Power grid management system

Abstract

To provide a configuration for determining a CO2 emission coefficient of a storage battery in a power grid where power generation facilities having varying different CO2 emission coefficients, a storage battery that stores the amount of electricity from the power generation facilities, and a load that uses the electricity from the power generation facilities and the storage battery are connected.SOLUTION: In a management system MS for a power grid EL connected with a plurality of power generation facilities PG1, ..., a storage battery BT capable of storing the power generated by the plurality of power generation facilities, and a load LD capable of using the power from the plurality of power generation facilities and the storage battery, storage battery CO2 emission coefficient means 10 for calculating the CO2 emission coefficient of the storage battery is configured to calculate the CO2 emission coefficient of the storage battery based on the CO2 emission coefficient of the power generation facility that generates the power charged to the storage battery among the plurality of power generation facilities and the amount of power charged to the storage battery.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power grid in which electrical energy is transmitted between power generation equipment, loads, and storage batteries, and more specifically, to a system for managing the amount of CO2 emitted during power generation in such a power grid. [Background technology]

[0002] Various system configurations have been proposed to generate electricity while minimizing CO2 emissions in order to prevent global warming and decarbonize the economy. For example, Patent Document 1 proposes a configuration that simulates the power supply plan of the power grid to the customer's equipment based on the temporal changes in the amount of electricity used by the customer's equipment, the contract details of the cost or carbon dioxide emissions due to the power supply from the power grid to the customer's equipment (including information on carbon dioxide intensity), the connection plan of the battery of a vehicle equipped with a storage battery to the customer's equipment, the specifications of the storage battery, and the temporal changes in the amount of electricity supplied from the power grid to the customer's equipment, and calculates the reduction in the cost or carbon dioxide emissions due to the power supply when a vehicle's storage battery is introduced to the customer's equipment. Patent Document 2 proposes a configuration in which electricity generated by power generation equipment of multiple customers can be supplied to the power grid from each storage battery that stores electricity, and assigns a higher priority to each customer's storage battery that emits less carbon dioxide when generating the electricity to be stored, and discharges to the power grid starting with the storage batteries of customers with higher priority. Patent Document 3 proposes a configuration in a power grid network having multiple power plants, substations, and multiple storage batteries attached thereto, in which the power generation amounts of power plants and storage batteries selected in descending order of their power generation intensity, which represents the environmental burden such as carbon dioxide emissions per unit of energy, are added together until the demand is met. Patent Document 4 proposes a configuration in a power distribution network to which batteries of multiple electric vehicles are connected, in which the batteries of electric vehicles are charged when the CO2 emissions of the power source are low, thereby reducing CO2 emissions in the network. Patent Document 5 proposes a residential system that enables power transmission between a house equipped with solar power generation equipment and the battery of an electric vehicle. In order to charge the electric vehicle from the solar power generation equipment without substantially using grid power, the system stores the amount of CO2 emitted when power is generated from the grid power supply to the battery of the electric vehicle as a count value when power is charged from the grid power supply to the battery of the electric vehicle. When power is discharged from the battery of the electric vehicle to the house, the count value is subtracted according to the amount of discharge. When an electric vehicle with power stored in its battery is connected to the house, the system manages the power so that power is discharged from the battery to the house until the count value becomes 0. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International release 2020 / 230276 [Patent Document 2] Japanese Patent Publication No. 2018-186607 [Patent Document 3] Japanese Patent Publication No. 2013-158153 [Patent Document 4] Special Publication 2022-510390 [Patent Document 5] Japanese Patent Publication No. 2013-110881 [Overview of the project] [Problems that the invention aims to solve]

[0004] The CO2 emission coefficients (the amount of CO2 emitted in conjunction with the generation of a unit amount of electricity) of power generation facilities vary. When electricity consumers use electricity, it is preferable to be able to selectively use electricity from power generation facilities with lower CO2 emission coefficients in order to minimize the CO2 emissions associated with the generation of that electricity. In a power grid where various power generation facilities, including thermal power generation facilities using fossil fuels and renewable energy power generation facilities such as solar and wind power generation facilities, are connected, if the amount of electricity generated by each power generation facility is stored in a battery, and electricity consumers use that stored electricity, that is, if the battery is used as a power source similar to a power generation facility, it would be convenient for electricity consumers to know the "CO2 emission coefficient" (the CO2 emission coefficient of the battery), that is, the amount of CO2 emitted in conjunction with the generation of a unit amount of electricity stored in that battery, when they select a battery as a power source and intend to minimize the CO2 emissions associated with the amount of electricity they use. In other words, by looking at the CO2 emission coefficient of a particular battery, it becomes easy to estimate how much CO2 was emitted when generating the electricity used from that battery. Regarding the determination of such a "battery CO2 emission coefficient," once electricity generated by various power generation facilities in the power grid as described above is stored in a battery, the origin of that electricity cannot be distinguished when the electricity is taken out of the battery. Therefore, it is not possible to measure the battery's CO2 emission coefficient by referring to the electricity taken out (discharged power). However, by using the amount of electricity received from each power generation facility and the CO2 emission coefficient of each power generation facility when charging the battery, it is possible to determine the battery's CO2 emission coefficient.

[0005] Thus, the main object of the present invention is to provide a configuration for determining the CO2 emission factor of a battery in a power grid where power generation equipment with various CO2 emission factors, a battery for storing the amount of electricity generated from them, and loads that utilize the electricity from the power generation equipment and the battery are connected. [Means for solving the problem]

[0006] According to the present invention, the above problem is solved by a power grid management system in which a plurality of power generation facilities, a storage battery capable of storing the electricity generated by the plurality of power generation facilities, and loads capable of using the electricity from the plurality of power generation facilities and the storage battery are connected, Battery CO2 emission coefficient means for calculating the CO2 emission coefficient of the aforementioned battery Includes, The battery CO2 emission coefficient means is achieved by a management system configured to calculate the CO2 emission coefficient of the battery based on the CO2 emission coefficient of each of the power generation facilities that generated the electricity charged to the battery, and the amount of electricity charged to the battery from each of them.

[0007] In the above configuration, "power generation equipment" may be any power generation equipment that generates electricity using any method, and may include thermal power generation equipment using fossil fuels, nuclear power generation equipment, renewable energy power generation equipment such as solar power generation and wind power generation, and vehicle-mounted power generation equipment (power-generating drive units such as hybrid vehicles and fuel cell vehicles). "Storage battery" may be any storage battery commonly used in this field, for example, a stationary energy storage device or a storage battery (battery) installed in an electric vehicle. "Load" may be any machine or device that operates using electricity. "Power grid" may be a network of transmission lines that transmit electricity in the usual manner between the power generation equipment, storage battery and load. "CO2 emission factor of storage battery" is, as already mentioned, the amount of CO2 emitted per unit of generated electricity when the amount of electricity stored in the storage battery is used to generate electricity. The CO2 emission factor of storage battery is calculated as described above based on the CO2 emission factor of each power generation equipment that generated the electricity charged to the storage battery and the amount of electricity charged from each power generation equipment to the storage battery. The CO2 emission factor of each power generation facility can be known in advance by any method (the amount of CO2 generated per unit of electricity may be measured by any method). The amount of electricity transferred from each power generation facility to the battery may be measured by any method when the battery is being charged.

[0008] According to the configuration of the present invention described above, the CO2 emission coefficient of a battery that stores electricity generated by various power generation facilities, that is, the amount of CO2 emitted per unit of electricity generated when the amount of electricity stored in the battery is generated, can be calculated. Therefore, when an electricity consumer takes out any amount of electricity from the battery, it becomes easy to know how much CO2 was emitted when obtaining that amount of electricity. In particular, in the case of the present invention, even when the battery receives electricity from power generation facilities with different CO2 emission coefficients, the CO2 emission coefficient of the battery is calculated from the CO2 emission coefficient of each power generation facility and the actual amount of electricity received from each power generation facility. As a result, the CO2 emission coefficient of the battery can be obtained with greater accuracy (for example, compared to when the average value of the CO2 emission coefficients of each power generation facility is used), and the amount of CO2 emitted when generating electricity taken out from the battery can be grasped with greater accuracy.

[0009] In the implementation of the above configuration, the CO2 emissions associated with the generation of electricity stored in the battery are the sum of the product of the CO2 emission coefficient of each power generation facility that generated the electricity charged into the battery from each of those facilities and the amount of electricity charged into the battery from each of those facilities. and Since it can be considered as such, the CO2 emission factor of the battery may be a value obtained by dividing the sum of the product values ​​of the CO2 emission factor of each power generation facility and the amount of electricity charged to the battery by the sum of the amounts of electricity charged to the battery from each of the power generation facilities that generated the electricity charged to the battery. Specifically, the current value of the CO2 emission factor of the battery is calculated by adding the CO2 emissions associated with the generation of the amount of stored energy (the amount of electricity stored in the battery) at a predetermined time prior to the present (which can be set arbitrarily), the CO2 emissions associated with the generation of the amount of electricity charged during that predetermined time, and then dividing the result by the current amount of stored energy (when the battery is discharged, the proportion of the amount of electricity generated by each power generation facility in the amount of electricity taken out of the battery is the same as when it is charged, so the CO2 emission factor of the battery does not change).

[0010] Furthermore, if electricity consumers can ascertain the CO2 emission coefficient of the load, that is, the amount of CO2 emitted per unit of electricity during the generation of the amount of electricity used by the load, they can easily know the increase in the amount of CO2 emitted during the generation of electricity used in conjunction with the operation of the load, which is convenient when planning to reduce CO2 emissions associated with the operation of the load. Therefore, in the management system of the present invention described above, a load CO2 emission coefficient means for calculating the load's CO2 emission coefficient may be provided, and the load CO2 emission coefficient means may be configured to calculate the load's CO2 emission coefficient based on the CO2 emission coefficient of each of the power generation facilities that supplied power to the load from among the multiple power generation facilities and the amount of electricity supplied to the load from each of them, and the CO2 emission coefficient of the storage battery and the amount of electricity supplied to the load.

[0011] Furthermore, in the above-mentioned management system, it would be convenient to be able to determine the proportion of electricity stored in the battery or used in the load that originates from power generation, that is, the proportion of electricity generated by each power generation facility in the amount of electricity stored in the battery or used in the load, when considering using electricity obtained from power generation facilities with lower CO2 emissions. Therefore, the management system of the present invention may further be provided with means for calculating the proportion of electricity stored in the battery or used in the load that originates from power generation.

[0012] In the power grid to which the above system is applied, batteries mounted on electric vehicles may be selectively connected, and may be charged with electricity from power generation equipment via the power grid and discharged to loads. In this case, the CO2 emission factor of the battery may be calculated, or the CO2 emission factor of the load may be calculated using the CO2 emission factor of the battery. Therefore, the above management system may be a battery mounted on a vehicle that is selectively connected to the power grid.

[0013] The means for calculating the CO2 emission coefficient of a battery in the above system may be implemented as a device on its own. Thus, according to the present invention, the above problem is solved by a battery CO2 emission coefficient calculation device for calculating the CO2 emission coefficient of a battery that stores electricity generated by multiple power generation facilities, the device being configured to calculate the CO2 emission coefficient of the battery based on the CO2 emission coefficients of the multiple power generation facilities and the amount of electricity charged to the battery. [Effects of the Invention]

[0014] Thus, in the power grid management system of the present invention described above, the CO2 emission coefficient of a storage battery that receives electricity from various power generation facilities is calculated, and electricity consumers can understand to what extent the electricity they are trying to extract from the storage battery is being obtained with an environmental burden per unit amount of energy. Furthermore, when attempting to minimize CO2 emissions, electricity consumers will try to extract electricity from the storage battery with the lowest possible CO2 emission coefficient, so it is expected that the reduction of CO2 emissions will be promoted. In addition, the CO2 emission coefficient of a storage battery calculated by the system of the present invention is calculated based on the CO2 emission coefficient of each power generation facility that generated the electricity charged to the storage battery, and the amount of energy charged to the storage battery from each of those facilities. Therefore, even when electricity from power generation facilities with different CO2 emission coefficients is charged to the storage battery, it can be used as an accurate indicator representing the amount of CO2 emitted per unit amount of energy. In other words, the CO2 emission coefficient of the battery in the present invention represents the degree of environmental load per unit amount of energy, which changes depending on the power generation source of the electricity stored in the battery. The smaller the value, the cleaner the electricity stored in the battery is considered to be. Therefore, it can be used as an indicator to grasp the degree of cleanliness of the electricity stored in the battery, which changes depending on the power generation source of the electricity used during charging. The configuration of the present invention can be applied to power grids of various scales, such as power grids for houses and apartment buildings configured to supply electricity from the commercial power grid (grid power) and electricity from solar power generation facilities to the battery and load, or power grids that cover areas receiving electricity from various power generation facilities.

[0015] Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention. [Brief explanation of the drawing]

[0016] [Figure 1] Figures 1(A) and 1(B) are schematic diagrams of a power grid to which the management system according to this embodiment is applied. (A) shows the flow of power during battery charging, and (B) shows the flow of power during battery discharge. Figure 1(C) is a schematic diagram showing the amount of CO2 emitted in conjunction with the power generation of the electricity stored in the battery. [Figure 2] Figure 2 is a block diagram showing the configuration of the battery and the calculation unit for calculating the CO2 emission coefficient of the load in the management system according to this embodiment. [Figure 3] Figure 3 is a flowchart illustrating the calculation process in the management system according to this embodiment. [Explanation of symbols]

[0017] PG1, PG2, PG3... Power generation equipment BT…Storage battery LD...Load EL…Power transmission line MS... Management System 10…Calculation unit (computer) 12...Indicator [Best Mode for Carrying Out the Invention]

[0018] Power grid configuration The power grid to which the management system of this embodiment is applied is schematically shown in Figures 1(A) and (B), in which a plurality of power generation equipment PG1, PG2, PG3, ..., storage batteries BT, and loads LD are connected to a power transmission line EL, and power can be selectively supplied from each power generation equipment PG1, PG2, PG3, ... to the storage batteries BT and loads LD, and power can be selectively supplied from the storage batteries BT to loads LD. In such a power grid, the transmission of power from each power generation equipment PG1, ... to the storage batteries BT and loads LD, and the transmission of power from the storage batteries BT to loads LD may be controlled appropriately by the management system MS by referring to the state of each power generation equipment PG1, ..., storage batteries BT, and loads LD. The power generation equipment PG1, PG2, PG3, ... may be power sources that generate and output power in any manner, and may be equipment that generates power by various means such as thermal power generation, nuclear power generation, hydroelectric power generation, solar power generation, and wind power generation. The power grid may be connected to the commercial power grid as a power generation facility. Furthermore, electric vehicles equipped with power generation devices, such as hybrid vehicles or fuel cell vehicles, may be connected as power generation equipment. Since each power generation equipment may emit a different amount of CO2 per unit of power generated, the characteristics of CO2 emissions are characterized by different CO2 emission coefficients e1, e2, e3, ... for each power generation equipment. The CO2 emission coefficient of each power generation equipment can be detected by any method. The battery BT may be any type of battery commonly used in this field, and may be a stationary energy storage device or a battery mounted on an electric vehicle. Although not shown in the diagram, multiple batteries may be connected to the power grid, and each may be able to charge and discharge independently of the others. The load may be any machine or device that operates using electricity. Although not shown in the diagram, multiple loads may be connected to the power grid, and each may be able to use electricity independently of the others. The management system MS may be any type of control device that controls power transmission between each piece of equipment (when simply referred to as "equipment," this includes power generation equipment, storage batteries, and loads) via the power transmission line EL, as described above, and may typically be a conventional computer device. The configuration and operation of each part of the management system MS of this embodiment, which will be described later, may be realized by the operation of a computer according to a program.Information transmission between the management system MS and each piece of equipment may be carried out using any type of communication system, and the operation of the management system MS may be achieved by operating a mobile terminal held by the electricity consumer.

[0019] In this embodiment, the power grid management system MS is provided with a calculation unit or calculation device that calculates the CO2 emission coefficient of the battery or the load, the proportion of the electricity stored in the battery that originates from power generation, or the proportion of the electricity used by the load that originates from power generation. The calculation results are provided with means to notify power consumers and others or to make them available for arbitrary control. As shown in Figure 2, the calculation device 10, which is the means for calculating the CO2 emission coefficient of the battery, etc., may be a computer device, and parameters used in the calculations to be described later are input to it. Specifically, such parameters include the CO2 emission coefficient e1, ... and output power P1, ... of each power generation equipment PG1, etc., and the charge / discharge power P of the battery BT. B , storage capacity W B CO2 emissions associated with power generation during energy storage F B The ratio of charging and discharging power to the amount of stored energy R WB , input power P in load LD L This may include the following. Furthermore, the calculation results from the computing device 10 may be displayed on the display unit 12 in any manner that can be recognized by the power grid administrator and power consumers, transmitted to any control unit 13, and used for any control.

[0020] Power flow during battery charging and discharging In the above power grid, when the battery BT is charged, as shown in Figure 1(A), the output power (P1~) from each selected power generation facility among the power generation facilities PG1~ connected to the power grid is supplied to the battery BT and the load LD in use. On the other hand, when the battery BT is being discharged (supplied to the load), as shown in Figure 1(B), the output power P from the battery BT is supplied. BD Then, the output power (P2~) from each selected power generation equipment among the power generation equipment PG1~ is supplied to the load LD currently in use.

[0021] Changes in CO2 emissions during battery charging and discharging, compared to power generation. The change in CO2 emissions associated with the power generation of the stored electricity due to the increase and decrease in the stored electricity during charging and discharging of the above battery BT can be considered as follows. First, the increment in CO2 emissions associated with the power generation of the stored electricity during charging of the battery BT is the sum of the increments in the amount of CO2 emitted (ΔF1, ΔF2, ΔF3, …) associated with the power generation of the increment in the amount of electricity input from each power generation facility to the battery BT (see the left side of Fig. 1(C)). Here, it is considered that the ratio of the increment in the amount of electricity input from each power generation facility to the battery BT in the increment in the amount of electricity input to the battery BT is consistent with the ratio of the electricity output from each power generation facility to the power grid to the sum of the electricity output from all power generation facilities to the power grid. Therefore, the increment in CO2 emissions ΔF1~ for each power generation facility is given by the multiplication value of the input power amount P B Δt to the CO2 emission coefficient (e1~) of each power generation facility and the ratio of the output power (P1~) of each power generation facility to the sum of the output powers of all power generation facilities (ΣP i ). (Δt is the unit time or a predetermined cycle time that may be arbitrarily set). And the CO2 emissions F B (t) associated with the power generation of the stored electricity of the battery BT after charging (at time t) will increase by ΔF1 + ΔF2 + ΔF3 + …. Also, since the amount of electricity once charged into the battery BT becomes indistinguishable from its origin of power generation (see the middle of Fig. 1(C)), the CO2 emission coefficient of the battery, that is, the amount of CO2 emissions per unit amount of electricity discharged associated with the power generation of the stored electricity, e B is given by the CO2 emissions F B associated with the power generation of the stored electricity with respect to the total stored electricity W B of the battery.

[0022] On the other hand, during discharging of the battery BT, it is considered that the electricity is discharged without distinction as to its origin of power generation. In that case, since there is no change in the CO2 emission coefficient e B of the battery (the CO2 emissions F B is proportional to the total stored electricity W B of the battery), the decrement in the amount of CO2 emitted associated with the power generation of the decrement in the amount of electricity discharged from the battery is the CO2 emission coefficient e BAnd the amount of power output P from the battery BT. BD It is given by multiplying it by Δt (see Figure 1(C) right).

[0023] CO2 emission factor of storage batteries e B Calculation As already stated in the section on the summary of the invention, in the power grid management system of this embodiment, the calculation unit calculates the CO2 emission coefficient of the storage battery e B The CO2 emission factor e of such a battery is calculated. B Having this information is useful when electricity consumers are trying to minimize CO2 emissions when using electricity for their loads, and when selecting power sources from various power generation facilities and storage batteries.

[0024] CO2 emission factor of storage batteries e B In calculating this, the computing unit calculates the power P charged from the battery BT as battery information when the battery is being charged. B (t) (When charging, <0. P B (Assuming discharge is >0,) and the amount of stored energy before charging is W. B (t-Δt), CO2 emissions F associated with power generation of the stored energy before charging. B Each value of (t-Δt) is received, and each power generation equipment PG i (i is the code for the power generation equipment. The same applies below.) Power generation information is obtained from each power generation equipment PG. i CO2 emission factor e i , output power P i It receives each of the values. And the amount of stored energy after charging W B (t), CO2 emissions F B (t), CO2 emission factor e B (t) is calculated using the following formulas. W B (t) = W B (t-Δt)-P B (t)·Δt / 3600 …(1a) F B (t) = F B (t-Δt)-P B (t)·Δt / 3600·Σe i (t)P i (t) / ΣP i(t) …(1b) (Σ represents the sum of the power generation equipment PGi that is generating electricity.) e B (t) = F B (t) / W B (t) …(1c) Note that in the above formula, P i (t), P B (t), P L (t) [Input power to the load] ΣP i (t) = -P B (t) + P L (t) …(1d) This was assumed (and so on).

[0025] Furthermore, when the battery is discharged, the computing unit processes the power P discharged from the battery BT as battery information. B (t)(>0), stored energy W before discharge B (t-Δt), CO2 emissions F associated with power generation, based on the amount of stored energy before discharge. B The values ​​of (t-Δt) are received, and the amount of stored energy after discharge is W. B (t), CO2 emissions F B (t) is calculated using the following formula. Note that, as already mentioned, the CO2 emission coefficient e B (t) does not change during discharge. W B (t) = W B (t-Δt)-P B (t)·Δt / 3600 …(2a) F B (t) = F B (t-Δt) / (1+P B (t)·Δt / W B (t) / 3600) …(2b) Or, F B (t) = F B (t-Δt)-e B (t)·P B (t)·Δt / 3600 …(2b)

[0026] CO2 emission factor e of the above battery BAs can be understood from its derivation formula, the CO2 emissions increase as the CO2 emission coefficient of each power generation facility that generates the stored electricity increases, and as the amount of stored electricity increases, the CO2 emissions increase, and this value is obtained by dividing the CO2 emissions by the total amount of stored electricity. Therefore, it is an indicator of the CO2 emissions per unit amount of electricity generated during the storage amount, and the CO2 emission coefficient e B The smaller the value, the lower the CO2 emissions per unit amount of energy used, i.e., the cleaner it is. Therefore, as described above, the CO2 emission factor e of a battery B When this is obtained, as shown in Figure 1(B), when supplying power to the load, the CO2 emission factor of the battery e is higher than the CO2 emission factor of a certain power generation facility (e.g., e1). B If the CO2 emission factor is low, it is easy to see that choosing a battery as a power source can reduce the amount of CO2 emissions associated with power generation for the amount of electricity used, and it becomes easier to decide to choose a battery as a power source instead of power generation equipment with a high CO2 emission factor. (Conversely, if the CO2 emission factor of the available power generation equipment is low, the CO2 emission factor of the current battery is low.) B If the value is lower than that, it becomes easy to understand that it is better not to choose a battery as a power source.

[0027] As mentioned earlier, the above-mentioned battery may also be a battery installed in an electric vehicle. In that case, the vehicle battery is connected to the power grid. The CO2 emission coefficient of the battery is e B The calculation process is the same as described above. Furthermore, the battery installed in the electric vehicle may be connected as a load to the power grid during charging, making it easier to determine whether or not to select a battery connected to the power grid as the power source when charging the vehicle's battery.

[0028] CO2 emission factor of load e B Calculation As already mentioned, in the power grid management system of this embodiment, the calculation unit calculates the CO2 emission coefficient of the load e L In other words, the amount of CO2 emissions per unit of electricity generated for the amount of electricity used in the load may be calculated. The CO2 emission factor of the load is e LOnce understood, it becomes possible to easily know the increment of the amount of CO2 emitted with the operation of the load, which is convenient when attempting to reduce the CO2 emissions associated with the operation of the load. In the arithmetic unit, the CO2 emission coefficient e of the load L may be calculated by the following formula. e L ={Σe i (t)P i (t)+ e B (t)P B (t)} / {ΣP i (t)+ P B (t)} …(3) When calculating the CO2 emission coefficient e of the load L each power generation facility PG i sends the CO2 emission coefficient e i of each power generation facility PG i , the output power P i as power generation information to the arithmetic unit, and the power P B (t) discharged from the storage battery BT as storage battery information is input.

[0029] Calculation of the ratio of stored energy to the amount of electricity used by the load that originates from power generation. Furthermore, in the power grid management system of this embodiment, the ratio of the power generation origin of the stored power amount and the load usage power amount, that is, the ratio of the power amount generated by each power generation facility in the power amount stored in the storage battery, or further, the ratio of the power amount generated by each power generation facility in the power amount used by the load, may be calculated. Once these are known, it is convenient when attempting to use the power obtained from the power generation facility with less CO2 emissions. In the arithmetic unit, the ratio of the power amount generated by each power generation facility in the stored power amount may be calculated as follows.

[0030] First, the power amount W B i(t) generated by each power generation facility i in the stored power amount at time t B uses the power amount W i(t-Δt) before charge and discharge, B W B i(t)=W B (t-Δt)- P B (t)·Δt / 3600·Pi(t) / ΣPi(t) …(4a) It is calculated at. And the ratio Rwi(t) of the amount of power generated by each power generation facility i in the stored power amount is Rwi(t)= W B i(t) / ΣW B i(t) …(4b) It is calculated at.

[0031] The amount of power W L i(t) generated by each power generation facility i in the load usage power amount at time t is when receiving power supply from the storage battery (P B ≧0) (during discharge of the storage battery), W L i(t)=(Pi(t)+P B (t)·Rwi(t))·Δt / 3600 …(5a) is given by, and when the storage battery is receiving power supply (P B <0) (during charging of the storage battery), W L i(t)=Pi(t)(1+P B (t) / ΣPi(t))·Δt / 3600 …(5b) is given by. And the ratio of the amount of power generated by each power generation facility i is R L i(t)= W L i(t) / ΣW L i(t) …(5c) is given by. When calculating the above ratio derived from power generation, parameters necessary for the calculation are input from each facility to the arithmetic unit.

[0032] Calculation process flow In the management system of this embodiment, the above series of calculations may be executed sequentially, for example, as shown in Figure 3. The process in Figure 3 may be repeatedly executed at a predetermined cycle time that can be set as appropriate. Specifically, first, when the calculation process starts (S0), the parameters necessary for the calculation are read (S1), and it may be determined whether or not a battery is connected to the power grid (S2). If a battery is not connected, the proportion of the amount of electricity used by the load that originates from power generation is calculated using the above equations (5a) to (5c) (S6), and the CO2 emission coefficient of the load e L This can be calculated using equation (3) (S7).

[0033] If a battery is connected (S2), it is determined whether the battery is being charged or discharged (S3). If charging is being performed (C), the amount of stored energy originating from power generation and its proportion are calculated using the above equations (4a) to (4b) (S4), and the CO2 emission coefficient e of the stored energy is calculated. B The following can be calculated (S5). On the other hand, when the battery is being discharged (D), the amount of stored energy originating from power generation and its proportion (S8), the amount of stored energy after discharge, and the amount of CO2 emissions can be calculated using the above formula (S9). The results of this series of calculations can then be displayed on the display unit 12 or used to control the operation of each piece of equipment in any power grid.

[0034] Applications of arithmetic processing The series of calculations in this embodiment described above are basically processes for calculating the CO2 emission coefficient of the battery, the CO2 emission coefficient of the load, or the proportion of stored energy or load-used electricity that originates from power generation in real time. When the future CO2 emission coefficients of each power generation facility can be detected, they may be used to calculate the future CO2 emission coefficient of the battery, the CO2 emission coefficient of the load, or the proportion of stored energy or load-used electricity that originates from power generation. For example, when the CO2 emission coefficient and output power of a power generation facility can be predicted depending on the time of day, these values ​​can be used to perform the series of calculations described above and a predicted value for the CO2 emission coefficient of the battery can be calculated. Furthermore, knowing such predicted values ​​is useful when creating future power supply and demand control plans.

[0035] Furthermore, in the system of this embodiment, since the CO2 emission factor of the storage battery can be calculated, it becomes easy to appropriately control the charging timing and amount so as to further reduce the CO2 emission factor of the storage battery. For example, if it is predicted that power generation equipment with a low CO2 emission factor will be available in the future, the amount of energy stored in the storage battery may be controlled so that the charging timing of the storage battery is set to a time when power generation equipment with a low CO2 emission factor is available. In this regard, for example, the CO2 emission factor of the storage battery may be reduced by referring to solar radiation information that can predict the amount of solar power generation and charging the battery with electricity generated by solar power generation equipment with a CO2 emission factor of virtually zero.

[0036] While the above description is made in relation to embodiments of the present invention, many modifications and changes are readily possible for those skilled in the art, and it will be clear that the present invention is not limited to the embodiments illustrated above, but can be applied to various devices without departing from the concept of the present invention.

Claims

1. A power grid management system connected to multiple power generation facilities, a battery capable of storing the electricity generated by the multiple power generation facilities, and loads capable of using the electricity from the multiple power generation facilities and the battery, Battery CO2 emission coefficient means for calculating the CO2 emission coefficient of the aforementioned battery Includes, The battery CO2 emission coefficient means is configured to calculate the CO2 emission coefficient of the battery based on the CO2 emission coefficient of each of the power generation equipment that generated the electricity charged to the battery from among the plurality of power generation equipment, and the amount of electricity charged to the battery from each of them. The CO2 emission coefficient of each of the aforementioned power generation facilities is the amount of CO2 emitted in conjunction with the generation of each unit amount of electricity by each of the aforementioned power generation facilities. A management system in which the CO2 emission coefficient of the storage battery is obtained by dividing the value obtained by adding the sum of the product of the CO2 emission coefficient of each power generation facility that generated the electricity charged to the storage battery from the storage amount at a predetermined time prior to the present, and the amount of electricity charged to the storage battery from each of those facilities during the predetermined time, by the amount of storage at the present time.

2. A management system according to claim 1, further including a load CO2 emission coefficient means for calculating the CO2 emission coefficient of the load, wherein the load CO2 emission coefficient means is configured to calculate the CO2 emission coefficient of the load based on the CO2 emission coefficient of each of the power generation facilities that supplied power to the load from among the plurality of power generation facilities and the amount of electricity supplied to the load from each of them, and the CO2 emission coefficient of the storage battery and the amount of electricity supplied to the load by it.

3. A management system according to any one of claims 1 to 2, wherein the battery is a battery mounted on a vehicle that is selectively connected to the power grid.

4. A battery CO2 emission coefficient calculation device for calculating the CO2 emission coefficient of a battery that stores electricity generated by multiple power generation facilities, The system is configured to calculate the CO2 emission coefficient of the battery based on the CO2 emission coefficient of each of the power generation facilities that generated the electricity charged to the battery, and the amount of electricity charged to the battery from each of them. The CO2 emission coefficient of each of the aforementioned power generation facilities is the amount of CO2 emitted in conjunction with the generation of each unit amount of electricity by each of the aforementioned power generation facilities. The CO2 emission coefficient of the battery is obtained by dividing the value obtained by adding the sum of the product of the CO2 emission coefficient of each power generation facility that generated the electricity charged to the battery from among the plurality of power generation facilities during the predetermined time period, and the amount of electricity charged to the battery from each of them, by the amount of electricity stored at the present time.

Images