID of the power generation equipment 130 of the residence 120, the amount of power received from the power generation equipment 130, and the time. The charging equipment 110 generates encrypted data E2 by signing the detailed data D2 with the private key of the charging equipment 110 and the public key of the HEMS 100. Similarly, the charging equipment 110 generates signature data G2 by signing the detailed data D2 with the private key of the charging equipment 110 and the public key of the certification system 700. The charging equipment 110 passes the encrypted data E2 and signature data G2 to the HEMS 100.

[0074] When the charging equipment 110 transfers power to the vehicle 410, in step S31, the charging equipment 110 generates detailed data D3 indicating the ID of the charging equipment 110, the ID of the vehicle 410, the amount of power transferred to the vehicle 410, and the time. The charging equipment 110 generates encrypted data E3 by signing the detailed data D3 with the private key of the charging equipment 110 and the public key of the HEMS 100. Similarly, the charging equipment 110 generates signature data G3 by signing the detailed data D3 with the private key of the charging equipment 110 and the public key of the certification system 700. The charging equipment 110 transfers the encrypted data E3 and the signature data G3 to the HEMS 100.

[0075] In step S32, the vehicle 410 generates detailed data D4 indicating the ID of the vehicle 410, the ID of the charging facility 110 of the residence 120, the amount of power received from the charging facility 110, and the time. The vehicle 410 generates encrypted data E4 by signing the detailed data D4 with the private key of the vehicle 410 and the public key of the HEMS 100. Similarly, the vehicle 410 generates signature data G4 by signing the detailed data D4 with the private key of the vehicle 410 and the public key of the certification system 700. The vehicle 410 passes the encrypted data E4 and signature data G4 to the HEMS 100.

[0076] In step S33, the vehicle 410 generates encrypted data E5 by signing detailed data D5, which has the same content as the detailed data D4 generated in step S32, with the private key of the vehicle 410 and the public key of the vehicle management server 400. Similarly, the vehicle 410 generates signature data G5 by signing the detailed data D5 with the private key of the vehicle 410 and the public key of the certification system 700. The vehicle 410 passes the encrypted data E5 and signature data G5 to the vehicle management server 400.

[0077] When the power generation equipment 130 transfers power to another equipment in the house 120 that consumes power other than the charging equipment 110, in step S41, the power generation equipment 130 generates detailed data D6 that indicates the ID of the power generation equipment 130, the ID of the other equipment, the amount of power transferred to the other equipment, and the time. The power generation equipment 130 generates encrypted data E6 by signing the detailed data D6 with the private key of the power generation equipment 130 and the public key of the HEMS 100. Similarly, the power generation equipment 130 generates signature data G6 by signing the detailed data D6 with the private key of the power generation equipment 130 and the public key of the certification system 700. The power generation equipment 130 transfers the encrypted data E6 and the signature data G6 to the HEMS 100.

[0078] In step S42, the other facility generates detailed data D7 indicating the ID of the other facility, the ID of the power generation facility 130 of the house 120, the amount of power received from the power generation facility 130, and the time. The other facility generates encrypted data E7 by signing the detailed data D7 with the private key of the other facility and the public key of the HEMS 100. Similarly, the other facility generates signature data G7 by signing the detailed data D7 with the private key of the other facility and the public key of the certification system 700. The other facility passes the encrypted data E7 and signature data G7 to the HEMS 100.

[0079] The specific processing of each step shown in FIG. 6 is described below.

[0080] In steps S51 and S52, the HEMS 100 compares the encrypted data E0, E1, E2, E3, E4, E6, and E7 to verify that the power transactions between the subordinate elements are consistent. The HEMS 100 then generates power data P1 indicating the amount of power generated by the power generation equipment 130 of the residence 120 using renewable energy, the amount of that power remaining in the power grid 600, the amount of power used by the charging equipment 110 of the residence 120 for charging and the amount of power not covered by renewable energy, if any, and the amount of power used by the residence 120 and the amount of power not covered by renewable energy, if any. The HEMS 100 generates encrypted data E8 by signing the power data P1 with the private key of the HEMS 100 and the public key of the energy management system 200. Similarly, the HEMS 100 generates signature data G8 by signing the power data P1 with the private key of the HEMS 100 and the public key of the certification system 700. The HEMS 100 registers the encrypted data E8 in the energy management system 200, and also registers the signature data G0, G1, G2, G3, G4, G6, G7, and G8 in the certification system 700. The HEMS 100 may pass the power data P1 to the energy management system 200 instead of the encrypted data E8. In other words, the HEMS 100 may pass the power data P1 to the energy management system 200 without encrypting it.

[0081] In step S61, the control unit 201 of the energy management system 200 stores in the database 220 the power data P1 acquired from the HEMS 100 and similarly acquired power data from other lower-level systems, such as the BEMS 300. The control unit 201 of the energy management system 200 generates report data R1 by referring to the power data stored in the database 220. The report data R1 includes, for example, the amount of power generated by power generation equipment under each lower-level system using renewable energy, the amount of remaining power flowing into the power grid 600, the amount of power used for charging by charging equipment under each lower-level system and the amount of power not covered by renewable energy, if any, and the amount of power consumed by other equipment under each lower-level system and the amount of power not covered by renewable energy, if any. The control unit 201 of the energy management system 200 generates encrypted data E9 by signing the report data R1 with the private key of the energy management system 200 and the public key of the certification system 700. The control unit 201 of the energy management system 200 registers the encrypted data E9 in the certification system 700. The control unit 201 of the energy management system 200 may pass the report data R1 to the certification system 700 instead of the encrypted data E9. That is, the control unit 201 of the energy management system 200 may pass the report data R1 to the certification system 700 without encrypting it. When the control unit 201 of the energy management system 200 receives an inquiry about the amount of power from a user, the vehicle management server 400, or a lower-level system such as the HEMS 100 or the BEMS 300, the control unit 201 returns a response by referring to the power data stored in the database 220 or the generated report data R1.

[0082] In step S62, the control unit 401 of the vehicle management server 400 acquires from the energy management system 200 report data R2 indicating the amount of power charged to the vehicle 410 belonging to the user, the supply source, and the supply ratio for each supply source.

[0083] In step S71, the control unit 401 of the vehicle management server 400 registers the signature data G5 in the certification system 700.

[0084] In step S72, the control unit 401 of the vehicle management server 400, having received detailed data D5 from the vehicle 410 indicating the amount and time of charging, compares the report data R2 with the detailed data D5 to calculate the percentage of the vehicle 410 charged with electricity generated by renewable energy, the percentage of electricity generated by renewable energy in the remaining energy amount obtained by subtracting electricity consumed for driving, etc., and the percentage for each supply source. The control unit 401 of the vehicle management server 400 generates encrypted data E10 by signing report data R3 including the calculation results with the private key of the vehicle management server 400 and the public key of the certification system 700. The control unit 401 of the vehicle management server 400 registers the encrypted data E10 in the certification system 700. The control unit 401 of the vehicle management server 400 may pass the report data R3 to the certification system 700 instead of the encrypted data E10. That is, the control unit 401 of the vehicle management server 400 may pass the report data R3 to the certification system 700 without encrypting it. When the control unit 401 of the vehicle management server 400 receives an inquiry about the amount of power from a user or the energy management system 200, the control unit 401 of the vehicle management server 400 compares the report data R2 with the detailed data D5 or refers to the generated report data R3 and returns a response.

[0085] In step S81, the certification system 700 certifies the integrity of energy management by the energy management system 200. Because the certification system 700 receives transaction data that only the certification system 700 can verify as report data R1 from the energy management system 200, the certification system 700 can detect differences between the report data R1 and transactions of lower-level systems such as the HEMS 100 directly under the control of the energy management system 200. The certification system 700 can also verify where the discrepancy occurred.

[0086] In step S82, the certification system 700 certifies the integrity of the energy management of the vehicle 410 by the vehicle management server 400. The certification system 700 can detect inconsistencies in the report content between the energy management system 200 and the vehicle management server 400 from report data R2 from the energy management system 200 and report data R3 from the vehicle management server 400. The certification system 700 can also verify where the inconsistency occurred.

[0087] As described above, in this embodiment, a hierarchical structure is formed: certification system 700 > energy management system 200 > HEMS 100 > charging equipment 110, power generation equipment 130, and other equipment in the home 120; certification system 700 > energy management system 200 > BEMS 300 > charging equipment 310, power generation equipment 330, and other equipment in the large-scale facility 320; and certification system 700 > vehicle management server 400 > vehicle 410. In these hierarchical structures, the equipment and vehicle 410 register power generation and usage between adjacent elements as transactions in a higher-level system. The contents of reports sent from each system can be verified at the higher level, and inconsistencies can also be detected at the higher level, reducing the processing load.

[0088] According to this embodiment, for example, it is possible to provide a method and system for certifying the source of power supply for charging the vehicle 410. By mutually signing the transfer amount between adjacent elements on the path between power generation and supply and registering it in a higher-level system, it becomes possible to detect tampering and certify the proportion of the travel distance of the vehicle 410 that is derived from renewable energy. In addition to certifying the amount of power supplied from facilities that generate power using renewable energy, it is also possible to certify the amount and source of power supplied that was used to charge the vehicle 410, thereby making it possible to detect tampering.

[0089] The present disclosure is not limited to the above-described embodiments. For example, two or more blocks shown in the block diagrams may be integrated, or one block may be divided. Two or more steps shown in the flowcharts may be executed in parallel or in a different order, instead of being executed in chronological order as described, depending on the processing capabilities of the device executing each step, or as needed. Other modifications are possible within the scope of the present disclosure. [Explanation of symbols]

[0090] 100 HEMS 110 Charging equipment 120 Housing 130 Power generation facilities 200 Energy Management System 201 Control Unit 202 Storage section 203 Communications Department 220 databases 300 BEMS 310 Charging equipment 320 Large-scale facilities 330 Power Generation Facilities 400 Vehicle management server 401 Control Unit 402 Storage section 403 Communications Department 410 vehicles 420 databases 500 communication network 600 Power grid 610 Power Plant 620 Power Generation Facilities 700 Proof System 800 Communication Systems

Claims

1. a certification system that stores signature data obtained by encrypting detailed data indicating the time and amount of power supplied and received between a plurality of elements including a power generation facility that generates power using renewable energy, a charging facility that charges a vehicle, and the vehicle, by the power supplying element or the power receiving element using a private key of the power supplying element or the power receiving element and a public key of the certification system; an energy management system that receives, for each element included in the plurality of elements, power data indicating at least a supply amount or a usage amount of power generated by the renewable energy from a lower-level system, stores the received power data, and, upon receiving an inquiry about at least a supply status or a usage status of power generated by the renewable energy, refers to the stored power data and returns a response to the inquiry; The energy management system refers to the power data, generates report data indicating a supply status and a usage status of the power generated by at least the renewable energy, and transmits the generated report data to the certification system; The certification system receives the report data from the energy management system, and when it detects an inconsistency between the supply status and usage status indicated in the report data, it decrypts the signature data to obtain the detailed data and analyzes the detailed data to identify the source of the inconsistency.

2. a certification system that stores signature data obtained by encrypting detailed data indicating the time and amount of power supplied and received between a plurality of elements including a power generation facility that generates power using renewable energy, a charging facility that charges a vehicle, and the vehicle, by the power supplying element or the power receiving element using a private key of the power supplying element or the power receiving element and a public key of the certification system; an energy management system that receives, for each element included in the plurality of elements, power data indicating a supply amount or a usage amount of at least the power generated by the renewable energy from a lower-level system, stores the received power data, and, upon receiving an inquiry about a supply status or a usage status of at least the power generated by the renewable energy, refers to the stored power data and returns a response to the inquiry; a vehicle management server that monitors the power usage status of the vehicle; the attestation system further stores another signature data obtained by encrypting, by the vehicle, another detailed data indicating the time and amount of power charged to the vehicle using the private key of the vehicle and the public key of the attestation system; the energy management system refers to the power data, generates report data indicating a supply status of at least the power generated by the renewable energy, and transmits the generated report data to the vehicle management server and the certification system; the vehicle management server receives the report data from the energy management system, identifies the usage status of at least the electricity generated by the renewable energy in the vehicle based on the supply status indicated in the report data and the electricity usage status in the vehicle, generates another report data indicating the identified usage status, and transmits the generated another report data to the certification system; The certification system receives the report data from the energy management system and the other report data from the vehicle management server, and when it detects an inconsistency between the supply status indicated in the report data and the usage status indicated in the other report data, it decrypts the signature data and the other signature data, respectively, to obtain the detailed data and the other detailed data, and analyzes the detailed data and the other detailed data to identify the source of the inconsistency.

3. The communication system described in claim 2, wherein when the vehicle management server receives an inquiry about the usage status of electricity generated by at least the renewable energy in the vehicle, the server identifies the usage status of electricity generated by at least the renewable energy in the vehicle based on the supply status indicated in the report data and the usage status of electricity in the vehicle, and returns a response about the identified usage status.

4. The communication system according to any one of claims 1 to 3, wherein the energy management system receives encrypted data from the lower-level system obtained by encrypting the power data by the lower-level system using a private key of the lower-level system and a public key of the energy management system, and stores data obtained by decrypting the received encrypted data as the power data.

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