1
DESCRIPTION
ELECTRIC POWER MANAGEMENT SYSTEM AND ELECTRIC POWER
MANAGEMENT METHOD
5
TECHNICAL FIELD
[OOO 11
The present invention relates to an electric power management system and an electric
power management method for managing an electric power system to which a photovoltaic
10 (PV: Photovoltaic) system is connected.
BACKGROUND ART
[0002]
The so called environment and energy problem have become widely recognized due to
15 actual evidence of global warming resulting from carbon dioxide emissions, due to peak oil
theory and due to energy security problem caused by the growth of developing and middle
developed countries.
[0003]
In order to realize a sustainable society, mass spreading of photovoltaic generation, wind
20 power generation and other renewable electric power generation has gained trends throughout
the world. However, increase of renewable electric supply systems, in particular, the
widespread introduction of PV systems causes "surplus electricity issue", which begins to be
recognized as an emerging problem, and measures against this problem are needed.
[0004]
2 5 The surplus electricity issue is the problem in which many consumers who has a PV
system cannot make full use of the generated power from the PV system sell surplus electricity
to the electric power company, resulting in an excessive power supply in the total electric power
system. In the prior art, if surplus electricity from electric power generation of a PV system is
generated, the amount of electric power that is generated is controlled by controllable power
30 generation facilities such as thermal power plants and the like to thereby optimize the electric
power supply in the electric power system and balance the power supply with the amount of
electric power that is needed. However, if, in the future, PV systems spread on a large scale,
the amount of surplus electricity is expected to exceed the regulating capacity of the thermal
power plants etc., and it is recognized that at worst, an imbalance between power supply and
demand will lead to power failure, causing a serious problem.
[OOOS]
Various kinds of methods have been conventionally investigated, as measures to resolve
5 this surplus electricity issue. For example, these are some known methods: (1) a method to
prevent the PV system from generating electric power at a specific date and time (e.g., 11 a.m.
to 3 p.m. in the day of the early-May holiday season in Japan) during which of power
consumption is low, based on the calendar; (2) a method to prevent multiple PV systems from
generating electric power at the same time by sending a control signal using FM broadcasting;
10 (3) a scheduling method that prevents a PV system, in advance, from generating electric power
in the power conditioner (PCS) equipped in the PV system; and the like.
[0006]
However, all of these methods are to avoid the occurrence of surplus electricity by
preventing the amount of electric power generated by the PV system, aiming at a technique for
15 operating the PV system at a power level equal to or lower than its power generation capability.
This is a waste of the power generation capability of the PV system, and this is not an efficient
method for using a PV system that is to be introduced for the purpose of realizing a sustainable
society.
[0007]
20 For this reason, another technique has been researched in which electric power is
consumed by the user such that the electric power generated by the PV system does not cause
reverse power flow at the moment when the PV system initiates control to prevent the
generation of electric power.
[0008]
2 5 In general, however, surplus electricity is generated at a time when consumer
requirements for electricity are low for facilities equipped with the PV system, and the
consumer may be forced to use electricity that helshe does not need and there is concern that
this inconvenience may alienate consumers.
[0009]
30 Further, patent document 1, for example, proposes a control method of charging and
discharging for efficiently storing surplus electricity to the storage battery of the consumer.
However, the storage battery is still expensive at present, and it is conceivable that spread of a
sufficient number of storage batteries or storage batteries having high enough capacity to solve
the above surplus electricity issue will take a considerable time.
[OO 1 01
Though it is not a technique to present a solution to the surplus electricity problem,
patent document 2 discloses an electric power system having a low-voltage system to which the
5 consumers that are equipped with the distributed generator is connected, and a high-voltage
system to which the low-voltage system is connected. Patent document 2 discloses that the
low-voltage system is separated from the high-voltage system when a problem occurs in the
high-voltage system, and that the electric power generated by the distributed generators is
shared between the consumers in the low-voltage system.
10 [OOll]
Of the above-described electric power systems in the background art, the technique that
avoids generation of surplus electricity by preventing electric power generation in the PV
system is the same as eliminating green electric power generated by the PV system, and this is
not an efficient method for using a PV system that is to be introduced for the purpose of
15 realizing a sustainable society.
[OO 121
Further, the technique in which electric power is consumed by the user at the moment
when the PV system initiates control to prevent the generation of electric power, the consumer
may be forced to use electricity that helshe does not need and there is concern that this
20 inconvenience may alienate consumers.
[00 131
Moreover, the technique for storing surplus electricity in a storage battery as described
in patent document 1 requires consumers to have both a PV system and a storage battery, so that
the technique is costly for the consumers.
2 5
RELATED ART DOCUMENTS
PATENT DOCUMENT
[00 141
Patent Document 1 : Japanese Patent Laid-Open No. 2009-284586
30 Patent Document 2: Japanese Patent Laid-Open No. 2008-125290
SUMMARY
[00 1 51
It is therefore an object of the present invention to provide a power control system and
an electric power management method which contribute to solving the surplus electricity
problem in an electric power system with a photovoltaic system connected thereto.
[00 1 61
5 In order to achieve the above object, the electric power management system according
to an exemplary aspect of the present invention is an electric power management system for
managing an electric power system having, at least, one or more first consumers having a
photovoltaic system, and at least, one or more second consumers having a controllable load,
connected thereto, and is constructed such that the first consumer and the second consumer
10 include a consumer energy management system for controlling the amount of electric power
generated by the photovoltaic system and/or for controlling the controllable load,
the electric power management system includes a server apparatus that is connected to
the consumer energy management systems so as to be able to exchange data via a network,
the server apparatus, based on the amount of surplus electricity that is expected to be
15 generated in a predetermined time slot on a predetermined date on which surplus electricity of
the photovoltaic system is expected to be generated and based on the expected amount of
electric power that the second consumer needs in the predetermined time slot on the
predetermined date, which are notified from the consumer energy management systems,
combines the first consumer and the second consumer so that the amount of electric power
20 needed by the second consumer in the predetermined time slot on the predetermined date will
be equal to or greater than the amount of surplus electricity generated at the first consumer, and
makes the controllable load consume the surplus electricity generated at the first consumer by
controlling the consumer energy management system of the second consumer.
[OO 1 71
2 5 The electric power management method according to an exemplary aspect of the present
invention is an electric power management method for managing an electric power system
having, at least, one or more first consumers having a photovoltaic system, and at least, one or
more second consumers having a controllable load, connected thereto, is implemented such that
a consumer energy management system equipped for the first consumer to control the amount
30 of electric power that is generated by the photovoltaic system andlor to control the controllable
load, notifies the amount of surplus electricity that is expected to be generated in a
predetermined time slot on a predetermined date on which surplus electricity of the
photovoltaic system to a server apparatus,
wherein, a consumer energy management system equipped for the second consumer
notifies the amount of electric power that is expected to be needed by the second consumer in
the predetermined time slot on the predetermined date to the server apparatus,
wherein, the server apparatus, based on the amount of surplus electricity that is expected
5 to be generated in a predetermined time slot on a predetermined date on which surplus
electricity of the photovoltaic system is expected to be generated and based on the expected
amount of electric power that the second consumer needs in the predetermined time slot on the
predetermined date, which are notified from the consumer energy management systems,
combines the first consumer and the second consumer so that the amount of electric power
10 needed by the second consumer in the predetermined time slot on the predetermined date will
be equal to or greater than the amount of surplus electricity generated at the first consumer, and
makes the controllable load consume the surplus electricity generated at the first consumer by
controlling the consumer energy management system of the second consumer.
15 BRIEF DESCRIPTION OF THE DRAWINGS
[0018]
[FIG. I]
FIG. 1 is a block diagram showing one configurational example of an electric power
system of the present invention.
20 [FIG.2]
FIG. 2 is a block diagram showing one configurational example of a central server
shown in FIG. 1.
[FIG. 31
FIG. 3 is a sequence diagram showing the procedure of an electric power management
25 method of the present invention.
EXEMPLARY EMBODIMENT
[00 1 91
Next, the present invention will be described with reference to the drawings.
30 [0020]
In the electric power management system of the present invention, consumers (first
consumers) An (n is a positive integer) having a PV system and consumers (second consumers)
Bn (n is a positive integer) having a controllable load are combined so that surplus electricity
from the PV systems of consumers An is consumed by the controllable loads of combined
consumers Bn. The most simple example of a combination is to combine consumers An and
Bn that are to be operated in cooperation on a one-to-one,
[002 11
5 Combination of consumer An and consumer Bn is designated based on the amount of
surplus electricity expected to be generated in consumer An in a predetermined time slot on a
predetermined date on which surplus electricity of the PV system is expected to be generated
and the expected amount of power needed by the controllable load of consumer Bn and assured
in the predetermined time slot of the predetermined date so that the amount of surplus
10 electricity will become equal to the amount of power needed by the controllable load or that the
amount of power needed by the controllable load will be greater than the amount of surplus
electricity. When consumer Bn has a PV system, the combination with consumer An may and
should be determined based on the amount of power needed by consumer Bn (=the amount of
electric power needed by the controllable load - the amount of electric power generated by the
15 PV system). In the following description, to make the description simple, it is assumed that
consumer Bb has no PV system but only has a controllable load.
[0022]
The reason that combination of consumer An and consumer Bn is determined based on
the expected amount of surplus electricity of consumer An that is to be generated and the
20 expected amount of power needed by the controllable load of consumer Bn in a predetermined
time slot on a predetermined date, is to avoid forcible consumption of power such as
excessively consuming power by consumer An alone in order to use up surplus electricity to
assure QOL (Quality of Life).
[0023]
2 5 Also, determination of combination of consumer An and consumer Bn based on the
expected amount of surplus electricity of consumer An and the expected amount of power
needed by the controllable load of consumer Bn in a predetermined time slot on a
predetermined date, makes it possible for the system operator such as an electric power
company that manages the entire electric power system to precisely predict the power
30 requirements in the entire system based on the clusters of combined consumers (consumers An,
Bn), hence, the power company can prepare the controllable power generation facilities (such
as a thermal power plant etc.) thereof in accordance with the expected needs of electric power.
Further, on that day (the aforementioned predetermined date), other consumers An and Bn may
be added or omitted in order to satisfy the relation: the amount of electricity generated by the
PV system 5 the amount of electric power that is needed, so that control over the
supply-demand balance in the entire electric power system can be made simple.
[0024]
5 The amount of surplus electricity generated by the PV system and the amount of electric
power needed by the controllable load are calculated by a well-known HEMS (Home Energy
Management System: Consumer energy management system) installed, for example at the
consumer site and notified through a network to CEMS (Central Energy Management System:
which will be referred to hereinbelow as central server) to which the HEMS of each consumer
10 is connected. The central server selects consumers An and Bn to be operated in cooperation,
from the amounts of surplus electricity in a predetermined time slot on a predetermined date,
notified from consumers An and the amounts of power needed by the controllable loads,
notified from consumers Bn. It is desirable that energy storage (ES: Energy Storage), such as,
for example storage batteries and heat pump water heaters that can store electric and thermal
15 energies, and the like, and storage batteries for electric vehicles, etc, is used as the controllable
load. The electric power needs (the amount of electric power demanded by the controllable
load) of consumer Bn may be declared via a bidding process for the amount of surplus electicity
of consumer An that is expected to be generated.
[0025]
2 0 FIG. 1 is a block diagram showing one configurational example of an electric power
system of the present invention.
[0026]
As shown in FIG. 1, the electric power system of the present invention includes, at least,
one or more consumers An having a PV system, at least, one or more consumers Bn having a
25 controllable load CL, and central server (server apparatus) 120 connected to consumers An and
Bn so as to communicate with each of them via network 11 0.
[0027]
Consumers An and Bn include an HEMS for controlling the amount of electric power
generation by a PV system and/or a controllable load CL so that data is exchanged between
30 central server 120 and the HEMS of each of consumers An and Bn via network 110 using wired
communication means such as the well-known internet, PCL (Power Line Communications),
optical fibers, etc., or wireless communication means such as Zigbee, WiFi, WiMax and the like.
Here, HEMS may employ any device as long as it can control the amount of electric power
generated by the PV system and as long as it can control controllable load CL, and can
exchange data with central server 120. For example, HEMS may be realized by an
information processor (computer) or the like including an electric power sensor and well-known
communicating functionality.
5 [0028]
The PV system is a well-known electric power generation system including, for example,
a PV panel for generating electricity using solar energy and a PCS (Power Conditioning
System) that converts the d.c. power generated by the PV panel into a.c. power suited to electric
power system 100 and supplies the a.c. power to a distribution line.
10 [0029]
Controllable load CL is a device in which power consumption can be externally
controlled and which can store energy like a heat pump water heater such as EcoCute etc., an
electric vehicle, a plug-in hybrid electric vehicle, a stationary storage battery and the like.
Controllable load CL may include electric power devices such as an automatic dishwasher,
15 washing machine and the like, which are relatively unlikely to lose usefulness (lose QoL) if the
device is not operated by consumer's intention.
[0030]
Central server 120 can be realized by a computer shown in FIG. 2, for example.
[003 11
20 The computer shown in FIG. 2 includes processing apparatus 10 for executing a
predetermined process in accordance with a program, input device 20 for inputting a command,
information, etc. to processing apparatus 10, and output device 30 for outputting the processed
result from processing apparatus 10.
[0032]
2 5 Processing apparatus 10 includes CPU 11, main storage 12 for temporarily storing
information necessary for the process in CPU 11, recording medium 13 on which the program
for executing the process of the present invention is recorded, data accumulation unit 14 in
which the aftermentioned power generation history data etc. is stored, memory control interface
unit 15 for controlling data transfer between main storage 12, recording medium 13 and data
30 accumulation device 14, I10 interface unit 16 as an interface device for input device 20 and
output device 30, and communication control device 17 for exchanging data with the HEMSs of
consumers An and Bn, all these being connected by bus 18.
[0033]
Processing apparatus 10 executes the aftermentioned process as central server 120, in
accordance with the program recorded on recording medium 13. Recording medium 13 may
be a magnetic disk, semiconductor memory, optical disk or any other recording medium. Data
accumulation device 14 does not need to be provided inside processing apparatus 10 but may be
5 given as a separate device.
[0034]
Here, if the HEMS is realized by an information processing device, the information
processing device can be realized by a configuration similar to the computer shown in FIG. 2,
except using a different program.
10 [0035]
Next, the electric power management method of the electric power system of the present
invention will be described with reference to the drawings.
[0036]
FIG. 3 is a sequence diagram showing the procedure of the electric power management
15 method of the present invention.
[0037]
Here, FIG. 3 shows a state in which data is exchanged between one consumer cluster (a
pair of consumer An and consumer Bn) and central server 120. However, in reality, central
server 120 exchanges data with many consumer clusters.
20 [0038]
The HEMS of consumer An measures the amount of electric power generated by the PV
system every predetermined unit time and stores the measurements as power generation history
data. This power generation history data may be stored in the HEMS of consumer An or may
be stored in central server 120. The power generation history data may be stored in units of a
25 day, a week, a month or the like. However, in view of the fact that one PV system has a
lifetime of about 20 years, it is desirable that the data should be stored continually from the start
of electric power generation by the PV system until the PV system is no longer usable. The
aforementioned unit time is desirably set as short as possible taking into account that the
amount of power generated by the PV system varies depending upon the weather. However,
30 since the shorter the unit time the more frequent the data should be collected, which results in a
large amount of data, in order to follow the rules on balancing the electric power system 100,
the unit time should be set as short as one minute at a minimum, and may be set as long as 30
minutes, for example. Here, it is preferable that the aforementioned power generation history
data be stored in a corresponding manner to the sunshine data installed in a separate system
(business purpose PV system or the like) collected on central server 120, based on the location
of the consumer.
[0039]
5 As shown in FIG. 3, the HEMS of consumer An, based on the past sunshine data and
sunshine predicted data stored in central server 120 and the aforementioned power generation
history data, calculates the expected amount of electric power generation CP(t) in a
predetermined time slot on a predetermined date at which generation of surplus electricity or
prevention of electric power generated by the PV system is expected, and transmits the result to
10 central server 120.
[0040]
As a way to find the predetermined date and predetermined time slot in which
preventing the generation of electric power can be expected, it is thought that an electric power
company, a whether forecast agency, and a third agency, that each predict the amount of electric
15 power that may be generated by the PV system or the like, will notify central server 120.
[0041]
The HEMS of consumer An determines the amount of electric power Yh that is needed
by controllable load CL of consumer An in the predetermined time slot on the predetermined
date, before the aforementioned predetermined date, for example, on the previous day of the
20 aforementioned predetermined date. Similarly, the HEMS of consumer Bn determines the
amount of electric power YBn that is needed by controllable load CL of consumer Bn in the
predetermined time slot on the predetermined date, on the previous day of the aforementioned
predetermined date.
COO421
25 As to the amounts of demanded electric power Yh and YB~in, order for consumer An
andlor Bn not to be forced to use up hot water boiled by a heat pump water heater or not to be
forced to drive the electric vehicle and thus reduce the amount of accumulated electricity on the
storage battery so as to ensure the charging capacity by an electric vehicle, etc., each of the
amounts of energy (the amount of electric power) storable in controllable loads CL is measured
30 at a point of time T on the previous day after consumer An and Bn's bedtime, for example, to
set up as the amount of electric power Yh and YB,, that is needed by controllable loads CL in
the predetermined time slot on the next day (the predetermined date). The HEMSs of
consumers An and Bn respectively transmit the determined amount of electric power Yh and
YB, that is needed to central server 120 via network 11 0.
[0043]
Upon receiving the aforementioned CP(t), Yh and YBn from each of the consumers,
center server 120 selects consumer An and consumer Bn that satisfy the relation CP(t)<=
5 Yh+Y~, to determine the combination (consumer cluster) of consumers An and Bn to be made
to cooperate. In this case, it is preferable that consumer An and consumer Bn that are to be
combined be selected within the consumers connected in the same pole transformer in order to
minimize the transmission loss of the surplus electricity (=CP(t)-Yh) from consumer An to
consumer Bn.
10 [0044]
There is another reason why the cluster is preferably formed of consumers connected to
the same pole transformer. When surplus electricity is reverse flowed from consumer An to
the pole transformer so that the electric power is used at consumer Bn located beyond the pole
transformer, there is a risk of a new problem in which the reverse power flow from consumer
15 An raises the distribution voltage above, and deviates from, the proper range (the proper range
of the distribution voltage is 101*6V for the standard voltage of 100 V, and 202*20V for the
standard voltage of 200 V in Japan). This new problem can also be solved by forming a
cluster of consumers connected to the same pole transformer.
[0045]
20 When it is impossible to select consumers An and Bn to be operated in cooperation,
from those connected to the same pole transformer, central server 120 determines that a
combination of consumers An and Bn be made to cooperate, from among those connected to the
same distribution feeder line, as the second best combination. The distribution feeder line
indicates a high-voltage power line for transmitting high-voltage power (e.g., 6.6kV) output
25 from the distribution transformer of a transformer substation.
[0046]
When it is impossible to select consumers An and Bn that are to be operated in
cooperation, from among those connected to either the same pole transformer or the same
distribution feeder line, central server 120 may determine a combination of consumers An and
30 Bn that are to be operated in cooperation, from among those connected to the same distribution
transformer substation. Further, the server may determine a combination of consumers An and
Bn that are to be operated in cooperation, from among those connected to the different
distribution transformer substations. If the distance between the connection points of
consumer An and consumer Bn is large, it cannot be said that electric power from consumer An
will actually supplied to the combined consumer Bn, but balance between supply and demand
may and should be coordinated in a wide area including the consumer cluster.
[0047]
5 After determination of the combination (consumer cluster) of consumers An and Bn that
are to be operated in cooperation, central server 120 prepares an expected pattern of electric
power to be generated by the PV system of consumer An in the predetermined time slot on the
aforementioned predetermined date, based on the aforementioned power generation history data
of consumer An. The pattern of electric power that is expected to be generated is determined
10 using, for example, the power generation history data in the predetermined time slot on the
aforementioned predetermined date in the previous year, or the average of the power generation
history data in the predetermined time slot in the past one week, or the like, taking into account
the weather forecast and sunshine prediction in the predetermined time slot on the
predetermined date. The final pattern of electric power that is expected to be generated may
15 be created from a ratio R(t) = P(t)/ CP(t), the ratio of expected amount of electric power that is
expected to be generated per unit time, P(t), to the integrated value of the amount of electric
power that is expected to be generated in the predetermined time slot, CP(t).
[0048]
Though the present exemplary embodiment was shown by taking an example where the
20 pattern of power that is expected to be generated is prepared based on the power generation
history data for every consumer An, the pattern of electric power that is expected to be
generated may be prepared by other methods. For example, by referencing the prediction of
electric power that is to be generated by the PV system on the aforementioned predetermined
date, presented from the electric power company or the like, an electric power generation
25 pattern similar to the referenced pattern (for example, in a case of a PV system having a power
output of 3 kW, an electric power generation pattern having the same pattern form with its peak
power adjusted to about 3 kW) may be used as a pattern of electric power that is expected to be
generated by consumer An.
[0049]
30 The pattern of electric power that is expected to be generated in the aforementioned
predetermined time slot is used to prepare the pattern of the amount of stored electric (thermal)
energy to be assigned per unit time to controllable load CL in the predetermined time slot on the
aforementioned predetermined date.
[0050]
Specifically, central server 120 determines the amount of stored electric (thermal)
energy Yh(t)+YBn(t) to be assigned per unit time to controllable CL whose total amount of
stored electric (thermal) power in the predetermined time slot on the aforementioned date is the
5 amount of electric power Yh and YBn that is needed by the controllable loads, each notified
from the consumers. Here, Yh(t)+YBn(t) is set to be equal to P(t) or greater than P(t). Then,
central server 120 notifies the HEMS of consumer An of the amount of stored electric (thermal)
power Yh(t) to be assigned per unit time to controllable load CL in the predetermined time slot
on the aforementioned predetermined date and notifies the HEMS of consumer Bn of the
10 amount of stored electric (thermal) power YBn(t) to be assigned per unit time to controllable
load CL in the predetermined time slot on the aforementioned predetermined date.
The HEMSs of consumers An and Bn control controllable loads CL so as to consume
power in the predetermined time slot on the predetermined date, in accordance with Yh(t) and
15 Yen(t) indicated by central server 120.
[0052]
At this time, central server 120 may modify as appropriate the amount of stored electric
(thermal) power per unit time to be assigned to each of controllable loads CL, Yh(t)+Y~n(t),
based on CPx(t), the actual measurement of the total amount of electric power that has been
20 generated, an that has been obtained by measuring and adding up the amounts of generated
power Px(t) on the predetermined date, notified from the HEMS of consumer An. The amount
of stored electric (thermal) power Yh(t)+YBn(t) is preferably modified by using a sufficiently
short time interval a (e.g., one minute interval) as the unit time.
[0053]
2 5 Yh(t)+YBn(t), the amount of stored eclectic (thermal) power per unit time a assigned to
each controllable load CL can be conceivably modified in the following method, based on the
relationship between CPx(t), CYh(t) and CYBn(t).
(a) In a case of CPx(t) < CYh(t):
In this case, the controllable load CL of consumer An stores the electric power (CPx(t))
30 actually generated by the PV system while no electric power is stored in the controllable load
CL of consumer Bn.
[0054]
The HEMS of consumer An notifies the shortage of electricity to be stored in
controllable load CL of consumer An, CYh(t) - CPx(t) as the shortage of charging Yh-(t), to
central server 120. The HEMS of consumer Bn notifies the shortage of electricity to be stored
in controllable load CL of consumer Bn, CYB,(t) as the shortage of charging YB~-(~to) c, entral
server 120.
5 (b) In a case of CYh(t) < CPx(t) < CYh(t) + CYBn(f):
In this case, the controllable load CL of consumer An stores electricity in accordance
with YAn(t)a, nd the controllable load CL of consumer Bn stores electricity of CPx(t)- CYh(t).
[0055]
The HEMS of consumer Bn notifies the shortage of electricity to be stored in
10 controllable load CL of consumer Bn, CYh(t)+ Cy~,(t)- CPx(t) as the shortage of charging
YBn-(t)t,o central server 120.
(c) In a case of CPx(t) > CYh(t) + CYBn(f):
In this case, the controllable load CL of consumer An stores electricity in accordance
with Yh(t), and the controllable load CL of consumer Bn stores electricity in accordance with
15 YBn(f).
[0056]
The HEMS of consumer An notifies the surplus electricity by the PV system,
CPX(~)-C(Y~(~)+Yt~o ,c(e~n)tr}a l server 120. Central server 120, based on the notice from
the HEMS of consumer An, assigns a task of storing the surplus electricity
20 CPx(t)-C(Yh(t)+YBn(t)} to the controllable load CL of a consumer that is located nearest to the
consumer An in electric power system 100 and that is notified of the shortage of charging
YBn-(t).
[0057]
Here, in the electric power system of the present exemplary embodiment, since there are
25 many combinations (consumer clusters) of consumer An and consumer Bn) (such as consumers
A1 and B 1, consumers A2 and B2, . . . , and the like), if all the consumer clusters perform
operations of storing electric (thermal) power to controllable loads at the same time, large
imbalance between power supply and demand in unit time a will occur. For this reason, it is
preferable that central server 120 mitigate the imbalance between supply and demand by
30 shifting the timing of the operation of storing electrical (thermal) power to the controllable
loads CL of each consumer cluster from the others. The shift time of electrical (thermal)
storage operation of each consumer cluster may and should be set to be sufficiently shorter, for
example, as short as 10 seconds or 1 minute, than the duration (usually 30 minutes) required by
6 15
the aforementioned rules on balancing the electric power system.
[0058]
Though the description heretofore of the present exemplary embodiment was given
taking an example in which a consumer cluster is formed by combining one consumer An
5 having PV and one consumer Bn having controllable load CL, a consumer cluster may be
formed by combining one consumer An with a plurality of consumers Bn or by combining a
plurality of consumers An with one consumer Bn.
[0059]
Further, it is not necessary that the above amount of used electric power Yh(t) + Y~n(t)
10 and the amount of electric power that is expected to be generated should strictly satisfy the rules
on balancing the electric power system at any time. That is, all the surplus electricity that is
generated at consumer An does not need to be consumed by consumer Bn. It is sufficient that
central server 120 can combine consumers An and Bn appropriately so as not to increase
surplus electricity that is generated in all the consumers in each consumer cluster.
15 [0060]
According to the electric power system of the present exemplary embodiment, consumer
An having a PV system and a consumer Bn having a controllable load CL without a PV system
are combined so that the amount of electric power demand of controllable load CL will be equal
to or greater than the surplus electricity generated at consumer An, to thereby let the
20 controllable load CL consume the surplus electricity that is generated at consumer An, thus
making it possible to mitigate preventing electric power from being generated by the PV system
and to prevent reducing surplus electricity that is generated in electric power system 100.
[006 11
Accordingly, it is possible to provide an electric power system that contributes to
25 solving the problem of surplus electricity in electric power system 100 in which many reusable
electric power sources are connected.
[0062]
This technology shown in the present exemplary embodiment is effective even when
consumer An and consumer Bn include a fuel cell which is a controllable device that controls
30 the generation of electricity. On the other hand, as controllable load CL, electric vehicles (EV),
plug-in hybrid electric vehicles (PHEV) and the like, including a high-speed charger or normal
charger for charging, may be used.
[0063]
Although the present invention has been explained with reference to the exemplary
embodiment, the present invention should not be limited to the above exemplary embodiment.
Various modifications that can be understood by those skilled in the art may be made to the
structures and details of the present invention within the scope of the present invention.
5 [0064]
This application claims priority of Japanese Patent Application No. 20 1 1-0 18322 filed
on January 3 1,201 1, the disclosures of which are incorporated herein by reference.

CLAIMS
I. An electric power management system for managing an electric power system having, at
least, one or more first consumers having a photovoltaic system, and at least, one or more
5 second consumers having a controllable load, connected thereto,
wherein the first consumer and the second consumer include a consumer energy
management system for controlling the amount of electric power generated by the photovoltaic
system andlor for controlling the controllable load,
the electric power management system includes a server apparatus that is connected to
10 the consumer energy management systems so as to be able to exchange data via a network,
the server apparatus, based on the amount of surplus electricity that is expected to be
generated in a predetermined time slot on a predetermined date on which surplus electricity of
the photovoltaic system is expected to be generated and based on the expected amount of
electric power that the second consumer needs in the predetermined time slot on the
15 predetermined date, which are notified from the consumer energy management systems,
combines the first consumer and the second consumer so that the amount of electric power
needed by the second consumer in the predetermined time slot on the predetermined date will
be equal to or greater than the amount of surplus electricity generated at the first consumer, and
makes the controllable load consume the surplus electricity generated at the first consumer by
20 controlling the consumer energy management system of the second consumer.
2. The electric power management system according to claim 1, wherein the server
apparatus sets up a pattern for electric power that is needed for making the controllable load
consume every predetermined unit time in the predetermined time slot on the predetermined
25 date such that it will be similar to the pattern of electric power that is expected to be generated
by the photovoltaic system in the predetermined time slot on the predetermined date.
3. The electric power management system according to claim 2, wherein the consumer
energy management system of the first consumer transmits the actual measurement of the
30 amount of electric power generated by the photovoltaic system, measured in the predetermined
time slot on the predetermined date, and,
the server apparatus, based on the actual measurement of the amount of electric power
that is generated, modifies the pattern of electric power that is needed for every said unit time,
C
which has been set for the controllable load.
4. An electric power management method for managing an electric power system having,
at least, one or more first consumers having a photovoltaic system, and at least, one or more
5 second consumers having a controllable load, connected thereto,
wherein a consumer energy management system equipped for the first consumer to
control the amount of electric power that is generated by the photovoltaic system andlor to
control the controllable load, notifies the amount of surplus electricity that is expected to be
generated in a predetermined time slot on a predetermined date on which surplus electricity of
10 the photovoltaic system to a server apparatus,
wherein, a consumer energy management system equipped for the second consumer
notifies the amount of electric power that is expected to be needed by the second consumer in
the predetermined time slot on the predetermined date to the server apparatus,
wherein, the server apparatus, based on the amount of surplus electricity that is expected
15 to be generated in a predetermined time slot on a predetermined date on which surplus
electricity of the photovoltaic system is expected to be generated and based on the expected
amount of electric power that the second consumer needs in the predetermined time slot on the
predetermined date, which are notified from the consumer energy management systems,
combines the first consumer and the second consumer so that the amount of electric power
20 needed by the second consumer in the predetermined time slot on the predetermined date will
be equal to or greater than the amount of surplus electricity generated at the first consumer, and
makes the controllable load consume the surplus electricity generated at the first consumer by
controlling the consumer energy management system of the second consumer.
25 5. The electric power management method according to claim 4, wherein the server
apparatus sets up a pattern for electric power that is needed for making the controllable load
consume every predetermined unit time in the predetermined time slot on the predetermined
date in such that it will be similar to the pattern of electric power that is expected to be
generated by the photovoltaic system in the predetermined time slot on the predetermined date.
30
6. The electric power management method according to claim 5, wherein the consumer
energy management system of the first consumer transmits the actual measurement of the
amount of electric power generated by the photovoltaic system, measured in the predetermined
rC
time slot on the predetermined date, and
the server apparatus, based on the actual measurement of the amount of electric power
that is generated, modifies the pattern of electric power that is needed for every said unit time,
which has been set for the controllable load.
5
7. A server apparatus for managing an electric power system having, at least, one or more
first consumers having a photovoltaic system, and at least, one or more second consumers
having a controllable load, connected thereto, comprising:
a processing unit which, based on the amount of surplus electricity that is expected to be
10 generated in a predetermined time slot on a predetermined date on which surplus electricity of
the photovoltaic system is expected to be generated and based on the expected amount of
electric power that the second consumer needs in the predetermined time slot on the
predetermined date, notified from the consumer energy management systems equipped for the
first consumer and second consumer to control the amount of electric power generated by the
15 photovoltaic system and/or the controllable load, combines the first consumer and the second
consumer so that the amount of electric power needed by the second consumer in the
predetermined time slot on the predetermined date will be equal to or greater than the amount of
surplus electricity that is generated at the first consumer, and makes the controllable load
consume the surplus electricity that is generated at the first consumer by controlling the
20 consumer energy management system of the second consumer; and,
a communication control device for exchanging data with the consumer energy
management systems via a network.
8. The server apparatus according to claim 7, wherein the processing unit sets up an
25 electric power demand pattern for making the controllable load consume every predetermined
unit time in the predetermined time slot on the predetermined date such that it will be similar to
the expected pattern of electric power that will be generated by the photovoltaic system in the
predetermined time slot on the predetermined date.
30 9. The server apparatus according to claim 8, wherein, when the actual measurement of the
amount of electric power generated by the photovoltaic system, measured in the predetermined
time slot on the predetermined date is transmitted from the consumer energy management
system of the first consumer, the processing unit, based on the actual measurement of the
amount of electric power that is generated, modifies the electric power consumption pattern for
every said unit time, which has been set for the controllable load.
10. A consumer energy management system equipped for a consumer connected to an
5 electric power system and having at least one of a photovoltaic system and a controllable load,
comprising:
a processing unit that notifies the amount of surplus electricity that is expected to be
generated in a predetermined time slot on a predetermined date on which surplus electricity of
the photovoltaic system is expected to be generated or the arnou* of electric power that is
10 expected to be needed by the consumer in the predetermined ti* slot on the predetermined
date to a server apparatus; and
a communication control device for exchanging data with the server apparatus via a
1 network.
Dated this 22/07/20 13
OF REMFRY & SAGAR
ATTORNEY FOR THE APPLICANT[S]