Abstract:
An electric power demand adjusting system restrains fluctuation in an incentive for adjusting the demand for electric power or fluctuation in an electric power demand adjustment amount caused by an incentive. The system includes a central apparatus, lower units, and computing machine systems of consumers, which are connected through a communication network. The computing machine system of the central apparatus has a device for predicting a demand, a device for determining the electric power demand adjustment amounts to be sent to the lower units on the basis of the predicted demand and information that includes historical data regarding the electric power demand adjustments of the lower units, and a device for transmitting the determined electric power demand adjustment amounts to the lower units. The arrangement restrains the fluctuation in incentives required for adjusting the demand for electric power.

Description:
This application is based on Application No. 2001-281466, filed in Japan on Sep. 17, 2001, the contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electric power demand adjusting system and, more particularly, to the restraint of the fluctuation in an incentive necessary for adjusting the electric power demand or the restraint of the fluctuation in an electric power demand adjustment amount attributable to incentive. 
     2. Description of the Related Art 
     A conventional load-leveling type electric power demand and supply adjusting system disclosed in, for example, Japanese Unexamined Patent Publication No. 2000-333369, stores nighttime electric power, which is in low demand, in a different form of energy and puts the stored energy back into electric power during a daytime time zone when the demand reaches its peak. The system also applies electric power accommodated from another electric power company when there is a shortage of electric power supply. 
     Such a load-leveling type electric power demand and supply adjusting system makes up for the difference between a planned demand value and an actual result value by accommodation from another electric power system demand and supply controller. The system, therefore, has been disadvantageous in that the system is not effective if there is a shortage in absolute supply amount. There has been also a problem in that the system does not have any means to restrain by itself the fluctuation involved in demand and supply adjustment, so that considerable uncertainty remains in company&#39;s revenue management, a project for leveling load, etc. especially in the recent circumstances where demand adjustment is priced in supporting the liberalization of electric power. Hence, there has been a demand for an electric power demand and supply adjusting system suited for the liberalization of electric power. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made with a view toward solving the above problems, and it is an object thereof to provide an electric power demand adjusting system that remains effective even if a shortage in an absolute supply amount occurs and that is capable of successfully dealing with the liberalization of electric power. 
     To this end, according to one aspect of the present invention, there is provided an electric power demand adjusting system for restraining fluctuation in an incentive required for adjusting electric power demand in an electric power system for supplying electric power energy to a plurality of consumers through the intermediary of a plurality of lower units of an electric power supplier that have demand adjusting functions from a central apparatus of the electric power supplier that has an electric power demand adjusting function, the lower units transmitting an adjustment amount for demand adjustment and an amount associated with load conditions, including incentive, so as to make a decision by negotiating with the consumers, the central apparatus being accessed by the plurality of lower units, and the central apparatus, the plurality of lower units, and the computing machine systems of the consumers being linked through the intermediary of a communication network, wherein a computing machine system of the central apparatus includes a device for projecting a demand, a device for determining electric power demand adjustment amounts to the individual lower units on the basis of information that includes a projected situation and history data related to electric power demand adjustment of the plurality of lower units, and a device for transmitting the determined electric power demand adjustment amounts to the plurality of lower units. 
     With this arrangement, the following advantage will be provided. When an attempt is made to perform necessary adjustment of the demand for electric power according to the consumption of electric power by a consumer that varies depending upon natural conditions, such as weather, the location of a consumer, season, a day of the week, time, etc., the incentives necessary for performing such demand adjustment vary from one consumer to another. Furthermore, from a macroscopic viewpoint, the incentives vary also in the lower units involved in a plurality of consumers. The system in accordance with the present invention is advantageous in that the demand adjustment amounts for the individual lower units are determined, taking into account the history data or the like regarding the demand adjustment of a plurality of lower units to accomplish demand adjustment so as to control the influences of the fluctuation in incentives. This enables a central apparatus at, for example, an electric power supplier to reduce the influences of fluctuation in cost involved in incentives. 
     According to another aspect of the present invention, there is provided an electric power demand adjusting system for restraining fluctuation in an electric power demand adjustment amount due to an incentive in an electric power system for supplying electric power energy to a plurality of consumers through the intermediary of a plurality of lower units of an electric power supplier that have demand adjusting functions from a central apparatus of the electric power supplier that has an electric power demand adjusting function, the lower units transmitting an adjustment amount for demand adjustment and an amount associated with load conditions, including incentive, so as to make a decision by negotiating with the consumers, the central apparatus being accessed by the plurality of lower units, and the central apparatus, the plurality of lower units, and the computing machine systems of the consumers being linked through the intermediary of a communication network, wherein a computing machine system of the central apparatus includes a device for projecting a demand, a device for determining incentives to the individual lower units on the basis of information that includes a projected situation and history data related to electric power demand adjustment of the plurality of lower units, and a device for transmitting the determined incentives to the plurality of lower units. 
     With this arrangement, the following advantage will be provided. When an attempt is made to perform necessary adjustment of the demand for electric power according to the consumption of electric power by a consumer that varies depending upon natural conditions, such as weather, the location of a consumer, season, a day of the week, time, etc. or an alternative factor, such as a private power generation by a consumer, the demand adjustment amounts for incentives vary from one consumer to another. Furthermore, from a macroscopic viewpoint, the demand adjustment amounts vary also in the lower units involved in a plurality of consumers. The system in accordance with the present invention is advantageous in that the incentives to be allotted to the individual lower units are determined, taking into account the history data or the like regarding the demand adjustment of a plurality of lower units to accomplish demand adjustment so as to control the influences of the fluctuation in demand adjustment amounts. This enables a central apparatus at, for example, an electric power supplier, to reduce the influences of fluctuation in demand adjustment amounts obtained by a certain incentive. 
     According to yet another aspect of the present invention, there is provided an electric power demand adjusting system for restraining fluctuation in an incentive required for adjusting electric power demand or fluctuation in an electric power demand adjustment amount attributable to an incentive in an electric power system for supplying electric power energy to a plurality of consumers through the intermediary of a plurality of lower units of an electric power supplier that have demand adjusting functions from a central apparatus of the electric power supplier that has an electric power demand adjusting function, the lower units transmitting an adjustment amount for demand adjustment and an amount associated with load conditions, including incentive, so as to make a decision by negotiating with the consumers, the central apparatus being accessed by the plurality of lower units, and the central apparatus, the plurality of lower units, and the computing machine systems of the consumers being linked through the intermediary of a communication network, wherein a computing machine system of the central apparatus includes a device for projecting a demand situation, a device for determining electric power adjustment amounts or incentives to be transmitted to the individual lower units on the basis of information that includes a projected situation and history data related to electric power demand adjustment of the plurality of lower units, and a device for transmitting the determined electric power adjustment amounts or incentives to the plurality of lower units. 
     With this arrangement, the following advantage will be provided. The demand adjustment amounts observed from the lower units involved in a plurality of consumers are classified into two types according to the characteristics of individual consumers, one type being characterized by considerable fluctuation attributable to incentives, while the other type being characterized by considerable fluctuation attributable to changes in demand. The system in accordance with the present invention is advantageous in that one of the above two types, whichever is appropriate, is selected to accomplish demand adjustment so as to control the influences of the fluctuation. This enables a central apparatus at, for example, an electric power supplier to reduce the influences of fluctuation associated with demand adjustment. 
     According to a further aspect of the present invention, there is provided an electric power demand adjusting system for restraining fluctuation in an incentive required for adjusting electric power demand in an electric power system for supplying electric power energy to a plurality of consumers from a demand adjusting apparatus of an electric power supplier that has an electric power demand adjusting function, the demand adjusting apparatus transmitting an adjustment amount for demand adjustment and an amount associated with load conditions, including incentive, so as to make a decision by negotiating with the consumers, the demand adjusting apparatus being accessed by the plurality of consumers, and the demand adjusting apparatus and the computing machine systems of the plurality of consumers being linked through the intermediary of a communication network, wherein a computing machine system of the demand adjusting apparatus includes a device for determining electric power demand adjustment amounts to be transmitted the individual consumers on the basis of information that includes history data related to electric power demand adjustment, and a device for transmitting the determined electric power demand adjustment amounts to the plurality of consumers. 
     With this arrangement, the following advantage will be provided. When an attempt is made to perform necessary adjustment of the demand for electric power according to the consumption of electric power by a consumer that varies depending upon natural conditions, such as weather, the location of a consumer, season, a day of the week, time, etc., then the incentives necessary for demand adjustment vary from one consumer to another. The system in accordance with the present invention is advantageous in that the demand adjustment amounts for the individual consumers are determined, taking into account the history data or the like regarding the demand adjustment of a plurality of consumers to accomplish demand adjustment so as to control the influences of the fluctuation in incentives. This enables an electric power supplier to reduce the influences of fluctuation in cost involved in incentives. 
     According to another aspect of the present invention, there is provided an electric power demand adjusting system for restraining fluctuation in an electric power adjustment amount attributable to an incentive in an electric power system for supplying electric power energy to a plurality of consumers from a demand adjusting apparatus of an electric power supplier that has an electric power demand adjusting function, the demand adjusting apparatus transmitting an adjustment amount for demand adjustment and an amount associated with load conditions, including incentive, so as to make a decision by negotiating with the consumers, the demand adjusting apparatus being accessed by the plurality of consumers, and the demand adjusting apparatus and the computing machine systems of the plurality of consumers being linked through the intermediary of a communication network, wherein a computing machine system of the demand adjusting apparatus includes a device for determining incentives to be transmitted to the individual consumers on the basis of information that includes history data related to electric power demand adjustment, and a device for transmitting the determined incentives to the plurality of consumers. 
     With this arrangement, the following advantage will be provided. When an attempt is made to perform necessary adjustment of the demand for electric power according to the consumption of electric power by a consumer that varies depending upon natural conditions, such as weather, the location of the consumer, season, a day of the week, time, etc. or an alternative factor, such as a private power generation by a consumer, the demand adjustment amounts for incentives vary from one consumer to another. The system in accordance with the present invention is advantageous in that the incentives to be allotted to the individual consumers are determined, taking into account the history data or the like regarding the demand adjustment of a plurality of consumers to accomplish demand adjustment so as to control the influences of the fluctuation in demand adjustment amounts. This enables an electric power supplier to reduce the influences of fluctuation in demand adjustment amounts obtained by a certain incentive. 
     According to another aspect of the present invention, there is provided an electric power demand adjusting system for restraining fluctuation in an incentive required for adjusting electric power demand or fluctuation in an electric power demand adjustment amount attributable to an incentive in an electric power system for supplying electric power energy to a plurality of consumers from a demand adjusting apparatus of an electric power supplier that has an electric power demand adjusting function, the demand adjusting apparatus transmitting an adjustment amount for demand adjustment and an amount associated with load conditions, including incentive, so as to make a decision by negotiating with the consumers, the demand adjusting apparatus being accessed by the plurality of consumers, and the demand adjusting apparatus and the computing machine systems of the plurality of consumers being linked through the intermediary of a communication network, wherein a computing machine system of the demand adjusting apparatus includes a device for determining electric power adjustment amounts or incentives to be transmitted to the individual consumers on the basis of information that includes history data related to electric power demand adjustment, and a device for transmitting the determined electric power adjustment amounts or incentives to the plurality of consumers. 
     With this arrangement, the demand adjustment amounts observed from the demand adjusting apparatus are classified into two types according to the characteristics of individual consumers, one type being characterized by considerable fluctuation attributable to incentives, while the other type being characterized by considerable fluctuation attributable to changes in demand. The system in accordance with the present invention is advantageous in that parameters suited for individual consumers are selected to accomplish demand adjustment so as to control the influences of the fluctuation, as a whole. This enables an electric power supplier to further reduce the influences of fluctuation associated with demand adjustment. 
     Preferably, allocated incentives or demand adjustment amounts to be transmitted to the foregoing lower units or consumers are determined at certain time intervals by computation using the values of such incentives or demand adjustment amounts obtained one previous time on the basis of the history data regarding electric power demand adjustment. To determine an incentive or demand adjustment amount to be allotted to a lower unit or a consumer, an initial value therefor will be required to carry out optimization computation. When the system is operated at certain time intervals, using the value obtained at a closest time as the initial value makes it possible to shorten the time required for the computation. 
     Preferably, allocated incentives or demand adjustment amounts to be transmitted to the foregoing lower units or consumers are determined at certain time intervals by searching for data indicating a situation similar to the current situation on the basis of history data regarding electric power demand adjustment, and by using the data values obtained by the search. An incentive or demand adjustment amount allotted to a lower unit or a consumer is considered to be correlated to an external parameter, e.g., total demand for electric power, temperature, and a day of the week. The system is actuated at given time intervals to accumulate history data, and the accumulated history data is searched for the data that indicates highest similarity to a current situation. By using the search result as the initial value, the time required for the computation can be shortened. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a configuration of an electric power demand adjusting system according to an embodiment of the present invention; 
     FIG. 2 is a flowchart showing an operation of an electric power demand adjusting system according to a first embodiment of the present invention; 
     FIG. 3 is a flowchart showing an operation of an electric power demand adjusting system according to a second embodiment of the present invention; 
     FIG. 4 is a flowchart showing an operation of an electric power demand adjusting system according to a fourth embodiment of the present invention; 
     FIG. 5 shows a configuration of an electric power demand adjusting system according to another embodiment of the present invention; and 
     FIG. 6 is a flowchart showing an operation of an electric power demand adjusting system according to a sixth embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
     The following will illustrate a case where a central apparatus is an upper unit functioning as a demand adjustment center server of an electric power company for adjusting the demand of electric power energy, while a lower unit functions as a demand adjustor server of the electric power company for implementing negotiations with consumers to adjust demand. In the following descriptions, an electric power company is used as an example of an electric power supplier. The electric power supplier, however, will include any person, company, or group engaged in business of supplying electric power, such as an electric power supplier who purchases electric power from an electric power company and supplies the purchased electric power to consumers. 
     FIG. 1 shows a configuration of an electric power demand adjusting system according to an embodiment of the present invention. Referring to FIG. 1, in the electric power demand adjusting system, a demand adjustment center server S is connected with a plurality of (“n” pieces in this case) demand adjustor servers ( 1  through n) CS 1  through CSn through the intermediary of a communication network  109 . The demand adjustment center server S and a plurality of demand adjustor servers ( 1  through n) CS 1  through CSn are constructed of computing machine systems  101 ,  201 , and  301 , respectively. Reference numerals  102  through  108  denote internal functional units of the computing machine system  101 . Similarly, reference numerals  202  through  205  denote the internal functional units of the computing machine system  201 , and reference numerals  302  through  305  denote the internal functional units of the computing machine system  301 . The demand adjustor servers ( 1  through n) CS 1  through CSn are respectively connected to the computing machine systems (not shown) of a plurality of consumers  401  through the intermediary of a communication network (not shown). 
     The computing machine system  101  has an electric power demand projecting unit  102 , an electric power demand adjustment amount setting unit  103 , an electric power demand adjustment incentive setting unit  104 , a parameter setting unit  105  for setting parameters, such as initial values, necessary for the computation of optimization, a demand adjustment optimizing unit  106 , an electric power demand adjustment actual result value management unit  107 , and an input/output control unit  108  connected to the communication network  109 . 
     The computing machine systems  201  and  301  have electric power demand adjustment actual result value measuring units  202  and  302 , respectively, electric power demand adjusting units  203  and  303 , respectively, for negotiating with consumers  401  and  402  to adjust demand, electric power demand adjustment amount &amp; adjustment incentive display units  204  and  304  for the consumers, and input/output control units  205  and  305 , respectively, connected with the communication network  109 . 
     An operation of a first embodiment will now be described with reference to the flowchart shown in FIG.  2 . The steps from  501  through  506  in FIG. 2 are carried out by a demand adjustment center server S. The steps from  508  through  511  are carried out by a plurality of demand adjustor servers CS 1  through CSn. 
     In the steps  501  through  504  carried out by the demand adjustment center server S, the operations are performed to make setting for determining, by computation, the electric power adjustment amounts to be allotted to the demand adjustor servers CS 1  through CSn. The steps can be associated with the units of the demand adjustment center server S shown in FIG.  1 . More specifically, step  501  for projecting the demand for electric power is implemented by the electric power demand projecting unit  102 , step  502  for calculating an electric power adjustment amount D is implemented by the electric power demand adjustment amount setting unit  103 , step  503  for setting a total amount W of a demand adjustment incentive is implemented by the electric power demand adjustment incentive setting unit  104 , and step  504  for setting initial values di_init of the electric power adjustment amounts of demand adjustor servers (i) CS 1  through CSn is implemented by the parameter setting unit  105 . 
     The total amount D of electric power adjustment amount can be set by, for example, taking the amount of electric power generated by a generator having higher power generating cost as a target amount from a projected value of the demand for electric power when leveled load is a goal to be attained. Furthermore, when a projected value of the demand for electric power exceeds a maximum amount of generated electric power, the difference of the projected value from the maximum amount can be set as a load reduction amount D. An incentive may be, for example, a cooperative bonus or an electric power charge discount. The demand adjustment center server S decides beforehand the total amount W that can be used as an incentive. Then, in step  505 , electric power adjustment amounts di to be allotted to the demand adjustor servers (i) CS 1  through CSn that minimize the fluctuation in incentives are determined by, for example, solving the problem for minimization shown below. Among the demand adjustment actual result value data shown in a database  507 , expected values ri of the incentives of the demand adjustor servers and covariances σ of the incentives among the demand adjustor servers are used.            ∑   i   n                       ∑   j   n                       σ   ij   r          d   i          d   j           →   min                   s   .   t   .              ∑   j   n                       r   j          d   j           =   W                            ∑   j   n                     d   j       ≥   D                            d   j     ≥     0                   (       j   =   1     ,   2   ,   ⋯              ,   n     )                                      
     In step  506 , the electric power adjustment amounts di calculated in step  505  are transmitted to the demand adjustor servers (i) CS 1  through CSn through the intermediary of the communication network  109 . The demand adjustor servers that have received in step  508  the electric power adjustment amounts di through the input/output control units  205  and  305 , respectively, carry out negotiations with a plurality of local consumers  401  and  402  through the electric power demand adjustment amount &amp; adjustment incentive display units  204  and  304 , respectively, so as to implement the allotted electric power adjustment amounts di in step  509 . In step  510 , demand adjustment is performed by the electric power demand adjusting units  203  and  303  on the basis of the negotiation results. In step  511 , the actual result values are measured by the electric power demand adjustment actual result value measuring units  202  and  302 . The demand adjustment, although it depends on the contents of contracts by negotiations, can be performed by, for example, adjusting owned loads by consumers themselves or by cutting off the loads by the demand adjustor servers or the like when there is a shortage in an absolute supply amount. The actual results of the demand adjustor servers are sent to the demand adjustment center server S through the intermediary of the communication network  109 , and stored and managed as data by the electric power demand adjustment actual result value management unit  107 , which corresponds to the database  507 . 
     By carrying out the series of operations illustrated by the flowchart shown in FIG. 2 in the configuration shown in FIG. 1, it is possible to minimize the fluctuation in incentives necessary for the adjustment of the demand for electric power so as to adjust the demand. This enables a demand adjustment center server, such as an electric power company, to obviate an unwanted increase in cost by controlling beforehand the fluctuation in revenue as much as possible, the fluctuation being caused by the adjustment of the demand for electric power. 
     Second Embodiment 
     In the first embodiment set forth above, the example has been described in which the adjustment amounts allotted to the demand adjustor servers are used as decision variables, and the operations are performed according to the flowchart shown in FIG. 2 so as to minimize the fluctuation in the expected values of the total incentive amounts necessary for the demand adjustment. In the second embodiment, the descriptions will be given of a case where the operations will be performed using, as the decision variables, incentives wi allotted to the demand adjustor servers (i) CS 1  through CSn. 
     The operations are performed by a system having the configuration shown in FIG. 1 according to the flowchart shown in FIG.  3 . The same operation procedure used in the first embodiment shown in FIG. 2 will be used. In step  604  shown in FIG. 3, the incentive wi of each demand adjustor server is set, and in step  605 , the value of wi that will minimize the fluctuation in the demand adjustment amount can be determined by, for example, solving the optimization problem shown below. In the following expression, qi denotes an expected value of a demand adjustment amount per unit incentive in each demand adjustor server, and σ q  denotes a covariance related to q.            ∑   i   n                       ∑   j   n                       σ   ij   q          w   i          w   j           →   min                   s   .   t   .              ∑   j   n                     w   j         =   W                            ∑   j   n                       w   j          q   j         ≥   D                            w   j     ≥     0                   (       j   =   1     ,   2   ,   ⋯              ,   n     )                                      
     Thus, it is possible to achieve demand adjustment by minimizing the fluctuation in the demand adjustment amount obtained by a certain incentive. This enables a demand adjustment center server S, such as an electric power company, to more securely expect a demand adjustment amount by a certain incentive so as to plan more accurate demand adjustment. 
     Third Embodiment 
     As described in the second embodiment in which the operations were performed according to the flowchart of FIG. 3 by the configuration shown in FIG. 1, the allotment of incentives to the demand adjustor servers (i) CS 1  through CSn to minimize the fluctuation in the demand adjustment amount obtained by a certain incentive will be considered. In this case, if, for instance, it is discussed to purchase an amount of electric power corresponding to the demand adjustment amount based on a certain incentive from another electric power company or IPP, then it is possible to make a decision by comparing the incentive and the cost of purchase from another electric power company. 
     Thus, suspending its costly power generator that can be replaced by the purchase of electric power leads to reduced cost. In this case, a decision is made only on the purchase, so that no actual demand adjustment is performed or partial demand adjustment is performed according to a certain amount of purchased electric power. 
     Fourth Embodiment 
     In the first embodiment set forth above, the example has been described in which the adjustment amounts allotted to the demand adjustor servers are used as decision Variables, and the operations are performed according to the flowchart shown in FIG. 2 so as to minimize the fluctuation in the expected values of the total incentive amounts necessary for the demand adjustment. In the fourth embodiment, the descriptions will be given of a case where desirable parameters are selected in accordance with the local demand characteristics of the demand adjustor servers (i) CS 1  through CSn in order to restrain the fluctuation involved in demand adjustment. The fourth embodiment shares the same configuration shown in FIG. 1, and the operation thereof follows the flowchart shown in FIG.  4 . 
     Referring to FIG. 4, the operations are basically formed of a combination of the operations of the foregoing first and second embodiments. Steps  805  and  807  and steps  810  through  813  correspond to steps  605  and  606  and steps  608  through  611  shown in FIG.  3 . Similarly, steps  806  and  808  and steps  815  through  818  correspond to steps  505  and  506  and steps  508  through  511  shown in FIG.  2 . 
     In step  804 , the characteristics of all consumers associated with demand adjustor servers (i) CS 1  through CSn are classified into group A that shows considerable fluctuation in demand adjustment amounts and group B that shows considerable fluctuation in incentives. In step  805 , the incentives to be allotted are determined by computation so as to reduce the fluctuation in demand adjustment amounts for group A. In step  806 , the demand adjustment amounts to be allotted are determined by computation so as to reduce the fluctuation in incentives for group B. Thus, the fluctuation factors involved in demand adjustment can be controlled. 
     Fifth Embodiment 
     The foregoing embodiments illustrate the cases where the central apparatus is the upper apparatus, namely, the demand adjustment center server at an electric power company that adjusts the demand for electric power energy, while the lower units are the demand adjustor servers at an electric power company that perform the negotiations for demand adjustment with consumers. The present invention, however, can be also applied to a case where the central apparatus is a demand adjustor server at an electric power company, while the lower units are the servers at consumers, as shown in FIG.  5 . 
     FIG. 5 shows the configuration of an electric power demand and supply adjustment system according to another embodiment of the present invention. Like the one shown in FIG. 1, the electric power demand adjusting system according to this embodiment has a demand adjustor server CS connected to a plurality of (“n” pieces in this embodiment) consumer servers ( 1  through n) DM 1  through DMn via a communication network  1109 . The demand adjustor server CS and the plurality of consumer servers ( 1  through n) DM 1  through DMn are constituted by computing machine systems  1101 ,  1201 , and  1301 , respectively. Reference numerals  1102  through  1108  denote internal functional units of the computing machine system  1101 . Similarly, reference numerals  1202  through  1205  denote the internal functional units of the computing machine system  1201 , and reference numerals  1302  through  1305  denote the internal functional units of the computing machine system  1301 . 
     The computing machine system  1101  has an electric power demand projecting unit  1102 , an electric power demand adjustment amount setting unit  1103 , an electric power demand adjustment incentive setting unit  1104 , a parameter setting unit  1105  for setting parameters, such as initial values, necessary for the computation of optimization, a demand adjustment optimizing unit  1106 , an electric power demand adjustment actual result value management unit  1107 , and an input/output control unit  1108  connected to the communication network  1109 . 
     The computing machine systems  1201  and  1301  have electric power demand adjustment actual result value measuring units  1202  and  1302 , respectively, electric power demand adjusting units  1203  and  1303 , respectively, electric power demand adjustment amount &amp; adjustment incentive display units  1204  and  1304 , respectively, and input/output control units  1205  and  1305 , respectively, connected with the communication network  1109 . 
     The above units correspond to those units shown in FIG.  1 . 
     Like advantages can be obtained by performing the operations described in the foregoing embodiments by the demand adjustor server CS and the consumer servers ( 1  through n) DM 1  through DMn shown in FIG.  5 . More specifically, the demand adjustor server CS will be able to use the data regarding the history of the negotiations with the consumer servers ( 1  through n) DM 1  through DMn to allot demand adjustment amounts to the consumers so as to minimize the fluctuation in a total incentive amount. Furthermore, the demand adjustor server CS will be able to use the data regarding the history of the negotiations with the consumer servers ( 1  through n) DM 1  through DMn to provide the consumers with incentives so as to minimize the fluctuation in demand adjustment amounts. 
     Thus, the fluctuation can be controlled even at lower levels in the demand adjustor server CS and the consumer servers ( 1  through n) DM 1  through DMn, permitting more accurate demand adjustment to be accomplished. 
     Sixth Embodiment 
     Another case will be described where the central apparatus is a demand adjustment center server at an electric power company, which acts as an upper apparatus for adjusting the demand for electric power energy, while a lower unit is a demand adjustor server at the electric power company for negotiating with consumers to perform adjustment of their demands, as shown in FIG.  1 . It is obvious that the combination of the demand adjustor server and the consumer servers, shown in FIG. 5, may be used for the same purpose. In this embodiment, the demand adjustment amounts to be transmitted to demand adjustor servers are computed at certain time intervals. 
     In a configuration similar to the one shown in FIG. 1, an operation is performed according to the flowchart shown in FIG.  6 . Steps  701  through  706  in FIG. 6 correspond to steps  501  through  506  in FIG. 2, and steps  708  through  711  in FIG. 6 correspond to steps  508  through  511  in FIG.  2 . 
     In the operation, the actual result value data regarding demand adjustment is stored at each time t in succession. An appropriate initial value should be given to perform the computation in step  705  by using the data. In the computation performed at time t, taking out data di(t−1), which is the previous data obtained one time before, from a database  707  to set this data as the initial value for the computation makes it possible to set a value close to a solution to be converged to, allowing the required computation time to be shortened. To determine an incentive or demand adjustment amount to be allotted to the demand adjustor server at the electric power company or a consumer, an initial value therefor will be required to carry out optimization computation. When the system is operated at certain time intervals, performing the above operation permits the time required for the computation to be shortened by using the value obtained at a closest time as the initial value. 
     Measuring and storing actual demand record data and closely correlated external parameters together leads to shortened computation time. More specifically, a situation closest to the current time t is searched for through the actual result data stored in the database  707  by using a stored external parameter as a clue, and the search result is set as the initial value for computation at time t. Thus, an optimum value can be selected from the actual result data as the value close to the solution to be converged to, so that efficient computation can be expected, leading to reduced computation time. An incentive or demand adjustment amount allotted to a demand adjustor server of an electric power company or a consumer is considered to be correlated to an external parameter, e.g., total demand for electric power, temperature, and a day of the week. Performing the above operation makes it possible to actuate the system at given time intervals to accumulate history data, and to search the accumulated history data for the data that indicates highest similarity to a current situation. By using the search result as the initial value, the time required for the computation can be shortened.