Patent Publication Number: US-2019193573-A1

Title: Traveling energy distribution system, traveling energy distribution method, and traveling energy distribution program

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese patent application No. 2017-251869, filed on Dec. 27, 2017, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND 
     The present disclosure relates to an energy distribution system, an energy distribution method, and an energy distribution program. 
     An energy management system that manages an operating state of a power device including a storage battery connected to a power grid has been known (see, for example, International Patent Publication No. WO2015/129734). 
     SUMMARY 
     The present inventors have found the following problem. In a situation where a large number of electric vehicles and fuel-cell vehicles come and go, it may be necessary to locally supply energy to these vehicles. It is possible to store an amount of energy corresponding to the maximum demand at all times. However, there are many problems, such as a need for huge facilities. 
     The present disclosure has been made to solve such problems and provides a technique for distributing necessary amounts of energy to places where energy is required according to energy demands from vehicles traveling in an area of interest. 
     A first exemplary aspect is a traveling energy distribution system including: a plurality of supply facilities each of which is able to supply traveling energy to a vehicle; an information acquisition unit configured to acquire, from a vehicle, vehicle information relevant to an amount of traveling energy remaining in the vehicle and acquire, from each of the plurality of supply facilities, supply facility information relevant to an amount of traveling energy that can be supplied from that supply facility; and a determination unit configured to determine a transfer source supply facility and a transfer destination supply facility for traveling energy to be transferred from among the plurality of supply facilities and determine an amount of the traveling energy to be transferred based on the vehicle information and the supply facility information acquired by the information acquisition unit. 
     A traveling vehicle continues to travel until the vehicle actually needs to be supplied with traveling energy. If a distribution system can acquire information about the vehicle, the distribution system can predict in which supply facility the vehicle will need to be supplied with traveling energy. Then, it is possible, when the amount of traveling energy stored in the predicted supply facility is small, to transfer traveling energy from other supply facilities to the predicted supply facility before the vehicle arrives at the predicted supply facility. By dynamically performing the above-described transfer of traveling energy according to the actual traffic situation in the area of interest, it is possible to distribute necessary amounts of energy to places where energy is required according to unevenly-distributed energy demands. 
     The above-described traveling energy distribution system may include a plurality of production facilities, each of the plurality of production facilities being configured to generate renewable energy for supplying traveling energy to at least one of the plurality of supply facilities. Even if plants that supply traveling energy to respective supply facilities are those which generate renewable energy and whose outputs are unstable, traveling energy can be interchanged among the supply facilities. Therefore, it is possible to actively adopt such plants. 
     That is, the above-described distribution system contributes to the promotion of renewable energy. 
     In this case, by having the information acquisition unit acquire, from each of the plurality of production facilities, production facility information relevant to an amount of renewable energy generated in that production facility, the determination unit can determine a transfer source production facility for traveling energy from among the plurality of production facilities and determine a transfer destination supply facility for the traveling energy from among the plurality of supply facilities based on the vehicle information, the supply facility information, and the production facility information acquired by the information acquisition unit. That is, if traveling energy can be directly supplied from a plant that generates renewable energy to a supply facility that does not have enough traveling energy, the generated traveling energy can be consumed without wasting it even when a storage capacity of the supply facility, which supplies the traveling energy, is small in an ordinary state. 
     Further, the above-described traveling energy distribution system may include a transfer facility configured to transfer traveling energy between a plurality of supply facilities, and the transfer facility may be further configured to transfer an amount of traveling energy determined by the determination unit from the transfer source supply facility determined by the determination unit to the transfer destination supply facility determined by the determination unit. If the transfer facility, which transfers traveling energy, can also be controlled directly from the distribution system, the whole system can be automated. Therefore, it is possible to transfer traveling energy more reliably. 
     In this case, the determination unit may predict a time at which the vehicle, whose vehicle information has been acquired, arrives at the transfer destination supply facility and determine a speed of the transfer of traveling energy by the transfer facility based on the predicted arrival time. Further, the transfer facility may transfer the traveling energy according to the transfer speed determined by the determination unit. When electric power is transferred and stored in a storage battery, the electric power is preferably transferred at a relatively low speed because, by doing so, the deterioration of the storage battery can be prevented or minimized. However, when there is not an enough time before a vehicle of interest arrives at a supply facility of interest, the storage battery can be quickly charged by increasing the transfer speed. By controlling the transfer speed according to the demand as described above, it is possible to extend the life of the system while satisfying the demand from customers. 
     Further, the above-described traveling energy distribution system may include an auxiliary supply facility installed in a transfer path through which the transfer facility transfers traveling energy, the auxiliary supply facility being capable of supplying traveling energy to a vehicle. Further, the transfer facility may be configured to supply traveling energy to the auxiliary supply facility. It is assumed that the transfer facility is installed along a road. Therefore, the transfer facility is preferably configured to supply traveling energy to a traveling vehicle in an emergency as an emergency measure in order to improve the traffic environment of the area of interest. 
     Further, in the above-described traveling energy distribution system, the information acquisition unit may be configured to further acquire, as the vehicle information, at least one of a current location, a destination, a traveling speed, a traveling distance per unit traveling energy, and history information relevant to supplies of traveling energy. If such information can be acquired, the distribution system can predict the demand for traveling energy more accurately. 
     Further, in the above-described traveling energy distribution system, each of the plurality of supply facilities may include a storage battery configured to store electric power as traveling energy. Further, each of the plurality of supply facilities may include a hydrogen tank configured to generate hydrogen as traveling energy by using electric power and store the generated hydrogen. By including the storage battery and/or the hydrogen tank as described above, when the vehicle of interest is an electric vehicle, the vehicle can be supplied with electric power from the storage battery. Further, when the vehicle of interest is a fuel-cell vehicle, the vehicle can be supplied with hydrogen from the hydrogen tank. 
     Further, in the above-described traveling energy distribution system, the plurality of supply facilities are preferably installed along a motorway. For example, when vehicles traveling on an expressway are the vehicles for which energy demands are predicted, the distribution system can be accurately operated. 
     Another exemplary aspect is a traveling energy distribution method including: a vehicle information acquisition step of acquiring, from a vehicle, vehicle information relevant to an amount of traveling energy remaining in the vehicle; a supply facility information acquisition step of acquiring, from each of a plurality of supply facilities capable of supplying traveling energy to a vehicle, supply facility information relevant to an amount of traveling energy that can be supplied from that supply facility; a determination step of determining a transfer source supply facility and a transfer destination supply facility for traveling energy to be transferred from among the plurality of supply facilities and determine an amount of the traveling energy to be transferred based on the acquired vehicle information and the supply facility information; and a transfer step of transferring traveling energy equivalent to the determined amount of the traveling energy from the transfer source supply facility to the transfer destination supply facility. 
     Another exemplary aspect is a traveling energy distribution program for causing a computer to execute: a vehicle information acquisition step of acquiring, from a vehicle, vehicle information relevant to an amount of traveling energy remaining in the vehicle; a supply facility information acquisition step of acquiring, from each of a plurality of supply facilities capable of supplying traveling energy to a vehicle, supply facility information relevant to an amount of traveling energy that can be supplied from that supply facility; a determination step of determining a transfer source supply facility and a transfer destination supply facility for traveling energy to be transferred from among the plurality of supply facilities and determine an amount of the traveling energy to be transferred based on the acquired vehicle information and the supply facility information; and a transfer step of transferring traveling energy equivalent to the determined amount of the traveling energy from the transfer source supply facility to the transfer destination supply facility. 
     Similarly to the first aspect, each of the above-described second third aspects can distribute necessary amounts of energy to places where energy is required according to unevenly-distributed energy demands. 
     According to the present disclosure, it is possible to provide a technique for distributing necessary amounts of energy to places where energy is required according to energy demands from vehicles traveling in an area of interest. 
     The above and other objects, features and advantages of the present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a conceptual diagram showing an electric power distribution system according to an embodiment; 
         FIG. 2  shows a configuration of a server; 
         FIG. 3  is an example of vehicle information acquired by the server; 
         FIG. 4  is an example of station information generated by the server; 
         FIG. 5  is an example of power plant information generated by the server; 
         FIG. 6  is an example of a transfer plan among charging stations; 
         FIG. 7  is an example of a transfer plan of electric power of a power plant; 
         FIG. 8  is a flowchart showing processes performed by the server; 
         FIG. 9  is a conceptual diagram showing another example of an electric power distribution system; and 
         FIG. 10  is a conceptual diagram showing another example of an electric power distribution system. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIG. 1  is a conceptual diagram showing an electric power distribution system  100  according to an embodiment. The distribution system  100 , which is described as a first example, is a system that distributes electric power as traveling energy according to the demand. The distribution system  100  sets a certain section of an expressway  900  as an area of interest (hereinafter also referred to as a target area). In the target area, a plurality of service areas  910  are provided along the expressway  900 . Further, in each of the service areas  910 , a charging station  500  that charges a rechargeable battery of a vehicle  300 , which is an electric vehicle in the example, is provided. That is, the charging station  500  functions as a supply facility that supplies electric power to the vehicle  300 . 
     The charging station  500  includes a storage battery  501  for temporarily storing electric power. Further, a power plant  600  is installed near each of the service areas  910 . The charging station  500  and the nearest power plant  600  are electrically connected by a main power transmission line  402 , and the storage battery  501  is charged mainly by electric power transmitted through the main power transmission line  402 . The power plant  600  in this embodiment is, for example, a facility that generates electric power as renewable energy, such as a solar power generation facility and a wind power generation facility. 
     When the remaining amount of the rechargeable battery of the vehicle  300  traveling on the expressway  900  becomes small, the vehicle  300  stops at the service area  910 , and is able to connect the rechargeable battery to the charging station  500  and thereby charge the rechargeable battery. The electric power with which the rechargeable battery of the vehicle  300  is charged may be electric power directly supplied from the power plant  600  or may be electric power stored in the storage battery  501 . 
     Note that although  FIG. 1  shows a state in which vehicles  300  that are target vehicles of the distribution system  100  are traveling on the expressway  900 , other vehicles such as gasoline-driven cars may also travel on the expressway  900 . Further, regarding electric vehicles, only vehicles having specific properties such as vehicles for which memberships are registered may be regarded as vehicles  300 . 
     A power transmission line  400  and a control panel  404  are transfer facilities for transferring electric power. The power transmission line  400  is installed along the expressway  900 . The power transmission line  400  and each of the charging stations  500  are electrically connected through a drop wire  401 . The control panel  404  is a control unit that controls, for the transfer of electric power through the power transmission line  400 , a transfer source of the electric power, a transfer destination of the electric power, and an amount of the electric power to be transferred. Under the control of the control panel  404 , the power transmission line  400  can transfer electric power stored in the storage battery  501  of one of the charging stations  500  to the storage battery  501  of another charging station  500 . 
     Further, the power transmission line  400  and each of the power plants  600  is electrically connected through a sub transmission line  403 . Under the control of the control panel  404 , the power transmission line  400  can transfer electric power generated by one of the power plants  600  to the storage battery  501  of a charging station  500  different from the charging station  500  connected to that power plant  600  by the main power transmission line  402 . 
     Each vehicle  300  includes a processing unit and a communication interface. Further, each vehicle  300  creates vehicle information relevant to that vehicle and transmits the created vehicle information to a server  200 . Further, each charging station  500  includes a processing unit and a communication interface. Further, each charging station  500  creates supply facility information relevant to an amount of electric power that the charging station  500  can supply and transmits the created supply facility information to the server  200 . Further, each power plant  600  includes a processing unit and a communication interface. Further, each power plant  600  creates production facility information relevant to an amount of renewable energy that the power plant  600  generates and transmits the created production facility information to the server  200 . 
     The server  200  acquires the vehicle information, the supply facility information, and the production facility information through an Internet network  800 . Further, an external DB  700  is connected to the Internet network  800 , and the server  200  acquires weather forecast information, such as information about weather and wind, stored in the external DB  700 . The server  200  predicts an amount of generated electricity and a demand for electric power by using these information items. Then, the server  200  determines how much electric power should be transferred from which charging station to which charging station. That is, the server  200  determines a charging station that is expected to have an extra amount of stored electric power, a charging station where an amount of stored electric power is expected to be tight, and an amount of electric power that should be transferred between these charging stations. 
     Further, the server  200  determines how much electric power should be transferred from which power plant to which charging station. That is, the server  200  determines a power plant that is expected to have an extra amount of stored electric power, a charging station where an amount of stored electric power is expected to be tight, and an amount of electric power that should be transferred from the power plant to the charging station. The control panel  404  includes a communication IF (Interface) and is connected to the server  200  through the Internet network  800 . The control panel  404  receives a transfer instruction in which information about the charging station and the power plant at the transfer source, the charge station at the transfer destination, and the amount of electric power to be transferred are described from the server  200 , and performs the transfer of electric power according to the described content of the transfer instruction. The distribution system  100  transfers and distributes electric power to each of the charging stations  500  as described above and, by doing so, can cope with demands for electric power that could locally occur. 
       FIG. 2  shows a configuration of the server  200 . A processing unit  210  is, for example, an MPU and controls the server  200  by executing a control program loaded from a system memory. 
     The communication IF  211  includes, for example, a wired LAN interface and is a communication interface for connecting with and communicating through the Internet network  800 . The processing unit  210  receives the vehicle information, the supply facility information, and the production facility information through the communication IF  211  and transmits a transfer instruction to the control panel  404 . An operation unit  212  is an input device, such as a keyboard and a mouse, connected to the server main unit. Further, the operation unit  212  is operated when a system administrator starts up or shuts down the system, adjusts parameter values, modifies programs, and the like. 
     An information storage unit  213  is, for example, a HDD (Hard Disk Drive), and stores various parameters and data and stores a database (DB) in which these parameters and data are systematically accumulated. Examples of information stored in the information storage unit  213  include a location of each charging station  500 , information on the storage battery  501  provided in each charging station  500 , a location and a power generating capability of each power plant  600 , power generating performances of each power plant  600  in the past and information on weathers at those performances, and a record of demands for electric power in the past. The processing unit  210  reads and refers to these information items as required. 
     Note that the information storage unit  213  may not be integrally formed with the server  200 . They may be connected to each other through the Internet network  800 . Further, the whole DB may not be stored in one information storage unit  213 . The information storage unit  213  may be formed by a plurality of storages and these storages may store respective DBs. Further, the whole DB does not need to be formed as a part of the distribution system  100 . That is, the server  200  may use DBs that belong to other systems. 
     The processing unit  210  also functions as a function execution unit that performs various computations and controls related to the processing. An acquisition unit  210   a  acquires vehicle information from the vehicle  300  through the communication IF  211  at a timing specified by the control program. Similarly, the acquisition unit  210   a  acquires supply facility information from each charging station  500  through the communication IF  211  and acquires production facility information from each power plant  600  through the communication IF  211 . 
     A determination unit  210   b  predicts amounts of generated electricity and demands for electric power by analyzing the vehicle information, the supply facility information, and the production facility information acquired by the acquisition unit  210   a . Then, the determination unit  210   b  determines how much electric power should be transferred from which charging station to which charging station. Further, the determination unit  210   b  determines how much electric power should be transferred from which power plant to which charging station. The determination unit  210   b  creates a transfer instruction in which these information items are described and transmits the created transfer instruction to the control panel  404  through the communication IF  211 . That is, the transfer instruction is information about the amount of electric power determined by the determination unit  210   b . Further, the communication IF  211  cooperates with the processing unit  210  and thereby functions as an output unit that outputs the transfer instruction. 
     Next, specific processes performed by the acquisition unit  210   a  and the determination unit  210   b  are described.  FIG. 3  shows an example of the vehicle information acquired by the acquisition unit  210   a  of the server  200 . Each vehicle  300  creates vehicle information at regular intervals. The acquisition unit  210   a  acquires the created vehicle information through the Internet network  800 . The acquisition unit  210   a  may request vehicle information when the vehicle  300  enters the target area or may simultaneously request vehicle information from each vehicle  300  traveling in the target area at regular intervals. The vehicle  300  transmits the created vehicle information to the server  200  in response to the request from the server  200 . 
     The vehicle information includes (P1) Traveling Information, (P2) Rechargeable Battery Information, and (P3) History Information. In (P1) Traveling Information, a latitude and a longitude of a current location S identified from an output of a GPS unit, a latitude and a longitude of a destination G entered by a passenger, and an average traveling speed over one hour in the past are recorded. By using these information items, the determination unit  210   b  predicts which charging station the vehicle passes through together with a time at which the vehicle passes through that charging station. 
     In (P2) Battery Information, a remaining amount of the rechargeable battery at the present moment, a full capacity in a fully-charged state, a distance that the vehicle can travel by the remaining amount (hereinafter also referred to as a travelable distance) are recorded. The travelable distance is calculated from the remaining amount and a distance that the vehicle can travel by a unit amount of electric power. By using these information items, the determination unit  210   b  predicts which charging station the vehicle is likely to stop at and also predicts how much electric power needs to be supplied at the charging. In (P3) History Information, an average remaining amount at the time of charging, which is, for example, an average remaining amount of the rechargeable battery over ten times of charging in the past, is recorded. The determination unit  210   b  compares this information with the remaining amount in the item (P2) and thereby predicts whether the vehicle is likely to stop at the nearest charging station. 
     Each of the charging stations  500  creates supply facility information relevant to an amount of electric power that the charging station  500  can supply and transmits the created supply facility information to the server  200  at regular intervals. The acquisition unit  210   a  acquires the supply facility information from each charging station  500  at regular intervals. The supply facility information includes an amount of charged electricity at the present moment (hereinafter also referred to as a current charge amount) of each storage battery  501 . When the determination unit  210   b  takes over (i.e., receives) the supply facility information from the acquisition unit  210   a , the determination unit  210   b  creates station information by comprehensively analyzing the vehicle information collected from vehicles  300  traveling in the target area and the information on each charging station  500  stored in the information storage unit  213 .  FIG. 4  shows an example of the station information created by the determination unit  210   b  of the server  200 . 
     The station information includes a current charge amount, a capacity in a fully-charged state, and a prediction of a demand for electric power in each charging station. In the example shown in  FIG. 4 , the prediction of the demand for electric power includes a prediction from the present moment to one hour later, a prediction from one hour later to two hours later, and a prediction from two hours later to three hours later. For example, the prediction of the demand from the present moment to one hour later in the charging station S 1  is 2,300 kWh, which is a result obtained by adding up amounts of electric power required for charging rechargeable batteries of all the vehicles that are predicted to charge in the charging station S 1  between the present moment to one hour later to their full capacities. 
     Each of the power plants  600  creates production facility information relevant to an amount of renewable energy to be generated and transmits the created production facility information to the server  200  at regular intervals. The acquisition unit  210   a  acquires the production facility information from each power plant  600  at regular intervals. The production facility information includes an amount of generated electricity at the present moment. When the determination unit  210   b  takes over (i.e., receives) the production facility information from the acquisition unit  210   a , the determination unit  210   b  creates power plant information by comprehensively analyzing the information on each power plant  600  stored in the information storage unit  213  and the weather forecast information stored in the external DB  700 .  FIG. 5  shows an example of the power plant information created by the determination unit  210   b  of the server  200 . 
     The power plant information includes a prediction of an amount of generated electricity in each power plant. In the example shown in  FIG. 5 , the prediction of the amount of generated electricity includes a prediction from the present moment to one hour later, a prediction from one hour later to two hours later, and a prediction from two hours later to three hours later. For example, a prediction of an amount of generated electricity from the present moment to one hour later in a power plant G 1 , which is a solar power generation plant, is 500 kWh. Further, a prediction from two hours later to three hours later is zero. This is a result of a prediction based on an electric power generating performance at the present moment and a sunset time. Further, a prediction of an amount of generated electricity from two hours later to three hours later in a power plant G 3 , which is a wind power generation plant, increases from a prediction of an amount of generated electricity one hour earlier (i.e., a prediction from one hour later to two hours later). This is because it is predicted that the wind will increase after the sunset based on the weather forecast information and the location of the power plant G 3 . 
     The determination unit  210   b  further analyzes the created station information and the power plant information and thereby draws up an electric power transfer plan between charging stations.  FIG. 6  is an example of the transfer plan between charging stations. Specifically, a time period from the present moment to one hour later, a time period from one hour later to two hours later, a time period from two hours later to three hours later are defined. Then, in each time period, a charging station that is expected to have an extra amount of stored electric power, a charging station where an amount of stored electric power is expected to be tight are determined. Further, it is determined how much electric power should be transferred between these charging stations. 
     An example of processes for the determination is described. Firstly, based on the station information, it is confirmed that while the current charge amount of the charging station S 1  is 2,457 kWh, a prediction of a demand up to one hour later is 2,300 kWh and a prediction of a demand from one hour later to two hours later is 1,000 kWh. Further, based on the power plant information, it is confirmed that a prediction of an amount of electricity generated in the power plant G 1 , which mainly supplies electric power to the charging station S 1 , in the time period up to one hour later is 500 kWh. From these facts, it is expected that the amount of electric power stored in the charging station S 1  will become tight in the time period up to one hour later and in the time period from one hour later to two hours later unless electric power is transferred to the charging station S 1 . 
     Further, based on the station information, it is confirmed that while the current charge amount of the charging station S 3  is 1,505 kWh, a prediction of a demand up to one hour later is 800 kWh and a prediction of a demand from one hour later to two hours later is 1,500 kWh. Further, based on the power plant information, it is confirmed that a prediction of an amount of electricity generated in the power plant G 3 , which mainly supplies electric power to the charging station S 3 , in the time period up to one hour later is 150 kWh. From these facts, it is expected that the amount of electric power stored in the charging station S 3  will become tight in the time period up to one hour later and in the time period from one hour later to two hours later unless electric power is transferred to the charging station S 3 . 
     Meanwhile, based on the station information, it is confirmed that while the current charge amount of the charging station S 2  is 1,250 kWh, a prediction of a demand up to one hour later is 150 kWh and a prediction of a demand from one hour later to two hours later is 2,000 kWh. From these facts, it is expected that the charging station S 2  will have an extra amount of stored electric power in the time period up to one hour later and in the time period from one hour later to two hours later. 
     Therefore, the determination unit  210   b  determines to transfer electric power of 400 kWh from the charging station S 2  to the charging station S 1  and transfer electric power of 300 kWh from the charging station S 2  to the charging station S 3  in the time period from the present moment to one hour later. Further, it is also expected that the amount of electric power stored in the charging station S 3  will become tight in the time period from one hour later to two hours later. Therefore, the determination unit  210   b  also determines to transfer electric power of 300 kWh from the charging station S 2  to the charging station S 3  in the time period from one hour later to two hours later. Note that the determination unit  210   b  determines that there is no charging station where the amount of electric power will be tight in the time period from two hours later to three hours later and hence determines that transfer of electric power will not be performed in this time period. 
     The determination unit  210   b  creates a transfer instruction in accordance with the above-described transfer plan and transmits the created transfer instruction to the control panel  404  so that the transfer of electric power will be performed in accordance with the transfer plan. Note that in this example, the station information and the power plant information up to three hours later are creased on the assumption that the transfer plan is drawn up every three hours. However, the updating period is not limited to three hours. That is, various time periods may be defined according to the configuration of the distribution system  100  and/or the traffic condition of the target area. Further, the unit time period is also not limited to one hour and various time periods may be defined as the unit time period. 
     The determination unit  210   b  further analyzes the created station information and the power plant information and thereby draws up an electric power transfer plan for the power plants.  FIG. 7  shows an example of the electric power transfer plan for the power plants. Specifically, similarly to the transfer plan among charging stations, a time period from the present moment to one hour later, a time period from one hour later to two hours later, a time period from two hours later to three hours later are defined. Then, in each time period, a power plant that is expected to generate an extra amount of electric power, a charging station where an amount of stored electric power is expected to be tight are determined. Further, it is determined how much electric power should be transferred between them. 
     An example of processes for the determination is described. As described above, it is expected that the amount of the stored electric power will become tight in the time period up to one hour later and the time period from one hour later to two hours later in each of the charging stations S 1  and S 3 . Further, it is determined that the amount of electric power stored in the charging station S 2  will not become tight in the time period up to one hour later. Therefore, the determination unit  210   b  determines to transfer electric power generated in the power plant G 2 , which mainly supplies electric power to the charging station S 2 , in the time period up to one hour later to the charging stations S 1  and S 3 . At this point, since the necessity that the power plant G 2  charge the storage battery of the charging station S 2  is small, the determination unit  210   b  determines to transfer the whole amount of electricity generated in the power plant G 2  to the charging stations S 1  and S 3 . In this example, electric power of 600 kWh and 400 kWh are allocated to the charging stations S 1  and S 3 , respectively, in consideration of the degrees of tightness of their electric power. 
     The determination unit  210   b  determines that no transfer of electric power will be performed in the time period from one hour later to two hours later. Further, the determination unit  210   b  determines to transfer surplus electric power in the power plant G 3  to the charging station S 1  in the time period from two hours later to three hours later in which the amount of electricity generated in the power plant G 3  is large. 
     The determination unit  210   b  creates a transfer instruction in accordance with the above-described transfer plan and transmits the created transfer instruction to the control panel  404  so that the transfer of electric power will be performed in accordance with the transfer plan. Note that similarly to the electric power transfer plan for the charging stations, the updating period for the electric power transfer plan for the power plants is not limited to three hours. Further, the unit time period is also not limited to one hour. Further, since electric power transfer from a power plant to a charging station is performed to supplement the electric power transfer between charging stations, it is not indispensable in the distribution system  100 . Further, when electric power is transferred from a power plant to a charging station, it is possible to determine only the transfer destination of generated electric power without determining the amount of electric power to be transferred. 
     Next, a flow of a series of processes in this example is described.  FIG. 8  is a flowchart showing processes performed by the server  200 . In a step S 101 , the acquisition unit  210   a  acquires vehicle information from each vehicle  300 . Further, in a step S 102 , the acquisition unit  210   a  acquires supply facility information from each charging station  500 . Further, in a step S 103 , the acquisition unit  210   a  acquires production facility information from each power plant  600 . The order of the steps S 101  to S 103  does not need to be the above-described order. Further, the acquisition timings are as described above. 
     In a step S 104 , the determination unit  210   b  predicts a demand in each charging station  500  in the target area. Specifically, the determination unit  210   b  creates the above-described station information by using the acquired vehicle information, the supply facility information, and information in the external DB  700 , which the determination unit  210   b  refers to, and by using the information storage unit  213 . Further, in a step S 105 , the determination unit  210   b  predicts amounts of electricity generated in the power plants  600 . Specifically, the determination unit  210   b  creates the above-described power plant information by using the acquired production facility information, and the information in the external DB  700 , which the determination unit  210   b  refers to, and by using the information storage unit  213 . The order of the steps S 104  and S 105  may be reversed. 
     The determination unit  210   b  analyzes the station information created in the step S 104  and the power plant information created in the step S 105 , and thereby determines an electric power transfer plan. Specifically, the determination unit  210   b  draws up the above-described electric power transfer plan among the charging stations and the electric power transfer plan for the power plants. 
     In a step S 107 , the determination unit  210   b  creates a transfer instruction in accordance with the drawn-up transfer plan and transmits the created transfer instruction to the control panel  404 . That is, the server  200  makes the control panel  404  perform a transfer(s) of electric power according to the transfer plan. After a certain time has elapsed, the acquisition unit  210   a  acquires supply facility information from each charging station  500  in a step S 108 . Then, in a step S 109 , the processing unit  210  checks whether or not the predicted demand for electric power deviates from the actual demand for electric power by a predetermined amount or larger. When the deviation is equal to or larger than the predetermined amount, the process returns to the step S 101  and the series of processes is performed again. When the deviation is smaller than the predetermined amount, the process proceeds to a step S 110 . 
     When the processing unit  210  proceeds to the step S 110 , it checks whether or not it becomes a time at which a transfer plan should be drawn up again. When it has become the time, the process returns to the step S 101  and the series of processes is performed again. When it still has not become the time, the process proceeds to a step S 111  and the processing unit  210  determines whether or not the system has been stopped. When the system has not been stopped, the process returns to the step S 107  and the transfer of electric power is continued. When the system has been stopped, the processing unit  210  performs a termination process and thereby finishes the series of processes. 
     The above-described first example is described on the assumption that charging stations  500  and power plants  600 , which mainly supply electric power to the charging stations, are installed in a one-to-one manner. However, one power plant  600  may supply electric power to two charging stations  500  or more. Further, the distribution system may include a charging station(s)  500  that receives electric power from a conventional power generation facility such as a thermal power generation facility, and may include a charging station(s)  500  that receives electric power from both a power plant  600  and a conventional power generation facility. 
     The above-described first example is described on the assumption that the speed of the transfer of electric power is constant. However, depending on the equipment in the charging station  500 , the amount of electric power that the charging station  500  can receive in a unit time can be adjusted. In the case of the transfer of electric power to the charging station  500  having the above-described function, the transfer speed may be changed according to the degree of changes in the demand. In particular, when it is possible to predict a time at which a vehicle  300  arrives at a charging station  500 , electric power may be transferred so as to be in time for the predicted arrival time. 
     In this case, the determination unit  210   b  predicts the time at which the vehicle  300 , whose vehicle information has been acquired, arrives at the charging station and determines the transfer speed of electric power through the power transmission line  400  so that the electric power is transferred in time for the predicted arrival time. The control panel  404  transfers electric power at the determined transfer speed. In this way, when the transfer should be performed quickly, the demand from the consumer is satisfied by increasing the transfer speed. On the other hand, when transfer does not need to be performed quickly, the transfer speed is lowered to prevent the deterioration of the storage battery which would otherwise be caused due to the quick charging. 
     In the first example described above, an example in which the power transmission line  400 , which is the transfer facility, is installed along the expressway  900  is described. In such an example, an auxiliary charging facility for urgently supplying electric power to a vehicle  300  is preferably installed in the path of the power transmission line  400 . By installing such a facility, it is possible to take an emergency measure in an emergency or the like of the vehicle  300  and thereby to improve the traffic environment of the target area. 
     Further, the target area may not be limited to a certain section of the expressway  900 . When the charging station  500  is installed in the service area  910  of the expressway  900 , the demand for electric power can be accurately predicted. However, it is expected to produce some results even when the target area includes a motorway and/or an ordinary road such as a main road. 
     Further, in the first example described above, demands for electric power and amounts of generated electricity are predicted by using various parameters. However, all of the aforementioned parameters are not necessarily indispensable. Further, other parameters may also be taken into consideration. What kind of parameters should be taken into consideration is determined in view of the accuracy for the prediction that should be guaranteed. For example, as the vehicle information, a current location, a destination, a traveling speed, a traveling distance per unit traveling energy, and history information relevant to supplies of traveling energy are mentioned. However, which parameters should be used as the vehicle information is determined based on the specifications of the distribution system  100 . 
     Next, a second example of this embodiment is described.  FIG. 9  is a conceptual diagram showing an electric power distribution system  101  according to the second example. The distribution system  101  differs from the distribution system  100  in the arrangement of power plants. In the distribution system  100 , charging stations  500  and power plants  600 , which mainly supply electric power to the charging stations, are installed in a one-to-one manner. In contrast to this, in the distribution system  101 , solar power generation units  610  are continuously installed along the expressway  900 . 
     In the case where solar power generation units  610  are continuously installed as described above, the solar power generation units  610  may be divided into a plurality of sections and each section of the solar power generation units  610  may supply electric power to a corresponding charging station  500 . Further, the solar power generation units  610  may be connected to the power transmission line  400  through sub transmission lines  403  at any parts of the solar power generation units  610 . Similarly to the distribution system  100 , the distribution system  101  can also transfer electric power. 
     Next, a third example of this embodiment is described.  FIG. 10  is a conceptual diagram showing another electric power distribution system  102  according to the third example. The distribution system  102  differs from the distribution system  100  because the distribution system  102  does not include the power transmission line  400 , the drop wire  401 , the sub transmission line  403 , and the control panel  404 , which are the transfer facility. Further, target vehicles  300  of the distribution system  102  are vehicles each of which travels by electric power supplied from a detachable storage battery module  410 . Further, when the storage battery module  410  has used up all the electric power, it is replaced by a charged one. The storage battery module  410  is lent by an operator (e.g., a business proprietor). The operator charges the storage battery module  410  at the charging station  500  and receives a request from a passenger of the vehicle  300  as to whether the passenger wants to rent/replace the storage battery module  410 . Therefore, the operator needs to prepare a necessary number of charged storage battery modules  410  in the charging station  500  according to the demand from the vehicles  300 . 
     The distribution system  102  according to the third example functions in the above-described rental system. Specifically, similarly to the distribution system  100 , the acquisition unit  210   a  acquires vehicle information, supply facility information, and production facility information. Then, the determination unit  210   b  creates station information. Note that it is assumed that the prediction of the demand is a prediction of the number of storage battery modules  410  in each time period. Then, in each of the charging stations  500 , the number of rechargeable storage battery modules  410  is determined and a transfer plan among charging stations is drawn up. Note that the amount of the transfer is not the amount of electric power but is the number of storage battery modules  410 . Further, no transfer plan for the power plants is drawn up. 
     The determination unit  210   b  uses the transfer plan among charging stations, which has been drawn up as described above, as a transfer instruction and transmits the transfer instruction to an operator terminal  405  of the operator OP. The transfer plan is displayed in the operator terminal  405 . Then, the operator OP loads the specified number of storage battery modules  410  onto a transport vehicle  450  in the charging station at the designated transfer source and the transport vehicle  450  carries them to the charging station at the designated transfer destination. In this way, in the distribution system  102 , electric power is stored in the storage battery modules  410  and is transferred (i.e., transported) in the form of the storage battery modules  410 . Even in the above-described embodiment, it is expected that the distribution system  102  provides advantageous effects similar to those of the distribution system  100 . 
     Further, as a modified example of the distribution system  102 , the target vehicle  300  may be a vehicle that travels by supplied hydrogen energy. Similarly to electric power, hydrogen energy is an example of traveling energy by which a vehicle can travel. 
     In this modified example, the charging station  500  is replaced by a hydrogen supply station. The hydrogen supply station includes a hydrogen plant that generates hydrogen by using electric power supplied from a power plant  600 . The generated hydrogen is stored in a hydrogen tank and supplied to a vehicle  300  according to a request. In this case, the demand to be predicted is an amount of hydrogen to be supplied. Further, the object to be transferred (i.e., transported) is a hydrogen tank storing hydrogen. The operator OP loads the specified number of hydrogen tanks onto a transport vehicle  450  in the hydrogen station at the designated transfer source and the transport vehicle  450  carries them to the hydrogen station at the designated transfer destination. Even in the above-described embodiment, it is expected that the distribution system  102  provides advantageous effects similar to those of the distribution system  100 . 
     The program can be stored and provided to a computer using any type of non-transitory computer readable media. Non-transitory computer readable media include any type of tangible storage media. Examples of non-transitory computer readable media include magnetic storage media (such as floppy disks, magnetic tapes, hard disk drives, etc.), optical magnetic storage media (e.g. magneto-optical disks), CD-ROM (compact disc read only memory), CD-R (compact disc recordable), CD-R/W (compact disc rewritable), and semiconductor memories (such as mask ROM, PROM (programmable ROM), EPROM (erasable PROM), flash ROM, RAM (random access memory), etc.). The program may be provided to a computer using any type of transitory computer readable media. Examples of transitory computer readable media include electric signals, optical signals, and electromagnetic waves. Transitory computer readable media can provide the program to a computer through a wired communication line (e.g. electric wires, and optical fibers) or a wireless communication line. 
     From the disclosure thus described, it will be obvious that the embodiments of the disclosure may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure, and all such modifications as would be obvious to one skilled in the art are intended for inclusion within the scope of the following claims.