JP7717014B2 - Power Generation Management System - Google Patents

Description

The present invention relates to a power generation management system.

For example, Patent Document 1 discloses a cogeneration system with a fuel cell unit that generates electricity and heat using fuel gas. The gas meter, which measures the amount of fuel gas used, has a safety function that issues a gas leak alarm if it detects that fuel gas has been flowing continuously for a predetermined period of time or longer. If the fuel cell unit continues to use fuel gas for a predetermined number of days or longer, the gas meter's safety function will issue a gas leak alarm, even though there is no actual gas leak. Therefore, to temporarily halt the continuous use of fuel gas, the fuel cell unit is shut down before the fuel cell unit's continuous operating time reaches the predetermined number of days. The technology in Patent Document 1 extracts candidate time periods during which the fuel cell unit can be shut down from the amount of power consumed during a predetermined period of continuous fuel gas flow, and then shuts down the fuel cell unit during the extracted time period after the period has elapsed.

Patent No. 4511878

When a power generation unit in a distributed power system stops, the power required for the time the power generation unit is down must be supplied from the power grid. An administrator, such as an aggregator that manages the supply and demand of power for consumers with power generation units, supplies (sells) power to the consumer through the power grid while the power generation unit is down. The administrator incurs a corresponding cost (e.g., the unit price of electricity) to secure the power to be supplied to the consumer. If the power generation unit stops during a time period when the unit price of electricity is high, the administrator may be forced to raise the selling price of the electricity, depending on the extent to which the unit price of electricity rises. Consequently, the shutdown of the power generation unit during a time period when the unit price of electricity is high leads to the consumer purchasing more expensive electricity. In this way, if the price of electricity purchased by the consumer increases, the benefit of introducing a distributed power system is reduced for the consumer.

In light of these issues, the present invention aims to provide a power generation management system that can reduce the purchase price of electricity when a power generation unit is shut down.

To solve the above problem, the power generation management system of the present invention comprises a power generation unit that consumes fuel gas to generate at least electricity, an operation time determination unit that determines the continuous operation time indicating the time the power generation unit has been operating continuously, and a shutdown determination unit that determines whether to shut down the power generation unit, wherein the price per unit amount of electricity traded on the electricity market is the electricity market price, the cost per unit amount of electricity incurred to generate electricity from a private power source managed by a power supplier that supplies electricity to consumers having power generation units is the private power source price, the cost per unit amount of electricity based on an electricity trading contract concluded between the power supplier and another power utility is the electricity trading price, which includes at least one of the electricity market price, the private power source price, and the electricity trading price, and the cost per unit amount of electricity incurred by the power supplier to secure electricity to supply to consumers having power generation units is the power source price, and the shutdown determination unit determines whether to shut down the power generation unit based on the power source price at a predetermined control timing when the continuous operation time is equal to or exceeds a predetermined time.

Furthermore, the power generation unit and operation time determination unit may be provided in the distributed power supply apparatus, and the stop determination unit may be provided in a server device capable of communicating with the distributed power supply apparatus, and if the continuous operation time is equal to or longer than a predetermined time, the operation time determination unit may transmit operation information indicating that the continuous operation time is equal to or longer than the predetermined time to the server device, and the stop determination unit may determine whether to stop the power generation unit based on the unit cost of electricity in response to receiving the operation information, and if it is determined that the power generation unit should be stopped, transmit a stop command to stop the power generation unit to the distributed power supply apparatus.

In addition, the system may have multiple distributed power supply devices, and the shutdown determination unit may determine whether to shut down the power generation unit based on the unit cost of electricity in response to receiving operation information transmitted from one of the multiple distributed power supply devices, and if it determines that the power generation unit should be shut down, may transmit a shutdown command to the multiple distributed power supply devices.

Furthermore, the power generation unit, operating time determination unit, and shutdown determination unit may be provided in a distributed power supply device.

The shutdown determination unit may also determine to shut down the power generation unit if the continuous operation time is equal to or longer than a predetermined time and the unit cost of electricity is less than a predetermined reference value at a predetermined control timing.

The stop determination unit may also periodically acquire the electricity unit price and store it in a storage device, and set the reference value based on past electricity unit prices stored in the storage device.

The shutdown decision unit may also derive multiple predicted values for future electricity unit costs in association with future dates, and decide to shut down the power generation unit on the day corresponding to the lowest predicted value.

This invention makes it possible to reduce the purchase price of electricity when a power generation unit is shut down.

FIG. 1 is a schematic diagram showing the configuration of a power generation management system according to the first embodiment. FIG. 2 is a flowchart illustrating the flow of operations in the operating time determination unit. FIG. 3 is a flowchart illustrating the flow of operations of the stop determination unit. FIG. 4 is a flowchart illustrating another example of the flow of the operation of the stop determination unit. FIG. 5 is a flowchart illustrating the flow of operations of the stop determination unit according to the second embodiment. FIG. 6 is a schematic diagram showing the configuration of a power generation management system according to the third embodiment. FIG. 7 is a schematic diagram showing the configuration of a power generation management system according to the fourth embodiment. FIG. 8 is a flowchart illustrating the flow of operations of the operating time determination unit and the stop determination unit according to the fourth embodiment.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values shown in these embodiments are merely examples to facilitate understanding of the invention and, unless otherwise specified, do not limit the present invention. Furthermore, in this specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

(First embodiment)
1 is a schematic diagram showing the configuration of a power generation management system 1 according to a first embodiment. The power generation management system 1 includes a distributed power supply device 10, an electricity market 12, a first server device 14, and a second server device 16.

The distributed power supply system 10 is installed in a building such as a house. The distributed power supply system 10 may also be installed across multiple buildings. The distributed power supply system 10 includes a power generation unit 20, a communication device 22, and a control device 24.

The power generation unit 20 consumes fuel gas to generate at least electricity. The fuel gas is, for example, city gas, but is not limited to this example and may be propane gas, hydrogen gas, or the like. The power generation unit 20 is, for example, a cogeneration unit, such as a fuel cell unit, that consumes fuel gas to generate electricity and heat. However, the power generation unit 20 is not limited to a cogeneration unit. For example, the power generation unit 20 may be a monogeneration unit that consumes fuel gas to generate electricity, or any device that consumes fuel gas to generate at least electricity.

A conduit 30 is connected to the power generation unit 20 of the distributed power supply system 10, and fuel gas is supplied through the conduit. The conduit 30 may also be connected to other gas appliances in the building in which the distributed power supply system 10 is installed. A gas meter 32 is provided in the conduit 30. The gas meter 32 measures the amount of gas used in the building. The gas meter 32 may be a smart meter that digitally measures the measurement target and has communication capabilities.

The gas meter 32 has a safety function of monitoring the flow of fuel gas within the conduit 30 and detecting fuel gas leaks (inner pipe leaks). Specifically, if the gas meter 32 detects that fuel gas has been flowing continuously for a predetermined period of time or longer, it issues an alert that fuel gas is leaking. Hereinafter, this predetermined period of time during which a leak is determined may be referred to as the leak detection period. The leak detection period is set to, for example, 30 days, but is not limited to this example and may be set to any period that allows for appropriate leak detection. Furthermore, the alert may be issued by lighting or flashing an abnormality lamp, sounding an alarm, or by communication.

The power generation unit 20 of the distributed power supply apparatus 10 is electrically connected to the power grid 42 via a power meter 40, and is also electrically connected to a load equipment 44. The power meter 40 measures the amount of power received from the power grid 42. The power meter 40 can also measure the amount of power supplied from the distributed power supply apparatus 10 to the power grid 42. The power meter 40 may be a smart meter. The load equipment may be any device that consumes power.

The communication device 22 establishes communication with the second server device 16 via wired or wireless communication. As will be described later, the second server device 16 is capable of communicating with the first server device 14, and therefore the communication device 22 can communicate with the first server device 14 via the second server device 16.

The control device 24 is composed of a semiconductor integrated circuit including a central processing unit, ROM storing programs, etc., and RAM as a work area. The control device 24 controls the entire distributed power supply device 10 by executing the program. The control device 24 also functions as the operating time determination unit 50 by executing the program.

The operating time determination unit 50 determines the continuous operating time, which indicates the time the power generation unit 20 has been operating continuously. The operating time determination unit 50 has a counter that counts the continuous operating time. The operating time determination unit 50 will be described in detail later.

The electricity market 12 is, for example, the Japan Electric Power Exchange (JEPX). In the electricity market 12, electricity market unit prices (yen/kWh), which indicate the price per unit of electricity, are traded. The electricity market unit prices fluctuate in real time.

The first server device 14 is, for example, a server device managed by the upper aggregator of the upper aggregator and the lower aggregator. The second server device 16 is, for example, a server device managed by the lower aggregator of the upper aggregator and the lower aggregator. The upper aggregator can be involved in the control of the distributed power supply apparatus 10 via the lower aggregator. The lower aggregator controls the distributed power supply apparatus 10 under the instructions of the upper aggregator. Note that an aggregator refers to an entity that provides a service that manages the supply and demand of electricity for consumers. The administrator of the first server device 14 (for example, the upper aggregator) manages the supply and demand of electricity for consumers that have distributed power supply apparatuses 10 (i.e., power generation units 20).

The first server device 14 comprises a communication device 60, a storage device 62, and a control device 64. The communication device 60 establishes communication with the second server device 16 via wired or wireless communication. Because the second server device 16 is capable of communicating with the distributed power supply apparatus 10, the communication device 60 can communicate with the distributed power supply apparatus 10 via the second server device 16. The storage device 62 is a hard disk drive, flash memory, or other non-volatile element. The storage device 62 stores various types of information used by the control device 64.

The control device 64 is composed of a semiconductor integrated circuit including a central processing unit, ROM storing programs, etc., and RAM as a work area. The control device 64 controls the entire first server device 14 by executing the programs. The control device 64 also functions as a stop determination unit 70 by executing the programs.

Now, let's assume that the power generation unit 20 of the distributed power supply apparatus 10 stops operating. In this case, the consumer that owns the power generation unit 20 will receive power from the power grid 42 to be consumed by the load equipment 44 while the power generation unit 20 is stopped. In this case, the administrator of the first server device 14 will manage the power supplied from the power grid 42 to the consumer (i.e., the distributed power supply apparatus 10).

In other words, the administrator of the first server device 14 secures power to be supplied to consumers having power generation units 20 through the power grid 42, and supplies the secured power to the consumers (i.e., distributed power supply devices 10) through the power grid 42. At this time, the administrator of the first server device 14 sells the supplied power to the consumers. In other words, the administrator of the first server device 14 can be said to be both a power supplier that supplies power to consumers having power generation units 20, and a power seller that sells power to the consumers.

The administrator of the first server device 14 may secure power in the following three ways (first, second, and third ways). The administrator of the first server device 14 may secure power using at least one of the first, second, and third ways, or may secure power by combining two or more of the first, second, and third ways.

The first method involves procuring electricity from the electricity market 12 and supplying it to consumers. When securing electricity using this first method, the administrator of the first server device 14 incurs costs equal to the electricity market unit price determined by transactions in the electricity market 12.

A second aspect is to supply electricity generated by a private power source managed independently by the administrator of the first server device 14 to consumers. A private power source is a power source managed by an electricity supplier that supplies electricity to consumers with power generation units 20, and is a power source that is prepared separately from the power sources of other electricity providers and the consumer's distributed power supply device 10. When securing electricity using this second aspect, the administrator of the first server device 14 incurs a cost equal to the private power source unit price, which indicates the cost per unit of electricity required to generate electricity using a private power source.

A third method is to enter into a trading contract for the interchange of electricity in advance between the administrator of the first server device 14 and another electric power supplier, and then receive electricity from the other electric power supplier based on this trading contract and supply it to consumers. When securing electricity using this third method, the administrator of the first server device 14 will incur a cost equal to the electricity trading unit price, which indicates the cost per unit of electricity based on the electricity trading contract that the administrator (electric power supplier) has entered into with the other electric power supplier.

Considering these three aspects, the administrator of the first server device 14 incurs a cost equal to the unit price of electricity as shown in the following formula (1) in order to secure the electricity to be supplied to the consumer having the power generation unit 20. The unit price of electricity indicates the cost per unit of electricity that an electricity supplier incurs in order to secure the electricity to be supplied to the consumer having the power generation unit 20. The unit price of electricity is the sum of the electricity market unit price, the private power source unit price, and the electricity trading unit price.
Electricity unit price = electricity market price + private power supply price + electricity trading price ... (1)

The electricity unit price is not limited to the sum of the electricity market price, the self-power source price, and the electricity trading price. The electricity unit price may include at least one of the electricity market price, the self-power source price, and the electricity trading price. For example, the electricity unit price may be equal to the electricity market price, with the self-power source price and the electricity trading price omitted. The electricity unit price may be equal to the self-power source price, with the electricity market price and the electricity trading price omitted. The electricity unit price may be equal to the electricity trading price, with the electricity market price and the self-power source price omitted. The electricity unit price may be the sum of the electricity market price and the self-power source price, with the electricity trading price omitted. The electricity unit price may be the sum of the electricity market price and the self-power source price, with the electricity trading price omitted. The electricity price may be calculated by omitting the electricity market price and adding up the private power source price and the electricity trading price.

Electricity market unit prices fluctuate more than private power generation unit prices and electricity trading unit prices. As a result, electricity unit prices are easily affected by fluctuations in electricity market unit prices.

The private power source unit price and the electricity trading unit price are stored in advance, for example, in the storage device 62. The control device 64 determines the current private power source unit price every predetermined period, for example, every week, and updates the private power source unit price by storing the determined private power source unit price in the storage device 62. In addition, the control device 64 updates the electricity trading unit price by storing the current electricity trading unit price in the storage device 62 each time the electricity trading unit price is revised.

Here, if the power generation unit 20 stops during a time period when the unit price of electricity (or the market price of electricity) is high, the administrator of the first server device 14 will have to raise the selling price of electricity sold to consumers who own the power generation unit 20, depending on the degree to which the unit price of electricity (or the market price of electricity) rises. As a result, consumers who own the power generation unit 20 will have to purchase expensive electricity from the administrator of the first server device 14.

The shutdown determination unit 70 therefore determines whether to shut down the power generation unit 20 based on the unit price of electricity of the power supplier supplying power to the consumer having the power generation unit 20, at a predetermined control timing when the power generation unit 20 has been continuously operating for a predetermined period of time or more. Specifically, the shutdown determination unit 70 acquires the market price of electricity from the power market 12 at a predetermined control timing when the power generation unit 20 has been continuously operating for a predetermined period of time or more. The shutdown determination unit 70 derives the market price of electricity based on the market price of electricity. If the market price of electricity is less than a predetermined reference value, the shutdown determination unit 70 determines to shut down the power generation unit 20. In other words, if the market price of electricity is equal to or greater than a predetermined reference value, the shutdown determination unit 70 determines not to shut down the power generation unit 20. The predetermined period of time is set to be at least shorter than the leakage detection period. The predetermined control timing occurs at a predetermined control cycle, such as once a day.

Here, the stop determination unit 70 periodically (e.g., daily) acquires the electricity market unit price and derives the electricity source unit price each time it acquires the electricity market unit price. For example, the stop determination unit 70 derives the current electricity source unit price by summing the acquired electricity market unit price, the private power source unit price, and the electricity trading unit price stored in the storage device 62. The stop determination unit 70 stores the derived electricity source unit price in the storage device 62 in association with the date on which the electricity source unit price was derived. The stop determination unit 70 sets the current reference value based on past electricity source unit prices stored in the storage device 62.

Specifically, the stop determination unit 70 sets the average value of the electricity unit cost from the present to one year ago as the current reference value. The stop determination unit 70 may also set the average value of the electricity unit cost for the same month one year ago for the current month as the current reference value. For example, if the current month is May, the average value of the electricity unit cost for May one year ago may be set as the current reference value. The stop determination unit 70 may also set the average value of the electricity unit cost from the present to one month ago as the current reference value. The stop determination unit 70 may also set the current reference value to a value that is a predetermined value lower than the maximum value of the electricity unit cost for the same month one year ago for the current month. The stop determination unit 70 may also set the current reference value to a value that is a predetermined value higher than the minimum value of the electricity unit cost for the same month one year ago for the current month. As described above, any method can be used to set the reference value.

In this way, because the current reference value fluctuates depending on past actual values of the electricity unit price, the stoppage judgment unit 70 can always set the reference value to an appropriate value. As a result, the stoppage judgment unit 70 can appropriately judge whether the current electricity unit price is relatively low.

Note that the reference value is not limited to a variable value set based on past electricity unit prices. For example, the reference value may be set in advance as a fixed value.

The second server device 16 includes a communication device 80 and a control device 82. The communication device 80 establishes communication with the first server device 14 and the distributed power supply apparatus 10 via wired or wireless communication. The communication device 80 transmits information received from the first server device 14 to the distributed power supply apparatus 10, and transmits information received from the distributed power supply apparatus 10 to the first server device 14.

The control device 82 is composed of a semiconductor integrated circuit including a central processing unit, ROM storing programs, etc., and RAM as a work area. The control device 82 controls the entire second server device 16 by executing programs.

Figure 2 is a flowchart explaining the flow of operation in the operating time determination unit 50. The operating time determination unit 50 repeats the series of processes shown in Figure 2 at each predetermined control timing that occurs in a predetermined control cycle. The predetermined control cycle is, for example, once a day, but is not limited to this example and can be set arbitrarily, for example, once an hour.

When a predetermined control timing occurs, the operation time determination unit 50 increments the count value of a counter that counts the continuous operation time (S10). Next, the operation time determination unit 50 determines whether the count value is equal to or less than a predetermined upper threshold (S11). If the leak detection period is 30 days, the predetermined upper threshold is set to, for example, 26 days. Note that the predetermined upper threshold is not limited to this example and may be set to any time (number of days) shorter than the leak detection period.

If the count value is equal to or greater than the upper threshold (YES in S11), the operating time determination unit 50 stops the operation of the power generation unit 20 (S12). This stops the supply of fuel gas to the power generation unit 20. Because the flow of fuel gas is temporarily stopped before the leak detection period is reached, it is possible to prevent the safety function of the gas meter 32 from issuing an unintended alarm.

After step S12, the operating time determination unit 50 resets the count value (S13) and ends the series of processes. As a result, when the power generation unit 20 is restarted, the count value starts counting from the initial value.

The safety function of the gas meter 32 resets the leak detection duration when the period of non-use during which fuel gas is not circulating through the gas meter 32 exceeds a predetermined reference time. This predetermined reference time is set to, for example, 12 hours. Therefore, the control device 24 of the distributed power supply device 10 keeps the power generation unit 20 stopped for a period of time at least longer than the reference time. The control device 24 then restarts the power generation unit 20 after the period of non-use during which fuel gas is not circulating through the gas meter 32 has exceeded the reference time. Note that if fuel gas is used in another gas appliance while the power generation unit 20 is stopped, the control device 24 restarts the power generation unit 20 after the period of non-use since the other gas appliance stopped using fuel gas exceeds the reference time.

If the count value is less than the upper threshold in step S11 (NO in S11), the operating time determination unit 50 determines whether the count value is greater than or equal to a predetermined threshold (S14). This predetermined threshold is set to a value smaller than the upper threshold in step S11. For example, if the upper threshold in step S11 is 26 days, the predetermined threshold in step S14 is set to 21 days, etc. Note that the predetermined threshold is not limited to this example and may be set to any time (number of days) shorter than the upper threshold.

If the count value is less than the predetermined threshold (NO in S14), the operation time determination unit 50 ends the series of processes. If the count value is equal to or greater than the predetermined threshold (YES in S14), the operation time determination unit 50 transmits operation information indicating that the continuous operation time is equal to or greater than the predetermined time to the second server device 16 via the communication device 22 (S15), and ends the series of processes. Upon receiving the operation information from the distributed power supply device 10, the second server device 16 transmits the operation information to the first server device 14.

Figure 3 is a flowchart explaining the operation of the stop determination unit 70. When a predetermined interrupt timing occurs at a predetermined control cycle, the stop determination unit 70 executes the series of processes shown in Figure 3.

When the specified interrupt timing arrives, the stop determination unit 70 determines whether operation information has been received (S20). If operation information has not been received (NO in S20), the stop determination unit 70 ends the series of processes.

If operation information has been received (YES in S20), the shutdown determination unit 70 acquires the electricity market unit price from the electricity market 12 (S21). The shutdown determination unit 70 reads the private power source unit price and the electricity trading unit price from the storage device 62, and derives the electricity source unit price by summing the read private power source unit price, the read electricity trading unit price, and the acquired electricity market unit price (S22). Next, the shutdown determination unit 70 sets the current reference value based on the past electricity source unit prices stored in the storage device 62 (S23).

Next, the stop determination unit 70 determines whether the unit price of electricity is less than a reference value (S24). The processing of step S24 corresponds to determining whether to stop the power generation unit 20 based on the unit price of electricity. If the unit price of electricity is equal to or greater than the reference value (NO in S24), the stop determination unit 70 ends the series of processes. In other words, the stop determination unit 70 waits while the unit price of electricity is equal to or greater than the reference value.

If the electricity unit cost is less than the reference value (YES in S24), i.e., if it is determined that the power generation unit 20 should be shut down, the shutdown determination unit 70 transmits a shutdown command to shut down the power generation unit 20 to the second server device 16 via the communication device 60 (S25). Upon receiving the shutdown command from the first server device 14, the second server device 16 transmits the shutdown command to the distributed power supply apparatus 10.

When the operating time determination unit 50 of the distributed power supply device 10 receives a shutdown command, it shuts down the power generation unit 20 and resets the count value. As a result, when the power generation unit 20 is restarted, the count value starts from the initial value.

The operation time determination unit 50 transmits operation information when the count value is equal to or greater than the predetermined threshold and less than the upper threshold. The stop determination unit 70 waits if the unit price of electricity is equal to or greater than the reference value when it receives the operation information. In this case, the operation time determination unit 50 transmits the operation information again at the next control timing when the count value is again equal to or greater than the predetermined threshold and less than the upper threshold. If the unit price of electricity is less than the reference value when the retransmitted operation information is received, the stop determination unit 70 transmits a stop command at this timing. In other words, while the count value satisfies the condition of being equal to or greater than the predetermined threshold and less than the upper threshold, the operation time determination unit 50 repeatedly transmits operation information at each predetermined control cycle until it receives a stop command from the first server device 14. Each time it receives operation information, the stop determination unit 70 determines whether the unit price of electricity is less than the reference value, and transmits a stop command when the unit price of electricity falls below the reference value.

As described above, in the power generation management system 1 of the first embodiment, when the continuous operation time of the power generation unit 20 is equal to or longer than a predetermined time, a determination is made based on the unit price of the power source as to whether to shut down the power generation unit 20. Specifically, the shutdown determination unit 70 determines whether to shut down the power generation unit 20 based on the unit price of the power source in response to receiving operation information. The shutdown determination unit 70 determines to shut down the power generation unit 20 if the unit price of the power source is less than a predetermined reference value. Because the power generation unit 20 is shut down when the unit price of the power source is less than the reference value, in the power generation management system 1 of the first embodiment, the selling price of electricity sold by the power supplier to consumers having the power generation unit 20 while the power generation unit 20 is shut down can be set to a price based on the unit price of the power source less than the reference value.

Therefore, the power generation management system 1 of the first embodiment makes it possible to reduce the purchase price of electricity purchased by consumers when the power generation unit 20 is stopped, while avoiding unintended alerts due to the safety function of the gas meter 32.

In the first embodiment, the first server device 14 and the distributed power supply system 10 communicate with each other via the second server device 16. However, the second server device 16 may be omitted, and the first server device 14 and the distributed power supply system 10 may communicate with each other directly.

In the first embodiment, as shown in FIG. 2, when the count value is equal to or greater than the predetermined threshold, the operation time determination unit 50 transmits operation information indicating that the continuous operation time is equal to or greater than the predetermined time. However, the operation time determination unit 50 may transmit the count value that is equal to or greater than the predetermined threshold as operation information to the first server device 14 via the second server device 16. In this case, when the stop determination unit 70 of the first server device 14 receives operation information indicating the count value that is equal to or greater than the predetermined threshold, it may perform the processing from step S21 onward, which acquires the electricity market price shown in FIG. 3. Also, in FIG. 2, when the count value is less than the upper threshold (NO in S11), the operation time determination unit 50 may omit the processing of step S14, which determines whether the count value is equal to or greater than the predetermined threshold, and transmit the count value at that time to the first server device 14 via the second server device 16. In this case, the stop determination unit 70 of the first server device 14 may determine whether the count value has been received, and, upon receiving the count value, determine whether the count value is equal to or greater than the predetermined threshold. If the count value is equal to or greater than the predetermined threshold, the stop determination unit 70 may perform the processes from step S21 onwards, which acquires the electricity market unit price shown in Figure 3.

(Modification of the first embodiment)
In the first embodiment, whether to shut down the power generation unit 20 is determined based on the unit price of the power source. However, the shutdown determination unit 70 may determine whether to shut down the power generation unit 20 based on the power market unit price indicating the price per unit amount of power traded in the power market 12.

Figure 4 is a flowchart illustrating another example of the operational flow of the stop determination unit 70. As in the example of Figure 3, when a predetermined interrupt timing occurs, the stop determination unit 70 determines whether operation information has been received (S20), and if operation information has been received (YES in S20), it obtains the electricity market unit price from the electricity market 12.

Next, the shutdown determination unit 70 sets the current reference value based on the past electricity market unit price stored in the storage device 62 (S23a).

Specifically, the stop determination unit 70 sets the average value of the electricity market unit price from the present to one year ago as the current reference value. The stop determination unit 70 may also set the average value of the electricity market unit price for the same month one year ago for the current month as the current reference value. For example, if the current month is May, the average value of the electricity market unit price for May one year ago may be set as the current reference value. The stop determination unit 70 may also set the average value of the electricity market unit price from the present to one month ago as the current reference value. The stop determination unit 70 may also set the current reference value to a value that is a predetermined value lower than the maximum value of the electricity market unit price for the same month one year ago for the current month. The stop determination unit 70 may also set the current reference value to a value that is a predetermined value higher than the minimum value of the electricity market unit price for the same month one year ago for the current month. As described above, any method can be used to set the reference value.

Next, the shutdown determination unit 70 determines whether the electricity market unit price is less than the reference value (S24a). The processing of step S24a corresponds to determining whether to shut down the power generation unit 20 based on the electricity market unit price. If the electricity market unit price is equal to or greater than the reference value (NO in S24a), the shutdown determination unit 70 ends the series of processes. In other words, the shutdown determination unit 70 waits while the electricity market unit price is equal to or greater than the reference value.

If the electricity market unit price is less than the reference value (YES in S24a), that is, if it is determined that the power generation unit 20 should be shut down, the shutdown determination unit 70 transmits a shutdown command to the second server device 16 via the communication device 60 to shut down the power generation unit 20 (S25). Upon receiving the shutdown command from the first server device 14, the second server device 16 transmits the shutdown command to the distributed power supply apparatus 10. This shuts down the power generation unit 20.

In this modified example, while the power generation unit 20 is stopped, the selling price of electricity sold by the power supplier to the consumer having the power generation unit 20 can be set to a price based on the market price of electricity that is less than the reference value. Therefore, according to this modified example, as in the first embodiment described above, it is possible to reduce the purchase price of electricity purchased by the consumer when the power generation unit 20 is stopped, while avoiding unintended alerts due to the safety function of the gas meter 32.

Second Embodiment
The shutdown determination unit 70 of the first embodiment shuts down the power generation unit 20 when the current power source unit price derived from the current power market unit price acquired from the power market 12 is less than a reference value. In contrast, the shutdown determination unit 70 of the second embodiment derives multiple predicted values of future power source unit prices in association with future dates. The multiple future dates here are set, for example, to a period from the present to a date corresponding to an upper limit threshold for the continuous operation time of the power generation unit 20. Note that the multiple future dates may also be set to a period up to a date corresponding to the end of the leakage detection period. For convenience, the multiple future dates will be described below as dates up to one week from the present.

Here, the storage device 62 of the first server device 14 stores multiple pieces of training data for predicting future electricity unit prices. The training data is data that associates, for example, past electricity unit prices, the date (day of the week, public holiday) on which the electricity unit price was derived, the weather (or hours of sunshine) when the electricity unit price was derived, and the temperature when the electricity unit price was derived. The date, weather, and temperature affect electricity consumption and are therefore considered to be related to the electricity market unit price, which in turn is related to the electricity unit price.

The shutdown determination unit 70 performs machine learning using the training data described above to generate a specific machine learning model. The machine learning model outputs a predicted value for the unit price of electricity corresponding to the input of date, weather, and temperature.

The stoppage determination unit 70 obtains the weather and predicted average temperature for each day up to one week into the future from weather forecasts, etc., which serve as the source data for predicting the electricity cost. The stoppage determination unit 70 inputs the date, weather, and predicted average temperature for each day from the present to one week into a specified machine learning model, and obtains predicted values for the electricity cost for each day from the present to one week into the future. This obtains seven predicted values for the period from the present to one week into the future.

Then, the shutdown determination unit 70 of the second embodiment determines to shut down the power generation unit 20 on the day corresponding to the lowest predicted value among the multiple predicted values. For example, if the predicted value for the power source cost on the third day is the lowest among the predicted values for the power source cost for each day up to one week from now, the shutdown determination unit 70 determines to shut down the power generation unit 20 three days from now.

Figure 5 is a flowchart illustrating the operational flow of the stop determination unit 70 according to the second embodiment. The stop determination unit 70 according to the second embodiment executes the series of processes shown in Figure 5 when a predetermined interrupt timing occurs at a predetermined control cycle.

When the specified interrupt timing arrives, the stop determination unit 70 determines whether operation information has been received (S30). If operation information has not been received (NO in S30), the stop determination unit 70 ends the series of processes.

If operation information has been received (YES in S30), the shutdown determination unit 70 generates a machine learning model based on the training data stored in the storage device 62 (S31). Next, the shutdown determination unit 70 acquires raw data such as the weather and predicted average temperature for the period to be predicted (S32). Next, the shutdown determination unit 70 inputs the dates, weather, and predicted average temperature for the period to be predicted into the machine learning model to derive a predicted value for the electricity cost (S33).

Next, the stop determination unit 70 obtains the date on which the minimum predicted value is obtained from the derived multiple predicted values (S34). Next, the stop determination unit 70 reserves the transmission of a stop command on the obtained date (S35), and ends the series of processes. As a result, when the reserved date arrives, the stop determination unit 70 transmits a stop command to the second server device 16 via the communication device 60. Upon receiving the stop command, the second server device 16 transmits the stop command to the distributed power supply apparatus 10. The operating time determination unit 50 of the distributed power supply apparatus 10 stops the power generation unit 20 at the timing when the stop command is received and resets the count value.

As described above, the power generation management system 1 of the second embodiment can shut down the power generation unit 20 at the timing when the unit price of electricity is predicted to be lowest. Therefore, the power generation management system 1 of the second embodiment can further reduce the purchase price of electricity purchased by consumers when the power generation unit 20 is shut down.

(Modification of the second embodiment)
In the second embodiment, multiple predicted values of the future electricity price are derived in association with future dates, and it is determined that the power generation unit 20 should be shut down on the day corresponding to the lowest predicted value. However, the shutdown determination unit 70 may also derive multiple predicted values of the future electricity market price in association with future dates, and determine that the power generation unit 20 should be shut down on the day corresponding to the lowest predicted value.

For example, the storage device 62 of the first server device 14 stores multiple pieces of training data for predicting future electricity market unit prices. The training data is data that associates, for example, past electricity market unit prices, the dates (days of the week, holidays) on which the electricity market unit prices were acquired, the weather (or hours of sunshine) when the electricity market unit prices were acquired, and the temperature when the electricity market unit prices were acquired.

The shutdown determination unit 70 performs machine learning using the training data described above to generate a specific machine learning model. The machine learning model outputs a predicted value for the electricity market unit price corresponding to the input of date, weather, and temperature.

The shutdown determination unit 70 obtains the weather and predicted average temperature for each day up to one week into the future from weather forecasts, etc., which serve as the source data for predicting the electricity market unit price. The shutdown determination unit 70 inputs the date, weather, and predicted average temperature for each day from the present to one week into a specified machine learning model, and obtains predicted values for the electricity market unit price for each day from the present to one week into the future. This obtains seven predicted values for the period from the present to one week into the future.

The shutdown decision unit 70 then decides to shut down the power generation unit 20 on the day corresponding to the lowest predicted value among the multiple predicted values. For example, if the predicted value for the electricity market unit price on the third day is the lowest among the predicted values for the electricity unit price for each day up to one week from now, the shutdown decision unit 70 decides to shut down the power generation unit 20 three days from now.

In this variant, the power generation unit 20 can be shut down at the timing when the market price of electricity is predicted to be lowest. As with the second embodiment, this variant makes it possible to further reduce the purchase price of electricity purchased by consumers when the power generation unit 20 is shut down.

(Third embodiment)
Fig. 6 is a schematic diagram showing the configuration of a power generation management system 100 according to the third embodiment. The power generation management system 100 of the third embodiment differs from the first embodiment in that it has a plurality of distributed power supply devices 10. Although Fig. 6 shows two distributed power supply devices 10 as an example, the number of distributed power supply devices 10 is not limited to two, and three or more distributed power supply devices 10 may be provided.

In the third embodiment, the shutdown determination unit 70 of the first server device 14 determines whether to shut down the power generation unit 20 based on the unit price of electricity in response to receiving operation information transmitted from one of the multiple distributed power supply devices 10. In other words, in the third embodiment, when the continuous operation time of any of the multiple distributed power supply devices 10 reaches or exceeds a predetermined time, a determination is made as to whether to shut down the power generation unit 20.

Then, when the shutdown determination unit 70 determines that the power generation unit 20 should be shut down, it sends a shutdown command to the multiple distributed power supply devices 10. In other words, in the second embodiment, the multiple distributed power supply devices 10 are shut down simultaneously at the same time.

Therefore, in the power generation management system 100 of the third embodiment, it is possible to reduce the processing load on the shutdown determination unit 70 compared to a configuration in which the distributed power supply devices 10 are shut down individually.

Furthermore, in the third embodiment, as in the first embodiment, it is possible to reduce the purchase price of electricity purchased by consumers when the power generation unit 20 is stopped.

The third embodiment may be combined with the features of the second embodiment. Specifically, the shutdown determination unit 70 may derive a predicted value for the future unit price of electricity and send a shutdown command to multiple distributed power generation devices 10 on the day corresponding to the lowest predicted value among the multiple predicted values. The third embodiment may also be combined with the features of the modified first embodiment, or the third embodiment may be combined with the features of the modified second embodiment.

(Fourth embodiment)
7 is a schematic diagram showing the configuration of a power generation management system 200 according to a fourth embodiment. In the first embodiment described above, the stop determination unit 70 was provided in the first server device 14. In contrast, in the fourth embodiment, the first server device 14 and the second server device 16 are omitted, and a stop determination unit 270 is provided in the distributed power supply apparatus 10. The control device 24 of the distributed power supply apparatus 10 in the fourth embodiment functions as the operating time determination unit 50 and also as the stop determination unit 270.

In the fourth embodiment, the shutdown determination unit 270 acquires the electricity market unit price from the electricity market 12 at a predetermined control timing when the continuous operation time is equal to or longer than a predetermined time. The shutdown determination unit 270 derives the electricity source unit price based on the acquired electricity market unit price. If the electricity source unit price is less than a predetermined reference value, the shutdown determination unit 270 determines to shut down the power generation unit 20.

Figure 8 is a flowchart illustrating the operation of the operating time determination unit 50 and the stop determination unit 270 according to the fourth embodiment. Steps S10 to S14 in Figure 8 are the same as steps S10 to S14 in Figure 2. Figure 8 differs from Figure 2 in the processing that follows when step S14 is YES. In addition, the operating time determination unit 50 starts the series of processing in Figure 8 at each predetermined control timing that occurs in a predetermined control cycle.

In step S14, if the count value is equal to or greater than the predetermined threshold (YES in S14), i.e., if the continuous operation time is equal to or greater than the predetermined time, the stop determination unit 270 acquires the electricity market unit price from the electricity market 12 (S40). The stop determination unit 270 reads the private power source unit price and the electricity trading unit price from the storage device 62, and derives the electricity source unit price by summing the read private power source unit price, the read electricity trading unit price, and the acquired electricity market unit price (S41). Next, the stop determination unit 270 sets the current reference value based on the past electricity source unit prices stored in the storage device 62 (S42).

Next, the stop determination unit 270 determines whether the unit price of electricity is less than the reference value (S43). If the unit price of electricity is equal to or greater than the reference value (NO in S43), the stop determination unit 270 ends the series of processes.

If the electricity unit cost is less than the reference value (YES in S43), the stop determination unit 270 determines to stop the power generation unit 20, and the control device 24 accordingly stops the power generation unit 20 (S44). The stop determination unit 270 then resets the count value (S45), and the series of processes ends.

As described above, in the power generation management system 200 of the fourth embodiment, similar to the first embodiment, when the continuous operation time is equal to or longer than a predetermined time, a decision is made based on the unit cost of electricity as to whether to shut down the power generation unit 20.

Therefore, in the fourth embodiment, the power generation management system 200, like the first embodiment, makes it possible to reduce the purchase price of electricity purchased by consumers when the power generation unit 20 is stopped.

The fourth embodiment may be combined with the features of the second embodiment. Specifically, the shutdown decision unit 270 of the distributed power supply device 10 may derive a predicted value for the future unit price of electricity and decide to shut down the power generation unit 20 on the day corresponding to the lowest predicted value among multiple predicted values. The fourth embodiment may also be combined with the features of the modified first embodiment, or the fourth embodiment may be combined with the features of the modified second embodiment.

While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that a person skilled in the art could conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

For example, in each of the above embodiments and variations, the electricity unit price is the sum of the electricity market unit price, the private power source unit price, and the electricity trading unit price. However, if electricity from a private power source is not used to secure power, the private power source unit price does not need to be included in the electricity unit price. Similarly, if electricity based on a trading contract with another power supplier is not used to secure power, the electricity trading unit price does not need to be included in the electricity unit price. In other words, the electricity unit price may be equal to the electricity market unit price.

Reference Signs List 1, 100, 200 Power generation management system 10 Distributed power supply device 12 Electricity market 14 First server device 20 Power generation unit 50 Operation time determination unit 70, 270 Stop determination unit

Claims (7)

a power generation unit that consumes fuel gas to generate at least electrical power;
an operation time determination unit that determines a continuous operation time indicating a time during which the power generation unit has been operating continuously;
a stop determination unit that determines whether or not to stop the power generation unit;
Equipped with
The price per unit of electricity traded in the electricity market is the electricity market unit price.
The cost per unit of electricity required to generate electricity from a private power source managed by an electricity supplier that supplies electricity to a consumer having the power generation unit is the private power source unit price,
The cost per unit of electricity based on an electricity trading contract concluded between the electricity supplier and another electricity supplier is the electricity trading unit price,
an electricity price is a cost per unit of electricity that the electricity supplier incurs to secure electricity to be supplied to the consumer having the power generation unit, the cost including at least one of the electricity market price, the private power source price, and the electricity trading price;
The stop determination unit
a power generation management system that determines, at a predetermined control timing when the continuous operation time is equal to or longer than a predetermined time, whether to stop the power generation unit based on the unit price of electricity. the power generation unit and the operating time determination unit are provided in a distributed power supply apparatus,
the stop determination unit is provided in a server device that can communicate with the distributed power supply apparatus,
the operation time determination unit, when the continuous operation time is equal to or longer than a predetermined time, transmits operation information indicating that the continuous operation time is equal to or longer than the predetermined time to the server device;
The power generation management system described in claim 1, wherein the shutdown judgment unit judges whether to shut down the power generation unit based on the unit cost of electricity in response to receiving the operation information, and if it judges to shut down the power generation unit, sends a shutdown command to the distributed power supply device to shut down the power generation unit. a plurality of the distributed power supply devices;
The power generation management system of claim 2, wherein the shutdown determination unit determines whether to shut down the power generation unit based on the unit cost of electricity in response to receiving the operation information transmitted from any of the plurality of distributed power generation devices, and if it determines that the power generation unit should be shut down, transmits the shutdown command to the plurality of distributed power generation devices. The power generation management system of claim 1, wherein the power generation unit, the operating time determination unit, and the shutdown determination unit are provided in a distributed power supply device. A power generation management system according to any one of claims 1 to 4, wherein the stop determination unit determines to stop the power generation unit if the unit price of electricity is less than a predetermined reference value at a predetermined control timing when the continuous operation time is equal to or longer than a predetermined time. The stop determination unit
The electricity unit price is periodically acquired and stored in a storage device,
The power generation management system according to claim 5 , wherein the reference value is set based on the past unit price of electricity stored in the storage device. A power generation management system according to any one of claims 1 to 4, wherein the shutdown decision unit derives multiple predicted values of the future unit cost of electricity in association with future dates, and decides to shut down the power generation unit on the day corresponding to the lowest predicted value.