JP7165045B2 - building power supply system - Google Patents

Description

The present invention relates to power supply systems for buildings.

2. Description of the Related Art As a power supply system for a building, Patent Literature 1 discloses a system that includes a solar cell that generates power by irradiating sunlight and a cogeneration device that generates power using a fuel cell. In this power supply system, the power generated by the solar cell and the power generated by the fuel cell are supplied to various electric loads (household appliances, lighting fixtures, etc.) in the building.

A cogeneration system has a function of generating hot water using heat generated during power generation by a fuel cell. Also, the cogeneration system has a hot water storage tank for storing the generated hot water. In this case, the hot water in the hot water storage tank can be used as needed.

Moreover, the power supply system of Patent Document 1 includes a storage battery, and the power generated by the solar battery and the fuel cell can be stored in the storage battery. Specifically, in this power supply system, when the total power generated by the solar cells and fuel cells exceeds the power consumed by the electrical load in the building, that is, when there is a surplus of generated power In addition, the surplus is stored in a storage battery.

Here, when the storage battery is in a fully charged state, even if there is a surplus in the generated power, the surplus cannot be charged to the storage battery. Therefore, in the power supply system of Patent Document 1, when the storage battery is fully charged, power supply control is performed to increase the proportion of power generated by the solar cell and decrease the proportion of power generated by the fuel cell. That is, when there is a surplus in the power generated by the solar cell and the fuel cell, even if the power generated by the fuel cell is reduced to some extent, the power generated by these cells can cover the power consumption of the electric load. can. Therefore, in the power supply system of Patent Document 1, in such a case, by performing power supply control as described above to suppress power generation by the fuel cell, it is possible to obtain advantages such as saving energy. there is

JP 2015-149861 A

By the way, when the storage battery is fully charged, when the above-described power supply control is performed to increase the ratio of the power generated by the solar cell and decrease the ratio of the power generated by the fuel cell, the amount of hot water generated by the fuel cell is increased. It may be difficult to secure a certain amount of hot water in the hot water storage tank because the hot water is not sufficiently generated.

The present invention has been made in view of the above circumstances, and provides a power supply system for a building that supplies power generated by a photovoltaic power generation device and power generated by a cogeneration device having a hot water storage tank to electrical loads in the building. The main purpose is to obtain an energy saving effect while securing hot water in the hot water storage tank.

In order to solve the above problems, the power supply system for a building of the first invention has a photovoltaic power generation device that performs photovoltaic power generation and a power generation function that uses fuel to generate power. and a cogeneration system having a hot water storage tank for storing hot water generated using heat, and supplying the power generated by the solar power generation system and the power generated by the cogeneration system to each electrical load in the building. a power supply system comprising: acquiring means for acquiring stored hot water amount information relating to the heat amount of hot water stored in the hot water storage tank; power determination means for determining whether or not the power consumed by the load exceeds the power consumption; and power generation that exceeds the power consumption when the power determination means determines that the total generated power exceeds the power consumption. supply possibility determination means for determining whether or not the surplus power can be supplied to a predetermined power supply destination; and the supply availability determination means determines that the surplus generated power cannot be supplied to the predetermined power supply destination. a control means for controlling the power generated by the cogeneration device based on the stored hot water amount information acquired by the acquisition means when the information is obtained.

According to the present invention, when the total power that can be generated by the photovoltaic power generation system and the cogeneration system exceeds the power consumed by each electrical load in the building, the excess generated power is reduced to a predetermined amount. It is determined whether or not the power can be supplied to the power supply destination (for example, a storage battery), and if the result of the determination is that the power cannot be supplied, the power generated by the cogeneration system is controlled based on the stored hot water amount information regarding the heat amount of the hot water in the hot water storage tank. .

As a result, when the amount of hot water stored in the hot water storage tank is large, for example, when a certain amount of hot water is secured in the hot water storage tank, the electric power generated by the cogeneration system is reduced (suppressed) so that each electric load power consumption can be covered preferentially by the power generated by the photovoltaic power generation device. In this case, since the fuel used for power generation in the cogeneration system can be reduced, energy can be saved. Also, when the amount of hot water stored in the hot water storage tank is small, for example, when a certain amount of hot water is not secured in the hot water storage tank, the power generated by the cogeneration system is increased to encourage the generation of hot water as power is generated. be able to. In this case, it is possible to secure hot water in the hot water storage tank. Therefore, as described above, it is possible to obtain an energy saving effect while ensuring hot water in the hot water storage tank.

The stored hot water amount information (information about the heat amount of hot water) includes, for example, information on the temperature and amount of hot water in the hot water storage tank.

A power supply system for a building according to a second invention is characterized in that, in the first invention, when the heat quantity of the hot water in the hot water storage tank acquired by the acquisition means is lower than a predetermined threshold, When the power generated by the cogeneration device is controlled to be equal to or higher than a predetermined power regardless of the power generated by the solar power generation device, and the heat quantity of the hot water in the hot water storage tank obtained by the obtaining means is equal to or higher than the threshold. (2) is characterized in that the power generated by the cogeneration system is controlled based on the power generated by the photovoltaic power generation system.

According to the present invention, when the calorific value of the hot water in the hot water storage tank is lower than a predetermined threshold value, for example, when a certain amount of hot water is not secured in the hot water storage tank, the power generated by the solar power generation device Regardless, the power generated by the cogeneration system is controlled to be equal to or higher than the predetermined power. As a result, when the hot water in the hot water storage tank is insufficient, it is possible to encourage the generation of hot water and secure the hot water.

Further, when the heat quantity of the hot water in the hot water storage tank is equal to or higher than a predetermined threshold value, for example, when a certain amount of hot water is secured in the hot water storage tank, based on the power generated by the solar power generation device, Power generated by the cogeneration system is controlled. In this case, when the power generated by the photovoltaic power generation device is high, the power generated by the cogeneration device can be reduced accordingly. As a result, when the hot water in the hot water storage tank is secured, an energy saving effect can be obtained.

A power supply system for a building according to a third aspect of the invention is characterized in that, in the second aspect of the invention, the control means controls each of the A difference between the power consumption of the electrical load and the power generated by the photovoltaic power generation device is calculated, and the power generated by the cogeneration device is controlled to the same magnitude as the calculated difference.

According to the present invention, when the heat quantity of the hot water in the hot water storage tank is equal to or greater than the threshold value, the difference between the power consumption of each electric load and the power generated by the solar power generation device is calculated, and the calculated difference is calculated. The power generated by the cogeneration system is controlled to the same magnitude as In this case, the power generated by the cogeneration system can be reduced to the minimum power required to cover the power consumption of each electric load, thereby enhancing the energy saving effect.

A power supply system for a building according to a fourth invention is the power supply system for a building according to any one of the first to third inventions, wherein when a power failure occurs in the building, each process by the power determination means, the supply availability determination means, and the control means is characterized by executing

When a power outage occurs in a building due to a disaster or the like, it is particularly important to secure hot water in a hot water storage tank in a cogeneration system and secure fuel. In this regard, in the present invention, when a power outage occurs in the building, each processing by the power determination means, the supply availability determination means, and the control means in the first invention is executed. In this case, it is possible to suitably secure hot water and fuel for the cogeneration system in the event of a power failure.

1 is an overall configuration diagram showing an outline of a power supply system; FIG. The figure which shows the electrical structure of a power feeding system. 5 is a flowchart showing power supply processing during power failure;

An embodiment embodying the present invention will be described below with reference to the drawings. Note that FIG. 1 is an overall configuration diagram showing an outline of the power feeding system according to the present embodiment.

As shown in FIG. 1, a distribution board 11 is provided in a building 10 such as a house. The distribution board 11 is supplied with AC 100V commercial power from a commercial power supply (system power supply) through a lead-in line 12 . A breaker 13 is provided on the lead-in line 12, and the breaker 13 enables connection and disconnection between the distribution board 11 and the commercial power supply side.

A solar power generation device 17 is provided in the building 10 . The photovoltaic power generation device 17 includes a solar panel installed on the roof 16 and generates power by being irradiated with sunlight. Power generated by the photovoltaic power generation device 17 is supplied to the distribution board 11 via the electric wiring 18 . Also, the amount of power generated by the photovoltaic power generation device 17 is measured by a power sensor 19 .

A cogeneration device 21 is provided on the outdoor side of the building 10 . The cogeneration device 21 is configured as a domestic fuel cell cogeneration system. The cogeneration device 21 uses a fuel cell to generate electricity by chemically reacting hydrogen as a fuel with oxygen in the air. The cogeneration device 21 also has an adjustment function of adjusting (controlling) the amount of power to be generated.

The cogeneration device 21 has a function of heating water using heat generated during power generation to generate hot water. The cogeneration device 21 also has a hot water storage tank 23 for storing the produced hot water. The hot water storage tank 23 is provided with a hot water temperature sensor 26 for detecting the temperature of the hot water in the tank 23 . Note that the hot water temperature sensor 26 corresponds to an acquisition means.

The power generated by the cogeneration device 21 is supplied to the distribution board 11 via the electrical wiring 25 . Therefore, the distribution board 11 is supplied with commercial power from the commercial power supply, power generated by the photovoltaic power generation device 17 , and power generated by the cogeneration device 21 . These electric powers supplied to the distribution board 11 are supplied from the distribution board 11 to each electric load E (lighting equipment, air conditioning equipment, home appliances, etc.) in the building 10 via electric wiring 27 .

The distribution board 11 is provided with a power sensor 28 that detects the amount of power supplied to each electric load E. As shown in FIG. The amount of power supplied from the distribution board 11 to each electric load E corresponds to the amount of power consumed by the electric loads E. FIG. Therefore, the power sensor 28 detects the power consumption of each electric load E in the building 10 .

A storage battery 29 is provided on the outdoor side of the building 10 . The storage battery 29 is connected to the distribution board 11 via electric wiring 31 . The commercial power supplied to the distribution board 11 , the power generated by the solar power generation device 17 , and the power generated by the cogeneration device 21 are each supplied from the distribution board 11 to the storage battery 29 via the electric wiring 31 . Then, the storage battery 29 is charged with the supplied electric power.

The storage battery 29 is connected to the distribution board 11 via electric wiring 32 . Electric power (accumulated power) stored in the storage battery 29 is supplied to the distribution board 11 through the electric wiring 32, and the supplied electric power is supplied from the distribution board 11 through the electric wiring 27 to each electric load E. be. Further, the storage battery 29 is provided with a storage amount sensor 34 that detects the amount of power stored in the storage battery 29 .

A switch 35 is provided in the building 10 . The switch 35 includes a breaker 36 provided on the electrical wiring 31 and a breaker 37 provided on the electrical wiring 32 . The cutoff device 36 permits or cuts off (prohibits) the supply of electric power from the distribution board 11 to the storage battery 29 through the electric wiring 31 by an opening/closing operation. The power supply to the storage battery 29 is permitted or cut off by the cutoff device 36, thereby executing or stopping the charging of the storage battery 29. FIG.

The cutoff device 37 permits or cuts off (prohibits) the supply of power (stored power) from the storage battery 29 to the distribution board 11 through the electric wiring 32 by an opening/closing operation. When the power supply from the storage battery 29 to the distribution board 11 is permitted or cut off by the cutoff device 37, the power supply from the storage battery 29 to each electric load E via the distribution board 11 is executed or stopped. .

Next, the electrical configuration of the power feeding system will be described with reference to FIG. FIG. 2 is a diagram showing the electrical configuration of the power supply system.

As shown in FIG. 2, the power supply system includes a controller 40 as control means. The controller 40 is configured with a well-known microcomputer having a CPU and the like. The controller 40 is attached to a wall inside the building 10, for example.

The power sensors 19 and 28, the electricity storage amount sensor 34, and the hot water temperature sensor 26 are connected to the controller 40. As shown in FIG. The controller 40 is sequentially input with detection results from these sensors 19 , 26 , 28 and 34 .

The solar power generation device 17 and the cogeneration device 21 are connected to the controller 40 . The controller 40 controls power generation of the photovoltaic power generation device 17 and the cogeneration device 21 based on the detection results from the sensors 19, 26, 28, and 34 described above.

The controller 40 is connected to the blocking device 13 and the switch 35 (the blocking devices 36 and 37). The controller 40 performs opening/closing control of the blocking devices 13, 36, 37 based on the detection results from the sensors 19, 26, 28, 34 described above.

Here, in this power supply system, when a power failure occurs in the building 10, that is, when commercial power cannot be supplied to the electric load E in the building 10, the controller 40 performs power supply processing during power failure. there is In this power failure time power supply process, the power generated by the photovoltaic power generation device 17 and the power generated by the cogeneration device 21 are supplied to each electric load E in the building 10 . The power supply processing during power failure will be described below with reference to FIG. Note that FIG. 3 is a flowchart showing power supply processing during power failure.

The power failure process is started when a power failure occurs in the building 10 as a trigger. For example, the building 10 is provided with a power failure detection sensor that detects whether or not a power failure has occurred. Power supply processing at power failure is started. Further, the power supply process during power failure is repeatedly executed at a predetermined cycle during power failure, and ends when power failure is restored. For example, when a detection result indicating that a power failure has not occurred (power failure has been restored) is input to the controller 40 from a power failure detection sensor, the controller 40 terminates power supply processing during power failure.

As shown in FIG. 3, first, in step S11, the breaker 13 of the lead-in line 12 is opened. As a result, the connection between the distribution board 11 and the commercial power supply side is cut off.

In the subsequent step S12, power generation by the cogeneration device 21 is executed. As a result, during a power outage, the power generated by the photovoltaic power generation device 17 and the power generated by the cogeneration device 21 are each supplied to each electric load E via the distribution board 11 . If the cogeneration system 21 is already generating power, the power generation is continued.

In step S13, the total generated power Pt that can be generated by the photovoltaic power generation device 17 and the cogeneration device 21 is calculated. Specifically, in this step, the power generated by the photovoltaic power generation device 17 is acquired based on the detection result from the power sensor 19, and power can be generated by the cogeneration device 21 together with the power generated by the photovoltaic power generation device 17 acquired. The total generated power Pt is calculated by adding up the maximum generated power. It should be noted that this total generated power Pt corresponds to the maximum generated power Pt that can be generated by each of the power generators 17 and 21 . In addition, the cogeneration device 21 has a predetermined range of generated power that can be generated, and the maximum value within that range is the maximum generated power.

In step S14, the power consumption Pc of each electrical load E in the building 10 is acquired based on the detection result from the power sensor 28, and the acquired power consumption Pc and the total power generation that can be generated by the power generators 17 and 21 are calculated. By comparing with the power Pt, it is determined whether or not the total generated power Pt exceeds the power consumption Pc (corresponding to power determination means). When the total generated power Pt exceeds the consumed power Pc (Pt>Pc), the process proceeds to step S15. In this case, the portion of the total generated power Pt that exceeds the consumed power Pc corresponds to the surplus ΔP of the total generated power Pt (Pt−Pc=ΔP).

In step S15, the supply of stored power from the storage battery 29 to each electric load E, which is executed in step S25 described later, is stopped. In this case, the power supply from the storage battery 29 to the distribution board 11 is stopped by opening the cutoff device 37 . In addition, when the power supply from the storage battery 29 has already been stopped, the stop is continued.

In step S16, the amount of electric power stored in the storage battery 29 is acquired based on the detection result from the storage amount sensor 34, and whether or not the storage battery 29 is fully charged is determined based on the acquired amount of electric power. judge. Here, when the storage battery 29 is not fully charged, the surplus ΔP of the total electric power Pt generated by each of the power generators 17 and 21 can be supplied to the storage battery 29 and used for charging the storage battery 29 . On the other hand, when the storage battery 29 is fully charged, the surplus ΔP of the total generated power Pt cannot be supplied to the storage battery 29, so the surplus ΔP cannot be used to charge the storage battery 29. Can not. Therefore, in this step S16, in other words, it is determined whether or not it is possible to supply the surplus ΔP of the total generated power Pt to the storage battery 29 (corresponding to the supply possibility determination means).

If the storage battery 29 is not fully charged in step S16, the process proceeds to step S21 to adjust the generated power of the cogeneration device 21 to the maximum generated power. As a result, the power generated by each of the power generators 17 and 21 becomes the total power Pt calculated in step S13. Therefore, in this case, a surplus ΔP that is not consumed by the electric load E occurs in the power generated by each of the power generators 17 and 21 .

In step S22, charging processing of the storage battery 29 is performed. In this process, the surplus ΔP of the generated power is supplied from the distribution board 11 to the storage battery 29 by closing the cutoff device 36 . As a result, the storage battery 29 is charged with the supplied surplus ΔP. In this case, of the generated power (total generated power) of the power generators 17 and 21, the amount corresponding to the consumed power Pc is supplied to each electric load E, and the remaining surplus ΔP is supplied to the storage battery 29 to be charged. used for After the charging process, this process ends.

On the other hand, when the storage battery 29 is fully charged in step S16, the process proceeds to step S17. In step S17, based on the detection result from the hot water temperature sensor 26, it is determined whether or not the temperature of the hot water stored in the hot water storage tank 23 is equal to or higher than a predetermined temperature Ta (corresponding to a predetermined threshold value). Here, in the present embodiment, it is assumed that the hot water in the hot water storage tank 23 is taken out directly from the hot water storage tank 23 and used during a power outage. A predetermined temperature Ta is set as a temperature suitable for use when taking out such hot water. The predetermined temperature Ta is set at 40° C., for example. When the hot water temperature in the hot water storage tank 23 is lower than the predetermined temperature Ta, the process proceeds to step S20. Information on the hot water temperature in the hot water storage tank 23 corresponds to information on the heat quantity of hot water (hot water storage amount information).

In step S20, the generated power of the cogeneration device 21 is adjusted to the maximum generated power. That is, the power generated by the cogeneration device 21 is adjusted to the maximum power regardless of the power generated by the photovoltaic power generation device 17 . As a result, when the temperature of the hot water in the hot water storage tank 23 is low, the cogeneration device 21 is encouraged to generate hot water along with power generation. In this case, the power Pc of each electric load E that cannot be covered by the power generated by the cogeneration device 21 (maximum power generated) is compensated by the power generated by the solar power generation device 17. become. Therefore, in such a case, of the power generated by the power generators 17 and 21 that cover the power consumption Pc, the proportion of the power generated by the cogeneration device 21 is high, and the proportion of the power generated by the photovoltaic power generation device 17 is low. . After the process of step S20, the process ends.

If the temperature of the hot water in the hot water storage tank 23 is equal to or higher than the predetermined temperature Ta in the previous step S17, the process proceeds to step S18, where the power consumption Pc of each electric load E and the power generated by the solar power generation device 17 are calculated. Calculate the difference. That is, here, the power shortage that cannot be covered by the power generated by the photovoltaic power generation device 17 is calculated out of the power consumption Pc of each electric load E. FIG.

In the subsequent step S19, the power generated by the cogeneration system 21 is adjusted to the compensation power. The supplementary generated power is the generated power for compensating for the power shortage that cannot be covered by the power generated by the photovoltaic power generation device 17; The generated power is of the same magnitude. This supplementary generated power is lower than the maximum generated power of the cogeneration system 21 adjusted in step S20. In this case, of the power consumption Pc of each electric load E, the power generated by the cogeneration device 21 compensates for the shortfall that cannot be covered by the power generated by the photovoltaic power generation device 17 . Therefore, in this case, of the power generated by the power generators 17 and 21 that cover the power consumption Pc of each electrical load E, the proportion of the power generated by the cogeneration device 21 is low, and the proportion of the power generated by the photovoltaic power generation device 17 is reduced. becomes higher. Therefore, the power generation of the cogeneration device 21 is suppressed and energy saving is achieved. After the process of step S19, the process ends.

In step S14 described above, if the total generated power Pt that can be generated by each of the power generators 17 and 21 is equal to or less than the power consumption Pc of each electrical load E (Pt≤Pc), that is, the total generated power Pt has a surplus ΔP has not occurred, the process proceeds to step S23. In step S23, the charging process of the storage battery 29 is stopped. In this process, the power supply from the distribution board 11 to the storage battery 29 is stopped by opening the cutoff device 36 . If the charging of the storage battery 29 has already been stopped at this time, the stopped state is continued.

In the subsequent step S24, it is determined whether or not the total power Pt that can be generated by each power generator 17, 21 is lower than the power consumption Pc of each electric load E. When the total generated power Pt of each power generator 17, 21 is lower than the power consumption Pc (Pt<Pc), that is, the power generated by each power generator 17, 21 with respect to the power consumption Pc of each electric load E is If the amount is insufficient, the process proceeds to step S25.

In step S25, the supply of stored electric power from the storage battery 29 to each electric load E is executed. In this process, by closing the cutoff device 37 , the stored power is supplied from the storage battery 29 to the distribution board 11 . As a result, when the power generated by each power generation device 17, 21 is insufficient, the power stored in the storage battery 29 in addition to the power generated by each power generation device 17, 21 is supplied to each electric load E via the distribution board 11. be done. After that, the process proceeds to step S20, and after adjusting the generated power of the cogeneration device 21 to the maximum generated power, the process ends.

Further, in step S24, when the total generated power Pt of each power generation device 17, 21 is the same as the power consumption Pc of each electric load E (Pt=Pc), the process proceeds to step S20 and the cogeneration device. After adjusting the generated power of 21 to the maximum generated power, this processing ends.

According to the configuration of the present embodiment described in detail above, the following excellent effects are obtained.

When the total power Pt that can be generated by the photovoltaic power generation device 17 and the cogeneration device 21 exceeds the power consumption Pc consumed by each electrical load E in the building 10, the surplus power generated is stored in the storage battery 29. If the result of the determination is that it is not possible to supply the hot water, the power generated by the cogeneration device 21 is controlled based on the temperature of the hot water in the hot water storage tank 23 .

Specifically, when the hot water temperature in the hot water storage tank 23 is lower than the predetermined temperature Ta, that is, when a certain amount of hot water is not secured in the hot water storage tank 23, the power generation of the solar power generation device 17 is The generated power of the cogeneration device 21 is controlled to the maximum generated power regardless of the power. As a result, when the hot water in the hot water storage tank 23 is insufficient, the generation of hot water can be promoted and the hot water can be ensured.

On the other hand, when the hot water temperature in the hot water storage tank 23 is equal to or higher than the predetermined temperature Ta, that is, when a certain amount of hot water is secured in the hot water storage tank 23, the electric power generated by the solar power generation device 17 is , the power generated by the cogeneration device 21 is controlled. In this case, when the power generated by the photovoltaic power generation device 17 is high, the power generated by the cogeneration device 21 can be reduced accordingly. As a result, when the hot water in the hot water storage tank 23 is secured, an energy saving effect can be obtained.

Therefore, as described above, it is possible to obtain the energy saving effect while ensuring the hot water in the hot water storage tank 23 .

Further, when the temperature of the hot water in the hot water storage tank 23 is equal to or higher than the predetermined temperature Ta, the difference between the power consumption Pc of each electric load E and the power generated by the solar power generation device 17 is calculated. The power generated by the cogeneration device 21 is controlled to have the same magnitude as the difference. In this case, the power generated by the cogeneration device 21 can be the minimum power required to cover the power consumption Pc of each electric load E, so the energy saving effect can be enhanced.

When a power outage occurs in the building 10, securing hot water in the hot water storage tank 23 in the cogeneration system 21 and securing fuel are particularly important. In this respect, in the above-described embodiment, when power failure occurs in building 10, power generated by cogeneration device 21 is controlled based on the hot water temperature in hot water storage tank 23 described above. , and fuel can be secured.

Further, when the storage battery 29 is not fully charged during a power outage, the power generated by the cogeneration device 21 is controlled to the maximum power that can be generated, and thereafter the power generated by each of the power generators 17 and 21 is charged to the storage battery. 29 to charge the storage battery 29 . In this case, the storage battery 29 can be quickly charged during a power outage in the building 10 . Therefore, considering that the power generated by the power generators 17 and 21 may not be enough to cover the power consumption of each electric load E during a power outage, this is a preferable configuration.

The present invention is not limited to the above embodiments, and may be implemented as follows, for example.

(1) In the above embodiment, when the temperature of the hot water in the hot water storage tank 23 is equal to or higher than the predetermined temperature Ta, the difference between the power consumption Pc of each electric load E and the power generated by the solar power generation device 17 is equal to the difference. 2, the power generated by the cogeneration system 21 is controlled, but this may be changed. For example, when the difference is greater than a predetermined value, the power generated by the cogeneration device 21 is controlled to the same magnitude as the difference, and when the difference is equal to or less than the predetermined value, the power generated by the cogeneration device 21 is controlled. It is conceivable to control the power to the predetermined value. In this case, the power generated by the cogeneration device 21 is controlled to be equal to or higher than the predetermined value regardless of the power generated by the solar power generation device 17 or the power consumption Pc. It becomes possible to obtain an energy effect.

(2) In the above embodiment, when the hot water temperature in the hot water storage tank 23 is lower than the predetermined temperature Ta, the generated power of the cogeneration device 21 is controlled to the maximum generated power (equivalent to the predetermined power). However, this may be changed so that the generated power is controlled to be lower than the maximum generated power (hereinafter referred to as first generated power). In this case as well, if the first generated power is a level of power that promotes the generation of hot water when the cogeneration device 21 generates power, it is possible to secure the hot water in the hot water storage tank 23 . In this case, the first power corresponds to the predetermined power.

Further, when the temperature of the hot water in the hot water storage tank 23 is lower than the predetermined temperature Ta, the power generated by the cogeneration device 21 may be variably controlled to be equal to or higher than the first power. In other words, the power generated by the cogeneration device 21 may be variably controlled instead of being controlled to a fixed value. For example, it is conceivable to control (adjust) the power generated by the cogeneration device 21 based on the temperature of the hot water in the hot water storage tank 23 . Specifically, it is conceivable to control so that the power generated by the cogeneration device 21 is increased as the hot water temperature is lower. In this case, the lower the temperature of the hot water, the more the hot water is generated, so it is possible to secure the hot water.

(3) In the above-described embodiment, the power generated by the cogeneration device 21 is controlled based on the hot water temperature information in the hot water storage tank 23 (corresponding to the stored hot water amount information regarding the heat quantity of the hot water). The electric power generated by the cogeneration device 21 may be controlled based on information on the amount of hot water in the hot water storage tank 23 (corresponding to stored hot water amount information regarding the heat amount of hot water). In this case, a hot water amount sensor (corresponding to acquisition means) for detecting the amount of hot water in the hot water storage tank 23 is provided. It is conceivable to perform the processing of S19 and perform the processing of step S20 when the amount of hot water detected is less than a predetermined amount.

(4) In the above embodiment, when surplus ΔP occurs in the power generated by each of the power generators 17 and 21, the surplus ΔP is supplied to the storage battery 29 (corresponding to a predetermined power supply destination) provided in the building 10. However, this may be changed so that the surplus ΔP is supplied to an on-vehicle storage battery (corresponding to a predetermined power supply destination) provided in a vehicle such as a hybrid vehicle. Further, the surplus ΔP may be supplied to a power selling destination (corresponding to a predetermined power feeding destination) outside the building 10 instead of or in addition to the storage battery.

(5) In the above embodiment, the predetermined temperature Ta, which is the determination threshold in step S17, was set to 40° C. on the assumption that hot water is taken out directly from the hot water storage tank 23 in the event of a power failure. No need to set. For example, when the hot water in the hot water storage tank 23 is mixed with tap water and taken out as mixed water, it is conceivable to set the predetermined temperature Ta so that the temperature of the mixed water is about 40.degree. In this case, the amount of hot water used by the user may be estimated, and the predetermined temperature Ta may be set based on the estimated amount of hot water used and the temperature of the tap water.

Note that the predetermined temperature Ta does not necessarily have to be a fixed value, and may be variably set based on a user's operation.

(6) In the above embodiment, steps S13 to S25 in FIG. during a power outage). An example of such a case will be described below.

In normal times, basically, the processes of steps S13 to S25 in FIG. 3 are repeated. Specifically, in step S14, when the total generated power Pt of each power generator 17, 21 exceeds the power consumption Pc of each electric load E (Pt>Pc), that is, the power generated by each power generator 17, 21 If there is a surplus ΔP in the electric load E, the breaker 13 is opened and the supply of commercial power from the commercial power source to each electric load E is stopped. As a result, each electric load E is supplied with the electric power (only) generated by each of the power generators 17 and 21 . Therefore, in normal times, control is performed such that the electric power generated by each of the generators 17 and 21 is supplied to each electric load E with priority over commercial electric power. After that, the process proceeds to step S16, and each process of S16 to S22 is performed. As a result, even in normal times, if there is a surplus in the generated power, the surplus is supplied to the storage battery 29 and used to charge the storage battery 29 . Further, when the storage battery 29 is fully charged and the surplus cannot be supplied to the storage battery 29, the electric power generated by each of the power generators 17 and 21 is controlled based on the temperature of the hot water in the hot water storage tank 23. It is possible to obtain an energy saving effect while securing hot water.

In normal times, in steps S14 and S24, when the total power generation Pt of each power generation device 17 and 21 is lower than the power consumption Pc of each electric load E (Pt<Pc), that is, each power generation device 17 , 21, in step S25, the circuit breaker 13 is closed and commercial power is supplied from the commercial power supply to each electric load E. As shown in FIG. As a result, the shortage of the power generated by each of the power generators 17 and 21 is compensated for by the commercial power.

(7) In the above embodiment, the electric power (only) generated by the cogeneration device 21 is controlled based on the hot water temperature in the hot water storage tank 23. However, for example, based on the hot water temperature in the hot water storage tank 23, In addition to the power generated by 21, the power generated by the solar power generation device 17 may be controlled. In this case, for example, when the temperature of the hot water in the hot water storage tank 23 is equal to or higher than the predetermined temperature Ta, it is conceivable to control the power generated by the solar power generation device 17 to be small. It is conceivable that the amount of electric power generated by the photovoltaic power generation device 17 is controlled by a power conditioner of the same device 17, for example.

(8) In the above embodiment, a cogeneration system that generates power using a fuel cell is used as the cogeneration system 21. good too.

DESCRIPTION OF SYMBOLS 10... Building 17... Photovoltaic power generation apparatus 21... Cogeneration apparatus 23... Hot water storage tank 26... Hot water temperature sensor as acquisition means 29... Storage battery as predetermined power supply destination 40... Controller as control means.

Claims (3)

a photovoltaic power generation device for photovoltaic power generation;
A cogeneration device that has a power generation function of generating power using fuel and has a hot water storage tank that stores hot water generated by using the heat generated at the time of power generation,
A power supply system for a building that supplies power generated by the photovoltaic power generation device and power generated by the cogeneration device to each electrical load in the building,
an acquisition means for acquiring stored hot water amount information relating to the heat amount of hot water stored in the hot water storage tank;
power determination means for determining whether or not the total power that can be generated by the photovoltaic power generation device and the cogeneration device exceeds the power consumption consumed by each of the electrical loads;
When the power determining means determines that the total generated power exceeds the consumed power, it determines whether or not the surplus generated power exceeding the power consumption can be supplied to a predetermined power supply destination. a means for judging whether supply is possible,
When the supply propriety determining means determines that the surplus generated power cannot be supplied to the predetermined power supply destination, the generated power of the cogeneration device is controlled based on the stored hot water amount information acquired by the acquiring means. a control means;
with
When the heat quantity of the hot water in the hot water storage tank acquired by the acquisition means is lower than a predetermined threshold, the control means controls the cogeneration system regardless of the power generated by the photovoltaic power generation system. When the generated power is controlled to be equal to or greater than a predetermined power, and the heat quantity of the hot water in the hot water storage tank acquired by the acquisition means is equal to or greater than the threshold value, the code is generated based on the power generated by the solar power generation device. A power supply system for a building, characterized by controlling power generated by a generation device . When the heat quantity of the hot water in the hot water storage tank acquired by the acquisition means is equal to or greater than the threshold value, the control means determines the difference between the power consumption of each electrical load and the power generated by the solar power generation device. 2. The power supply system for a building according to claim 1 , wherein the difference is calculated and the power generated by the cogeneration system is controlled to the same magnitude as the calculated difference. 3. The power supply system for a building according to claim 1, wherein each process by said power determination means, said supply availability determination means, and said control means is executed when a power failure occurs in said building.

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