Patent Publication Number: US-11383611-B2

Title: Control apparatus, and computer-readable storage medium

Description:
The contents of the following Japanese patent application are incorporated herein by reference: 2019-006035 filed on Jan. 17, 2019. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a control apparatus, and a computer-readable storage medium. 
     2. Related Art 
     There are known systems for levelling power supply/demand by performing charge/discharge control of batteries of electric vehicles while they are parked at each power consumer according to a charge/discharge command output from a power supply/demand management center to each power consumer based on power supply/demand information from a power provider (see Patent Literature 1 explained below, etc., for example). 
     PRIOR ART LITERATURE 
     Patent Literatures 
     Patent Literature 1: Japanese Patent No. 5562423 
     Patent Literature 2: Japanese Patent No. 5714073 
     Patent Literature 3: Japanese Patent Application Publication No. 2011-130575 
     SUMMARY 
     In a system that performs power transfer between a power network and vehicles, it is not possible to make the most of the power supply capacity of the vehicles if the power demand at movement destinations is low, even if sufficient power supply capacities are left in driving power sources of the vehicles at the movement destinations of the vehicles. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically illustrates the basic configuration of a power transfer system  100 . 
         FIG. 2  schematically illustrates the functional configuration of a managing server  40 . 
         FIG. 3  illustrates, in a table format, one example of schedule information stored in a schedule information storage unit  282 . 
         FIG. 4  illustrates, in a table format, one example of movement history information stored in a history storage unit  284 . 
         FIG. 5  illustrates, in a table format, one example of connection history information stored in the history storage unit  284 . 
         FIG. 6  illustrates, in a table format, one example of user information stored in a user information storage unit  286 . 
         FIG. 7  is a schematic view illustrating one example of situations where a vehicle  30  to be preferentially charged or caused to discharge power is selected. 
         FIG. 8  is a schematic view illustrating another example of situations where a vehicle  30  to be preferentially charged or caused to discharge power is selected. 
         FIG. 9  is a schematic view illustrating another example of situations where a vehicle  30  to be preferentially charged or caused to discharge power is selected. 
         FIG. 10  is a schematic view illustrating another example of situations where a vehicle  30  to be preferentially charged or caused to discharge power is selected. 
         FIG. 11  is a flowchart related to processes at the managing server  40 . 
         FIG. 12  shows an example of a computer  2000  in which embodiments of the present invention may be wholly or partly embodied. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, (some) embodiment(s) of the present invention will be described. The embodiment(s) do(es) not limit the invention according to the claims, and all the combinations of the features described in the embodiment(s) are not necessarily essential to means provided by aspects of the invention. Note that the identical or similar portions in drawings are given the same reference numbers, and repetitive explanations are omitted in some cases. 
       FIG. 1  schematically illustrates the basic configuration of a power transfer system  100 . The power transfer system  100  is a system for a power aggregator, for example, to perform V2G (Vehicle-to-Grid) for exchange of power between vehicles and a power network by using batteries provided to the vehicles. The power transfer system  100  has a function of allowing vehicles to contribute to power supply/demand of regional power networks at movement destinations. Note that, in V2G, at least either release of power by a vehicle to the power network or reception of power by a vehicle from the power network is performed. 
     The power transfer system  100  includes: a plurality of vehicles including a vehicle  30   a , and a vehicle  30   b ; a plurality of stationary batteries including a stationary battery  14   a , a stationary battery  14   b , and a stationary battery  14   c ; a plurality of charge/discharge facilities including a charge/discharge facility  20   a , a charge/discharge facility  20   b , and a charge/discharge facility  20   c ; a plurality of power generation facilities including a power generation facility  12   a , a power generation facility  12   b , and a power generation facility  12   c ; a plurality of user terminals including a user terminal  82   a , and a user terminal  82   b ; and a managing server  40 . 
     A user  80   a  is a user of the vehicle  30   a , and a user  80   b  is a user of the vehicle  30   b . Note that a user of a vehicle may be any person who uses the vehicle such as an owner of the vehicle or a family member of the owner. In the present embodiment, the user  80   a , and user  80   b  are generally called a “user  80 ” in some cases. 
     The user terminal  82   a  is a communication terminal used by the user  80   a . The user terminal  82   b  is a communication terminal used by the user  80   b . The plurality of user terminals including the user terminal  82   a , and user terminal  82   b  are generally called a “user terminal  82 ” in some cases. 
     The user terminal  82  may be a mobile terminal, a personal computer, a vehicle navigation device, or the like, for example. Examples of the mobile terminal include a mobile phone, a smartphone, a PDA, a tablet, a notebook computer, a laptop computer, a wearable computer, and the like. 
     The vehicle  30   a  includes a battery  32   a . The vehicle  30   b  includes a battery  32   b . In the present embodiment, the plurality of vehicles including the vehicle  30   a , and vehicle  30   b  are generally called a “vehicle  30 ” in some cases. In addition, a plurality of batteries including the battery  32   a , battery  32   b , and battery  32   c  are generally called a “battery  32 ” in some cases. The battery  32  may be any of various secondary batteries such as lithium ion batteries or nickel hydrogen batteries. 
     Note that the battery  32  is one example of a driving power source of the vehicle  30 . The driving power source includes a power source that, like a fuel cell or the like, consumes a fuel to generate electric energy to be provided to a motive power source of the vehicle  30 . The fuel may be hydrogen, a hydrocarbon fuel such as gasoline, light oil or natural gas, an alcohol fuel, or the like. The driving power source may be any power source that can generate electric energy to be provided to a motive power source of the vehicle  30 . 
     The vehicle  30  is one example of a transportation device. The vehicle  30  is a vehicle including a motive power source to be driven by electric energy, such as an electric vehicle or a fuel cell vehicle (FCV), for example. Electric vehicles include a battery electric vehicle (BEV), a hybrid vehicle or plug-in hybrid electric vehicle (PHEV) including an internal combustion engine to provide at least part of motive power. In the present embodiment, the vehicle  30  is an electric vehicle including the battery  32  as a driving power source. In the form employing a battery as a driving power source, battery discharge corresponds to energy release from the driving power source, and battery charge corresponds to energy accumulation in the driving power source. 
     A power network  10   a , a power network  10   b , and a power network  10   c  are power transmission systems or power distribution systems of a power system, or power distribution networks of a power grid. The power network  10   a , power network  10   b , and power network  10   c  are generally called a “power network  10 ” in some cases. The power network  10  may be provided for each region. The power network  10  may be a micro grid. The power network  10  may be a power distribution network of any scale that connects power devices that consume power, and power sources. For example, the power network  10  may be a power distribution network provided to any of facilities such as commercial facilities. The power network  10  may be provided for each building. Power networks  10  may be interconnected by interconnection lines and the like. 
     The power generation facility  12   a  supplies power to the power network  10   a . The power generation facility  12   b  supplies power to the power network  10   b . The power generation facility  12   c  supplies power to the power network  10   c . The power generation facility  12   a , power generation facility  12   b , and power generation facility  12   c  are generally called a “power generation facility  12 ” in some cases. Power generation facilities  12  are each managed by a power provider such as an electric power company. 
     The charge/discharge facility  20   a  is connected to the power network  10   a , and charges the battery  32  of the vehicle  30  or causes the battery  32  of the vehicle  30  to discharge power. The charge/discharge facility  20   b  is connected to the power network  10   b , and charges the battery  32  of the vehicle  30  or causes the battery  32  of the vehicle  30  to discharge power. The charge/discharge facility  20   c  is connected to the power network  10   c , and charges the battery  32  of the vehicle  30  or causes the battery  32  of the vehicle  30  to discharge power. The charge/discharge facility  20   a , charge/discharge facility  20   b , and charge/discharge facility  20   c  are generally called a “charge/discharge facility  20 ” in some cases. Charge/discharge facilities  20  include, for example, a charger/discharger installed at a residence, a charge/discharge station installed at a parking lot or public space of a multi-dwelling unit, a building or a commercial facility, and the like. The charge/discharge facility  20  is one example of power transfer facilities. 
     The stationary battery  14   a  is connected to the power network  10   a , and performs charge/discharge with the power network  10   a . The stationary battery  14   b  is connected to the power network  10   b , and performs charge/discharge with the power network  10   b . The stationary battery  14   c  is connected to the power network  10   c , and performs charge/discharge with the power network  10   c . The stationary battery  14   a , stationary battery  14   b , and stationary battery  14   c  are generally called a “stationary battery  14 ” in some cases. 
     In each of the power networks  10 , the charge/discharge facility  20 , stationary battery  14 , and power generation facility  12  are capable of power transfer with the power network  10  to which they are connected. The vehicle  30  can move between regions where power is provided by the power networks  10 . The vehicle  30  is connected to any of the charge/discharge facilities  20 , and can perform charge or discharge of the battery  32 . 
     The managing server  40  is capable of communication with the vehicle  30 , stationary battery  14 , and user terminal  82  through a communication network. The managing server  40  is also capable of communication with a power transaction server  50  through a communication network. The communication networks may include wired communication or wireless communication transmission paths. The communication networks may include communication networks including the Internet, a P2P network, a dedicated line, a VPN, a power line communication line, a mobile phone line, and the like. 
     The vehicle  30  is connected to the charge/discharge facility  20  through a charge/discharge cable  22 . That is, the vehicle  30  is connected to the power network  10  through the charge/discharge cable  22 , and charge/discharge facility  20 . The vehicle  30  performs power transfer between the battery  32  and the power network  10  through the charge/discharge facility  20 . For example, the vehicle  30  releases power obtained by discharge of the battery  32  to the power network  10  via the charge/discharge cable  22 , and charge/discharge facility  20 . In addition, the vehicle  30  charges the battery  32  with power supplied from the power network  10  via the charge/discharge cable  22 , and charge/discharge facility  20 . Note that transfer of power between an entity and a power network  10  is called “power transfer with the power network  10 ” and the like in some cases. 
     The stationary battery  14  is managed by the power aggregator. The battery  32  of the vehicle  30  forms a virtual power plant along with the stationary battery  14 . The managing server  40  is managed by the power aggregator. The managing server  40  controls power transfer between the battery  32  and the power network  10 , and between the stationary battery  14  and the power network  10 . 
     The managing server  40  performs power transaction by bidding in a wholesale power market. The power transaction server  50  is managed by an operator of the wholesale power market. The length of each time segment is defined as 30 minutes, and the managing server  40  places a bid in the power transaction server  50  in every time segment. The managing server  40  causes the battery  32 , and stationary battery  14  to discharge power in each time segment based on a contract result to supply the power to the power network  10 . 
     For example, the managing server  40  causes the battery  32 , and stationary battery  14  to discharge power according to a contract amount which is a result of bidding in the wholesale power market by the power aggregator to supply the power network  10  with the power released from the battery  32 , and stationary battery  14 . In addition, the managing server  40  controls charge/discharge of the battery  32 , and stationary battery  14  to balance power supply and demand in the power network  10  to an extent of the balancing power agreed in a transaction which is a result of bidding in the supply/demand balancing market by the power aggregator. For example, the managing server  40  controls charge/discharge of the battery  32 , and stationary battery  14  according to an increased-demand response (increased-DR), a decreased-demand response (decreased-DR), and an increased/decreased-demand response (increased/decreased-DR) requested by a power transmission/distribution company or a retail electricity supplier. 
     Specifically, the managing server  40  controls at least one of the vehicle  30  and the charge/discharge facility  20  according to a increased-DR to thereby charge the battery  32  of the vehicle  30  with power received from the power network  10  through the charge/discharge facility  20 . In addition, the managing server  40  controls at least one of the vehicle  30  and the charge/discharge facility  20  according to a decreased-DR to thereby cause the battery  32  of the vehicle  30  to discharge power, and cause the power obtained by the discharge of the battery  32  to be released toward the power network  10  through the charge/discharge facility  20 . 
     In the present embodiment, the managing server  40  identifies regions of future movement destinations of the vehicle  30   a , and vehicle  30   b , and a period over which the vehicle  30  will be kept stopped in the region of the movement destination. For example, the managing server  40  identifies the region of the movement destination of the vehicle  30 , and the time segment over which the vehicle  30  will be kept stopped in the region, based on movement history information of the vehicle  30 , schedule information of the user  80 , destination information set in a navigation device of the vehicle  30 , and the like. The managing server  40  acquires a predicted value of power demand of each time segment in a power network  10  of each region. If the power network of the movement destination of the vehicle  30   a  is the power network  10   b , and the power network of the movement destination of the vehicle  30   b  is the power network  10   c , the vehicle  30   a  is preferentially charged over the vehicle  30   b , provided that there is a high possibility that a shortage of power will occur in the power network  10   b  during a period over which the vehicle  30   a  is kept stopped, and there is a low possibility that a shortage of power occurs in the power network  10   c  in a period over which the vehicle  30   b  is kept stopped. Thereby, the vehicle  30   a  can provide power to the power network  10   b  after the vehicle  30   a  moved to the movement destination. 
     On the other hand, if there is a high possibility hat an excess of power occurs in the power network  10   b  during a period over which the vehicle  30   a  is kept stopped, and there is a low possibility that an excess of power occurs in the power network  10   c  during a period over which the vehicle  30   b  is kept stopped, the managing server  40  causes the vehicle  30   a  to discharge power preferentially over the vehicle  30   b . Thereby, it is possible to cause excess power of the power network  10   b  to be absorbed by the vehicle  30   a  after the vehicle  30   a  moved to the movement destination. 
     A possible case to which the control of causing a particular vehicle  30  to be charged or to discharge power preferentially in the manner mentioned above can be applied is, for example, a case where there are a large number of vehicles  30  parked at a parking lot of a condominium, a building, a commercial facility, a free way parking area or the like, and a vehicle  30  to be charged or caused to discharge power preferentially is selected from the vehicles  30  parked in the same parking lot. In addition, the control of causing a particular vehicle  30  to be charged or to discharge power preferentially can be applied also to a case where the vehicles  30  are vehicles for commercial use such as buses or trucks that move over long distances, and a vehicle  30  to be charged or caused to discharge power preferentially is selected before departure. Note that if a vehicle  30  is to be charged or caused to discharge power, the vehicle  30  is charged or caused to discharge power not necessarily between the vehicle  30  and the power network  10 . For example, if a shortage of power is predicted in the power network  10   b  of a movement destination of the vehicle  30   a , and an excess of power is predicted in the power network  10   c  of a movement destination of the vehicle  30   b , power may be supplied from the battery  32   b  to the battery  32   a  through inter-vehicle charge/discharge (V2V: Vehicle to Vehicle) between the vehicle  30   a  and the vehicle  30   b.    
     Note that, in the present embodiment, power transfer means that power exchange from at least one of the vehicle  30  and the power network  10  to the other occurs. For example, power transfer may mean that power release is performed from the vehicle  30  toward the power network  10 . In addition, power transfer may mean that power transmission is performed from the power network  10  toward the vehicle  30 . Note that if the vehicle  30  releases power through a charger/discharger installed at a power consumer such as a home, net power supply to the power network  10  does not occur at a connection point between the power consumer&#39;s side and the power network  10  when the power consumption on the power consumer&#39;s side is greater than the power released from the vehicle  30 , and the amount of power supply from the connection point to the power consumer simply decreases in some cases. In this case also, it can be considered that power exchange has occurred with the outside of the power network  10  from the perspective of the power network  10 . Accordingly, it does not matter in the present embodiment whether or not the power network  10  receives net power from a particular connection point between the power network  10  and the vehicle  30  in power transfer with the power network  10  in which the vehicle  30  releases power. 
       FIG. 2  schematically illustrates the functional configuration of the managing server  40 . The managing server  40  includes a processing unit  42 , a storage unit  48 , and a communicating unit  46 . 
     The processing unit  42  is realized by a processing device including a processor. The storage unit  48  is realized by a nonvolatile storage device. The processing unit  42  performs processes by using information stored in the storage unit  48 . The communicating unit  46  is responsible for communication with the vehicle  30 , stationary battery  14 , user terminal  82 , and power transaction server  50 . Information received by the communicating unit  46  from the vehicle  30 , stationary battery  14 , user terminal  82 , and power transaction server  50  is supplied to the processing unit  42 . In addition, information to be sent to the vehicle  30 , stationary battery  14 , user terminal  82 , and power transaction server  50  is generated by the processing unit  42 , and sent via the communicating unit  46 . 
     The managing server  40  functions as a power transfer managing apparatus. The managing server  40  may be a system realized by one information processing device, or may be a system realized by a plurality of information processing devices. 
     The processing unit  42  includes a movement destination predicting unit  210 , a period predicting unit  220 , a control unit  280 , and a demand information acquiring unit  290 . 
     The storage unit  48  includes a schedule information storage unit  282 , a history storage unit  284 , and a user information storage unit  286 . The schedule information storage unit  282  stores information about a schedule of connection of the vehicle  30  to a charge/discharge facility  20 . The schedule information includes identification information of a charge/discharge facility  20  to which the vehicle  30  is connected in the future, and information indicating a period over which the vehicle  30  is kept connected to the charge/discharge facility  20  in the future. The schedule information may be generated by the managing server  40  acquiring, from the user terminal  82 , information registered with the user terminal  82  by the user  80 . The history storage unit  284  stores history information including movement history information of the vehicle  30 , and history information about connection between the vehicle  30  and the charge/discharge facility  20 . 
     The movement destination predicting unit  210  predicts a future movement destination of the vehicle  30 . The movement destination predicting unit  210  may predict the future movement destination of the vehicle  30  based on the movement history information stored in the history storage unit  284 . The movement destination predicting unit  210  may predict the future movement destination of the vehicle  30  based on the schedule information stored in the schedule information storage unit  282 . 
     The demand information acquiring unit  290  acquires information indicating power demand in each of the power networks  10 . Specifically, the demand information acquiring unit  290  acquires information indicating: power demand in a first power network  10  that supplies power in a first region including a future movement destination of the first vehicle  30 ; and power demand in a second power network  10  that supplies power in a second region including a future movement destination of the second vehicle. The information indicating the power demand may be information indicating demand for balancing power in the power network  10 . 
     Note that the contract amount in power transaction mentioned above is one example of the information indicating the power demand. The information indicating the power demand may be a contract price in power transaction or a contract type indicating whether a transaction is a buy contract or a sell contract. In addition, the information indicating the power demand may be information indicating a predicted value of an amount of future imbalance between supply and demand. The information indicating the power demand may be information indicating a predicted value of power consumption of the power network  10  at a power consumer. Information that can be applied to the information indicating the power demand is not limited to power amounts themselves, but include various types of information that directly or indirectly affects power demand such as temperature information, humidity information, weather information, or event information. Note that examples of the power transaction market include transaction markets such as a day-ahead market, an intraday market, and a supply/demand balancing power market. Forms that can be applied as the transaction form of power transaction include various transaction forms other than the transaction forms in these power transaction markets. 
     Based on power demand in the power network  10   b , and power demand in the power network  10   c , the control unit  280  causes the battery  32   a  provided to the vehicle  30   a  to be charged or to discharge power preferentially over the battery  32   b  provided to vehicle  30   b . Specifically, based on the power demand in the power network  10   b , and the power demand in the second power network  10 , the control unit  280  causes the battery  32   a  provided to the vehicle  30   a  to perform power transfer with the power network  10   a  that supplies power in a region where the vehicle  30   a  is currently present, preferentially over the battery  32   b  provided to the vehicle  30   b.    
     For example, if the power demand in the power network  10   b  is higher than the power demand in the power network  10   c , the control unit  280  causes the battery  32   a  provided to the vehicle  30   a  to be charged preferentially over the battery  32   b  provided to the vehicle  30   b . For example, the control unit  280  causes the battery  32   a  provided to the vehicle  30   a  to be charged preferentially over the battery  32  provided to the vehicle  30   b , provided that the power demand in the power network  10   a  that supplies power in a region where the vehicle  30   a  is currently present is lower than a predetermined value. Thereby, the battery  32   a  provided to the vehicle  30   a  can be charged with power from the power network  10   a , provided that there is not a stringent situation due to imbalance between the power demand and supply in the power network  10   a.    
     The information indicating the power demand may include information indicating an amount of excess power in the power network  10 . If an amount of excess power in the power network  10   b  is greater than an amount of excess power in the power network  10   c , the control unit  280  causes the battery  32   a  provided to the vehicle  30   a  to discharge power preferentially over the battery  32   b  provided to the vehicle  30   b . For example, the control unit  280  causes the battery  32   a  provided to the vehicle  30   a  to discharge power preferentially over the battery  32   b  provided to the vehicle  30   b , provided that the power demand in the power network  10   a  that supplies power in a region where the vehicle  30   a  is currently present is higher than a predetermined value. Thereby, the battery  32   a  provided to the vehicle  30   a  can be caused to discharge power to provide the power to the power network  10   a , provided that there is not an excess of power in the power network  10   a.    
     The period predicting unit  220  predicts a first period over which the vehicle  30   a  will be present in the first region, and a second period over which the vehicle  30   b  will be present in the second region. As mentioned above, the period predicting unit  220  predicts the first period, and second period based on the movement history information stored in the history storage unit  284 , and the schedule information stored in the schedule information storage unit  282 . Based on the power demand in he power network  10   b  during the first period, and the power demand in the power network  10   c  during the second period, the control unit  280  causes the battery  32   a  provided to the vehicle  30   a  to be charged or to discharge power preferentially over the battery  32   b  provided to the vehicle  30   b.    
     The control unit  280  may prioritize charge or discharge of the battery  32   a  provided to the vehicle  30   a  over charge or discharge of the battery  32   b  provided to the vehicle  30   b  by causing the battery  32   a  provided to the vehicle  30   a  to be charged or to discharge power before charge or discharge of the battery  32   b  provided to the vehicle  30   b . Thereby, if a chargeable capacity is limited as in a case where the vehicle  30   a , and vehicle  30   b  are connected to charge/discharge facilities  20  of the same parking lot or in other cases, a vehicle  30  that is scheduled to move to a power network  10  where a shortage of power is predicted to occur can be charged first. 
     In addition, the control unit  280  may prioritize charge or discharge of the battery  32   a  provided to the vehicle  30   a  over the battery  32   b  provided to the vehicle  30   b  by making a charge amount or discharge amount of the battery  32   a  provided to the vehicle  30   a  larger than a charge amount or discharge amount of the battery  32   b  provided to the vehicle  30   b . The control unit  280  may prioritize charge or discharge of the battery  32  provided to the vehicle  30   a  over the battery  32   b  provided to the vehicle  30   b  by making a charge amount or discharge amount per unit time of the battery  32   a  provided to the vehicle  30   a  larger than a charge amount or discharge amount per unit time of the battery  32   b  provided to the vehicle  30   b.    
     The user information storage unit  286  stores information indicating a first lower limit value which is the lower limit value of a capacity that should be kept in the battery  32   a  of the vehicle  30   a  for the user  80   a . The user information storage unit  286  stores information indicating a second lower limit value which is the lower limit value of a capacity that should be kept in the battery of the vehicle  30   b  for the user  80   b . The control unit  280  may prioritize charge of the battery  32   a  over charge of the battery  32   b  by charging the battery  32   a  such that the difference between the remaining capacity of the battery  32   a  and the first lower limit value becomes larger than the difference between the remaining capacity of the battery  32   b  and the second lower limit value. Note that if the control unit  280  causes the battery  32   a  provided to the vehicle  30   a  to discharge power, the control unit  280  may cause power transfer to be performed between the power network  10  and the battery  32   a  provided to the vehicle  30   a  such that the remaining capacity of the battery  32   a  provided to the vehicle  30   a  does not fall below the lower limit value. 
     The control unit  280  communicates with the ECU of the vehicle  30  to successively acquire power transferability information indicating whether or not the vehicle  30  is connected to a charge/discharge facility  20  available for power transfer with the power network  10 . If the vehicle  30  is available for power transfer with the power network  10 , the control unit  280  instructs the ECU provided to the vehicle  30  to perform charge/discharge of the battery  32  according to power demand indicated by information acquired by the demand information acquiring unit  290 . The ECU of the vehicle  30  communicates with the charge/discharge facility  20  according to the instruction of the control unit  280 , and controls a power converter of the vehicle  30  to perform charge of the battery  32  through the charge/discharge facility  20  or release of power obtained through discharge of the battery  32 . Note that the control unit  280  may successively acquire, from the ECU of the vehicle  30 , information indicating: an amount of power input from the charge/discharge facility  20  to the power converter at the time of charge of the battery  32 ; an amount of power output from the power converter to the charge/discharge facility  20  at the time of discharge of the battery  32 ; and the SOC (State of Charge) of the battery  32 . The control unit  280  may control power transfer between the vehicle  30  and the power network  10  based on the information acquired from the ECU of the vehicle  30 . 
     Note that functions of the control apparatus in the present invention may be realized singly by the managing server  40  or may be realized by a combination of the managing server  40  and the ECU of the vehicle  30 . For example, at least some of the functions for processes executed by the managing server  40  in the present embodiment may be executed by the ECU of the vehicle  30 . For example, at least some of processes executed by the control unit  280 , movement destination predicting unit  210 , and period predicting unit  220  may be executed by the ECU of the vehicle  30 . 
     The managing server  40  makes it possible to sufficiently charge the vehicle  30   a  in advance for example if it is predicted that a shortage of power will occur in the power network  10   b  of the movement destination of the vehicle  30   a , and it is predicted that a shortage of power will not occur in the power network  10   c  of the movement destination of the vehicle  30   b . Thereby, it is possible to lower the possibility that the vehicle  30   a  will not be able to supply power to the power network  10   b  at the movement destination of the vehicle  30   a . In addition, it is possible to appropriately cause the vehicle  30   a  to discharge power in advance if it is predicted that an excess of power will occur in the power network  10   b  of the movement destination of the vehicle  30   a , and it is predicted that an excess of power will not occur in the power network  10   c  of the movement destination of the vehicle  30   b . Thereby, it is possible to lower the possibility that power cannot be absorbed in the power network  10   b  at the movement destination of the vehicle  30   a . This contributes to stabilization of the power network  10 . 
       FIG. 3  illustrates, in a table format, one example of schedule information stored in the schedule information storage unit  282 . The schedule information associates a vehicle ID, a scheduled period, and a connection destination ID with each other. 
     As the vehicle ID, identification information of the vehicle  30  is stored. As the scheduled period, information about a period over which the vehicle  30  is kept connected to the charge/discharge facility  20  is stored. The period information includes information indicating the start date/time, and end date/time of the period over which the vehicle  30  is kept connected to the charge/discharge facility  20 . As the connection destination ID, identification information of the charge/discharge facility  20  to which the vehicle  30  is connected is stored. 
     The user  80  may register information indicating the charge/discharge facility  20  that the user  80  is planning to connect the vehicle  30  to, and the scheduled period therefor. The user terminal  82  sends, to the managing server  40 , the identification information of the charge/discharge facility  20  registered by the user  80 , the information indicating the scheduled period, and the identification information of the vehicle  30  registered with the user terminal  82 . The managing server  40  generates schedule information based on the information received from the user terminal  82  to store the schedule information in the schedule information storage unit  282 . 
     For example, based on the schedule information, the movement destination predicting unit  210 , and period predicting unit  220  predict a movement destination of the vehicle  30 , and a period over which the vehicle  30  will be kept stopped at the movement destination. For example, the movement destination predicting unit  210  predicts the position of the charge/discharge facility  20  identified with the connection destination ID as the movement destination of the vehicle  30 . In addition, the period predicting unit  220  predicts the period indicated by the scheduled period as the period over which the vehicle  30  will be kept stopped at the movement destination. 
       FIG. 4  illustrates, in a table format, one example of movement history information stored in the history storage unit  284 . The movement history information associates a vehicle ID, a time, a battery SOC, a vehicle position, and a vehicle state with each other. 
     As the time, information indicating the time or period at which or during which a history is acquired is stored. As the battery SOC, information indicating the SOC of the battery  32  is stored. As the vehicle position, information indicating the position of the vehicle  30  is stored. The positional information may include, in addition to geographic information such as latitude/longitude information, any information that allows identification of the position of the vehicle  30  such as identification information of the charge/discharge facility  20  to which the vehicle  30  is connected or information indicating whether or not the vehicle  30  is at home. As the vehicle state, information indicating the state of the vehicle  30  is stored. The state of the vehicle  30  may be “stopped”, “started travelling”, “travelling”, “started charging”, “charging”, “ended charging”, and the like. The managing server  40  may successively receive, from the ECU of the vehicle  30 , vehicle data acquired at the ECU of the vehicle  30  to generate the movement history information based on the received vehicle data. 
     Based on the movement history information stored in the history storage unit  284 , the movement destination predicting unit  210 , and period predicting unit  220  predict a movement destination of the vehicle  30 , and a period over which the vehicle  30  will be kept stopped at the movement destination. For example, based on the time, vehicle position, and vehicle state included in the movement history information stored in the history storage unit  284 , the movement destination predicting unit  210  analyzes a movement pattern of the vehicle  30 , and predicts a movement destination of vehicle  30  based on the movement pattern. For example, the movement destination predicting unit  210  predicts the position, and vehicle state of the vehicle  30  in each time segment of the next day based on the movement pattern. Based on the position in each time segment predicted by the movement destination predicting unit  210 , and a region where each of the power networks  10  supplies power, the period predicting unit  220  identifies a period over which each of the vehicles  30  is kept stopped in the power supply region of the power network  10  in the future. 
       FIG. 5  illustrates, in a table format, one example of connection history information stored in the history storage unit  284 . The connection history information associates a vehicle ID, a connection destination ID, a connection period, a power transfer amount, and points with each other. 
     As the connection destination ID, identification information of the charge/discharge facility  20  connected to the vehicle  30  is stored. The connection period includes a connection start time, and a connection end time. As the connection start time, information indicating a time at which the vehicle  30  became available for power transfer with the power network  10  is stored. The connection start time may be identified based on power transferability information sent periodically from the charge/discharge ECU of the vehicle  30  to the managing server  40 . As the connection start time, a time at which it became possible for the control unit  280  to control charge/discharge of the battery  32  after the charge/discharge cable  22  is attached to the vehicle  30 , and charge/discharge facility  20  may be stored. 
     As the connection end time, information indicating a time at which it became impossible to perform power transfer between the vehicle  30  and the power network  10  is stored. The connection end time may be identified based on power transferability information sent periodically from the charge/discharge ECU of the vehicle  30  to the managing server  40 . As the connection end time, information indicating an end time of a period over which the vehicle  30  was kept connected to the charge/discharge facility  20  through the charge/discharge cable  22  may be stored. As the connection end time, information indicating a time at which a power cable was disconnected from at least one of the vehicle  30  and the charge/discharge facility  20  may be stored. As the connection end time, information indicating a time at which it became impossible for the control unit  280  to control charge/discharge of the battery  32  may be stored. 
     As the power transfer amount, information indicating an amount of power transferred between the vehicle  30  and the power network  10  from the connection start time to the connection end time is stored. 
     The points indicate a consideration given for the fact that the vehicle  30  became available for power transfer with the power network  10 . For example, the points are calculated as the sum of fixed points for the fact that power transfer was possible between the vehicle  30  and the power network  10 , and points that vary according to an amount of power transfer with the power network  10 . Note that the points given to the vehicle  30  may be added up every month, and the monthly usage fee of the charge/discharge facility  20  to be billed to the user  80  may be reduced according to the points that are added up. 
       FIG. 6  illustrates, in a table format, one example of user information stored in the user information storage unit  286 . The user information associates a vehicle ID, a lower limit capacity, and an upper limit capacity with each other. 
     The lower limit capacity indicates a capacity that should be kept in the battery  32  for use by the user  80 . For example, if the lower limit capacity is 30 kWh, when controlling charge/discharge of the battery  32 , the control unit  280  performs control such that the SOC of the battery  32  does not fall below the SOC corresponding to 30 kW. For example, if the battery  32  is being caused to discharge power, the control unit  280  stops the discharge of the battery  32  if the SOC of the battery  32  reached the SOC corresponding to 30 kW. 
     The upper limit capacity indicates an upper limit value of the capacity that can be reached in the battery  32  with power transfer controlled by the control unit  280 . The control unit  280  performs control such that the SOC of the battery  32  does not exceed the SOC corresponding to 50 kW. For example, if the battery  32  is being charged, the control unit  280  stops charge of the battery  32  if the SOC of the battery  32  reached the SOC corresponding to 50 kW. 
     The lower limit capacity, and upper limit capacity may be specified by the user  80 . For example, the user  80  specifies the lower limit capacity, and upper limit capacity by telling a dealer the lower limit capacity, and upper limit capacity at the time of purchase of the vehicle  30 . The lower limit capacity, and upper limit capacity specified by the user  80  may be sent to the managing server  40  through a terminal of the dealer, and registered with the user information storage unit  286 . By setting the lower limit capacity, and upper limit capacity, it is possible to restrict the range of capacity within which the capacity can change under the control of the control unit  280 . 
     Here, one example of methods of selecting a battery  32  to be preferentially charged or caused to discharge power is explained about an exemplary case where the lower limit capacity of the battery  32   a  is 30 kWh, and the lower limit capacity of the battery  32   b  is 20 kWh. First, it is assumed that the remaining capacity of the battery  32   a , and the remaining capacity of the battery  32   b  are both 40 kWh. In this case, the difference between the remaining capacity, and the lower limit capacity of the battery  32   a  is 10 kWh, and the difference between the remaining capacity, and lower limit capacity of the battery  32   b  is 20 kWh. If either one of the battery  32   a  and the battery  32   b  is to be charged in this condition, the control unit  280  prioritizes charge of one with a smaller difference between the remaining capacity and the lower limit capacity, that is, the battery  32   a , over charge of the battery  32   b . For example, the control unit  280  may start charge of the battery  32   b  after charging the battery  32   a  until the difference between the remaining capacity, and lower limit capacity of the battery  32   a  reaches a prescribed value. Other than this, the control unit  280  may charge the battery  32   a  by rapid charging, and charge the battery  32   b  by normal charging. 
     If either one of the battery  32   a  and the battery  32   b  is to be caused to discharge power, the control unit  280  prioritizes discharge of one with a larger difference between the remaining capacity and the lower limit capacity, that is, the battery  32   b , over discharge of the battery  32   a . For example, the control unit  280  may start causing the battery  32   a  to discharge power after causing the battery  32   b  to discharge power until the difference between the remaining capacity, and lower limit capacity of the battery  32   b  reaches a predetermined value. Other than this, the control unit  280  may cause the battery  32   b  to discharge power at a discharge rate of 6 kW, and cause the battery  32   b  to discharge at a discharge rate of 2 kW. 
     By controlling charge/discharge of a vehicle  30  according to the lower limit capacity in this manner, it is possible to make the battery  32  keep a minimum power amount necessary for the user  80  of the vehicle  30  while the battery  32  is charged or caused to discharge power according to the power demand amount or amount of excess power of the power network  10  of a movement destination of the vehicle  30 . 
       FIG. 7  is a schematic view illustrating one example of situations where a vehicle  30  to be preferentially charged or caused to discharge power is selected. As illustrated in  FIG. 7 , it is predicted that there will be a shortage of power in the power network  10   b  of a movement destination of the vehicle  30   a  in a time segment in which the vehicle  30   a  is kept stopped. On the other hand, it is predicted that there will not be a shortage of power in the power network  10   c  of a movement destination of the vehicle  30   b  in a time segment in which the vehicle  30   b  is kept stopped. In addition, there are not shortages of power in the regional power network  10   a  where the vehicle  30   a , and vehicle  30   b  currently are. 
     In this case, the control unit  280  prioritizes charge of the battery  32   a  of the vehicle  30   a  over charge of the battery  32   b  of the vehicle  30   b . Since it is possible thereby to cause power to be supplied from the vehicle  30   a  to the power network  10   b  after the vehicle  30   a  moved to the region of the power network  10   b , the vehicle  30   a  can contribute to the power demand in the power network  10   b.    
       FIG. 8  is a schematic view illustrating another example of situations where a vehicle  30  to be preferentially charged or caused to discharge power is selected. As illustrated in  FIG. 8 , it is predicted that there will not be an excess of power in the power network  10   b  of a movement destination of the vehicle  30   a  in a time segment in which the vehicle  30   a  is kept stopped. On the other hand, it is predicted that there will be an excess of power in the power network  10   c  of a movement destination of the vehicle  30   b  in a time segment in which the vehicle  30   b  is kept stopped. In addition, there are no excesses of power in the regional power network  10   a  where the vehicle  30   a , and vehicle  30   b  currently are. 
     In this case, the control unit  280  prioritizes discharge of the battery  32   b  of the vehicle  30   b  over discharge of the battery  32   a  of the vehicle  30   a . Thereby, it is possible to cause excess power of the power network  10   c  to be absorbed by the vehicle  30   b  after the vehicle  30   b  moved to the region of the power network  10   c.    
     Note that if the battery  32   b  of the vehicle  30   b  is to be caused to discharge power, the control unit  280  may calculate an amount of power to be consumed until arrival at the predicted movement destination of the vehicle  30   b  to cause the battery  32   b  to discharge power such that the remaining capacity of the battery  32   b  will not fall below the lower limit which is set to the total value of the lower limit capacity illustrated in  FIG. 6 , and the power consumption amount. 
       FIG. 9  is a schematic view illustrating another example of situations where a vehicle  30  to be preferentially charged or caused to discharge power is selected. As illustrated in  FIG. 9 , it is predicted that the possibility that there will be shortages of power in both the power network  10   b  of the movement destination of the vehicle  30   a , and the power network  10   c  of the movement destination of the vehicle  30   b  is higher than a predetermined value. Here, the predicted amount of shortage of power in the power network  10   b  is greater than the predicted amount of shortage of power in the power network  10   b . In addition, there are not shortages of power in the regional power network  10   a  where the vehicle  30   a , and vehicle  30   b  currently are. 
     In this case, the control unit  280  prioritizes charge of the battery  32   a  of the vehicle  30   a  over charge of the battery  32   b  of the vehicle  30   b . Since it is possible to cause power to be supplied from the power network  10   a  to the power network  10   b  after the vehicle  30   a  moved to the region of the power network  10   b , the shortage of power in the power network  10   c  can be mitigated. 
       FIG. 10  is a schematic view illustrating another example of situations where a vehicle  30  to be preferentially charged or caused to discharge power is selected. As illustrated in  FIG. 10 , it is predicted that the possibility that there will be excesses of power in both the power network  10   b  of the movement destination of the vehicle  30   a , and the power network  10   c  of the movement destination of the vehicle  30   b  is higher than a predetermined value. Here, the predicted amount of excess of power in the power network  10   b  is greater than the predicted amount of excess of power in the power network  10   b . In addition, there are no excesses of power in the regional power network  10   a  where the vehicle  30   a , and vehicle  30   b  currently are. 
     In this case, the control unit  280  prioritizes discharge of the battery  32   b  of the vehicle  30   b  over discharge of the battery  32   a  of the vehicle  30   a . Thereby, it is possible to cause excess power of the power network  10   c  to be absorbed by the vehicle  30   b  after the vehicle  30   b  moved to the region of the power network  10   c.    
     Note that if the battery  32   b  of the vehicle  30   b  is to be caused to discharge power as explained with reference to  FIG. 8 , the battery  32   b  may be caused to discharge power such that the remaining capacity of the battery  32   b  will not fall below the lower limit which is set to the total value of the lower limit capacity explained with reference to  FIG. 6 , and the power consumption amount. 
       FIG. 11  is a flowchart related to processes at the managing server  40 . The processes in the flowchart of  FIG. 11  are executed mainly at the processing unit  42  of the managing server  40 . The processes in this flowchart may be executed periodically by the managing server  40 , for example. The processes in this flowchart may be executed by at each predetermined timing at which the priority of charge or discharge of vehicles  30  is updated. 
     At S 1102 , the movement destination predicting unit  210 , and period predicting unit  220  predict a movement destination of each of vehicles  30 , and a period over which the vehicle  30  is kept stopped at the movement destination. The movement destination predicting unit  210 , and period predicting unit  220  predict a movement destination, and a period over which a vehicle  30  is kept stopped in the movement destination, based on information stored in the schedule information storage unit  282 , and history storage unit  284 , and destination information set for a navigation device of the vehicle  30 . 
     At S 1104 , the control unit  280  predicts power demand in each of power networks  10 . For example, the control unit  280  predicts power demand in each power network  10  during each time segment based on power demand in each of the power networks  10  acquired by the demand information acquiring unit  290 . For example, the power demand in each power network  10  may be predicted based on contract information about a power transaction corresponding to each of the power networks  10  acquired by the demand information acquiring unit  290 . 
     At S 1106 , the control unit  280  selects a vehicle  30  to be preferentially charged or caused to discharge power based on power demand in each of the power networks  10  predicted at S 1104 . As mentioned above, a vehicle  30  to be preferentially charged or caused to discharge power is selected based on the predicted power demand in the power network  10  in the stop periods predicted at S 1102 , power demand in a power network  10  of a region where a vehicle  30  currently is, the current remaining capacity of the vehicle  30 , and the lower limit capacity of the vehicle  30 . 
     At S 1108 , the vehicle  30  selected at S 1106  is caused to perform power transfer with the power network  10  preferentially over other vehicles  30  to thereby preferentially charge the vehicle  30  selected at S 1106  or causes the vehicle  30  to discharge power preferentially. 
       FIG. 12  shows an example of a computer  2000  in which embodiments of the present invention may be wholly or partly embodied. A program that is installed in the computer  2000  can cause the computer  2000  to function as or perform operations associated with apparatuses such as the managing server  40  of the embodiments or sections thereof, and/or cause the computer  2000  to perform processes of the embodiments of the present invention or steps thereof. Such a program may be executed by the CPU  2012  to cause the computer  2000  to perform certain operations associated with some or all of the blocks of flowcharts and block diagrams described herein. 
     The computer  2000  according to the present embodiment includes a CPU  2012 , and a RAM  2014 , which are mutually connected by a host controller  2010 . The computer  2000  also includes a ROM  2026 , a flash memory  2024 , a communication interface  2022 , and an input/output chip  2040 . The ROM  2026 , the flash memory  2024 , the communication interface  2022 , and the input/output chip  2040  are connected to the host controller  2010  via the input/output controller  2020 . 
     The CPU  2012  operates according to programs stored in the ROM  2026  and the RAM  2014 , thereby controlling each unit. 
     The communication interface  2022  communicates with other electronic devices via a network. The flash memory  2024  stores programs and data used by the CPU  2012  within the computer  2000 . The ROM  2026  stores therein a boot program or the like executed by the computer  2000  at the time of activation, and/or a program depending on the hardware of the computer  2000 . The input/output chip  2040  may also connect various input/output units such as a keyboard, a mouse and a monitor to the input/output controller  2020  via an input/output port such as a serial port, a parallel port, a keyboard port, a mouse port, a monitor port, a USB port, an HDMI (registered trademark) port and the like. 
     A program is provided via a computer-readable medium such as a CD-ROM, a DVD-ROM, or a memory card or a network. The RAM  2014 , the ROM  2026 , or the flash memory  2024  is an example of the computer-readable medium. The program is installed in the flash memory  2024 , the RAM  2014 , or the ROM  2026 , and is executed by the CPU  2012 . The information processing described in these programs is read into the computer  2000 , resulting in cooperation between a program and the above-mentioned various types of hardware resources. An apparatus or method may be constituted by realizing the operation or processing of information in accordance with the usage of the computer  2000 . 
     For example, when communication is performed between the computer  2000  and an external device, the CPU  2012  may execute a communication program loaded onto the RAM  2014  to instruct communication processing to the communication interface  2022 , based on the processing described in the communication program. The communication interface  2022 , under control of the CPU  2012 , reads transmission data stored on a transmission buffering region provided in a recording medium such as the RAM  2014 , the hard disk drive  2024 , the DVD-ROM  2001 , or the IC card, and transmits the read transmission data to a network or writes reception data received from a network to a reception buffering region or the like provided on the recording medium. 
     In addition, the CPU  2012  may cause all or a necessary portion of a file or a database to be read into the RAM  2014 , the file or the database having been stored in an external recording medium such as the flash memory  2024 , and perform various types of processing on the data on the RAM  2014 . The CPU  2012  may then write back the processed data to the external recording medium. 
     Various types of information, such as various types of programs, data, tables, and databases, may be stored in the recording medium to undergo information processing. The CPU  2012  may perform various types of processing on the data read from the RAM  2014 , which includes various types of operations, processing of information, condition judging, conditional branch, unconditional branch, search/replace of information, etc., as described throughout this disclosure and designated by an instruction sequence of programs, and writes the result back to the RAM  2014 . In addition, the CPU  2012  may search for information in a file, a database, etc., in the recording medium. For example, when a plurality of entries, each having an attribute value of a first attribute associated with an attribute value of a second attribute, are stored in the recording medium, the CPU  2012  may search for an entry matching the condition whose attribute value of the first attribute is designated, from among the plurality of entries, and read the attribute value of the second attribute stored in the entry, thereby obtaining the attribute value of the second attribute associated with the first attribute satisfying the predetermined condition. 
     The program or software module explained above may be stored on the computer  2000  or a computer-readable medium located near the computer  2000 . A recording medium like a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet can be used as such a computer-readable medium. The program stored on the computer-readable medium may be provided to the computer  2000  via a network. 
     The programs that are installed on the computer  2000 , and make the computer  2000  function as the managing server  40  may act on the CPU  2012  or the like to make the computer  2000  function as each unit of the managing server  40 . Information processing described in these programs are read in by the computer  2000  to thereby make the computer  2000  function as the movement destination predicting unit  210 , period predicting unit  220 , control unit  280 , demand information acquiring unit  290 , schedule information storage unit  282 , history storage unit  284 , and user information storage unit  286 , which are specific means attained by cooperation between software and various types of hardware resources mentioned above. With these specific means, the unique managing server  40  corresponding to a purpose of use of the computer  2000  in the present embodiment can be constructed by realizing operations on or processing of information corresponding to the purpose of use. 
     Various embodiments of the present invention may be described with reference to block diagrams and the like whose blocks may represent (1) steps of processes in which operations are performed or (2) sections of apparatuses responsible for performing operations. Certain steps and sections may be implemented by dedicated circuitry, programmable circuitry supplied with computer-readable instructions stored on computer-readable media, and/or processors supplied with computer-readable instructions stored on computer-readable media. Dedicated circuitry may include digital and/or analog hardware circuits and may include integrated circuits (IC) and/or discrete circuits. Programmable circuitry may include reconfigurable hardware circuits comprising logical AND, OR, XOR, NAND, NOR, and other logical operations, flip-flops, registers, memory elements, etc., such as field-programmable gate arrays (FPGA), programmable logic arrays (PLA), etc. 
     Computer-readable media may include any tangible device that can store instructions for execution by a suitable device, such that the computer-readable medium having instructions stored therein comprises at least part of an article of manufacture including instructions which can be executed to create means for performing operations specified in the flowcharts or block diagrams. Examples of computer-readable media may include an electronic storage medium, a magnetic storage medium, an optical storage medium, an electromagnetic storage medium, a semiconductor storage medium, etc. More specific examples of computer-readable media may include a floppy disk, a diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an electrically erasable programmable read-only memory (EEPROM), a static random access memory (SRAM), a compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a BLU-RAY (registered trademark) disc, a memory stick, an integrated circuit card, etc. 
     Computer-readable instructions may include assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, JAVA (registered trademark), C++, etc., and conventional procedural programming languages, such as the “C” programming language or similar programming languages. 
     Computer-readable instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing device, or to programmable circuitry, locally or via a local area network (LAN), wide area network (WAN) such as the Internet, etc., to execute the computer-readable instructions to create means for performing operations specified in the flowcharts or block diagrams. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, etc. 
     While the embodiments of the present invention have been described, the technical scope of the invention is not limited to the above described embodiments. It is apparent to persons skilled in the art that various alterations and improvements can be added to the above-described embodiments. In addition, matters explained about a particular embodiment can be applied to another embodiment as long as such application does not cause technological contradictions. It is also apparent from the scope of the claims that the embodiments added with such alterations or improvements can be included in the technical scope of the invention. 
     The operations, procedures, steps, and stages of each process performed by an apparatus, system, program, and method shown in the claims, embodiments, or diagrams can be performed in any order as long as the order is not indicated by “prior to,” “before,” or the like and as long as the output from a previous process is not used in a later process. Even if the process flow is described using phrases such as “first” or “next” in the claims, embodiments, or diagrams, it does not necessarily mean that the process must be performed in this order. 
     EXPLANATION OF REFERENCE SYMBOLS 
     
         
           10 : power network 
           12 : power generation facility 
           14 : stationary battery 
           20 : charge/discharge facility 
           22 : charge/discharge cable 
           30 : vehicle 
           32 : battery 
           40 : managing server 
           42 : processing unit 
           46 : communicating unit 
           48 : storage unit 
           50 : power transaction server 
           80 : user 
           82 : user terminal 
           100 : power transfer system 
           210 : movement destination predicting unit 
           220 : period predicting unit 
           280 : control unit 
           282 : schedule information storage unit 
           284 : history storage unit 
           286 : user information storage unit 
           290 : demand information acquiring unit 
           2000 : computer 
           2010 : host controller 
           2012 : CPU 
           2014 : RAM 
           2020 : input/output controller 
           2022 : communication interface 
           2024 : flash memory 
           2026 : ROM 
           2040 : input/output chip