DESCRIPTION
POWER CONTROL DEVICE AND POWER CONTROL METHOD
TECHNICAL FIELD
5 The present invention relates to a power control
device and a power control method applied to control
of storage and supply of a power storage device
equipped in a home, for example.
10 BACKGROUND ART
In recent years, suppression of energy consumption
has been required in factories, offices (buildings), and
homes. According to statistical data of the energy
consumption, the proportion of the energy consumption in
15 homes is relatively high in total energy consumption.
Therefore, the suppression of the energy consumption in
homes is an issue to be addressed. A technology of
controlling energy in homes is called a "home energy
management system" (HEMS). The conventional HEMS
20 implements measures for energy conservation including
on/off control of electrical appliances such as an air
conditioner, collection of logs of power consumption, and
the like.
Meanwhile, power generation using renewable energy
25 in place of fossil fuel is being put to practical use,
and it is expected, in the future, this tendency becomes
stronger. As the power generation using the renewable
energy, solar power generation, wind power generation,
biomass power generation, wave activated power generation,
30 and the like have been developed. Actually, it has been
spread that a solar panel is disposed on a roof, a wall,
and the like, and the solar power generation is performed
in each home.
It can be considered that power by the solar power
generation is stored in a storage battery disposed in
5 each home and the power is supplied to a load in the home.
In this case, the power consumed by electrical appliances
in the home is mixed power from an existing power supply
network and from the storage battery. The storage
battery is charged with the power by the renewable energy
10 or with the power from the power supply network. Further,
even the power from the power supply network is mixed
power generated by different power generation methods
such as thermal power generation, nuclear power
generation, and the like.
15 The conventional measurements to suppress consumed
electric energy in the home do not focus on the origin of
the power, and therefore, have a problem of not
necessarily leading to the reduction of a C02 (carbon
dioxide) emission amount. As disclosed in Patent
20 Document 1, a system of managing the C02 emission amount
is proposed. In Patent Document 1, the C02 emission
amount is obtained for each site, the C02 emission amount
of each site is collected by a management device, and
whether the C02 emission amount is a target value or less
25 by each device group in each site is determined.
CITATION LIST
PATENT DOCUMENT
Patent Document 1: Japanese Patent Application Laid-Open
30 NO. 2009-199495
SUMMARY OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
The invention disclosed in Patent Document 1
manages the C02 emission amount in a manufacturing
5 factory of semiconductor devices. It is difficult to
apply the invention disclosed in Patent Document 1 to C02
emission amount management in a home and the storage
battery provided in the home.
Therefore, a purpose of the present invention is to
10 provide a power control device and a power control method
based on a C02 emission amount that can be applied to a
home and the like provided with a storage battery.
Further, another purpose of the present invention
is to provide a power control device and a power control
15 method based on a power rate that can be applied to a
home and the like provided with a storage battery.
SOLUTION TO PROBLEMS
The present disclosure provides a power control
2 0 device, including :
a storage device of power;
a carbon emission strength information acquisition
device configured to acquire information of carbon
emission strength of the power; and
a control device,
wherein the control device controls whether the
storage device stores the power or supplies the power in
accordance with change of the information of carbon
emission strength.
3 0 The power control device preferably further
includes :
a rate information acquisition device configured to
acquire information of a power rate of the power to be
supplied,
wherein the control device controls whether the
5 storage device stores the power or supplies the power in
accordance with the change of the information of carbon
emission strength and change of the information of a
power rate.
The power control device preferably further
10 includes a generation device of the power.
The present disclosure provides a power control
method, including the steps of:
storing power in a storage device;
supplying the power from the storage device;
15 acquiring information of carbon emission strength
of the power; and
controlling whether the storage device stores the
power or supplies the power in accordance with change of
the information of the carbon emission strength.
20 The power control method preferably further
includes the steps of:
acquiring information in relation to a power rate
of the power; and
controlling whether the storage device stores the
25 power or supplies the power in accordance with the change
of the information of carbon emission strength or change
of the information in relation to a power rate.
EFFECTS OF THE INVENTION
30 According to at least one of embodiments, an amount
of C02 emission emitted from a home can be reduced.
According to at least one of embodiments, a cost
required for storing power in the home can be reduced.
BRIEF DESCRIPTION OF DRAWINGS
5 Fig. 1 is a block diagram showing a power system of
an embodiment of a power control system according to the
present invention.
Fig. 2 is a block diagram showing a communication
system of an embodiment of the power control system
10 according to the present invention.
Fig. 3 is a block diagram used for conceptual
description of the power system according to the
embodiment of the present invention.
Fig. 4 is an outline diagram showing a display on a
15 display according to the embodiment of the present
invention.
Fig. 5 is a block diagram used for description of a
power conditioner connected to a solar panel and a
storage device.
20 Fig. 6 is a status transition diagram used for
description of a process of controlling
charging/discharging of the storage device.
MODE FOR CARRYING OUT THE INVENTION
25 Hereinafter, an embodiment of the present invention
will be described. Note that the description will be
given in the following order.
el. Embodiment>
e2. Modifications>
30 Note that an embodiment to be described herein is a
preferred specific example of the invention, and
technically preferred various limitations are applied.
However, the scope of the invention is not limited to the
embodiment unless otherwise specifically described.
c1. Embodiment>
5 [An example of a power control system]
An example of a power control system in a divided
area, for example, a power control system in a home will
be described with reference to Fig. 1. Fig. 1 shows a
supply channel of power and Fig. 2 shows a transmission
10 path of information data, a control signal, and the like.
Further, Fig. 3 is used for showing a concept of a home
power network. Direct current (DC) and alternate current
(AC) are shown as the type of power. For example,
alternate current power of 220 V (60 Hz) flows in the
15 home power network.
The power generated by a power plant is introduced
through a power supply network 1 to the home via a power
meter 2 in the home. The power plant includes a thermal
power plant, a nuclear power plant, and the like. A C02
20 emission amount of the power supplied to the home through
the power supply network 1 differs depending on a power
generation method. Further, a power rate of the power
bought by a householder, the power being supplied from
the power supply company, varies depending on the time of
25 day. For example, the power rate at nighttime when a
demand for power is small is set to be relatively
reasonable compared with the power rate at daytime.
As shown in Fig. 2, a power meter 2 is connected to
a gateway 4 in the home power network through a wireless
30 local area network (LAN), for example. Devices connected
through the wireless LAN are authenticated by mutual
authentication. Further, to ensure security, data
communicated through the wireless LAN is encrypted. The
path in a solid line in Fig. 2 shows a communication path
of a cable LAN and the path in a broken line shows a
5 communication path of the wireless LAN.
The power meter 2 performs accurate measurement of
the power supplied to the home through the power supply
network 1 with a predetermined period, and transmits a
measured value to the gateway 4 in the home power network
10 by a communication unit through the wireless LAN. In
this case, a measured time is transmitted as a time stamp
along with the measured value. The time is time
information common to the power network. For example, a
reference time source is provided on the power network.
15 Commercial power supply introduced to the home
through the power meter 2 is supplied to a plug strip 3.
The plug strip 3 is an appliance having a plurality of
power supply plugs in order to supply alternate current
power. The alternate current power is supplied from the
20 plug strip 3 to the gateway 4 and an appliance monitor 5.
The alternate current power is supplied through the
appliance monitor 5 to home electrical appliances
including a television device 6, an illumination 7, and a
hair dryer 8, for example. Note that these electrical
25 appliances are examples, and in reality, more various
types of electrical appliances are used in the home.
The appliance monitor 5 measures power consumption
of each electrical appliance connected thereto with a
predetermined period, for example, with a period of one
30 second. Information of measured consumed power of each
electrical appliance and a time stamp indicating a
measured time are transmitted from the appliance monitor
5 to the gateway 4 via wireless communication.
Direct current power generated by a solar panel 9
configured from a solar cell is supplied to a solar
5 module 10. Alternate current power synchronized with the
alternate current power in the home is generated by the
solar module 10. The generated alternate current power
is supplied to the plug strip 3. In the plug strip 3,
the alternate current power from the power meter 2 and
10 the alternate current power from the solar module 10 are
added and used as the power in the home. Not only the
solar panel 9 but also a wind power generation device or
the like that generates electricity by renewable energy
may be used as a power generation device.
15 The solar module 10 is connected with the gateway 4
through the wireless LAN. The solar module 10 measures
the direct current power generated by the solar panel 9
and the alternate current electric energy resulting from
conversion of the direct current power and supplied to
20 the power network. The measured value and the time stamp
indicating the measured time are transmitted from the
solar module 10 to the gateway 4 via the wireless
communication.
As the power storage device in the home, a storage
25 device 11 including three batteries 12a, 12b, and 12c is
equipped, for example. The batteries 12a to 12c are, for
example, lithium-ion batteries. The storage device 11
may employ an electrical double layer. A battery center
13 is provided in order to manage operations such as
30 charging/discharging of the batteries 12a, 12b, and 12c
in the storage device 11, and to convert the direct
current power stored in the storage device 11 into the
alternate current power. The storage device 11 and the
battery center 13 are connected by a cable interface.
For example, a serial peripheral interface (SPI) can be
5 used. The alternate current power from the battery
center 13 is supplied to the plug strip 3.
The battery center 13 is equipped with a plurality
of sockets as physical connection units. The batteries
12a, 12b, and 12c are respectively inserted
10 into/disconnected from the sockets. The batteries 12a,
12b, and 12c can employ different types. For example, a
lithium-ion battery, a capacitor, a fuel cell, a micro
cogenerator, and the like can be used. Each of the
batteries can be uniquely identified by a secure battery
15 identifier (battery ID). Even if the types of the
batteries are different, all of the batteries can be
inserted into the standardized sockets.
The socket secures physical connection and an
interface between the batteries 12a, 12b, and 12c and the
20 battery center 13. The battery center 13 manages the
status of the batteries 12a, 12b, and 12c and monitors
safety and reliability. The battery center 13 is
connected with the gateway 4 through the wireless LAN.
The gateway 4 receives information from the battery
25 center 13 and transmits a control signal in relation to
the batteries 12a to 12c to the battery center 13.
As shown in Fig. 3, the gateway 4 is connected with
a battery profile server 17 on an internet 16 through an
asymmetric digital subscriber line (ADSL) 15. The
30 gateway 4 receives a battery ID and storage information
corresponding thereto from the server 17, so that the
batteries can be safely and properly charged. Further,
information of use result of the batteries (the number of
charging, trouble, and the like) is transmitted from the
gateway 4 to the server 17, and storage information in a
5 database in the server 17 is renewed into latest
information.
As shown in Fig. 3, each of the batteries is
configured to be detachable from the battery center 13
and is detached and used for other purpose of use. That
10 is, the battery is used as a power source of an electric
device, for example, a power-assisted bicycle 18 or a
power tool 19. As described above, the battery can be
used as power supply other than the household storage
battery, and the control and the charging device are
15 common to the several types of batteries, whereby the
household storage battery can be configured at a low cost
without deteriorating safety.
A display 14 is connected to the gateway 4 through
the wireless LAN, and display information is transmitted
20 from the gateway 4 to the display 14. The display 14
displays information or a part of the information
exemplarily shown below to a user in the home.
The power supplied from the power supply network 1 to
the home
25 . The power supplied from the solar panel 9
Net power flowing into the battery center 13
- The status of a battery on the battery center 13
The power consumed by an electrical appliance in the
home
30 . The proportions of green power and non-green power in
used energy
- The carbon emission strength of used power in real time
A carbon footprint of the power consumed by the home
power network
(For example, a value obtained by integrating emitted
5 greenhouse effect gas (carbon emission strength) for one
month is displayed as the carbon footprint, so that the
carbon emission amount is visualized.)
The above-described information to be displayed on
the display 14 may also be displayed on a mobile display
10 20 on the internet 16. Examples of the mobile display 20
include a mobile phone and a mobile personal computer.
Further, a control signal for controlling the power
network can be transmitted to the gateway 4 in the home
using these mobile terminals.
15 [A time stamp associated with measured data]
The above-described information to be displayed on
the display 14 is generated such that a measured value
(with a time stamp) transmitted from the power meter 2,
the appliance monitor 5, the solar module 10, and the
20 battery center 13 through the wireless LAN is processed
by the gateway 4. In the gateway 4, used electric energy
is synchronized with each other by the time stamp.
Further, an integrated value of the used electric energy
in a time direction is calculated. As a power measuring
25 instrument, an instrument that satisfies a predetermined
specification is used in order to secure accuracy.
Further, accurate measurement in relation to the power
serves as a base of a function to inform a householder of
numerical value data that is obtained by
30 adjusting/converting energy consumed in the home into a
carbon dioxide emission amount with accuracy.
A typical example of monitoring the status of use
of the energy in the home is to integrate and display, on
a display, a total energy amount consumed during a
specific period (time). As described above, the measured
5 value is data associated with a time stamp that indicates
a measured time. Therefore, assuming that two measured
values are obtained, instant power P can be obtained by
dividing a difference between the two measured values El
and E2 of the energy by a difference between the times T1
10 and T2.
P = (E2 - El) / (T2 - TI)
Information can be secured by obtaining the
integrated value of data even if breakdown of devices and
the like due to power failure occurs. In a system that
15 treats data as power, even if only one data is missing,
the integration that includes a period in which the
measurement could not be carried out becomes a
speculation. Therefore, the conversion/adjustment of the
total energy amount becomes inaccurate. If it is a
20 system based on information in association with a time
stamp that indicates a measured time, recovery of the
breakdown and accuracy of the conversion can be realized.
[Control of a power control system from an outdoor]
Further, remote control of the storage device 11
25 from an outdoor with a mobile terminal on a network
through the internet 16 and the gateway 4 is possible. A
simple example of an application fully using this merit
is that the householder operates the power storage device
from the outdoor to flexibly change an operation of the
30 system in accordance with the action of thehouseholder.
In a case where larger power consumption than usual is
expected when the householder goes out and next comes
back home, the householder can give an instruction of
storing energy in advance to the storage device 11 from
the outdoor. Further, for example, when the householder
5 leaves a house on vacation and the like, it is possible
to make a long-term contract to entrust control of the
storage of the power to the public utility company (power
company) .
[Control of a storage device based on the carbon emission
10 strength of energy to be used]
When obtaining the carbon emission strength, it may
be possible to access a server on the internet 16, more
specifically, an application program interface (API), to
transmit information of consumed power and the like in
15 the home to the API, and to calculate thecarbon emission
strength in the API. An example of the API includes an
avoiding mass extinctions engine (AMEE) 21. The AMEE 21
collects energy data all around the world and stores
various forms of energy consumption data collected for
20 long periods. According to a profile defined by the AMEE
21, the gateway 4 can obtain information in relation to
the C02 emission amount of the home where the gateway 4
is located.
The gateway 4 can control when to store the energy
25 in the storage device 11 as the power and when to supply
the energy from the storage device 11 based on the carbon
emission strength calculated on its own or by the API.
Further, the gateway 4 can control allocation of the
storage and the supply.
3 0 An example of a rule of the control based on the
carbon emission strength will be described. This rule is
an algorithm for minimizing the total carbon emission
strength by the power consumption. The above-described
power control system is set to store the power in the
storage device 11 only when the carbon emission strength
5 of supplied energy is lower than a certain threshold
value. When the carbon emission strength is high, the
power is supplied from the storage device 11. Such a
power control system enables the householder to consume
the energy with a lower carbon emission amount.
10 In the power control system, the carbon emission
strength of energy to be used can be obtained as net
carbon emission strength based on the energy generated by
a power generator (solar panel 9) disposed in the home in
addition to the energy supplied from outside (power
15 company). The carbon emission strength varies depending
on how the energy has been generated. The energy stored
in the storage device 11 with lower carbon emission
strength is more favorable. Information in relation to
the carbon emission strength of the energy supplied from
20 the power company can be obtained not only from the power
company but also from the above-described AMEE.
There are two costs for storing the power in the
power control system. The first cost is a cost of the
power to be stored itself. The second cost is a cost
25 caused by durable years (deterioration) of a battery used
for storing the power. When determining the rule about
when to charge and what rate to charge, both aspects of
the costs: the power and an exchange of the battery
should be considered. According to the power control
30 system, by quickly storing the energy when the carbon
emission strength is low, an unnecessary cost caused by
the deterioration of the battery due to the quick
charging can be canceled out.
[Control of a storage device based on a buying power
rate]
5 When the storage device 11 is controlled, a buying
power rate of energy is considered. The buying power
rate of energy (power) varies depending on the time of
day, the season, and the like. The power control system
calculates the storage of power in the home and the
10 buying power rate of energy presented by the power
company. The buying power rate changes due to adjustment
of the demand and supply balance of power by the power
company and a spot price in the power market.
Information of the buying power rate can be
15 obtained by a consumer from the power company. The power
control system defines the rule of when to store the
energy as the power and when to supply the energy.
Further, the allocation of the storage and the supply can
be controlled. The power control system is set to store
20 the power only when the buying power rate by the consumer
to whom the energy is supplied is lower than a certain
threshold value. Such a power control system is
effective in enabling the householder to minimize the
cost of the energy consumed in the home.
25 The rule of determining when to store the energy as
the power and what rate to charge is determined
considering both of the cost of the storage, that is, the
cost of the power itself, and the life of the battery.
According to the power control system, when the buying
30 power rate by the consumer is low, an unnecessary cost
caused by the deterioration of the battery due to quick
charging can be canceled out by rapidly storing the
energy.
[An example of a display on a display]
An example of a display on the display 14 will be
5 described with reference to Fig. 4. The display on the
display 14 is a color display. A mark of a house is
displayed in a nearly center of a display area. The mark
of the house is divided into two, and a display 31A
indicating an amount of the power supplied from the power
10 supply network 1 to the home is displayed on the left
half of the mark facing the drawing. Usually, this power
is the non-green power (power with relatively high carbon
emission strength) and is therefore indicated in red.
However, when the green power (power with relatively low
15 carbon emission strength) exists in the power supplied
from the power supply network 1, a display 31B (green)
corresponding to an amount of the green electric energy
is displayed as shown in the broken line. These displays
31A, 31B, and 32 are animation displays changing in real
20 time.
The display 32 corresponding to an amount of the
green power generated by the solar panel 9 (shown by an
icon 33 in Fig. 4) is displayed on the right half of the
mark facing the drawing. Further, icons 34a, 34b, and
25 34c corresponding to the three batteries that constitute
the storage device 11 and indicating respective stored
amounts are displayed. Further, an area 35 that
indicates electrical appliances in the home is provided,
and respective icons of working electrical appliances in
30 the area 35 and current consumed power are displayed. A
display 36 indicating current total consumed electric
energy is displayed.
Further, an indicator 37 is displayed. The
position pointed by a pointer mark of the indicator 37
shows the degree of greenness (cleanness) of the electric
5 energy currently supplied to the home. A left hand icon
38a on the indicator 37 shows the most favorable position
and a right hand icon 38b shows the worst position.
Therefore, the more left the pointer mark points at, the
more favorable the degree of greenness is, whereas the
10 more right the pointer mark points at, the worse the
degree of greenness is.
Further, a display 39 of a carbon footprint is
displayed on a lower part of the display area. The
carbon footprint is a value resulting from conversion of
15 the total power consumed in the home during a
predetermined period such as one month into the C02
emission amount. As described above, when obtaining the
C02 emission amount, the carbon footprint is obtained
considering the carbon emission strength of each power in
20 accordance with a generation method.
A display 40 of my score card is displayed on a
lowermost part of the display area. A score displayed on
the display 40 of my score card is a meaningful value for
the user's (householder' s) interests. For example, the
2 5 score is a base of an environmental subsidy supplied by
the government. Alternatively, it serves as a
transaction object in a transaction market of a C02
emission amount.
[Regarding a scale of the degree of greenness (greenness
30 gauge) I
As described above, the total carbon emission
strength of the power consumed in the home is displayed
on the display 14. The total carbon emission strength is
shown in a form of a scale (gauge). The calculation of a
variable for obtaining this scale can consider the energy
5 generated by a solar cell disposed in each home, or by a
combined heat and power (CHP) facility and the like, as
well as the energy supplied from outside (power company).
For example, the scale is calculated with the following
formula. "E" represents an energy amount and "C"
10 represents a carbon cost.
G = CE (supply) , E (solar) , E (CHP) ,
E (battery) /CC (supply) , C (CHP) , C (battery)
In this calculation, it is assumed that a "carbon
cost" to the power obtained by the solar cell is zero or
15 is a "carbon cost" caused in the implementation. The
"carbon cost" of the power supplied from a battery may be
a "carbon cost" of the power for charging, or may be
integration of a specific "carbon cost" in each use of
the battery and/or a proportion of the specific "carbon
20 cost" in each use of the battery to a total cost.
Further, this scale (gauge) may include information
of total consumed power. In this way, this scale (gauge)
can serve as an indicator showing whether the home uses
carbons in an efficient manner. Another formula of
25 calculating the scale is shown below.
G = CE(supply), E(solar), E(CHP),
E (battery) /CE (supply) , E (solar) , E (CHP) , E (battery) +
CC(supply), C(CHP), C(battery)
With the display on the above-described display 14,
30 in the home, the householder can immediately get to know
a balance between the energy supplied from outside (power
company) and the energy generated in each home.
[Power conditioner]
A first power conditioner and a second power
conditioner provided in each of the solar module 10 and
5 the battery center 13 will be described with reference to
Fig. 5. Fig. 5 shows a partial configuration of the
battery center 13.
A direct current voltage generated in the solar
panel 9 is supplied to a DC-DC converter 51 and is output
10 as a predetermined direct current voltage. The output
voltage from the DC-DC converter 51 is supplied to a DCAC
inverter 52. The DC-AC inverter 52 is, for example,
configured to be a grid tie inverter (GTI) and outputs
alternate current power in synchronization with alternate
15 current power of the power supply network at an output
side.
Power generation by the solar panel 9 varies
depending on the weather, the time of day, and the like.
Therefore, when an output voltage of the solar panel 9 is
20 supplied to the DC-AC inverter 52, the DC-DC converter 51
is used in order to stabilize an input voltage of the DCAC
inverter 52. Further, the DC-DC converter 51 is
configured to adjust the impedance of an output in
accordance with the impedance of the solar panel under
25 any input light at any given time. This characteristic
of following a maximum value of a load on the solar panel
9 is known as "maximum peak point tracking" (MPPT, a
maximum power point tracking control function that
follows a point at which output power of the solar panel
30 is maximized) .
Further, the DC-DC converter 51 and the DC-AC
inverter 52 configured to be a GTI require an assumption
that an AC line obtains the power from other power supply
before the transmission of power. The reason is to
ensure the safety of an engineer who works in the wiring
5 network. Because of such a characteristic, a certain
amount of delay occurs during a period from a DC input
timing to an AC output timing in the DC-AC inverter 52.
Alternate current power from the power meter 2 is
converted into direct current power by a rectifier
10 circuit 53 of the battery center 13. The direct current
power from the DC-DC converter 51 of the solar module 10
and/or the direct current power from the rectifier
circuit 53 of the battery center 13 are supplied to a
charger 54. A battery of the storage device 11 is
15 charged by the charger 54.
The storage device 11 is similar to a solar panel
in generation of the direct current power, and a power
conditioner is also connected to an output of the storage
device 11. That is, the direct current power generated
20 by the storage device 11 is supplied to a DC-DC converter
55. Predetermined direct current power from the DC-DC
converter 55 is supplied to a DC-AC inverter 56.
Alternate current power output from the DC-AC inverter 56
is supplied to a home alternate current power system.
25 The DC-AC inverter 56 is configured to be a GTI.
As described above, when each battery is configured
to be detachable from the battery center 13,
authentication is performed between the battery center 13
and the battery before the charging and discharging of
30 the battery is performed, and only when the
authentication is established, the charging and
discharging are processed. In the authentication process,
an ID of each battery is used.
For such an authentication process and charging and
discharging operations, a controller 57 and a wireless
5 communication unit (not shown) are provided in the
battery center 13 in order to control each part of the
battery center 13. The controller 57 is configured from
a microcomputer. The above-described DC-DC converter 55
and the DC-AC inverter 56 constitute a first power
10 conditioner and the DC-DC converter 51 and the DC-AC
inverter 52 of the solar module 10 constitute a second
power conditioner. As each circuit block that
constitutes these power conditioners, an identical
configuration is used for the reason of consistency of
15 control, ease of access, and the like.
An example of control of a charging/discharging
process by the controller 57 will be described with
reference to Fig. 6. In Fig. 6, three types of the
status : "charging", "off", and "supply (allocation) " are
20 shown.
A condition of a transition S1 from "off" to
"charging"
(A solar panel output 2 150 W) and (the charging status <
90%)
25 A condition of a transition S2 from "charging" to
"off"
(A solar panel output < 150 W) or (the charging status 2
9 O"/o)
A condition of a transition S3 from "off" to
30 "supply"
(An electrical appliance load 2 50 W) and (the charging
status 2 25%), or (a solar panel output 2 150 W) and (the
charging status < 90%)
A condition of a transition S4 from "supply" to
"off"
5 (An electrical appliance load < 50 W) or (the charging
status < 25%)
The above-described control of a
charging/discharging process is an example of a control
of charging the storage device 11 only by an output from
10 the solar panel. Other control method may be available
when the storage device 11 is chargeable with an output
from the above-described rectifier circuit 53. Further,
the numerical values of the threshold values for
determination are mere examples and various values can be
15 set.
As described above, the DC-DC converter 51 and the
DC-AC inverter 52 have a certain amount of delay during
the period of the DC input timing to the AC output timing
in the DC-AC inverter 52. However, the output voltage
20 from the storage device 11 is desired to instantly supply
the power as demanded.
To satisfy such a demand, the DC-DC converter 55 is
configured to have two output voltages. The first output
voltage is a stand-by voltage. The stand-by voltage is
25 lower than the threshold value when the DC-AC inverter 56
begins to supply the power to outside, and is a
sufficient voltage for the DC-AC inverter 56 to operate.
The second voltage is a voltage with which the DC-AC
inverter 56 begins to supply the power to outside. In
30 this way, the DC-DC converter 56 outputs the first
voltage at which the DC-AC inverter 56 stands by in order
to instantly transfer to a supply mode.
The DC-DC converter 51 includes, as described above,
the maximum power point tracking control function.
Similarly, the DC-DC converter 55 into which the output
5 voltage from the storage device 11 is input includes the
maximum power point tracking control function. The
storage device 11 has an output characteristic that is
different from the solar panel. Therefore, when the DCDC
converter 55 connected to the storage device 11
10 includes the maximum power point tracking control
function, the storage device 11 causes a system (power
supply to the AC line) to be unstable. Therefore, the
DC-DC converter 55 is configured to dynamically change
the output impedance in such a way that the output
15 impedance traces a load curve of the solar panel.
Note that, in a system in which oneDC-AC inverter
(GTI) is included for a plurality of batteries and a
plurality of DC-DC converters, this load curve simulation
means that a plurality of outputs of a plurality of DC-DC
20 converters is merely connected in parallel.
c2. Modification>
As described above, an embodiment of the present
invention has been specifically described. However, the
present invention is not limited to the above-described
25 embodiment, and various modifications based on technical
ideas of the present invention are possible. For example,
a power controller system can be applied to a divided
area besides a home.
30 REFERENCE SIGNS LIST
1 Power supply network
2 Power meter
4 Gateway
5 Appliance monitor
9 Solar panel
5 10 Solar module
11 Storage device
13 Battery center
14 Display
51 and 55 DC-DC converter
10 52 and 56 DC-AC inverter

SP263527WO00
CLAIMS
1. A power control device, comprising:
a storage device of power;
5 a carbon emission strength information acquisition
device configured to acquire information of carbon
emission strength of the power; and
a control device,
wherein the control device controls whether the
10 storage device stores the power or supplies the power in
accordance with change of the information of carbon
emission strength.
2. The power control device according to claim 1,
15 further comprising:
a rate information acquisition device configured to
acquire information of a power rate of the power to be
supplied,
wherein the control device controls whether the
2 0 storage device stores the power or supplies the power in
accordance with the change of the information of carbon
emission strength and change of the information of a
power rate.
25 3. The power control device according to claim 1 or 2,
further comprising:
a generation device of the power.
4. The power control device according to claim 3,
3 0 wherein the generation device is a generation device
using renewable energy.
25
SP263527WO00
5. The power control device according to claim 3,
wherein charging/discharging of the generation device of
the power is controlled according to the carbon emission
5 strength of supplied power.
6. The power control device according to claim 1, 2,
or 3, wherein the control device is capable of being
remote-controlled from outside.
10
7. The power control device according to claim 1, 2,
or 3, wherein information of consumed power is
transmitted to an external server through a network, and
the information of carbon emission strength is acquired
15 from the server through the network.
8. The power control device according to claim 1, 2,
or 3, wherein control by the control device is an
algorithm minimizing total carbon emission strength by
2 0 power consumption.
9. The power control device according to claim 8,
wherein the algorithm causes the storage device to
store the power when the carbon emission strength is low,
25 and
causes the storage device to supply the power when
the carbon emission strength is high.
10. The power control device according to claim 8 or 9,
3 0 wherein the algorithm causes the control by the
control device to minimize a cost of the power
26
SP263527WO00
consumption.
11. The power control device according to claim 8, 9,
or 10,
5 wherein the algorithm causes the storage device to
store the power when the power rate is low, and
causes the storage device to supply the power when
the power rate is high.
10 12. The power control device according to claim 10,
wherein the cost includes deterioration of the storage
device.
13. The power control device according to claim 1, 2,
15 or 3, further comprising:
a display device configured to display the
information of carbon emission strength.
14. The power control device according to claim 1, 2,
2 0 or 3, further comprising:
a display device configured to identifiably display
proportions of electric energy supplied from outside and
electric energy internally generated.
25 15. The power control device according to claim 1, 2,
or 3, wherein a scale of total carbon emission strength
is calculated with a ratio between a total energy amount
and a carbon cost for generating the total energy amount.
3 0 16. A power control method, comprising the steps of:
storing power in a storage device;
27
^ SP263527WO00
,supplying the power from the storage device; ' z
acquiring information of carbon emission strength
of the power; and
controiring whether the storage device stores the
5 power or supplies the power in accordance with change of
the information of the carbon emission strength.
17. The power control method according to claim 16,
further comprising the step^ of:
10 acquiring information in relation fe«—a power rate
of the power; and
controlling whether the storage device stores the
power or supplies the power in accordance with the change
of the information of carbon emission strength or change
15 of the information in relation to a power rate.