Power exchange system

Abstract

To provide a technique for accurately determining the amount of power to be shared between bases even when the amount of power generated by a solar power generation system varies greatly depending on the weather.SOLUTION: A power interchange system according to the present invention searches for a power transmission source location with a weather pattern that causes small fluctuations in the amount of power generated by a solar power generation system, and transmits surplus power at that power transmission source location to a power transmission source location with the weather pattern that causes large fluctuations in the amount of power generated.SELECTED DRAWING: Figure 9A

Description

Technical Field

[0001] The present invention relates to a power sharing system that transmits electric power between bases via a power transmission network.

Background Art

[0002] In recent years, the awareness of power consumers and suppliers towards carbon neutrality has increased, and power generation systems with solar power generation (PV: Photo Voltaic) using natural energy and storage batteries installed in parallel are becoming widely popular. Such a power generation system can also be used as a power sharing system in which an operator or the like equipped with power generation facilities supplies (transmits) power to other systems via a power transmission network or the like owned by a power company, or receives power supply (receives power) from other systems.

[0003] When implementing power sharing from one or more bases, it is necessary to submit a sharing plan to an operating agency (e.g., a power wide-area operation promotion agency: OCCTO) before starting power transmission (e.g., the day before). Furthermore, while power sharing is being implemented, it is necessary to transmit power as planned at predetermined time intervals (e.g., 30 minutes). When the actual transmitted power deviates (is unbalanced) from the pre-planned power, penalties are generally imposed.

[0004] Patent Document 1, described below, aims to "provide an energy management system that can centrally manage the charging and discharging of in-home energy storage units in an area with multiple houses equipped with solar power generation units and in-home energy storage units, and can efficiently perform charging, discharging, and power exchange." The system describes a technology that "the energy management system 1 comprises a data receiving unit 27 that receives weather forecast data and data on the remaining charge of the in-home energy storage unit 13, and a control unit 26 that controls the charging and discharging of the in-home energy storage unit 13 based on information including the weather forecast data and the remaining charge data. The control unit 26 groups the houses 11 based on the magnitude of the power generation capacity of the first solar power generation unit 12 of each house 11 and the magnitude of the remaining charge data of the in-home energy storage unit 13 received by the data receiving unit 27, and for each group, it decides whether to charge or discharge the in-home energy storage unit 13 or to exchange power with the second area." (See abstract).

[0005] Patent Document 2, described below, aims to "provide a control device and control program for a power exchange system that can enable a battery to function as a backup power source for a long period of time by ensuring that the State of Charge (SOC) of the battery is secured when the power supply is cut off due to a disaster." It describes a technology that "the control device 1 comprises a power prediction unit 12 that predicts the power consumption of the load and the power generation of the solar cell, a disaster occurrence prediction unit 11 that predicts the probability of a disaster occurring based on weather data, and an operation plan optimization unit 13 that creates an operation plan for controlling the charging and discharging of the battery based on the prediction results of the power prediction unit 12 and the prediction results of the disaster occurrence prediction unit 11." (See abstract). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2017-225301 [Patent Document 2] Japanese Patent Publication No. 2017-108560 [Overview of the project] [Problems that the invention aims to solve]

[0007] Let's consider a power generation system that generates electricity for transmission through power sharing, for example, one composed of solar power generation and storage batteries. The amount of power output from solar power generation fluctuates depending on the amount of solar radiation. Depending on the weather, there are various fluctuation patterns in the amount of solar radiation, such as large fluctuations throughout the day or relatively stable fluctuations. Accordingly, the amount of power output from solar power generation also shows various fluctuation patterns, such as large fluctuations or relatively stable fluctuations, depending on the weather. For example, on a day when the amount of power generated (=actual power sharing) fluctuates greatly, in order to transmit power while adhering to the amount of power that was planned to be shared in advance (=spin-off plan), it is necessary to suppress the spin-off plan to be smaller than the point of maximum power, and to instruct the storage batteries to discharge to compensate for the power shortage.

[0008] In this situation, in order to avoid reducing the amount of electricity exchanged between sites as much as possible, the amount of curtailment in the exchange plan must be kept to a minimum. However, when there are large fluctuations in actual exchange data, accurately determining the amount of curtailment from the point of maximum power is not always easy. In particular, when exchanging electricity from a single site, if the amount of curtailment is not set correctly, a large amount of electricity generated will be wasted to avoid imbalance penalties, or the number of times the battery is discharged to compensate for the power shortage will increase, putting stress on the battery.

[0009] This invention has been made in view of the above-mentioned problems, and aims to provide a technology that can accurately determine the amount of electricity to be exchanged between locations, even when the amount of electricity generated by a solar power generation system fluctuates greatly depending on the weather. [Means for solving the problem]

[0010] The power exchange system according to the present invention searches for a power source base with a weather pattern in which the power generation amount of a solar power generation system fluctuates little, and transmits the surplus power amount at that power source base to a power source base with a weather pattern in which the power generation amount fluctuates greatly. [Effects of the Invention]

[0011] According to the power exchange system of the present invention, even when the amount of power generated by a solar power generation system fluctuates greatly depending on the weather, the amount of power to be exchanged between locations can be accurately determined. Other issues, configurations, effects, etc. will be clarified by the following description of embodiments. [Brief explanation of the drawing]

[0012] [Figure 1] This is an example of the configuration of power exchange system 1, which is used by a power exchange business operator. [Figure 2] This is a schematic diagram illustrating how power is exchanged between different locations. [Figure 3] This shows an example of weather forecast data provided by a weather information provider. [Figure 4] Figure 3 shows an example of determining each weather pattern from the weather codes in the weather forecast data. [Figure 5] Figure 3 is a flowchart illustrating the procedure for determining weather patterns from weather codes within weather forecast data. [Figure 6A] This graph compares actual and planned resource allocation under weather pattern A+. [Figure 6B] This graph compares actual and planned resource allocation under weather pattern A-. [Figure 6C] This graph compares actual and planned resource allocation under weather pattern B-. [Figure 7] This shows an example of data on the rated power generation capacity of solar power generation facilities at each location. [Figure 8] This is a flowchart illustrating the procedure by which the power control device 11 determines the combination of power exchange points according to the weather pattern. [Figure 9A] This diagram illustrates a method for sharing power from multiple locations to compensate for power shortages. [Figure 9B] This diagram illustrates a method for sharing power from multiple locations to compensate for power shortages. [Figure 10] An example of the user interface provided by the power control device 11.

Embodiments for Carrying Out the Invention

[0013] <Embodiment 1> FIG. 1 is a configuration example of a power trading system 1 provided by an operator who conducts power trading. The power trading system 1 is composed of at least one of a solar power generation (PV) system 12 and a battery system 13. The solar power generation system 12 and the battery system 13 are connected to the power grid via a DCDC converter and a DCAC converter. The power control device 11 controls the operations of the solar power generation and the battery respectively by transmitting operation commands to the driving devices of the solar power generation and the battery (each composed of the above-mentioned converters). There may be multiple arrangements of both the solar power generation system 12 and the battery system 13. The power control device 11 includes an arithmetic unit 111 and a storage unit 112. These will be described later.

[0014] FIG. 2 is a schematic diagram showing how power trading is carried out between bases. Base 1 includes the power trading system 1 described in FIG. 1, and Base 2 also has similar facilities. The power generated at Base 1 and Base 2 is transmitted to Base X via the power grid. The power control device 11 controls the transmission power according to the procedures described later, based on weather prediction data, demand prediction data, measurement data of each facility, etc.

[0015] Figure 3 shows an example of weather prediction data provided by a weather information provider. In the weather prediction data, the solar radiation amount per hour and the weather code provided by a broad classification such as 10 - 50 are described. For example, clear is classified as 10, cloudy as 20, and rain as 30. In the present invention, the types of weather codes during the power trading period (the period for power trading between bases: 7:00 - 18:00) are counted, and a weather pattern is determined based on the counted value. The weather pattern will be described later. For example, the weather code of DAY1(a) is only 10 (clear) during the power trading period. Therefore, the count is one type. For DAY3(c), 10 (clear) or 20 (cloudy) is mixed during the power trading period. In this case, the count is two types. Finally, for DAY5(e), since the weather codes of 10 (clear), 20 (cloudy), and 30 (rain) are mixed during the power trading period, the count value is three types.

[0016] Figure 4 shows an example of determining each weather pattern from the weather codes in the weather prediction data of Figure 3. Based on the count of the weather codes determined in Figure 3, the weather patterns of DAY1 to DAY5 are determined. When the count during the power trading period is one type and all are 10 (clear) (DAY1), the weather pattern of that day is set as A+. DAY2 with a count of one type and all 20 (cloudy) is set as A-. When the count is two types and 10 (clear) and 20 (cloudy) are mixed (DAY3, DAY4), the weather pattern is determined according to the higher ratio of 10 or 20 during the power trading period. For example, since the ratio of 10 (clear) is large in DAY3, the weather pattern is set as B+, and since the ratio of 20 (cloudy) is large in DAY4, it is set as B-. Finally, since DAY5 has a count of three types and 30 (rain) is included, the weather pattern is set as C. If any of the weather codes of 30 (rain), 40 (rain or snow), and 50 (snow) is included, power trading will not be carried out on that day. Since any weather pattern including three or more types of weather codes must include one of 30, 40, and 50, power trading will not be implemented.

[0017] Figure 5 is a flowchart illustrating the procedure for determining a weather pattern from the weather codes in the weather forecast data shown in Figure 3. This flowchart is performed by the calculation unit 111. The calculation unit 111 obtains weather forecast data from a weather information provider, which describes hourly solar radiation and weather codes. The calculation unit 111 counts the weather codes that correspond to the power exchange period from the obtained weather codes. If there is only one type of count and it is 10 (sunny), the weather pattern for that day is A+; if it is 20 (cloudy), it is A-. If there are two types of weather codes, B+ or B- is determined according to the ratio of 10 (sunny) to 20 (cloudy). If there are three types of weather codes and they include 30 (rain), 40 (rain or snow), and 50 (snow), it is C. The output result of this weather pattern is stored in the storage unit 113 as weather pattern data.

[0018] In this invention, we focus on weather patterns with large and small fluctuations in solar radiation. For example, the following procedure can be used to compare the fluctuation range and number of solar radiation fluctuations with other weather patterns. Solar radiation data provided by a weather information provider is described for each predetermined time period. When the fluctuation range of solar radiation between time periods is greater than or equal to a threshold, it is counted as one solar radiation fluctuation, and the weather pattern with the smallest count value corresponds to weather pattern A+ or A-, and the one with the largest count value corresponds to weather pattern B- (excluding pattern C). Alternatively, alternative methods such as summing the absolute values ​​of the differences in solar radiation between time periods over the entire exchange period may be used. Furthermore, since solar radiation and the power generated by a solar cell correspond, instead of solar radiation data, the fluctuation range and number of fluctuations of power generated may be similarly measured using historical data of solar cell power generation for each time period.

[0019] In this invention, the power generation command value for the solar power generation system 12 is set by multiplying the power exchange plan by a predetermined coefficient (referred to as likelihood, ≤1.0) so that the power generation capacity of the solar power generation system 12 has a certain amount of surplus. Therefore, the actual planned amount of power to be exchanged is the power exchange plan × likelihood. Hereinafter, the likelihood for weather pattern A+ is denoted as likelihood a, the likelihood for weather pattern A- is denoted as likelihood a', and the likelihood for weather pattern B- is denoted as likelihood b'.

[0020] Figure 6A is a graph comparing the actual and planned power exchanges under weather pattern A+. When the weather pattern is A+, the weather code during the power exchange period is always 10 (sunny), so the range and number of fluctuations in solar radiation are small (almost 0). Accordingly, the actual power exchange does not fluctuate significantly, and the actual power exchange increases gradually until the time when the amount of solar radiation during the day reaches its peak, and then decreases gradually thereafter. Therefore, the difference between the planned and actual power exchanges does not fluctuate significantly. In the case of weather pattern A+, the difference between the actual and planned power exchanges is always positive (actual power exchange - planned power exchange > 0). In other words, a surplus amount of power is always generated during the power exchange period. During the power exchange period, the power control device 11 commands the battery storage system 13 to charge, using the surplus amount of power for charging. In other words, if the difference between actual and planned power supply is always positive, such as in weather pattern A+, then during the power supply period, surplus power will be charged into the battery to prepare for the next day's power shortage while power is supplied to other locations.

[0021] Figure 6B is a graph comparing the actual power exchange and the power exchange plan for weather pattern A-. In weather pattern A-, the weather code for the entire power exchange period is 20 (cloudy), so, similar to weather pattern A+, there is almost no variation in the amount of solar radiation and the number of variations, and the actual power exchange does not fluctuate significantly. Also, the difference between the actual power exchange and the power exchange plan is always positive (actual power exchange - power exchange plan > 0), resulting in a surplus of power. Therefore, the power control device 11 instructs the battery storage system 13 to charge to use the surplus power for charging. In the case of weather pattern A-, the same amount of charging power as in weather pattern A+ is secured in the battery to prepare for the power shortage the following day. In weather pattern A-, the actual power exchange is relatively lower than in weather pattern A+, so the amount of power exchanged is also reduced.

[0022] Figure 6C is a graph comparing actual and planned power supply under weather pattern B-. Compared to weather patterns A+ and A-, weather pattern B- has a larger range and frequency of fluctuations in solar radiation, and consequently, actual power supply also fluctuates significantly and frequently. Therefore, the difference between actual and planned power supply fluctuates greatly during the power supply period. If the difference between actual and planned power supply is positive, the power control device 11 sends a charge command to the battery system 13, and if the difference is negative, it sends a discharge command to the battery system 13 to supply power while compensating for the power shortage. In particular, weather pattern B- has large fluctuations in actual power supply and a very large number of periods in which power shortages occur.

[0023] In this invention, for weather pattern B- sites where power generation performance fluctuates significantly and a large power shortage occurs, the shortfall in the amount of power supplied to other sites (site X in Figure 2) is compensated for by the surplus power of weather pattern A+ (or A-) sites. This is because weather pattern A+ (or A-) sites have small fluctuations in power generation performance and generate surplus power. This compensation ensures that even if a B- site cannot meet its predetermined supply plan, the supply plan can be maintained at the B- site through compensation from A+ (or A-) sites. The combination of A+ (or A-) sites to be used for compensation is searched when a B- site occurs. The difference between actual supply and supply plan can be made to correspond one-to-one with the weather pattern (the reason will be explained later). Therefore, the sites to be used for compensation can be searched by referring to the weather pattern at each site.

[0024] Figure 7 shows an example of data for the rated power generation of solar power generation at each site. The calculation unit 111 acquires the rated power generation information of the solar power generation system 12 in order to determine in detail the difference between the actual power exchange and the power exchange plan at each site. The difference between the actual power exchange and the power exchange plan is proportional to the magnitude of the rated power generation of the solar power generation system 12. Therefore, by acquiring the rated power generation information of the solar power generation system 12 after determining the weather pattern, the calculation unit 111 can correctly determine the difference between the actual power exchange and the power exchange plan at each site and combine the sites for which compensation will be carried out. The significance of determining the difference will be explained later.

[0025] The rated power generation of the solar power generation system 12 can also be used as a weighting for the combination of locations where compensation will be provided. In other words, the rated power generation of the solar power generation system 12 at each location under weather pattern A+ and weather pattern A- can be compared, and the location with the larger surplus power can be selected and determined as a combination.

[0026] Figure 8 is a flowchart illustrating the procedure by which the power control device 11 determines the combination of power exchange locations according to the weather pattern. This flowchart can be implemented for each power exchange location. The steps in Figure 8 are described below.

[0027] (Figure 8: Steps S801-S803) The calculation unit 111 obtains weather forecast data from a weather information provider, which includes hourly solar radiation and weather codes (S801). The calculation unit 111 counts the types of weather codes that correspond to the power exchange period (7:00 to 18:00) from the obtained weather codes (as explained in Figure 3) (S802). The calculation unit 111 identifies a weather pattern based on the count value (S803). The output result of this weather pattern is stored in the storage unit 112 as weather pattern data.

[0028] (Figure 8: Steps S804-S806) The calculation unit 111 obtains the rated power generation of the solar power generation system 12 from the storage unit 112 (S804). The calculation unit 111 determines the difference between the actual power exchange and the power exchange plan based on the weather pattern identified by the count value and the rated power generation of the solar power generation system 12 (S805). If the weather pattern at the site covered by this flowchart is B-, proceed to S807; otherwise, proceed to S809 (S806).

[0029] (Figure 8: Step S805: Supplement) S805 is significant as preparation for searching for power source stations under weather patterns A+ and A- in S807. Therefore, the difference between actual power exchange and power exchange plans only needs to be recognized with enough accuracy to identify these stations. Thus, in S805, data describing the rated power generation of each station (e.g., Figure 7) is acquired, and further, according to the weather pattern at each station, the extent to which that rated power generation will be utilized is estimated, thereby obtaining (determining) the difference between actual power exchange and power exchange plans in a simple manner. For example, by multiplying the rated power generation by a coefficient (a number that gradually decreases from A+ to C-) for each weather pattern, the extent to which the rated power generation will be utilized can be estimated for each weather pattern. The power that the power source stations actually transmit can be calculated when creating a specific power transmission plan (power exchange plan) in S809.

[0030] (Figure 8: Steps S807-S808) The calculation unit 111 searches for other locations that share power and whose weather pattern is A+ (or A-) (S807). For example, the weather pattern for each district where the locations are installed can be obtained from the weather pattern data. The calculation unit 111 determines the combination of the searched locations and the locations that are the subject of this flowchart (S808). At this time, the weight of the amount of power to be supplemented from the searched locations can also be determined based on the rated power generation of the solar power generation system 12.

[0031] (Figure 8: Steps S807-S808: Supplement 1) The calculation unit 111 searches for bases with weather patterns A+ or A- and their rated power generation, for example, in descending order of surplus power generation. If a single base found through the search can compensate for the shortage of power supplied by bases with weather pattern B- (the amount of power transmitted from base B- to the destination base), then the combination of that base and base B- is determined. If two or more bases are needed for compensation, the amount of power transmitted by each of those two or more bases is determined with weights. For example, the amount of surplus power can be simply calculated based on the weather pattern and rated power generation, and the ratio of that surplus power can be used as a weight. Alternatively, the ratio of the rated power generation of each base can be simply used as a weight. The burden ratio of the compensation can also be determined by other appropriate weightings.

[0032] (Figure 8: Steps S807-S808: Supplement 2) The calculation unit 111 may acquire a history of past power sharing at each location and perform S807 based on that history. For example, among locations with weather pattern A+ or A-, these locations may be searched for in descending order of the cumulative or instantaneous value of the amount of power shared with other locations in the past.

[0033] (Figure 8: Step S809) Based on the results of the above steps, the calculation unit 111 creates a power exchange plan for the site covered by this flowchart.

[0034] Figures 9A and 9B illustrate a method of power sharing to compensate for power shortages from multiple locations. Location 1 is experiencing weather pattern A+, and location 2 is experiencing weather pattern B-. Locations 1 and 2 each have the power sharing system 1 shown in Figure 1. Both locations 1 and 2 have plans to share power with other locations (location X in the example in Figure 2).

[0035] Figures 9A and 9B (middle section) show the power exchange plan and the amount of surplus or deficit power for each site (each weather pattern). Site 1 (weather pattern A+) has almost no fluctuation in solar radiation during the exchange period, so the surplus power is used to charge the battery system 13. Site 2 (weather pattern B-) has large fluctuations in solar radiation during the exchange period, so even if the exchange plan is multiplied by the likelihood, there will be times when the actual exchange amount is insufficient compared to the exchange plan, resulting in a large deficit. There are two possible methods to compensate for the deficit at Site 2, as explained in Figure 9A and as explained in Figure 9B.

[0036] In the method shown in Figure 9A, the power control device 11 sends a command to the solar power generation system 12 to reduce the likelihood a planned for weather pattern A+ (bringing the value of a closer to 1.0). As likelihood a is reduced, the amount of electricity transmitted from site 1 increases (and consequently, the amount of surplus electricity decreases). In other words, the amount of electricity generated by the reduction in likelihood can be used to compensate for the shortage of shared electricity at sites that are experiencing an electricity shortage. Therefore, the amount of electricity generated by the reduction in likelihood at site 1 is used to compensate for the electricity shortage at site 2. As a result, site 2 can compensate for its electricity shortage using the amount of electricity increased due to the reduction in likelihood at site 1, without having to restrict the shared electricity plan and keeping it constant.

[0037] In the method shown in Figure 9B, instead of changing likelihood a, the surplus power from weather pattern A+ is used to compensate for the power deficit at site 2. Without restricting the power sharing plans for sites 1 and 2, the amount of power that was planned to be charged at site 1 is diverted to compensate for the power deficit at site 2. As a result, the power deficit at site 2 can be resolved while maintaining the amount of power available for sharing with other systems. If the rated power output of the solar power generation at site A is small and cannot compensate for the power deficit at site 2, the deficit may be compensated for by combining sites with weather patterns A+ or A-. The same applies in Figure 9A.

[0038] <Embodiment 1: Summary> The power exchange system 1 according to this embodiment 1 compensates for the power shortage at a transmission destination site by supplying power from a site with less volatile power generation to a site with a weather pattern that causes large fluctuations in power generation. As a result, the constraint on the power exchange plan, which was a challenge when exchanging power from a single site in the past, is eliminated by combining multiple sites. Therefore, power exchange can be carried out by making maximum use of the amount of power generated by the solar power generation system 12 without constraining the power exchange plan. In particular, it is possible to suppress the large penalties associated with power shortages and imbalances.

[0039] The power exchange system 1 according to this embodiment 1 compensates for power shortages by combining multiple locations, so the amount of power compensated by discharging from the battery system 13 decreases, and consequently the number of discharges (or the amount of discharge) also decreases. Therefore, the stress on the battery system 13 is also reduced.

[0040] <Embodiment 2> The power control device 11 described in Embodiment 1 may include a calculation unit 111 that performs the operations described in Figures 4 to 9B. The calculation unit 111 can be configured using hardware such as a circuit device that implements its functions, or it can be configured by a calculation device executing software that implements its functions. The power control device may further include a storage unit that stores the history of each data (e.g., power generation forecast data, demand data, demand forecast data, etc.) described in Embodiment 1.

[0041] Figure 10 shows an example of a user interface provided by the power control device 11. The user interface can be displayed by the calculation unit 111 on a display device such as a display. For example, the user interface can display the amount of power that the power exchange system should output at the start and end times of the transmission period for each weather code, as well as the charge or discharge amount of the storage battery. Furthermore, it can display the amount of power shortage, the amount of power to be compensated, and the name of the combined base for each exchange period.

[0042] <Regarding variations of the present invention> The present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations.

[0043] In the embodiments described above, power transmission was supplemented from a power source station with a weather pattern of A+ or A- to a power source station with a weather pattern of B-. The source of the supplementation is not limited to these; if there is sufficient surplus power, the supplementation can also be made from a power source station with a weather pattern of B+.

[0044] In the above embodiments, the difference between the actual power exchange and the power exchange plan may be expressed as a ratio instead of the difference itself. When a ratio is used, a surplus of power occurs when the ratio of actual power exchange to power exchange plan is greater than 1, and a power shortage occurs when the ratio is less than 1. However, it should be noted that the difference and the ratio essentially represent the same thing.

[0045] In the embodiments described above, the procedure for determining the combination of locations and the amount of power to be exchanged during the power exchange period by the power control device 11 has been explained. However, the battery system 13 may be controlled by instructing the battery to exchange the determined amount of power, or the amount of power generated by the solar power generation system 12 may be controlled using the determined combination of locations. Control can be carried out, for example, by commands to the battery or the drive device (e.g., converter) that drives the solar power generation system. [Explanation of Symbols]

[0046] 1: Power exchange system 11: Power control device 111: Arithmetic section 112: Storage section 12: Solar power generation system 13: Battery storage system

Claims

1. A power exchange system that transmits electricity between locations via a power transmission network, A power generation system that generates electricity using solar cells. A power control device that controls the amount of power transmitted when the amount of power generated by the power generation system is transmitted to a destination base via the power transmission network. Equipped with, The power control device includes a calculation unit for calculating the amount of power transmitted, The calculation unit determines the weather variation pattern during the power transmission period based on the value of a weather code that describes the result of predicting the type of weather during the power transmission period in which the amount of power is transmitted to the power transmission destination base, The calculation unit determines that the weather fluctuation pattern at the power transmission base where the power generation system is installed is Among the combination patterns represented by the combination of weather codes for each time period, the first pattern is the one with the largest number of times the fluctuation range of the amount of power transmitted during the power transmission period is greater than or equal to a threshold. Among the above combination patterns, the second pattern is one in which the number of times the fluctuation range of the amount of power transmitted during the power transmission period is greater than or equal to the threshold is less than that of the first pattern. Determine which of the following applies: If the weather variation pattern at any of the multiple power source locations is the first pattern, the calculation unit searches for one or more of the multiple power source locations where the weather variation pattern is the second pattern. The calculation unit controls the amount of power to be transmitted so as to compensate for the shortage of power transmitted at the power source where the weather fluctuation pattern is the first pattern, using the amount of surplus power generated at the power source base that was searched. A power exchange system characterized by the following.

2. The aforementioned weather codes include codes for sunny and cloudy conditions. The calculation unit determines whether the weather variation pattern corresponds to either the first pattern or the second pattern based on the number of codes representing sunny weather and the number of codes representing cloudy weather among the weather codes for each time period. The first pattern is composed of the combination pattern in which the weather code for each time period during the power transmission period consists only of sunny and cloudy, and the number of cloudy days is greater than the number of sunny days. The second pattern is composed of combinations of weather codes for each time period during the power transmission period, where the weather code is either sunny only or cloudy only. The power exchange system according to claim 1, characterized in that it is the same as described in claim 1.

3. The aforementioned weather code includes a code representing at least one of rain or snow, The calculation unit controls the amount of power to be transmitted so as not to transmit the generated power to the transmission destination if the weather code describes a code that represents at least one of rain or snow. The power exchange system according to claim 1, characterized in that it is the same as described in claim 1.

4. The calculation unit obtains the planned amount of power that was planned as the amount of power to be transmitted during the power transmission period, The calculation unit acquires the actual amount of power output to the power transmission network as the amount of power transmitted during the power transmission period, The calculation unit calculates the difference between the corrected planned power amount obtained by applying a correction coefficient to the planned power amount and the actual power amount. The calculation unit controls the amount of power transmitted based on the difference. The power exchange system according to claim 1, characterized in that it is the same as described in claim 1.

5. The correction coefficient is a coefficient used to ensure that the power generation system has operating capacity to output an amount of power that is less than the power generation capacity of the power generation system. The calculation unit searches for a surplus power source among the power source bases that still has a surplus amount of generated power even after transmitting the amount of power to be transmitted. The calculation unit, at the surplus power bases it has searched, modifies the correction coefficient so that the corrected planned power amount increases, thereby allocating at least a portion of the corrected planned power amount to compensate for the deficit. The power exchange system according to claim 4, characterized in that it is a power exchange system.

6. The calculation unit searches for a surplus power source among the power source bases that still has a surplus amount of generated power even after transmitting the amount of power to be transmitted. The calculation unit allocates at least a portion of the surplus power generated at the searched surplus power bases to compensate for the deficit. The power exchange system according to claim 1, characterized in that it is the same as described in claim 1.

7. The calculation unit acquires the history of the amount of electricity transmitted to other locations in the past at the power source location where the weather variation pattern is the second pattern, The calculation unit performs the search by identifying the power source locations in descending order of the amount of electricity transmitted in the past, according to the history. The power exchange system according to claim 1, characterized in that it is the same as described in claim 1.

8. The aforementioned power exchange system further includes a battery storage system, The calculation unit is configured to compensate for the shortfall in the amount of power transmitted if the amount of power generated by the power generation system is less than the amount of power transmitted by the power source to the power destination, and if the compensation is not carried out, by discharging the battery system. The calculation unit, by performing the compensation, reduces at least one of the number of times the battery system discharges or the amount of discharge compared to when the compensation is not performed. The power exchange system according to claim 1, characterized in that it is the same as described in claim 1.

9. The calculation unit calculates the planned power amount based on the predicted power generation amount of the solar cells during the power transmission period and the predicted power demand during the power transmission period. The power exchange system according to claim 4, characterized in that it is a power exchange system.

10. The aforementioned calculation unit outputs a user interface, The user interface is configured to display the deficit at the power transmission source site and to display a statement indicating that the deficit has been compensated. The power exchange system according to claim 1, characterized in that it is the same as described in claim 1.

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