WO2016170700A1

WO2016170700A1 - Energy storage system and energy storage method

Info

Publication number: WO2016170700A1
Application number: PCT/JP2015/075357
Authority: WO
Inventors: 門田　行生
Original assignee: 株式会社東芝
Priority date: 2015-04-23
Filing date: 2015-09-07
Publication date: 2016-10-27
Also published as: PH12017501922A1; JP6114777B2; PH12017501922B1; JP2016208694A

Abstract

An energy storage system according to the present embodiment is equipped with a water electrolysis unit, a fuel cell, and a control unit. The water electrolysis unit uses power supplied from a power generation unit using renewable energy to electrolyze water, thereby generating hydrogen, and stores the generated hydrogen in a hydrogen storage unit. The fuel cell uses the hydrogen stored in the hydrogen storage unit to generate electricity. The control unit calculates the amount of power consumed during a prescribed period by a load to which power is supplied from the power generation unit and the fuel cell, and controls the water electrolysis unit so as to store in the hydrogen storage unit an amount of hydrogen in accordance with the calculated amount of power.

Description

Energy storage system and energy storage method

Embodiments of the present invention relate to an energy storage system and an energy storage method.

A power generation system that generates power using natural energy such as solar power generation or wind power generation is attracting attention. This power generation system includes, for example, a power generation unit, an auxiliary power supply unit, a fuel cell unit, and a control unit. Auxiliary power supply units such as secondary batteries and capacitors compensate for and stabilize short-term fluctuations in hours or days of power generated by the power generation unit. On the other hand, the fuel cell unit electrolyzes water with the electric power generated by the power generation unit to generate hydrogen, and stores the generated hydrogen. Then, the stored hydrogen is used as fuel to reconvert it into electric power, thereby compensating and stabilizing the amount of long-term fluctuation of the electric power generated by the power generation unit throughout the season or throughout the year.

The control unit controls the power generation unit, the auxiliary power source unit, and the fuel cell unit in an integrated manner, and constantly monitors the power generation amount and the power demand by the power generation system, so that the power generation amount generated by the power generation unit is short-term. Control is performed on one or both of the auxiliary power supply unit and the fuel cell unit so as to compensate for the lack of power generation. Furthermore, this control unit performs control to adjust the amount of hydrogen stored in the fuel cell unit throughout the season or throughout the year.

Japanese Patent Laid-Open No. 2006-164637

However, since the auxiliary power supply unit is used to compensate for and stabilize power fluctuations in units of hours or days, it is necessary to increase the capacity of the auxiliary power supply unit. In addition, when the power generation unit stops due to a disaster or the like, there is a possibility that hydrogen used in the fuel cell to supply power to the load is consumed in a short time.

Therefore, the present invention has been made in consideration of such points, and is an energy storage system capable of storing hydrogen in an amount corresponding to the amount of power consumed by a load in a predetermined period with higher accuracy. The purpose is to provide.

The control device according to the present embodiment includes an acquisition unit that acquires a first power value indicating a time-series value of first power in a predetermined period, and a second power value that indicates a time-series value of the planned power in the predetermined period The ratio between the added value of the insufficient power value based on the difference between the first power value and the second power value in the predetermined period and the added value of the surplus power value based on the difference A generation unit corresponding to the system efficiency of the hydrogen energy storage device, a control for producing hydrogen according to the surplus power value, and a control for performing power generation using the hydrogen according to the shortage power value, The control part which performs this with respect to the said hydrogen energy storage apparatus is characterized by the above-mentioned.

FIG. 1 is a block diagram illustrating the configuration of the energy storage system according to the first embodiment. FIG. 2 is a block diagram illustrating the configuration of the energy storage system according to the second embodiment. FIG. 3 is a block diagram illustrating the configuration of the energy storage system according to the third embodiment. FIG. 4 is a modification of the third embodiment, and is a block diagram when the third embodiment is applied in combination with the second embodiment. FIG. 5 is a block diagram illustrating the configuration of the energy storage system according to the fourth embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment does not limit the present invention.

(First embodiment)
The energy storage system according to the first embodiment calculates the amount of power consumed by a load supplied with power from the power generation unit and the fuel cell during a predetermined period, and supplies an amount of hydrogen corresponding to the calculated amount of power. By storing in the hydrogen tank, an amount of hydrogen corresponding to the amount of power consumed by the load during the predetermined period is stored in the hydrogen tank with higher accuracy. More details will be described below.

FIG. 1 is a block diagram illustrating a configuration of an energy storage system 100 according to the first embodiment. As shown in FIG. 1, the energy storage system 100 according to this embodiment includes a fuel cell unit 120, a control unit 140, and an auxiliary power unit 160.

The fuel cell unit 120 is a system unit that generates power using hydrogen and oxygen, and includes a water electrolysis unit 122, a hydrogen tank 124, an oxygen tank 126, and a fuel cell 128.

The water electrolysis unit 122 generates hydrogen and oxygen by electrolysis of water using the power supplied from the power system 2. Specifically, water used for electrolysis is supplied to the water electrolysis unit 122 via the water pipe 4. In addition, power is supplied to the power system 2 from the power generation unit 6 using renewable energy, and the water electrolysis unit 122 uses the power supplied via the power system 2 to perform electrolysis of water. Produce hydrogen and oxygen.

Hydrogen generated by the water electrolysis unit 122 is transferred to the hydrogen tank 124 via the hydrogen pipe 8 and stored in the hydrogen tank 124. This hydrogen tank 124 constitutes a hydrogen storage unit in the present embodiment. Further, oxygen generated by the water electrolysis unit 122 is transferred to the oxygen tank 126 through the oxygen pipe 10 and stored in the oxygen tank 126.

The fuel cell 128 is connected to the hydrogen pipe 8 for supplying hydrogen and the oxygen pipe 10 for supplying oxygen, and generates electricity using hydrogen and oxygen supplied from these pipes. The generated electricity is transmitted to the power system 2 to which the fuel cell 128 is connected.

Further, the hydrogen pipe 8 has a path directly connected to the water electrolysis unit 122 and the fuel cell 128, and a path connected between the water electrolysis unit 122 and the fuel cell 128 via the hydrogen tank 124. And have. Similarly, the oxygen pipe 10 is connected to a path directly connected to the water electrolysis unit 122 and the fuel cell 128 and between the water electrolysis unit 122 and the fuel cell 128 via an oxygen tank 126. Path. That is, when the water electrolysis unit 122 is not electrolyzing water, the fuel cell 128 generates power using hydrogen stored in the hydrogen tank 124 and oxygen stored in the oxygen tank 126. On the other hand, when the water electrolysis unit 122 performs electrolysis of water, the fuel cell 128 uses the hydrogen stored in the hydrogen tank 124 and the oxygen tank 126 in addition to the hydrogen and oxygen generated by the water electrolysis unit 122. Power is generated using oxygen stored in The fuel cell 128 can also obtain oxygen from the air. In this case, the oxygen pipe 10 and the oxygen tank 126 may be omitted.

The control unit 140 controls the fuel cell unit 120 and the auxiliary battery unit 160, and calculates the amount of power consumed by the load 12 supplied with power from the power generation unit 6 and the fuel cell 128 in a predetermined period. . That is, the load 12 is configured from a home, a factory, and the like, and each load 12 is provided with a power consumption measuring unit 14. And the control part 140 calculates the electric energy consumed in a predetermined period based on the measurement data which the electric power consumption measurement part 14 measured and shows the electric energy consumption in these loads 12, This calculated electric power The water electrolysis unit 122 is controlled to store an amount of hydrogen corresponding to the amount in the hydrogen tank 124.

The auxiliary power supply unit 160 charges and discharges the excess and deficiency of power supplied from the power generation unit 6 and the fuel cell 128 to the load 12. The auxiliary power supply unit 160 is configured such that the charge / discharge control response time is shorter than the control response time of the fuel cell unit 120. That is, the auxiliary power supply unit 160 includes a secondary battery, a capacitor, and the like, and has a capacity sufficient to compensate for excess or deficiency of power due to a delay in control response of the fuel cell unit 120.

Here, the power generation unit 6 is configured by a single machine or a plurality of power generation apparatuses among a solar power generation apparatus using sunlight and a wind power generation apparatus using wind power, and is configured by the same type of power generation apparatus. Alternatively, different types of power generation devices may be combined. That is, all of this electric power generation part 6 may be comprised with a solar power generation device, and may be comprised combining a wind power generator and a solar power generation device.

Generally, when the transmission distance is long, the transmission loss can be reduced by increasing the transmission voltage and reducing the transmission current. For this reason, the electric power system 2 is comprised by the alternating current system which can raise / lower a voltage easily using a transformer. In addition, you may comprise the electric power grid | system 2 with a direct current | flow system. Further, the load 12 is configured by a single machine or a plurality of devices, all of which may be the same device, or different types of devices may be combined.

The above is the description of the overall configuration of the energy storage system 100 according to the present embodiment. Next, operations of the fuel cell unit 120 and the auxiliary power supply unit 160 will be described with reference to FIG.

The generated power of the power generation unit 6 varies depending on the amount of light to the solar panel and the temperature of the solar panel in the case of solar power generation, and the amount of wind to the windmill in the case of wind power generation. Further, the power consumption in the load 12 varies depending on the usage status of the load 12 and the like. For this reason, excess or deficiency of power occurs between the power generation unit 6 and the load 12. The fuel cell unit 120 and the auxiliary power unit 160 compensate for this excess or deficiency of power. That is, the fuel cell unit 120 and the auxiliary power unit 160 operate to balance the power between the power generation unit 6 and the load 12.

First, when the power generated by the power generation unit 6 is insufficient, the auxiliary power supply unit 160 starts supplying power with a response in milliseconds. Subsequently, the fuel cell 128 generates electricity from hydrogen and oxygen and supplies insufficient power. Subsequently, in response to the supply of power, the auxiliary power supply unit 160 stops supplying power. That is, the auxiliary power supply unit 160 supplies power to the load 12 during a period during which there is a response delay in the control response of the generated power in the fuel cell 128. The response delay of the control response of the generated power in the fuel cell unit 120 is, for example, in minutes or more.

Next, when the generated power of the power generation unit 6 is surplus with respect to the power consumption of the load 12, the auxiliary power supply unit 160 accumulates power with a response in milliseconds. Then, the water electrolysis part 122 produces | generates hydrogen and oxygen from water by electrolysis, and consumes surplus electric power. Subsequently, in response to the start of electrolysis, the auxiliary power supply unit 160 stops the accumulation of electric power. That is, the auxiliary power unit 160 consumes excess power during a period during which a response delay of the control response of power consumption in the water electrolysis unit 122 occurs. The response delay of the power consumption control response in the fuel cell unit 120 is, for example, in minutes or more.

As described above, the auxiliary power supply unit 160 can detect the power surplus or deficiency from the millisecond unit to the minute unit, either of the control response of the power consumption in the water electrolysis unit 122 and the control response of the generated power in the fuel cell 128 cannot follow. Performs charging and discharging operations. In addition, the fuel cell unit 120 whose response delay of the control response is in units of seconds may be used for the energy storage system 100. In this case, the auxiliary power unit 160 charges / discharges power over / under in units of milliseconds to units of seconds. Perform the action.

Next, the relationship between the capacity of the auxiliary power supply unit 160 and the output time in the auxiliary power supply unit 160 will be described. In general, the capacity of the auxiliary power supply unit 160 increases in accordance with a value obtained by multiplying the output power and the output time. For example, if the multiplied value is halved by shortening the output time, the installed capacity of the secondary battery or capacitor constituting the auxiliary power supply unit 160 is halved, and cost reduction can be expected.

The auxiliary power supply unit 160 is configured with a capacity corresponding to a value obtained by multiplying a period in which a response delay of the storage battery unit 120 occurs and an output value of the auxiliary power supply unit 160. Since the period in which this response delay occurs is in minutes, the capacity of the auxiliary power supply unit 160 can be further reduced as compared with the case of compensating for power fluctuations in hours or days as in the past. That is, the installation capacity of the secondary battery and the capacitor constituting the auxiliary power supply unit 160 can be further reduced.

Next, the operation of the control unit 140 according to this embodiment will be described with reference to FIG. Here, an example of a control operation in which hydrogen corresponding to the power consumed by the load 12 is stored in the water electrolysis unit 122 in preparation for the case where the power generation of the power generation unit 6 is stopped will be described.

First, the power consumption measuring unit 14 outputs measurement data obtained by measuring the power consumption of the load 12 to the control unit 140. Next, the control unit 140 calculates the amount of power consumed by the load 12 during a predetermined period based on the measurement data. In other words, the control unit 140 calculates the amount of power consumed in the load 12 during the day, for example, as the predetermined period based on the measurement data.

Further, the measurement period of the measurement data used for calculation by the control unit 140 is about several times as long as this predetermined period. In this case, based on the average value of the measurement data measured during this measurement period, the control unit 140 calculates the electric energy. Further, the control unit 140 may calculate the amount of electric power based on the maximum value of measurement data measured during the measurement period.

Next, the control unit 140 controls the water electrolysis unit 122 so as to accumulate hydrogen corresponding to the amount of power consumed by the load 12 for a period of one day or more, for example. Subsequently, the water electrolysis unit 122 stores hydrogen generated by electrolyzing water in the hydrogen tank 124 using surplus power.

In this way, the control unit 140 calculates the amount of power consumed by the load 12 supplied with power from the power generation unit 6 and the fuel cell 128 during a predetermined period, and the amount corresponding to the calculated amount of power is calculated. Control for storing hydrogen in the hydrogen tank 124 is performed on the water electrolysis unit 122.

As a result, even when the power generation unit 6 using renewable energy is stopped, the fuel cell 128 uses the hydrogen stored in the hydrogen tank 124 to generate power for a predetermined period, for example, one day or more. , It can be supplied to the load 12.

As described above, according to the energy storage system 100 according to the present embodiment, the amount of power consumed by the load 12 during a predetermined period is calculated, and the amount of hydrogen corresponding to the calculated amount of power is The control unit 140 controls the water electrolysis unit 122 to store in the tank 124. For this reason, the amount of hydrogen corresponding to the power consumed by the load 12 can be stored with higher accuracy. Furthermore, even when the power generation of the power generation unit 6 is stopped, the fuel cell 128 generates power using the hydrogen stored in the hydrogen tank 124, so that the fuel cell 128 is loaded into the load 12 during this predetermined period. It will be possible to supply power.

(Second Embodiment)
The energy storage system according to the second embodiment includes measurement data obtained by measuring the generated power of the power generation unit, measurement data obtained by measuring the charge / discharge power of the fuel cell unit, measurement data obtained by measuring the charge / discharge power of the auxiliary power unit, By calculating the amount of power consumed by the load during a predetermined period based on the collected measurement data, the amount of power can be calculated without directly measuring the power consumption of the load. It is a thing. Hereinafter, a different part from 1st Embodiment mentioned above is demonstrated.

FIG. 2 is a block diagram illustrating the configuration of the energy storage system 100 according to the second embodiment. As shown in FIG. 2, the generated power measurement unit 16 is provided in the power generation unit 6 and outputs measurement data obtained by measuring the generated power of the power generation unit 6 to the control unit 140. The first charge / discharge power measuring unit 18 is provided in the fuel cell unit 120, and outputs measurement data obtained by measuring the charge / discharge power of the fuel cell unit 120 to the control unit 140. Similarly, the second charge / discharge power measuring unit 20 is provided in the auxiliary battery unit 160 and outputs measurement data obtained by measuring the charge / discharge power of the auxiliary power supply unit 160 to the control unit 140.

Then, based on the collected measurement data, the control unit 140 calculates the amount of power consumed by the load 12 per day, for example, and stores the amount of hydrogen corresponding to the calculated amount of power in the hydrogen tank 124. Control is performed on the water electrolysis unit 122. As a result, even when the power generation unit 6 is stopped, the fuel cell 128 generates power using the hydrogen stored in the hydrogen tank 124, so that it is possible to supply more than one day of power to the load 12. .

As described above, according to the energy storage system 100 according to the present embodiment, the control unit 140 measures the measurement data obtained by measuring the generated power of the power generation unit 6, and the measurement data obtained by measuring the charge / discharge power of the fuel cell unit 120. The measurement data obtained by measuring the charge / discharge power of the auxiliary power supply unit 160 are collected, and the amount of power consumed by the load 12 during a predetermined period is calculated based on the collected measurement data. For this reason, the amount of power consumed by the load 12 can be calculated without directly measuring the power consumption of the load 12.

(Third embodiment)
The energy storage system according to the third embodiment has insufficient power to be supplied to the load by further adding a generator that generates electricity using a fuel different from hydrogen to the energy storage system according to the first embodiment described above. That is what I tried to avoid. Hereinafter, a different part from 1st Embodiment mentioned above is demonstrated.

FIG. 3 is a block diagram illustrating the configuration of the energy storage system 100 according to the third embodiment. As shown in FIG. 3, the energy storage system 100 further includes a generator 180 in the first embodiment described above.

The generator 180 is connected to the power system 2 in parallel with the power generation unit 6, generates power using a fuel different from hydrogen, and supplies power to the load 12. For example, this fuel is a fossil fuel such as light oil. That is, the generator 180 is operated when the power generated by the power generation unit 6 is insufficient, and supplies power to the load 12. Thereby, it is possible to avoid a shortage of power supplied to the load 12.

Further, the electric power generated by the generator 180 may be used for water electrolysis in the water electrolysis unit 122. That is, this generator 180 can be used as a backup power source or a base power source when the power generation unit 6 is stopped.

Furthermore, as shown in FIG. 4, it is also possible to apply the present embodiment in combination with the second embodiment described above. That is, the generator measurement unit 22 may be provided in the generator 180, and the control unit 140 may be configured to further acquire measurement data obtained by measuring the generated power of the generator 180 from the generator measurement unit 22. And the control part 140 measures the measurement data which measured the generated electric power of the electric power generation part 6, the measurement data which measured the charging / discharging electric power of the fuel cell part 120, the measurement data which measured the charging / discharging electric power of the auxiliary power supply part 160, Measurement data obtained by measuring the power generated by the generator 180 is collected, and the amount of power consumed by the load 12 during a predetermined period is calculated based on the collected measurement data.

As described above, according to the energy storage system 100 according to the present embodiment, the generator 180 that generates power using a fuel different from hydrogen is operated when the power generated by the power generation unit 6 is insufficient. Thereby, the generator 180 can be used as a backup power source or a base power source, and a shortage of power supplied to the load 12 can be avoided.

(Fourth embodiment)
In the energy storage system according to the fourth embodiment, the power system is stopped by supplying hydrogen corresponding to the energy consumed by the load during a predetermined period to a household fuel cell that supplies power to the load. Even in this case, an attempt is made to avoid a shortage of power consumed by the load during a predetermined period. Hereinafter, a different part from 1st Embodiment mentioned above is demonstrated.

FIG. 5 is a block diagram illustrating the configuration of the energy storage system 100 according to the fourth embodiment. As shown in FIG. 5, in the energy storage system 100, the hydrogen pipe 8 is also connected to the household fuel cell 24 in the first embodiment described above. As a result, the hydrogen produced in the fuel cell unit 120 can be directly supplied to the home fuel cell 24.

The home fuel cell 24 is installed in each household, each factory, or the like as the load 12 and supplied with hydrogen from a hydrogen tank 124 connected to the hydrogen pipe 8. As a moving device for the hydrogen stored in the hydrogen tank 124, a moving hydrogen cylinder or a fuel cell vehicle may be used. Thereby, even when the power system 2 breaks down and power transmission is stopped, hydrogen for a predetermined period accumulated in the hydrogen tank 124 can be used as an energy source for the household fuel cell 24. For example, the predetermined period is one day or more, and one day or more of hydrogen is supplied to the household fuel cell 24. Thereby, even when the power transmission of the power system 2 is stopped, it is possible to supply the power consumed by the load 12 for one day or more.

As described above, according to the energy storage system 100 according to the present embodiment, hydrogen corresponding to the power consumed by the load 12 is supplied to the household fuel cell 24 during a predetermined period. As a result, even when the power system 2 is stopped, the power consumed by the load 12 can be supplied to the load 12 during a predetermined period.

Although several embodiments have been described above, these embodiments are presented only as examples, and are not intended to limit the scope of the invention. The novel systems and methods described herein can be implemented in a variety of other forms. Various omissions, substitutions, and changes can be made to the system and method embodiments described in the present specification without departing from the scope of the invention. The appended claims and their equivalents are intended to include such forms and modifications as fall within the scope and spirit of the invention.

Claims

A water electrolysis unit that generates hydrogen by electrolysis of water using electric power supplied from a power generation unit using renewable energy, and stores the generated hydrogen in a hydrogen storage unit;
A fuel cell that generates electricity using hydrogen stored in the hydrogen storage unit;
Control is performed to calculate the amount of power consumed by a load supplied with power from the power generation unit and the fuel cell during a predetermined period, and to store an amount of hydrogen corresponding to the calculated amount of power in the hydrogen storage unit. A control unit for the water electrolysis unit;
An energy storage system comprising:
An auxiliary power supply unit that charges and discharges the excess and deficiency of power supplied from the power generation unit and the fuel cell to the load, and has a capacity sufficient to compensate for the excess and deficiency of power due to a delay in control response of the fuel cell. The energy storage system according to claim 1, further comprising an auxiliary power supply unit having the power supply unit.
Either the control response of the power consumption in the water electrolysis unit or the control response of the generated power in the fuel cell cannot follow the excess or deficient power in the period from millisecond to second, or minute from the millisecond. The energy storage system according to claim 2, wherein the auxiliary power supply unit charges and discharges excess and deficient power in a unit period.
The energy storage system according to any one of claims 1 to 3, wherein the predetermined period is one day or more after power supply from the power generation unit is stopped.
The control unit collects measurement data obtained by measuring the power consumption of the load from the power consumption measurement unit, and calculates the amount of power consumed by the load during the predetermined period based on the collected measurement data. The energy storage system according to any one of claims 1 to 4.
The control unit collects measurement data obtained by measuring the generated power of the power generation unit, measurement data obtained by measuring charge / discharge power of the fuel cell, and measurement data obtained by measuring charge / discharge power of the auxiliary power unit, The energy storage system according to any one of claims 2 to 4, wherein an amount of electric power consumed by the load during the predetermined period is calculated based on the collected measurement data.
The energy storage system according to any one of claims 1 to 6, further comprising a generator that generates electricity using a fuel different from hydrogen in parallel with the power generation unit.
The energy storage system according to any one of claims 1 to 7, wherein hydrogen of one day or more of energy consumed by the load is supplied to a household fuel cell that supplies electric power to the load.
Using the electric power supplied from the power generation unit using renewable energy, hydrogen is generated by electrolysis of water, and the water electrolysis unit that stores the generated hydrogen in the hydrogen storage unit and the hydrogen storage unit An energy storage method for a fuel cell system comprising a fuel cell that generates power using hydrogen,
A calculation step of calculating an amount of power consumed by a load supplied with power from the power generation unit and the fuel cell in a predetermined period;
A control step for controlling the water electrolysis unit to cause the hydrogen storage unit to store an amount of hydrogen corresponding to the calculated amount of power;
An energy storage method comprising: