JP2024081165A - Scenario creating apparatus for generating, storing and transmitting power in wheeling system for self-consumption based on photovoltaic generation facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scenario creating apparatus for creating scenario data for generating, storing and transmitting power in a wheeling system for self-consumption, where the apparatus can minimize electricity charges to be paid.

SOLUTION: A wheeling system 1 for self-consumption is for transmitting power generated at a photovoltaic generation facility 3 in a location remote from a power-consuming facility 4 through a power transmission network 4 to the power-consuming facility 4. In the system, a scenario creating apparatus 2 for creating scenario data showing plans for generating, storing and transmitting power at the photovoltaic generation facility 3 creates the scenario data by creating the plans for each time period for: a power purchase amount, which is the amount of power purchased from a power market at the power-consuming facility 4; a power generation and transmission amount, which is the amount of power generated at the photovoltaic generation facility 3 and wheeled for self-consumption; and the amount of power stored at the photovoltaic generation facility 3 and wheeled for self-consumption.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

This invention relates to the creation of plans for power generation, storage, and transmission at a solar power generation facility in a so-called self-consignment system in which electricity generated at a solar power generation facility in a remote location is transmitted to a facility that is demanding electricity through a power transmission network.

Conventionally, in a self-consumption type solar power generation system, solar power generation equipment is installed within one's own facility, and the power consumed by the load within the facility is supplied by the power generated by the solar power generation facility. In such a self-consumption type solar power generation system, the solar power generation facility must be installed on one's own premises, and therefore a roof or open space must be secured on one's own premises.

In contrast to this type of self-consumption solar power generation system, a self-dispatch system is a system in which electricity generated at a solar power generation facility in a remote location is transmitted to the facility itself or to a closely related electricity demand facility via a power transmission grid (power transmission and distribution network). The use of a self-dispatch system makes it possible to utilize renewable energy even in demand facilities where it is difficult to secure a roof or free space, and self-dispatch systems have been attracting attention in recent years.

When using a self-dispatch system, it is necessary to match the power generation plan with the demand plan (called "same-time matching of planned values"). For "same-time matching of planned values," the amount of electricity demand at electricity demand facilities and the amount of electricity supplied from solar power generation facilities must be forecast in 30-minute increments, and these planned values must be submitted to a cross-regional organization such as OCCTO. If a discrepancy occurs between the planned values and the actual values (called an "imbalance"), a penalty is imposed according to the amount of the discrepancy.

Patent Document 1 discloses a technology that can avoid or suppress imbalances that occur between planned values and actual values. The technology described in Patent Document 1 is a system that supports self-dispatch, which transmits electricity generated using a power generation facility to an electricity demand facility located at a different location from the power generation facility via a general power transmission and distribution network of a general power transmission and distribution business operator. This system that supports self-dispatch includes at least one computer. The at least one computer acquires power generation plan data that describes planned values of power generation by the power generation facility for each of a plurality of time frames divided by a predetermined unit time, and after acquiring the power generation plan data, acquires power generation forecast data that describes predicted values of power generation by the power generation facility for at least one of the plurality of time frames, identifies a time frame in which the planned value described in the power generation plan data differs from the predicted value described in the power generation forecast data as an imbalance time frame, calculates a gate closing time a predetermined time before the imbalance time frame, and determines whether the current time is before the gate closing time. According to the above-mentioned system, for example, by providing a computer with power generation plan data describing the power generation plan reported to the cross-regional organization and power generation forecast data created after that taking into account weather forecasts, etc., the imbalance time frame in which an imbalance may occur is identified and it is also determined whether the imbalance time frame is past the gate closing time. This allows a person using self-consignment to select appropriate measures for the predicted imbalance, such as whether to revise the power generation plan already reported to the cross-regional organization or adjust the operation of the power generation equipment.

Patent No. 6991492 Patent No. 6216377

As a consumer, you want to pay as little electricity as possible. This is true even when using a self-dispatch system.

However, even when using solar power generation facilities, there are costs to be paid to external parties, such as investment and maintenance costs, transmission costs, and renewable energy surcharges, so the electricity generated by solar power generation incurs costs.

Depending on the time of day, it may be possible to reduce total electricity bills by purchasing electricity from the electricity market rather than self-dispatching the electricity generated by the solar power generation facility. Of course, even if a self-dispatching system is used, electricity must be purchased from the electricity market during times when the solar power generation facility is not generating electricity or when the remaining storage capacity is low and self-dispatching from the storage battery is difficult.

From this perspective, it is necessary to create power generation plans, power storage plans, and power transmission plans that can make electricity charges as cheap as possible in a self-dispatch system. However, no inventions that take such points into consideration have existed until now.

The present invention aims to provide a device for creating plans for power generation, storage, and transmission in a self-dispatch system that can reduce electricity charges as much as possible.

The power adjustment system described in paragraphs 0032 to 0048 of Patent Document 2 is not a self-dispatch system, but adjusts the period during which the storage battery (33) is charged or discharged in order to minimize the price paid for receiving (purchasing) electricity from the power grid (30). For example, the storage battery (33) is discharged during times when the unit price of purchasing electricity is high, and electricity is stored in the storage value (33) during times when the unit price of purchasing electricity is low. However, the power adjustment system described in Patent Document 2 is related to self-consumption within the consumer, and is not used in a self-dispatch system.

In order to solve the above problems, the present invention has the following features.
The present invention is a scenario creation device for creating scenario data that shows plans for power generation, storage, and transmission at a solar power generation facility in a self-wheeling system for transmitting electricity generated at a solar power generation facility located away from an electricity demand facility to the electricity demand facility via a power transmission grid.

The scenario creation device creates scenario data by creating plans for each time period for the amount of electricity purchased from the electricity market by the electricity demand facility, the amount of electricity generated and transmitted by the solar power generation facility, and the amount of electricity stored and transmitted by the solar power generation facility.

Preferably, the scenario creation device includes a comparison means for comparing the cost of purchasing electricity from the electricity market with the cost of self-consignment of electricity generated by the solar power generation facility, a first scenario data creation means for creating scenario data about the amount of electricity purchased, the amount of electricity generated and transmitted, and the amount of electricity stored and transmitted for the amount of electricity forecasted to be demanded for each time period at the electricity demand facility when the comparison means determines that the cost of purchasing electricity from the electricity market is lower, and a second scenario data creation means for creating scenario data about the amount of electricity generated and transmitted and the amount of electricity stored and transmitted for the amount of electricity forecasted to be demanded for each time period when the comparison means determines that the cost of purchasing electricity from the electricity market is higher.

Preferably, the first scenario data creation means creates scenario data assuming that electricity will be purchased from the electricity market if it is not a time period during which electricity generation is possible.

Preferably, the first scenario data creation means creates scenario data assuming that, when the price difference between the cost of purchasing electricity from the electricity market during a time period when electricity generation is possible and the cost of self-delivery of electricity generated by the solar power generation facility is greater than a first threshold, electricity is purchased from the electricity market and surplus electricity generated by the solar power generation facility is stored.

Preferably, the first scenario creation means creates scenario data taking into account the power demand at the power demand facility when the price difference between the cost of purchasing power from the power market and the cost of self-delivering the power generated by the solar power generation facility during a time period when power generation is possible is smaller than a threshold value.

Preferably, the first scenario creation means creates scenario data assuming that when the power demand at the power demand facility is smaller than the second threshold, power is purchased from the power market and the power generated at the solar power generation facility is self-delivered, and when the power demand at the power demand facility is greater than the second threshold, the first scenario creation means creates scenario data assuming that the power generated at the solar power generation facility and the stored power are self-delivered.

Preferably, the first scenario creation means takes into consideration the target achievement rate of the renewable energy ratio when deciding whether to purchase electricity from the electricity market, and creates scenario data assuming that if the target achievement rate of the renewable energy ratio is not achieved, electricity will not be purchased from the electricity market and will be generated and transmitted.

Preferably, when creating scenario data assuming that electricity is purchased from the electricity market and electricity generated by the solar power generation facility is self-consigned, the first scenario creation means creates the scenario data based on predetermined decision rules for purchase and power generation/transmission.

Preferably, the first scenario creation means creates the scenario data based on predetermined decision rules for power generation and transmission and stored power transmission, assuming that the power generated and stored in the solar power generation facility is self-consignment.

Preferably, when creating scenario data regarding the amount of generated and transmitted electricity and the amount of stored and transmitted electricity, the second scenario creation means creates the scenario data based on predetermined decision rules for generated and transmitted electricity and stored and transmitted electricity.

The present invention is also a program that causes a computer device for creating scenario data showing plans for power generation, storage, and transmission at a solar power generation facility in a self-dispatch system for transmitting power generated at a solar power generation facility located away from a power demand facility to the power demand facility through a power transmission network to function as a means for creating scenario data by creating plans for each time period for the amount of power purchased from the electricity market, the amount of power generated and transmitted by the solar power generation facility for self-dispatch, and the amount of stored and transmitted power for self-dispatch of power stored at the solar power generation facility.

Preferably, the computer device is a program that functions as a comparison means for comparing the cost of purchasing electricity from the electricity market with the cost of self-delivery of electricity generated by the solar power generation facility, a first scenario data creation means for creating scenario data regarding the amount of electricity purchased, the amount of electricity generated and transmitted, and the amount of stored electricity transmitted, for the forecasted amount of electricity demand for each time period at the electricity demand facility, when the comparison means determines that the cost of purchasing electricity from the electricity market is lower, and a second scenario data creation means for creating scenario data regarding the amount of electricity generated and transmitted, and the amount of stored electricity transmitted, for the forecasted amount of electricity demand for each time period, when the comparison means determines that the cost of purchasing electricity from the electricity market is higher.

The present invention also relates to a solar power generation facility including solar cells, a power conditioner unit, and a storage battery unit, and includes a control device for controlling the generation and transmission of electricity generated by the solar cells, the storage and transmission of electricity stored in the storage battery unit, and the storage of electricity in the storage battery unit, and the control device controls whether or not to generate and transmit electricity, store and transmit electricity, and store electricity based on scenario data created by a scenario creation device according to any one of claims 1 to 10.

The present invention also provides a control device used in a solar power generation facility equipped with solar cells, a power conditioner unit, and a storage battery unit, which controls the generation and transmission of electricity generated by the solar cells, the storage and transmission of electricity stored in the storage battery unit, and whether or not to store electricity in the storage battery unit, based on scenario data created by any of the scenario creation devices described above.

According to the present invention, scenario data can be created by creating plans for each time period for the amount of electricity purchased at the electricity demand facility, the amount of generated electricity to be transferred from the solar power generation facility, and the amount of stored electricity to be transferred from the solar power generation facility. Therefore, by creating this plan so that the electricity fee to be paid can be as low as possible, it is possible to make the electricity fee paid by the electricity demand facility as low as possible.

For example, when comparing the cost of purchasing electricity with the cost of generating and transmitting it, if purchasing electricity is cheaper, by creating scenario data on the amount of electricity purchased, the amount of electricity generated and transmitted, and the amount of electricity stored and transmitted, it becomes possible to use cheap purchased electricity at electricity demand facilities, making it possible to keep electricity bill payments as low as possible. On the other hand, by combining electricity purchases with generation and transmission and storage and transmission, it is possible to increase the proportion of renewable energy, thereby achieving the renewable energy utilization target.

Conversely, if the cost of purchased electricity is higher, electricity bills can be kept as low as possible by creating scenario data for the amount of electricity generated and transmitted and the amount of electricity stored and transmitted.

In addition, when the difference in cost between purchasing electricity and generating and transmitting it is large, since purchasing electricity is cheaper, electricity demand facilities can purchase electricity and store the surplus electricity they generate, making it possible to keep electricity bills as low as possible while also being able to store and transmit the electricity separately.

On the other hand, when the difference in cost between purchasing electricity and generating and transmitting it is small, by creating scenario data taking into account the electricity demand at electricity demand facilities, it becomes possible to adjust electricity rates and the renewable energy ratio according to demand.

If the renewable energy ratio does not reach the target, electricity bills may increase, but creating scenario data assuming that power generation and transmission will be used can contribute to achieving the renewable energy ratio target.

When the amount of electricity generated is low, reducing the amount of electricity purchased and increasing the amount of electricity generated and transmitted can contribute to increasing the proportion of renewable energy.

In addition, when the amount of electricity generated is low, reducing the amount of electricity generated and transmitted and increasing the amount of electricity stored and transmitted can also contribute to increasing the renewable energy ratio.

In addition, if the amount of electricity generated is small when the purchased electricity price is higher, reducing the amount of electricity generated and transmitted and increasing the amount of electricity stored and transmitted can also contribute to increasing the renewable energy ratio.

These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

FIG. 1 is a block diagram showing the overall configuration of a self-consignment system 1 according to an embodiment of the present invention. FIG. 2 is a block diagram showing the functional configuration of the scenario creating device 2. FIG. 3 is a diagram showing an example of scenario data for a certain day at a certain power demanding facility 8. FIG. 4 is a flowchart showing the operation of the scenario creating device 2. FIG. 5 is a flow chart showing the operation of process 1 in the scenario creating device 2. FIG. 6 is a flowchart showing the operation of process 2 in the scenario creating device 2. FIG. 7 is a table showing an example of rules for determining the ratio of purchase and generation/transmission of electricity. FIG. 8 is a flowchart showing an example of a rule for determining the ratio of electricity purchase and electricity generation/transmission. FIG. 9 is a table showing an example of a rule for determining the ratio of generated electricity and transmitted electricity and stored electricity and transmitted electricity. FIG. 10 is a flowchart showing the operation of the photovoltaic power generation facility 3.

In FIG. 1, the self-delivery system 1 includes a scenario creation device 2, a solar power generation facility 3, a power transmission network 4, a user terminal 5, a power generation prediction device 6, a new power information provider device 7, a power market price prediction device 8, and a network 9.

The electricity generated and stored in the solar power generation facility 3 is self-consignmented to the electricity demand facility 5 via the power transmission network 4. The electricity demand facility 5 receives electricity from the power transmission network 1. If the electricity demand facility 5 does not receive self-consignment, it purchases electricity from the electricity market.

The scenario creation device 2 creates data (referred to as "scenario data") that indicates a plan (referred to as "scenario") for whether the electricity demand facility 5 will purchase electricity from the electricity market and receive it (referred to as "electricity purchase"), receive electricity generated by the solar power generation facility 3 (referred to as "power generation and transmission"), receive electricity stored and transmitted by the solar power generation facility 3 (referred to as "storage and transmission"), or store the generated electricity without supplying it from the solar power generation facility 3 to the electricity transmission grid 4 (referred to as "power generation and storage").

The user terminal 5 instructs the scenario creation device 2 to create scenario data via the network 9.

The power generation prediction device 6 predicts the weather and amount of sunlight at the location where the solar power generation facility 3 is installed, creates information indicating the predicted amount of power generation at the solar power generation facility 3 (referred to as "power generation prediction information"), and transmits this information to the scenario creation device 2 via the network 9.

The new power information providing device 7 creates information on the costs required to transmit the electricity generated by the new power to the electricity demand facility 4 via the transmission network 4 (referred to as "new power transmission cost information") and transmits it via the network 10 in response to a request from the scenario creation device 2.

The electricity market price prediction device 8 creates prediction information (referred to as "electricity market price prediction information") for the price of new electricity to be traded in the electricity market (in Japan, the Japan Electric Power Exchange (JEPX)) and transmits it via the network 9 in response to a request from the scenario creation device 2. The price of electricity generated by new electricity, as determined in the electricity market, fluctuates, but the electricity market price prediction device 8 is a device that predicts that price.

As shown in FIG. 2, the scenario creation device 2 is a computer device including a control unit 21, an input unit 22, an output unit 23, a communication unit 24, and a storage unit 25. The control unit 21 creates scenario data by executing a program for performing the operations described in this specification. The program may be stored in the storage unit 25, or may be executed from external storage via the network 9 as appropriate. Furthermore, the data stored in the storage unit 25 may be stored on external storage via the network 9 as appropriate.

The memory unit 25 stores "electricity market price prediction information" per unit time (e.g., 30 minutes) obtained from the electricity price prediction device 8, and "new power transmission cost information" per unit time obtained from the new power information provider. The control unit 21 adds up the "electricity market price prediction information," "new power transmission cost information," and "renewable energy surcharge" (not shown), and stores "new power combined unit price prediction information (A)" per unit time (also called "new power charge unit price prediction value") in the memory unit 25.

The memory unit 25 stores "solar power generation cost information" indicating the cost of generating electricity per unit time at the solar power generation facility 3, and "solar power generation cost information" indicating the cost per unit time required to transmit the electricity generated at the solar power generation facility 3 to the electricity demand facility 5 via the power transmission network 4. The control unit 21 adds up the "solar power generation cost information" and the "solar power generation cost information" to store the "solar power generation facility combined cost (B)" (also called the "solar power generation facility combined cost") per unit time in the memory unit 25.

The control unit 21 stores the “power generation prediction information” per unit time downloaded from the power generation prediction device 6 in the storage unit 25 .
Control unit 21 stores demand forecasts at power demanding facilities 5 (referred to as “power demanding facility forecast information”) in memory unit 25. The “power demanding facility forecast information” is obtained from past performance and equipment used at power demanding facilities 5.

The control unit 21 predicts the remaining capacity of the storage battery based on the forecast information of the power demand facility, the power generation forecast information, and the amount of power generation and transmission, power generation and storage, and storage and transmission in the scenario data, and stores this in the memory unit 25 as "remaining storage capacity forecast information" per unit time.

The control unit 21 stores the created scenario data in the memory unit 25.

An example of scenario data will be described with reference to Figure 3. Between 0:00 and 1:30, since this is nighttime electricity, it is cheaper to purchase from the electricity market than to store and transmit it, so a scenario has been created in which 100% of the electricity purchased against the predicted demand is purchased. During this time, no electricity is generated at the solar power generation facility 3, so the predicted power generation amount is 0 [kWh]. No electricity is stored, so the predicted remaining storage amount remains unchanged at 2,603 [kWh]. Note that the solar power generation facility 3 is set not to store nighttime electricity, but it may also be set to store nighttime electricity.

As the sun rises, power generation at solar power generation facility 3 begins at 7:00. The predicted power generation from 7:00 to 7:30 is 214 [kWh], and the predicted demand is 427 [kWh]. At this time, since it is not possible to cover all demand with solar power generation, a scenario is created in which 50% of the predicted demand will be purchased, and 50% will be generated and transmitted. During this time, no remaining power generation occurs, so the predicted remaining storage capacity remains at 2,603 [kWh]. The same applies for the time period from 8:30 to 9:00.

The forecasted power demand from 9:00 to 9:30 is 1,052 [kWh]. The forecasted power generation during this period is 521 [kWh]. It is assumed that the new power supplier's combined unit price forecast information (A) is cheaper than the combined unit price (B) of the solar power generation facility. Therefore, the total cost will be cheaper if the power purchase is combined. It is assumed that the price difference between the new power supplier's combined unit price forecast information (A) and the combined unit price (B) of the solar power generation facility is smaller than the threshold Y1. It is also assumed that the forecasted power demand is smaller than the predetermined threshold Y2. In this case, the ratio of power purchase and power generation transmission is determined based on the purchase and power generation transmission ratio determination rule described later (see S209 in FIG. 5 described later). Here, scenario data is created with 70% purchased power, 30% generated power transmission, and 0% stored power transmission. The forecasted power demand is 1,052 kWh, and generating and transmitting 30% of that means transmitting 1,052 x 0.3 = 316 kWh (rounded off to the nearest whole number). The forecasted power generation during this period is 521 kWh, so there will be a surplus of 521-316 = 205 kWh. This surplus power will be stored in the storage battery ("power generation and storage" will be written as "execute"). The forecasted remaining storage capacity is 2,603 kWh, and 205 kWh will be stored, resulting in a remaining storage capacity of 2,808 kWh.

The forecasted power demand from 9:30 to 10:00 is 1,307 [kWh]. The forecasted power generation during this period is 616 [kWh]. It is assumed that the new power supplier's combined unit price forecast information (A) is cheaper than the combined unit price (B) of the solar power generation facility. Therefore, the total cost will be cheaper if the power purchase is combined. It is assumed that the price difference between the new power supplier's combined unit price forecast information (A) and the combined unit price (B) of the solar power generation facility is greater than the threshold Y1. In this case, 100% is purchased from the electricity market and the generated power is stored ("power generation and storage" is "executed") (see S204 in FIG. 5 described later). Here, scenario data is created with 100% purchased power, 0% power generation and transmission, and 0% storage and transmission. The forecasted power generation during this period is 616 [kWh], so all of it is stored. Therefore, the predicted remaining battery capacity is 2,808 kWh, and 616 kWh has been stored, resulting in a predicted remaining battery capacity of 3,424 kWh.

Similarly, let's assume that electricity purchases are 100% from the time period of 10:00-10:30 to the time period of 15:00-15:30, and power generation and storage continues. As a result, the predicted remaining amount of stored electricity from 15:00-15:30 is 6,169 [kWh].

The forecasted power demand from 15:30 to 16:00 is 1,422 [kWh]. The forecasted power generation during this period is 636 [kWh]. During this period, it is assumed that the combined unit price forecast information (A) of the new power company is higher than the combined unit price (B) of the solar power generation facility. Therefore, the total cost will be cheaper if power generation and transmission are combined with power storage and transmission. Here, scenario data is created with 40% power generation and transmission and 60% power storage and transmission (see S303 in Figure 6 described later). The forecasted power demand during this period is 1,422 [kWh], and since power generation and transmission is 40%, 1,422 x 0.4 = 569 [kWh] is generated and transmitted. Since the forecasted power generation is 636 [kWh], 636-569 = 67 [kWh] becomes surplus power and is stored. In addition, since the storage and transmission rate is 60%, 1,422 x 0.6 = 853 [kWh] will be stored and transmitted. Since the initial remaining storage amount was predicted to be 6,169 [kWh], the remaining storage amount during this period will be 6,169 + 67 - 853 = 5,383 [kWh].

Similarly, let us assume that power generation and transmission and storage and transmission continue from the time period of 16:00-16:30 to the time period of 18:00-18:30. As a result, the predicted remaining amount of stored power from 18:00-18:30 is 364 kWh. If any more storage and transmission is carried out, the remaining amount of stored power will be used up and power generation and transmission will no longer be possible after sunset, so the scenario data is created with power purchases at 100% from then until dawn.

The created scenario data is transmitted from the scenario creation device 2 to the control device 31 of the solar power generation facility 3 via the network 9.

In the above example, the scenario data is expressed as the ratio of power purchase, power generation and transmission, and power generation and storage to the demand forecast power amount [kWh], but it may be expressed in terms of power amount [kWh]. In other words, the scenario data may express the amount of power purchase (purchased power amount), the amount of power generated and transmitted (power generation and transmission amount), and the amount of power generated and stored (storage and transmission amount) to the demand forecast power amount [kWh] as a ratio, or as a power amount, or may be expressed in other ways, and does not limit the present invention. It can be said that the scenario data is data that shows plans (scenario) for each time period for the amount of power purchased from the electricity market, the amount of power generated and transmitted by the solar power generation facility 3 and the amount of stored and transmitted by the solar power generation facility 3 and the amount of stored and transmitted by the solar power generation facility 3.

The photovoltaic power generation facility 3 includes a control device 1, a PCS (Power Conditioning Subsystem) unit 32, a storage battery unit 33, solar cells 34, a switching device 35, and a power receiving and transforming facility 36.
The PCS unit 32 includes one or more PCSs 32a. A solar cell 34 is connected to each PCS 32a, and the generated power is converted to AC in each PCS 32a and sent to a switching device 35. The output power and the like of each PCS 32a are controlled based on a power generation control signal from the control device 31.

The storage battery unit 33 includes one or more storage batteries 33b and a bidirectional AC/DC converter 33a. Based on a storage control signal from the control device 31, the bidirectional AC/DC converter 33a can convert the electricity stored in the storage battery 33b into AC and supply it to the power grid via the switching device 35 and the substation equipment 36, or convert the electricity output from the PCS unit 32 into DC and store it in the storage battery 33b.

The switching device 35 is a device for switching whether to supply electricity from the PCS unit 32 or electricity from the storage battery unit 33 to the power transmission grid, or supply electricity from the PCS unit 32 to the storage battery 33, based on a power transmission/storage switching signal from the control device 31.
The substation equipment 36 is equipment for boosting the voltage to a level required for interconnection with the power transmission network 4 .

The control device 31 is a computer device that stores scenario data downloaded from the scenario creation device 2. Based on the scenario data, the control device 31 transmits a power generation control signal, a power storage control signal, and a power transmission/power storage switching signal to the PCS unit 32, the storage battery unit 33, and the switching device 35, thereby realizing power generation and transmission, power generation and storage, and power storage and transmission.

When generating and transmitting electricity, the control device 31 transmits a power generation control signal to the PCS unit 32 to output the generated electricity, and transmits a signal to the switching device 35 to switch the output electricity from the PCS 32 to be supplied to the electricity transmission grid 4.

In the case of power generation and storage, the control device 31 transmits a power generation control signal to the PCS unit 32 to output generated power, and transmits a signal to the switching device 35 to switch the output power from the PCS 32 to be supplied to the storage battery unit 33.

In the case of power storage and transmission, the control device 31 transmits a power storage control signal for discharging to the storage battery unit 33, and transmits a signal to the switching device 35 for switching the output power from the storage battery unit 33 to be supplied to the power transmission network 4.

When power generation and transmission are combined with power storage and transmission, the control device 31 outputs a power generation control signal and a power storage control signal such that power according to the respective ratios is output from the PCS unit 32 and the storage battery unit 33, and transmits a signal to the switching device 35 to switch the power from the PCS unit 32 and the storage battery unit 33 to be supplied to the power transmission network 4.

In the switching device 35, a circuit is formed so that surplus power is stored in the storage battery section 33.

The switching device 35 can be specifically realized by a device such as a PLC (Programmable Logic Controller), but is not limited to this.

Next, an example of a specific operational flow for creating scenario data will be described with reference to FIGS.
4, first, the control unit 21 of the scenario creation device 2 reads data to be used in the time period to be calculated (S101). The data are "price forecast information for the electricity market,""power transmission cost information for new power companies,""power generation unit price information for photovoltaic power generation facilities,""power transmission cost information for photovoltaic power generation facilities,""power generation amount forecast information,""demand forecast information for power demand facilities," and the most recent "remaining battery capacity forecast information."

The control unit 21 calculates "new power companies' combined unit price forecast information (A)" based on the "electricity market price forecast information" for the time period and the "new power companies' power transmission cost information" (S102).
The control unit 21 calculates the "total unit price (B) of the photovoltaic power generation facility" based on the "information on the unit price of power generation of the photovoltaic power generation facility" and the "information on the cost of power transmission of the photovoltaic power generation facility" for that time period (S103). The control unit 21 compares the two unit prices A and B to obtain C=A-B (S104).

If C is equal to or less than 0, i.e., if the unit price in the electricity market during that time period is lower than or equal to the unit price of the generated electricity, the control unit 21 executes process 1 (S105) to create a scenario. On the other hand, if C is greater than 0, i.e., if the unit price in the electricity market during that time period is higher than the unit price of the generated electricity, the control unit 21 executes process 2 (S106) to create a scenario.

The control unit 21 then repeats the above process until it has performed calculations for all time periods and created a scenario (S107). When calculations for all time periods are complete, the scenario data is complete (S108), and the control unit 21 transmits the scenario data to the control device 31 of the solar power generation facility 3 (S109).

The operation of creating scenario data in process 1 will be described with reference to FIG.
The control unit 21 determines whether the power generation amount prediction X2 for the relevant time period is greater than 0 (S201).

When X2 is not greater than 0 (i.e., when X2 is 0), it indicates that it is a time period when power generation is not possible. Since the electricity market is cheaper, the control unit 21 creates a scenario in which power purchase from the electricity market is 100%, without storing and transmitting electricity (storage and transmission is set to 0%) (S202).

When X2 is greater than 0, it indicates a time period during which power generation is possible. At this time, the control unit 21 judges whether the price difference C is greater than a predetermined threshold Y1 (S203). If it is greater than the threshold Y1, it means that the price difference is large, and that the unit price in the electricity market is sufficiently low. Therefore, the control unit 21 creates a scenario in which the amount of electricity purchased from the electricity market is set to 100%, and the surplus electricity generated is stored (executing "power generation and storage") (S204). After S204, the control unit 21 converts the surplus electricity to be stored into a predicted remaining amount of stored electricity, and creates a predicted remaining amount of stored electricity for that time period (S205).

If the price difference C is smaller than the threshold Y1, it means that the price difference is small, and the control unit 21 proceeds to operation S206 and beyond. If the electricity market price is lower, it may be possible to reduce electricity costs by purchasing all electricity during that time period, but this will not promote the use of renewable energy. Therefore, if the price difference C is smaller than the threshold Y1, renewable energy will be used by combining power generation and transmission and power storage and transmission.

In S206, the control unit 21 acquires demand forecast information X3 for the relevant time period at the power demanding facility 5. Then, the control unit 21 determines whether X3 is smaller than a predetermined threshold Y2 (S207).

If X3 is smaller than the threshold Y2, it means that demand is low. In this case, the control unit 21 determines the ratio of electricity purchased from the electricity market and the ratio of electricity generated and transmitted based on a predetermined "rule for determining the ratio of electricity purchased and electricity generated and transmitted," and creates a scenario (S209).

Figure 7 shows an example of a table that defines the "rules for determining the purchase and generation/transmission ratios." As shown in Figure 7, when the amount of power generation per time period is low, the purchase ratio is lowered and the generation/transmission ratio is increased. Conversely, when the amount of power generation per time period is high, the purchase ratio is increased and the generation/transmission ratio is decreased. The specific numerical values will be determined taking into consideration factors such as the amount of power that can be generated at the solar power generation facility 3.

Furthermore, after the ratio of purchase and power generation/transmission is determined based on FIG. 7, the determined ratio may be adjusted taking into consideration the current renewable energy ratio. Specifically, as shown in FIG. 8, the control unit 201 calculates the current annual target achievement rate of the renewable energy ratio (determined by the annual day elapsed rate and the addition of points) (S401). Then, the control unit 201 judges whether the current annual target achievement rate is equal to or lower than a threshold (S402). If it is equal to or lower than the threshold, the renewable energy ratio target has not been achieved, so a scenario is created in which power is generated and transmitted regardless of the time-of-day power generation (S403). On the other hand, if it is equal to or higher than the threshold, the renewable energy ratio has been achieved, so the control unit 201 creates a scenario in which the ratio of purchase and power generation/transmission according to FIG. 7 is used (S404).

Returning to the explanation of the operation from S207 onwards. In S207, if X3 is equal to or greater than the threshold Y2, this means that there is high demand. In this case, the control unit 21 creates a scenario based on the "rule for determining the ratio of power generation and transmission and power storage and transmission" assuming that power generation and transmission will be performed and that power storage and transmission will be performed (S208). In addition, since the remaining amount of stored power changes due to the storage and transmission, the control unit 21 updates the remaining amount of stored power prediction. However, if the remaining amount of stored power prediction falls below a lower limit (for example, 0), power storage and transmission will no longer be possible, and a scenario is created assuming that power will be purchased from the electricity market.

Figure 9 shows an example of a table that defines the "rules for determining the ratio of power generation and transmission and power storage and transmission." As shown in Figure 9, when the amount of power generation per time period is low, the power generation and transmission ratio is lowered and the power storage and transmission ratio is increased. Conversely, when the amount of power generation per time period is high, the power generation and transmission ratio is increased and the power storage and transmission ratio is decreased. The specific numerical values will be determined taking into consideration factors such as the amount of power that can be generated at the solar power generation facility 3.

As shown in FIG. 5, when the electricity market is cheaper, the ratio of purchase, power generation and transmission, and storage and transmission is determined by process 1. In summary, in the time period when power generation is not possible, power is purchased from the electricity market (S202), when the price difference between the unit price of purchased power and the unit price of generated power is large, power is purchased from the electricity market (S204), when the price difference is small and demand is low, purchase from the electricity market and power generation and transmission are combined (S209), and when the price difference is small and demand is high, power generation and transmission are combined and storage and transmission are combined (S208). The scenario is modified appropriately taking into account the renewable energy ratio. In this way, a scenario is created that can maintain the renewable energy usage ratio appropriately while keeping the costs to be paid as low as possible.

Next, the operation of creating scenario data in process 2 will be described with reference to FIG.
The control unit 21 determines whether the power generation amount prediction X2 for the relevant time period is greater than 0 (S301).

When X2 is not greater than 0 (i.e., when X2 is 0), it indicates that it is a time period during which power generation is not possible. The control unit 21 creates a scenario in which power storage and transmission is 100% (S302). In addition, since power storage and transmission causes a change in the remaining amount of power storage, the control unit 21 updates the remaining amount of power storage prediction. However, when the remaining amount of power storage prediction falls below a lower limit (e.g., 0), power storage and transmission is no longer possible, so a scenario is created in which power is purchased from the electricity market.

When X2 is greater than 0, it indicates a time period during which power can be generated. In this case, the control unit 21 creates a scenario based on the "rule for determining the ratio of power generation and transmission and power storage and transmission" assuming that power generation and transmission will be performed and that power storage and transmission will be performed (S303). In addition, since the remaining amount of stored power changes due to the storage and transmission, the control unit 21 updates the remaining amount of stored power prediction. However, if the remaining amount of stored power prediction falls below a lower limit (for example, 0), power storage and transmission will no longer be possible, and a scenario is created assuming that power will be purchased from the electricity market.

As shown in FIG. 6, when the electricity market price is higher, a choice is made between storing and transmitting electricity (S302) and generating and transmitting electricity and storing and transmitting electricity (S303). As a result, during times when the electricity market price is high, a scenario is created in which storing and transmitting electricity and/or generating and transmitting electricity is used to keep the costs to be paid as low as possible while maintaining the renewable energy usage ratio as appropriate.

The operation of the solar power generation facility 3 will be described with reference to FIG. 10. When the control timing for each time period (here, every 30 minutes) arrives (S501), the control device 31 of the solar power generation facility 3 refers to the downloaded scenario data for that time period (S502).

The control device 31 determines whether or not there is an allocation for stored power transmission (S503). If there is an allocation for stored power transmission, the control device 31 controls the switching device 35 and the storage battery unit 33 to supply the allocated amount of power to the grid (S504). However, if the capacity of the storage battery 33b is insufficient and it becomes impossible to supply the allocated amount of power, the control device 31 stops the stored power transmission.

Next, the control device 31 determines whether or not there is an allocation for power generation and transmission (S505). If there is an allocation for power generation and transmission, the control device 31 controls the switching device 35 and the PCS unit 32 to supply the allocated amount of power to the grid (S506). However, if contrary to prediction, the allocated amount of power cannot be generated due to insufficient sunlight, etc., the control device 31 controls to output the maximum power that can be generated.

Next, the control device 31 controls the PCS unit 32, the switching device 35, and the storage battery unit 33 so that the remaining generated electricity (surplus electricity) is stored in the storage battery 33b (S507).

As shown in FIG. 10, the control device 31 controls the PCS unit 32, the switching device 35, and the storage battery unit 33 for each time period according to the scenario data, thereby making it possible to provide power to the grid according to the scenario data.

In addition, the operational flows of processes 1 and 2 determined in S104 in the above embodiment may be inversely related, i.e., if the market price is cheaper, proceed to process 2, and so on, if this results in a cheaper price overall.
Furthermore, the operational flow of S204 based on the determination in S203 in the above embodiment may be executed in the opposite relationship, that is, when the price difference is small, if this results in a lower price overall, processing may be performed in that way.
Furthermore, the processes of S209 and S208 based on the determination in S207 in the above embodiment may be reversed. That is, when demand is low, a scenario based on a rule for determining the ratio of power generation and transmission and power storage and transmission may be created, and when demand is high, a scenario based on a rule for determining the ratio of purchase and power generation and transmission may be created.
In the processes of S302 and S303 based on the determination in S301 in the above embodiment, if the overall cost is reduced even if electricity is purchased during a time period when electricity generation is not possible, such a process may be performed.
The above-mentioned embodiments are merely examples of the decision rules for power generation and transmission and power storage and transmission, and the decision rules for purchase and power generation and transmission. They may be other than those illustrated, and may be determined by absolute values or relative values. As long as a scenario is created using a predetermined decision rule, any rule may be used. The decision rule may be a rule that determines an absolute value other than a ratio.

Although the present invention has been described in detail above, the above description is merely illustrative of the present invention in every respect and is not intended to limit its scope. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. Each of the constituent elements of the invention disclosed in this specification is considered to be an independent invention. Inventions in which the constituent elements are combined in any combination are also included in the present invention.

This is a scenario creation device for power generation, storage, and transmission in a self-delivery system using solar power generation facilities, and can be used industrially.

REFERENCE SIGNS LIST 1 Self-delivery system 2 Scenario creation device 21 Control unit 22 Input unit 23 Output unit 24 Communication unit 25 Memory unit 3 Photovoltaic power generation facility 31 Control device 32 PCS unit 32a PCS (power conditioner)
33 Storage battery unit 33a Bidirectional AC adapter converter 33b Storage battery 34 Solar cell 35 Switching device 36 Power receiving and transforming equipment 4 Power transmission network 5 User terminal 6 Power generation amount prediction device 7 New power information providing device 8 Power market price prediction device 9 Network

Preferably, the first scenario data creation means creates scenario data taking into account the electricity demand at the electricity demand facility when the price difference between the cost of purchasing electricity from the electricity market and the cost of self-delivering electricity generated by the solar power generation facility during a time period when electricity generation is possible is smaller than a threshold value.

Preferably, the first scenario data creation means creates scenario data assuming that when power demand at the power demand facility is smaller than a second threshold, power is purchased from the power market and power generated at the solar power generation facility is self-delivered, and when power demand at the power demand facility is greater than the second threshold, the first scenario data creation means creates scenario data assuming that power generated at the solar power generation facility and stored power are self-delivered.

Preferably, the first scenario data creation means takes into account the target achievement rate of the renewable energy ratio when deciding whether to purchase electricity from the electricity market, and creates scenario data in such a way that, if the target achievement rate of the renewable energy ratio has not been achieved, electricity is generated and transmitted without being purchased from the electricity market.

Preferably, when the first scenario data creation means creates scenario data assuming that electricity is purchased from the electricity market and electricity generated by the solar power generation facility is self-delivered, the scenario data is created based on predetermined decision rules for purchasing and power generation and transmission.

Preferably, the first scenario data creation means creates the scenario data based on predetermined decision rules for power generation and transmission and stored power transmission, assuming that the electricity generated and stored in the solar power generation facility is self-delivered.

Preferably, when creating the scenario data regarding the amount of generated electricity and transmitted electricity and the amount of stored electricity and transmitted electricity, the second scenario data creation means creates the scenario data based on a predetermined decision rule for generated electricity and transmitted electricity and stored electricity and transmitted electricity.

Claims (14)

A scenario creation device for creating scenario data indicating a plan for power generation, power storage, and power transmission at a solar power generation facility in a self-wheeling system for transmitting power generated at a solar power generation facility located away from a power demand facility to the power demand facility through a power transmission network, comprising:
A scenario creation device that creates the scenario data by creating plans for each time period for the amount of electricity purchased by the electricity demand facility from the electricity market, the amount of electricity generated and transmitted by the solar power generation facility and the amount of electricity stored and transmitted by the solar power generation facility. A comparison means for comparing a cost of purchasing electricity from an electricity market with a cost of self-transporting electricity generated by the solar power generation facility;
a first scenario data creation means for creating the scenario data regarding the amount of purchased electricity, the amount of generated electricity and transmitted electricity, and the amount of stored electricity and transmitted electricity, for the forecasted amount of electricity demand for each time period at the electricity demanding facility, when the comparison means determines that the cost of purchasing electricity from the electricity market is cheaper;
The scenario creation device as described in claim 1, further comprising a second scenario data creation means for creating the scenario data regarding the generated and transmitted amount and the stored and transmitted amount for the forecasted demand amount for each time period when the comparison means determines that the cost of purchasing electricity from the electricity market is higher. The scenario data creation device according to claim 2, characterized in that the first scenario data creation means creates the scenario data by assuming that electricity is purchased from the electricity market when it is not a time period during which electricity can be generated. The scenario creation device according to claim 2, characterized in that the first scenario data creation means creates the scenario data by purchasing electricity from the electricity market and storing surplus electricity generated by the solar power generation facility when the price difference between the cost of purchasing electricity from the electricity market and the cost of self-consignment of electricity generated by the solar power generation facility during a time period when electricity generation is possible is greater than a first threshold value. The scenario creation device according to claim 2, characterized in that the first scenario creation means creates the scenario data taking into account the power demand at the power demand facility when the price difference between the cost of purchasing power from the power market and the cost of self-consigning the power generated at the solar power generation facility during a time period when power generation is possible is smaller than a threshold value. The first scenario creation means includes:
When the power demand at the power demand facility is smaller than a second threshold, the scenario data is created assuming that power is purchased from the power market and that the power generated at the solar power generation facility is self-consignment;
The scenario creation device of claim 5, characterized in that when the electricity demand at the electricity demand facility is greater than a second threshold, the scenario data is created by assuming that the electricity generated and stored at the solar power generation facility will be self-delivered. The scenario creation device according to claim 6, characterized in that the first scenario creation means, when deciding whether to purchase electricity from the electricity market, takes into account the target achievement rate of the renewable energy ratio, and creates the scenario data by assuming that electricity will be generated and transmitted without purchasing electricity from the electricity market if the target achievement rate of the renewable energy ratio has not been achieved. The scenario creation device according to claim 6, characterized in that when the first scenario creation means creates the scenario data assuming that electricity is purchased from the electricity market and electricity generated by the solar power generation facility is self-consigned, the scenario data is created based on predetermined purchase and power generation/transmission decision rules. The scenario creation device according to claim 6, characterized in that when the first scenario creation means creates the scenario data assuming that the electricity generated and stored in the solar power generation facility is self-consigned, the scenario data is created based on predetermined decision rules for power generation and transmission and stored and transmitted electricity. The scenario creation device according to claim 2, characterized in that when creating the scenario data for the amount of generated and transmitted electricity and the amount of stored and transmitted electricity, the second scenario creation means creates the scenario data based on predetermined rules for determining generated and transmitted electricity and stored and transmitted electricity. In a self-transmission system for transmitting power generated at a solar power generation facility located away from a power demand facility to the power demand facility through a power transmission network, a computer device for creating scenario data showing a plan for power generation, storage, and transmission at the solar power generation facility,
The program functions as a means for creating the scenario data by creating plans for each time period for the amount of electricity purchased from the electricity market, the amount of electricity generated and transmitted by the solar power generation facility and the amount of electricity stored and transmitted by the solar power generation facility. The computer device,
A comparison means for comparing a cost of purchasing electricity from an electricity market with a cost of self-transporting electricity generated by the solar power generation facility;
a first scenario data creation means for creating the scenario data regarding the amount of purchased electricity, the amount of generated electricity and transmitted electricity, and the amount of stored electricity and transmitted electricity, for the forecasted amount of electricity demand for each time period at the electricity demanding facility, when the comparison means determines that the cost of purchasing electricity from the electricity market is cheaper;
The program according to claim 11, characterized in that when the comparison means determines that the cost of purchasing electricity from the electricity market is higher, the program functions as a second scenario data creation means for creating the scenario data regarding the generated and transmitted electricity amount and the stored and transmitted electricity amount for the forecasted demand electricity amount for each time period. A solar power generation facility including a solar cell, a power conditioner unit, and a storage battery unit,
a control device for controlling the power generation and transmission of the power generated by the solar cell, the power storage and transmission of the power stored in the storage battery unit, and the power storage in the storage battery unit,
A solar power generation facility, characterized in that the control device controls whether or not to generate and transmit electricity, store and transmit electricity, and store electricity based on the scenario data created by the scenario creation device described in claim 1 or 2. A control device used in a solar power generation facility including a solar cell, a power conditioner unit, and a storage battery unit,
A control device characterized by controlling the generation and transmission of electricity generated by the solar cell, the storage and transmission of electricity stored in the storage battery unit, and whether or not to store electricity in the storage battery unit, based on the scenario data created by the scenario creation device described in claim 1 or 2.