Wholesale electricity trading system

Abstract

To provide a wholesale electricity trading system that sets a trading schedule for a next day in advance based on an electricity market price for the next day announced by a wholesale electricity exchange, and always realizes advantageous operation with minimal effort.SOLUTION: In a wholesale electricity trading system 1000 including a control unit (control computer) 1050 connected to an Internet environment (Internet cloud) 3000 via LTE communication or the like, and a server 1010 provided in a cloud and connected to the control unit via the Internet environment, the control unit acquires electricity market price data EPD for a next day announced by the Japan Electric Power Exchange 2000, sets a schedule for purchasing electricity when an electricity market price is lower than a prescribed first reference value PT1 and discharging electricity when the electricity market price is higher than a prescribed second reference value PT2, and charges and stores the purchased electricity in a storage battery 1030. The PT1 and PT2 have a relation of PT1<PT2 or PT1≤PT2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wholesale electricity trading system for trading electricity with the Japan Electric Power Exchange and the like. [Background technology]

[0002] With the liberalization of the electricity market, power generation, transmission, and retail have become independent businesses, giving operators the opportunity to generate revenue from their own electricity and reduce costs of making up for power shortages.

[0003] For example, the energy trading system described in Patent Document 1 relates to an energy trading system for obtaining electricity for use in electric vehicles through energy trading, in which the user observes the ever-changing trading price on a display screen and decides on the operation details. However, the task of constantly observing a display screen is hard work, and it is not easy to always achieve advantageous operation.

[0004] Furthermore, the technology in Patent Document 1 relates to the power of a single electric vehicle, and is difficult to apply to wholesale electricity trading among businesses that use electricity for a wide range of purposes.

[0005] [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2021-149331 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to enable business operators to always achieve advantageous operations without the need for them to observe transaction prices. [Means for solving the problem]

[0008] The wholesale electricity trading system of the present invention obtains the electricity market price for the next day announced by the wholesale electricity exchange, sets a schedule for purchasing electricity when the electricity market price is lower than a predetermined first reference value and discharging electricity when the electricity market price is higher than a second reference value, and charges and stores the purchased electricity in a storage battery. Effect of the Invention

[0009] According to the present invention, since a trading schedule for the next day can be set in advance based on the electricity market price for the next day announced by the wholesale electricity exchange, advantageous operation can always be realized with a minimum of effort. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram showing an embodiment of a wholesale electricity trading system and charging and discharging of a storage battery according to the present invention. FIG. [Diagram 2] 4 is a flowchart showing a schedule setting process in the wholesale electricity trading system of FIG. 1. [Diagram 3] 3 is a flowchart showing a charge / discharge operation corresponding to a transaction based on the schedule created in FIG. 2. [Figure 4] This is a graph showing the relationship between the electricity market price (announced the day before) and charging and discharging operations. This is an example where there are clearly times when the price is low and times when it is high. [Diagram 5] This is a graph showing charging operations that take into consideration the BCP (Business Continuity Plan) measures for storage batteries. An example of electricity market prices is given, where the time periods when prices are low and high are not clearly defined. [Figure 6] 1 is a graph showing changes in electricity market prices on a given day. [Figure 7] 7 is a table showing details of electricity charges for a market-linked electricity contract consumer at the electricity market price in FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, an embodiment of a wholesale electricity trading system according to the present invention will be described with reference to the drawings. EXAMPLES

[0012] As shown in Fig. 1, the wholesale electricity trading system 1000 includes a control unit (control computer) 1050 connected to an Internet environment 3000 by LTE communication or the like, and a server 1010 provided in a cloud and connected to the control unit 1050 via the Internet environment (Internet cloud) 3000. The Japan Electric Power Exchange (JEPX) 2000 is connected to the Internet environment 3000, and the server 1010 acquires electricity market prices in the market provided by JEPX 2000 and executes electricity trading. That is, the server 1010 functions as an electricity market price acquisition means.

[0013] The JEPX2000 market consists of a "day-ahead spot market," a "hour-ahead market," and a "distributed green power selling market," but this invention focuses on the "day-ahead spot market." The day-ahead spot market trades the next day's electricity in 48 units of 30 minutes, and allows users to know the electricity market price for the next day the day before. Electricity market prices are announced as area prices for each region of Japan: Hokkaido, Tohoku, Tokyo, Chubu, Hokuriku, Kansai, Chugoku, Shikoku, and Kyushu, and can be obtained in CSV (Comma Separated Value) format data (hereinafter referred to as EPD).

[0014] The server 1010 obtains data EPD of the electricity market price for the next day in the area where wholesale electricity trading is carried out (e.g., the area where the wholesale electricity trading system 1000 is located) from JEPX2000, and compares the market prices PP1 to PP48 of 48 products every 30 minutes with a first reference value PT1 and a second reference value PT2.

[0015] When the server 1010 compares the market prices PP1 to PP48 with PT1 and finds that PPi (i = 1 to 48) is lower than PT1, it purchases power and charges the battery 1030 (described later). When PPi (i = 1 to 48) is higher than PT2, it discharges power and sets a schedule (hereinafter referred to as SCH). That is, the server 1010 functions as a schedule setting means. The power discharged here may be used within the business premises or sold to other consumers or the power company.

[0016] For the first reference value PT1, for example, the average value of the power market price of the data EPD may be adopted, or some specific market price may be adopted. The same applies to the second reference value PT2. PT1 and PT2 are in the relationship of PT1 < PT2 or PT1 ≤ PT2.

[0017] The control unit 1050 is connected to a power conditioner 1040, which is a power charge / discharge means, through an interface such as RS485. The purchased power (AC) PAI is charged from the power grid 4000 through the charging system 4010 to the power conditioner 1040. The sold power (AC) PAO is discharged from the power conditioner 1040 through the discharging system 4020 to the power grid 4000 and delivered to the consumer load. And a power measurement unit 4030 is provided to measure the amounts of purchased power and sold power.

[0018] The power conditioner 1040 is connected to a battery 1030, which is a power holding means. The charged power PAI is stored in the battery 1030 as power (DC) PDI. Also, the discharged power PAO is the power (DC) PDO discharged from the battery 1030. That is, the power conditioner 1040 has a converter function to convert AC power PAI into DC power PDI and an inverter function to convert DC power PDO into AC power PAO.

[0019] The control unit 1050 monitors the charging power to the storage battery 1030 in the power conditioner 1040, and this enables the server 1010 to constantly grasp the charge amount (hereinafter referred to as CH) of the storage battery 1030.

[0020] Furthermore, the control unit 1050 is provided with a demand power measurement unit 1060, which is a power demand measurement means, and the demand power measurement unit 1060 measures the current power demand (hereinafter referred to as DM) and its change amount (hereinafter referred to as DDM). The server 1010 acquires the power demand DM and the change amount DDM through the control unit 1050. When this power demand DM is low, there is little benefit to discharging from the storage battery 1030. Also, when the power demand is decreasing rapidly, there is a possibility that the power supply to the consumer will be excessive, resulting in a reverse power flow phenomenon, so discharging should be stopped.

[0021] That is, the server 1010 manages the energy trading in consideration of not only the schedule SCH based on the data EPD, but also the charge amount CH of the storage battery, the energy demand DM, and the change amount DDM in the energy demand.

[0022] In addition, a specific load changeover switch 1070 is connected to the control unit 1050, and power can be supplied from the storage battery 1030 to specific loads in the business establishment where the wholesale power trading system 1000 is installed. For example, when the general power used in the business establishment is cut off, it is necessary to use the storage battery 1030 as an emergency power source, but in order to carry out business operations using only the power from the storage battery 1030 until the power is restored, it is necessary to supply power only to the essential specific loads. The server 1010 operates the specific load changeover switch 1070 via the control unit 1050 and supplies power only to the specific loads.

[0023] It should be noted that a solar panel 1090 can also be connected to the power conditioner 1040, and the power generated by the solar panel 1090 can be used as charging power PDI and discharging power PAO.

[0024] Server 1010 is connected to the Internet cloud 3000 and can be operated using a general Internet browser from a personal computer. It can also be operated from the screen of smartphone 1020. Software written in languages such as html and Java script is placed in server 1010, and a database for storing data is also placed there.

[0025] As shown in FIG. 2, when creating schedule SCH in server 1010, the following processing is executed. Step S201: Obtain the electricity market price data EPD for the next day from JEPX2000. Step S202: Calculate the average values of the market prices PP1 to PP48 of 48 products every 30 minutes in the electricity market price data EPD, and set them as the values of PT1 and PT2, but they can be changed by the administrator. Step S203: Initialize the product number "i" to "1" for comparison with the market prices PP1 to PP48 of 48 products. Step S204: Determine whether PP1 < PT1. If PP1 < PT1, proceed to step S205; if PP1 ≥ PT1, proceed to step S206. Step S205: Enter a charging prompt in the schedule. As a result, charging will be executed for product 1 (electricity in the first time period) in schedule SCH. Step S206: Determine whether PP1 > PT2. If PP1 > PT2, proceed to step S207; if PP1 ≤ PT2, proceed to step S208. Step S207: Enter a discharging prompt in the schedule. As a result, discharging will be executed for product 1 (electricity in the first time period) in schedule SCH. Step S208: Determine whether the product number i is the last 48. When the process is completed up to the last product, end the process; when i < 48, proceed to step S209. Step S209: Increment the product number i by "1" and return to step S204. Thereafter, in steps S204 to S207, the determination process for i=2 to 48 (steps S204, S206) and the prompt process (S205, S207) are repeated, and when it is determined in step S208 that the process is to be ended, the process ends. As a result of the above, it is clearly stated in the schedule SCH whether charging or discharging should be performed.

[0026] As shown in FIG. 3, the charging and discharging operation process in the server 1010 is executed as follows. Step S301: First, it is determined whether or not the storage battery 1030 is lower than the minimum charge level in the BCP countermeasures. If it is lower, the process proceeds to step S302, and if it is not lower, the process proceeds to step S303. Step S302: The power conditioner 1040 is charged with the power PAI, and the process returns to step S301. That is, charging is performed until the storage battery 1030 reaches the minimum charge level in the BCP countermeasure. Step S303: The clock built into the server 1010 is referenced, and the process proceeds to step S304. Step S304: If it is midnight, which is the schedule execution start time, execution is started and the process proceeds to step S305. If it is before midnight, the process returns to step S303. Step S305: It is determined whether or not a charging prompt is described in the schedule SCH. If it is described, the process proceeds to step S306, and if it is not described, the process proceeds to step S308. Step S306: It is determined whether the storage battery 1030 is fully charged. If it is fully charged, the process proceeds to step S312, and if it is not fully charged, the process proceeds to step S307. Step S307: The power conditioner 1040 is charged with the power PAI, and the process proceeds to step S312. Step S308: It is determined whether or not a discharge prompt is described in the schedule SCH. If it is described, the process proceeds to step S309, and if it is not described, the process proceeds to step S312. Step S309: It is determined whether the current power demand DM is greater than a predetermined value. If it is greater, the process proceeds to step S310, and if it is not greater, the process proceeds to step S312. Step S310: It is determined whether or not the amount of decrease in the current power demand is less than a predetermined value. If it is less, the process proceeds to step S311, and if it is not less, the process proceeds to step S312. Step S311: Discharge the power PAO from the power conditioner 1040, and proceed to step S312. Step S312: The clock built into the server 1010 is referenced, and the process proceeds to step S313. Step S313: It is determined whether the end time of the charge / discharge operation is after midnight. If it is after midnight, the process is terminated, and if it is before midnight, the process proceeds to step S313. Step S314: The execution contents of the schedule SCH are adjusted to the current time, and the process returns to step S305. In this way, charge / discharge operation based on the schedule SCH and flexible charge / discharge operation that takes into consideration the power demand DM, the power demand reduction amount DDM, and the charge amount CH of the storage battery 1030 are performed regardless of the schedule SCH. In other words, the server 1010 functions as a power charge / discharge final decision means that sets the operation of the power charge / discharge means according to the state of the power holding means and the state of power demand, regardless of the schedule SCH.

[0027] Figure 4 is a graph showing the status of charging and discharging operations based on the Schedule SCH in relation to 24-hour changes in electricity market prices. In the graph, the charging standard value PT1 and the discharging standard value PT2 are set equally at 8 yen / kwh, discharging is performed from 0:00 to 7:30 when the market price is higher, charging is performed from 7:30 to 15:00 when the market price is lower, and discharging is performed from 15:00 to 24:00 when the market price is higher. Since such charging and discharging is automatically performed by the server 1010 based on a schedule, there is no burden on the operator.

[0028] Figure 5 shows a case where the price on the next day in the electricity market is, for example, when the weather in the electricity market area is bad with cloudy or rainy weather forecast for the next day, and even during the daytime when prices are usually cheaper, the amount of solar power generation in the area is low, resulting in higher demand and higher electricity prices even during the day.On the other hand, there is a clear difference between the times when the prices are cheap and the times when they are high.In other words, when the weather is good and there is a lot of solar power generation, the daytime electricity price is cheaper, so there is enough electricity to charge the storage battery during that time, and electricity for BCP can be charged immediately. The graph in FIG. 5 shows a state in which a charge / discharge operation based on the schedule SCH and a charge / discharge operation taking into consideration the charge amount CH of the storage battery 1030 are performed. On the graph, the market price fell below the reference value PT1 at around 0:30 and charging started, but while charging was in progress, the charge amount CH of the storage battery 1030 was lower than the minimum charge level in the BCP measures, so even though the market price rose above the reference value PT1 at 12:00, charging continued until 16:30 when the charge amount exceeded the minimum charge level in the BCP measures. In other words, the first half of the total charging time is charging based on the schedule SCH, but the rest is charging to ensure the minimum charge amount in accordance with the BCP. Such flexible charging and discharging operations realize a healthy wholesale electricity trading business.

[0029] Figure 6 is a graph of the electricity price in the "day-ahead spot market" on April 26, 2023, as actually announced by JEPX2000, and Figure 7 shows an example of how a certain consumer operates in relation to this electricity price.

[0030] As shown in Table 1 of Figure 7, a consumer contracted with an electric power company for a contracted power of 90KW and used 11,177KWH of electricity in April 2023. As shown in Table 2 of Figure 7, the electricity bill for April 2023 was 287,611 yen.

[0031] In the graph in Figure 6, the electricity price fluctuates between 6 yen / KWH and 15 yen / KWH from midnight to 7 am, then drops to 0.1 yen / KWH until 2 pm, then rises to a maximum of around 18 yen, and settles at around 12 yen / KWH at midnight. In other words, there are times when the price clearly drops, making it easy to plan charging and discharging schedules. In response to this price trend, the consumer purchased electricity from 8:00 to 14:00 and charged it into a storage battery, and discharged it from the storage battery at other times for use within the business. As shown in Table 1, the storage battery is 20 kW.

[0032] The basic charge, wheeling charge (daytime), wheeling charge (nighttime), KW surcharge, power charge, and renewable energy surcharge in Table 2 are the price details when general consumers purchase electricity through market-linked electricity, and the total of 452,927 yen is approximately 63% of the power charge of 287,611 yen calculated using a floating market rate system. If the price fluctuation trend with clear charging and discharging timing, as shown in Figure 6, occurs 50% of the time during a month, in other words, if there is a 50% probability of extremely cheap and expensive periods of time during a month, then the reduction in power consumption by power users due to battery discharge is equivalent to 16%, and multiplied by the aforementioned 63%, the monthly power price reduction effect is 0.16 x 0.63 = 0.1, or approximately 10%. Here, the 16% reduction in power consumption is based on the assumption that a general consumer with the above electricity rates will install a 120KWH storage battery with a 20KW power conditioner, fully charge it for 50% for 15 days (i.e., one month) in 6 hours every day, and charge it at a price of approximately 0.1 yen / KWH. Therefore, the cumulative monthly charging volume will be 20KW x 6h x 15 days = 1800KWH, which is 16% of the total monthly power consumption of 11,177KWH.

[0033] As shown in Fig. 6, charging the storage battery 1030 when the electricity price is low and discharging it when the price is high overturns the conventional idea that storage batteries do not generate money, and since the amount of electricity used can be substantially reduced and electricity bills can be saved by charging and discharging the storage battery 1030, the storage battery 1030 is a powerful tool for BCP measures, energy conservation, and electricity bill reduction. This allows consumers to generate economic benefits with just the storage battery, just like those who install solar power generation panels, without having to install solar power generation panels for personal consumption. [Industrial Applicability]

[0034] The above embodiment relates to electricity used in a business establishment, but it goes without saying that the present invention can be applied to power management for electric vehicles such as those described in Patent Document 1. [Explanation of symbols]

[0035] CH charge amount DM power demand DDM Electricity Demand Change EPD Area Price Data PAI AC charging PAI Purchased Electricity (AC) PAO Electricity sold (AC) PDI charging power (DC) PDO discharge power (DC) PP1~PP48 Commodity market price PT1 First Reference Value PT2 Second Reference Value SCH Schedule 1000 Wholesale Electricity Trading System 1010 Server 1020 Smartphone 1030 Storage battery 1040 Power Conditioner 1050 Control Unit 1060 Demand power measurement unit 1070 Specific load changeover switch 1080A~1080N load 1090 Solar Panel 2000 Japan Electric Power Exchange 3000 Internet environment (Internet cloud) 4000 power system 4010 Charging system 4020 Discharge system 4030 Power Measurement Unit

Claims

1. power retaining means for retaining power; An electricity market price acquisition means for acquiring the next day's electricity market price announced by the wholesale electricity exchange; A schedule setting means for setting a schedule for charging and discharging electricity based on the electricity market price; a power charging / discharging means for purchasing power and charging the power to the power storage means when charging power based on the schedule, and discharging power from the power storage means when discharging power based on the schedule; Equipped with the schedule setting means sets a schedule for purchasing and charging electricity when the electricity market price is lower than a predetermined first reference value, and discharging electricity when the electricity market price is higher than a second reference value; Wholesale electricity trading system.

2. 2. The wholesale electricity trading system according to claim 1, wherein the first and second reference values ​​are average values ​​of the electricity market price.

3. 2. The wholesale power trading system according to claim 1, further comprising a power charge / discharge final decision means for setting the operation of the power charge / discharge means in accordance with the state of the power holding means and the state of power demand, regardless of the schedule.

4. 4. The wholesale electricity trading system according to claim 3, further comprising an electricity demand measuring means for measuring electricity demand and changes therein.

5. 2. The wholesale power trading system according to claim 1, further comprising specific load limiting means for limiting loads connected to the power holding means to only specific loads set in advance.

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