JP5618952B2 - Renewable energy storage system - Google Patents

Description

  The present invention relates to a storage system for fluctuating energy such as renewable energy.

  Mass consumption of fossil fuels continues, and for example, global warming due to carbon dioxide, air pollution in urban areas, etc. are becoming serious. Under such circumstances, hydrogen is attracting attention as an energy source for the next generation to replace fossil fuels. Hydrogen can be produced by electrolysis using renewable energy typified by solar cells, wind power, and the like, and further, only water is produced by being burned. Therefore, hydrogen is a clean energy source that emits less environmental pollutants during production and use.

  As a method for producing hydrogen, steam reforming of fossil fuel is widely used industrially. In addition, a number of production methods are known such as by-product hydrogen, thermal decomposition, photocatalyst, microorganisms, and reaction using electrolysis of water associated with iron or soda production. Among other things, it is possible to use power from various sources as power necessary for electrolysis of water. Therefore, the method for producing hydrogen by electrolysis of water is regarded as important as a method for producing an energy source independent of a specific region.

  However, in order to use hydrogen as an energy source (ie, fuel), hydrogen transportation, storage, supply system, and the like can be a major issue. Specifically, since hydrogen is a gas at normal temperature and pressure, there is a problem that it is difficult to store and transport compared to liquid and solid. Furthermore, hydrogen is a combustible substance, and when air and hydrogen are mixed at a predetermined mixing ratio, hydrogen may react explosively.

  As a technique for solving these problems, after desulfurizing a hydrocarbon fuel with a desulfurization apparatus, steam is added and supplied to a steam reformer, where hydrogen is generated, this hydrogen is supplied to a fuel cell, and oxygen and There has been proposed a fuel cell power generation system that reacts to extract electric energy.

  In recent years, organic hydride systems using hydrocarbons such as cyclohexane and decalin have attracted attention as hydrogen storage methods having excellent safety, transportability and storage capacity. Since these hydrocarbons are liquid at normal temperature and pressure, they can be stored and transported more easily than in the case of gases. For example, benzene and cyclohexane are cyclic hydrocarbons having the same carbon number, while benzene is an unsaturated hydrocarbon having a double bond, whereas cyclohexane is a saturated hydrocarbon having no double bond. That is, by adding hydrogen to benzene that is an unsaturated hydrocarbon, cyclohexane that is a saturated hydrocarbon is obtained. Moreover, benzene is obtained by desorbing hydrogen from cyclohexane. Thus, for example, Patent Document 1 discloses a system that can store and supply hydrogen using a hydrogenation reaction and a hydrogen elimination reaction using benzene and cyclohexane.

  However, in order to construct an organic hydride system using renewable energy, it may be necessary to consider the amount of electric power (that is, the amount of power generation) generated by the renewable energy. That is, the amount of power generated by renewable energy usually varies depending on weather conditions. For example, in the case of wind power generation using wind power as renewable energy, the amount of power generation varies depending on the strength of the wind, and in the case of solar power generation using sunlight, the intensity of sunlight and the duration of sunlight.

  In order to cope with such a change in the amount of electric power, for example, Patent Document 2 discloses that the maximum output of the solar cell can be obtained by changing the number of electrical series connections of the water electrolysis device according to the generated power of solar power generation. The operation method of the water electrolysis system which utilizes the water efficiently is described.

  Further, for example, Patent Document 3 includes a plurality of cell stacks composed of a plurality of water electrolysis cells, and the water electrolysis apparatus configured by connecting the cell stacks electrically in series or in parallel to each other, and the water electrolysis apparatus. A power supply means for supplying power, a voltage control unit for variably controlling the voltage of power supplied to the water electrolysis device, and the number of stacks for selecting the number of cell stacks used according to the power supplied to the water electrolysis device By providing a control unit, an energy-efficient hydrogen production facility using a generator as a power source is described.

  Further, for example, Patent Document 4 discloses a water electrolysis apparatus having a plurality of water electrolysis stacks in which a predetermined number of water electrolysis cells are stacked, and a power supply apparatus having at least a voltage fluctuation power supply and supplying power to the water electrolysis apparatus. In the water electrolysis system provided, there is described a water electrolysis system that has a power adjustment unit for each water electrolysis stack so as to individually adjust supply power and drive variable power with the best electrolysis efficiency, and an operation method thereof.

International Publication No. 2006/120841 Pamphlet JP 2001-335982 A JP 2005-126792 A JP 2007-31813 A

  For example, when directly storing (that is, charging) electric power obtained by wind power generation, solar power generation, or the like in an electric storage device, the electric power storage has a capacity capable of storing a large amount of electric power when attempting to store electric power obtained over a long period of time. Equipment must be used. For this reason, there is a concern that the size of the power storage device may become extremely large or the manufacturing cost of the power storage device may increase. In addition, when it is considered to transport the electric power stored in the power storage device, an extremely large power storage device must be transported, and the transportation becomes complicated.

  In addition, according to the conventional technology, a dedicated device is required to control charging / discharging of the power storage device, resulting in an increase in equipment cost. Furthermore, as described above, for example, in the case of photovoltaic power generation, the amount of renewable energy changes depending on the intensity of sunlight and the duration of sunlight, so that in some cases, the loss of renewable energy occurs and the renewable energy cannot be used effectively. is there.

  On the other hand, in the water electrolysis system and its operation method described in Patent Documents 2 to 4, an operation method for adjusting the electrical connection configuration and supply power of the water electrolysis system according to the renewable energy fluctuation power has been proposed. The production hydrogen gas collection method is not considered and cannot be combined with the organic hydride system as it is.

  Further, it is impossible to connect all the gas pipes of a plurality of water electrolysis apparatuses to the buffer tank as the same pipe. The water electrolysis device is either in operation or not in operation. When all gas pipes are connected to form the same piping, hydrogen gas produced in the operation part flows into the water electrolysis device in the operation part, Gas leakage and, in the worst case, lead to failure of the hydrogen production apparatus that has flowed in.

  SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and its purpose is to provide a renewable energy storage capable of storing and supplying renewable energy with high energy efficiency while taking into account fluctuations in the amount of renewable energy. To provide a system.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention at least in a hydrogen production system including a switching control system, hydrogen gas piping connected to each hydrogen production means, and other devices such as a buffer tank Alternatively, the inventors have found that the above problem can be solved by providing a backflow prevention mechanism up to the joint point with other gas pipes, and have completed the present invention.

  According to the present invention, it is possible to provide a renewable energy storage system capable of storing and supplying renewable energy with high efficiency while taking into account fluctuations in the amount of renewable energy.

It is a figure showing typically the composition of the renewable energy storage system concerning a 1st embodiment of the present invention. It is a figure which represents typically the structure of the renewable energy storage system which concerns on 2nd Embodiment of this invention. It is a figure which represents typically the structure of the renewable energy storage system which concerns on 3rd Embodiment of this invention. It is a figure which represents typically the structure of the renewable energy storage system which concerns on 4th Embodiment of this invention. It is a figure which represents typically the structure of the renewable energy storage system which concerns on 5th Embodiment of this invention. It is a figure which represents typically the structure of the renewable energy storage system which concerns on 6th Embodiment of this invention.

  Hereinafter, the renewable energy storage system according to the present embodiment will be described with six specific examples with reference to the drawings as appropriate.

[1. First Embodiment]
FIG. 1 is a diagram schematically showing the configuration of a renewable energy storage system according to the first embodiment of the present invention. In FIG. 1, a thick solid line represents electrical wiring, a thin solid line represents a signal line (for example, a control signal, a measurement signal, etc.), and a thin broken line represents fuel energy (for example, hydrogen, methylbenzene, etc.). Is a wiring for connecting and indicating the transmission and reception of signals. Connections between signal lines are indicated by solid circles.

  As shown in FIG. 1, the renewable energy storage system 100 according to the first embodiment stores renewable energy. The renewable energy storage system 100 includes a power generation apparatus 1 as a renewable energy power generation means, a hydrogen production apparatus 2 as a hydrogen production means, a buffer tank 3 that is responsible for high purity of hydrogen gas, and a hydrogenation means. Hydrogenation device 4, hydrogen production string 5 in which a plurality of hydrogen production devices are electrically connected in series, hydrogen production array 6 in which a plurality of hydrogen production strings are electrically connected in parallel, and a series of hydrogen production devices in the hydrogen production string Switching means 7 for switching the number and the string parallel number in the hydrogen production array, a control device 8 for controlling the switching means, and a backflow prevention mechanism 9 before the junction of the hydrogen gas pipes connected to the hydrogen production apparatus, It is configured with at least.

  Further, the renewable energy storage system 100 according to the first embodiment shown in FIG. 1 includes a saturated hydrocarbon storage tank 10, an unsaturated hydrocarbon storage tank 11, a power storage device 12, an output measuring instrument 13, and a charging voltage. A measuring instrument 14, a current measuring instrument 15, a temperature measuring instrument 16, a signal processing unit 17, a power adjuster 18, and a pressure adjusting device 19 are provided.

  And the renewable energy storage system 100 which has such a structure is applied with respect to renewable energy.

  Renewable energy represents renewable energy, such as sunlight, wind power, geothermal heat, and hydropower. In addition, the renewable energy is based on the global weather conditions without any electrical or physical connection line, piping, or the like with the power generation apparatus 1. Specifically, when the renewable energy is, for example, sunlight, the power generation device 1 described later is, for example, a solar cell, a solar power generation system, or the like.

  The power generation apparatus 1 converts renewable energy such as sunlight and wind power into electric power. The power generation apparatus 1 is electrically connected to the hydrogen production means 2 so that the power generated by the power generation apparatus 1 can be supplied to the hydrogen production means 2.

  The hydrogen production device 2 produces hydrogen using the electric power obtained by the power generation device 1 and / or the electric power stored in the power storage device 12. Specifically, in the hydrogen production apparatus 2, at least hydrogen is generated by electrolyzing water (or an aqueous solution) using these electric powers. Therefore, the more electric power is supplied from the power generation device 1 and / or the power storage device 12 to the hydrogen production device 2, the more hydrogen is produced (generated) in the hydrogen production device 2. ing. The hydrogen production device 2 is electrically connected to the power generation device 1 and the power storage device 12, is connected to the buffer tank 3 through a gas pipe, and is connected to the temperature detector 16 through an electric signal line.

  Although the specific configuration of the hydrogen production apparatus 2 is not particularly limited, the hydrogen production apparatus 2 supplies, for example, water, an electrolyte, an electrode catalyst for promoting a reaction provided so as to sandwich the electrolyte, and external power. An electrolysis cell holding a current collector or the like is provided. Then, water is electrolyzed by this electrode catalyst, and hydrogen and oxygen are generated. In the present invention, the electrolysis cell or an electrolysis stack in which electrolysis cells are laminated in multiple layers is defined as a hydrogen production apparatus 2.

  The electrolyte is not particularly limited as long as at least hydrogen is generated by electrolysis, but a compound that exhibits alkalinity when dissolved in water, such as potassium hydroxide, is preferable. By using such a compound, the hydrogen production apparatus 2 that is inexpensive and hardly corrodes can be obtained. Further, as the electrolyte, for example, a solid polymer electrolyte such as Nafion (registered trademark) can be used.

  Each of the hydrogen production apparatuses 2 configured as described above can be operated at a low temperature of 100 ° C. or lower, and further has an advantage that it can be started in a short time.

  The electrolysis conditions of water are not particularly limited, and can be set arbitrarily as long as at least hydrogen can be generated. However, in order to increase the electrolytic efficiency, when the pressure during electrolysis (that is, during hydrogen production) is increased, the pressure resistance value of the backflow prevention mechanism 9 must be considered.

  Although the specific configuration of the buffer tank 3 is not particularly limited, the purpose is to increase the purity of the hydrogen generated in the hydrogen production apparatus 2 by removing water, and the water is removed before being supplied to the hydrogenation apparatus 4 (described later). The method by such is mentioned. For example, a gas-liquid separator or the like corresponds to this. The specific configuration of the gas-liquid separation device is not particularly limited, and for example, gas-liquid separation by cooling, a hydrogen separation membrane, or the like can be used. Among them, it is preferable to use a hydrogen separation membrane. The removed water circulates in the hydrogen production apparatus 2 so that the water is electrolyzed.

  And the hydrogen after moisture removal is supplied to the hydrogenation apparatus 4 connected by gas piping. In addition, although the hydrogen after moisture removal may be directly supplied to the hydrogenation device 4, in the sixth embodiment shown in FIG. 6 (described later), the hydrogen is supplied to the water via the pressure regulator 19. By supplying to the attachment device 4, the hydrogenation efficiency can be further increased, in other words, renewable energy can be stored without waste.

  Although not shown in FIG. 1, the hydrogen can be temporarily stored in a hydrogen storage means such as a high-pressure tank. The specific configuration of the hydrogen gas hydrogen storage means is not particularly limited. For example, a known hydrogen cylinder, a pressure vessel for high pressure gas, or the like can be used. These may be provided alone or in any combination of two or more. Examples of the material constituting the hydrogen storage means include, for example, a steel plate, a plastic reinforced with carbon fiber, and the like, and it is particularly preferable to use a pressure-resistant container having a pressure higher than that applied to the hydrogen production apparatus 2.

  Moreover, a hydrogen storage alloy can also be used as a hydrogen storage means. Examples of the hydrogen storage alloy include an AB5 type alloy such as rare earth metal-nickel type, and an alloy having a body-centered cubic (BCC) structure such as titanium type or chromium type. By making these hydrogen storage alloys exist in the above-mentioned container or the like, the hydrogen storage amount can be increased. Moreover, when storing the same volume of hydrogen, the pressure of the hydrogen storage means may be reduced.

  It is preferable that the buffer tank 3 and the hydrogenation apparatus 4 are connected by gas piping (pipeline). However, it is not always necessary that these are connected by gas piping. For example, the produced hydrogen may be transported to the hydrogenation device 4 (that is, supplied to the hydrogenation device 4) using a high-pressure tank or the like.

  The hydrogenation device 4 adds hydrogen produced by the hydrogen production device 2 to unsaturated hydrocarbons. The hydrogenation device 4 is connected to the buffer tank 3 and the gas pipe as described above, and is connected to a saturated hydrocarbon storage tank 10 and an unsaturated hydrocarbon storage tank 11 (both described later) by a liquid pipe. Yes. Therefore, the unsaturated hydrocarbon is supplied from the unsaturated hydrocarbon storage tank 11 to the hydrogenation device 4.

  Although the specific kind of unsaturated hydrocarbon used in the hydrogenation apparatus 4 is not particularly limited, for example, an aromatic compound that is liquid at room temperature such as methylbenzene can be suitably used. For example, when methylbenzene is used as the unsaturated hydrocarbon, the resulting saturated hydrocarbon is methylcyclohexane, and the amount of hydrogen molecules that can be stored per mole of methylbenzene is 2.5 moles. However, depending on the conditions at the time of the addition reaction, for example, anthracene, phenanthrene, and the like may become liquid. When performing the addition reaction under such conditions, these aromatic compounds may be used. By using these aromatic compounds, more hydrogen can be stored.

  Since such an aromatic compound is liquid at room temperature, it can be easily stored, and there is an advantage that a reaction interface is large when a hydrogenation reaction is performed. Further, by using an aromatic compound, the amount of hydrogen that can be added per molecule of the aromatic compound can be increased, and more hydrogen can be stored with a smaller amount of unsaturated hydrocarbons. In addition, an unsaturated hydrocarbon may be used by 1 type and may use 2 or more types by arbitrary ratios and combinations.

  In the hydrogenation apparatus 4, there is no particular limitation on the specific method for adding hydrogen to the unsaturated hydrocarbon. However, from the viewpoint of low cost and short reaction time, hydrogen is usually added to the unsaturated hydrocarbon using a catalyst. Examples of such a catalyst include metals such as Ni, Pd, Pt, Rh, Ir, Re, Ru, Mo, W, V, Os, Cr, Co, and Fe, and alloys thereof. As for the metal which comprises a catalyst, and those alloys, 1 type may be individual and 2 or more types may be used by arbitrary ratios and combinations.

  These catalysts are preferably finely divided from the viewpoint of further cost reduction by reducing the amount of catalyst and an increase in reaction surface area. When a finely divided catalyst is used, it may be supported on an arbitrary carrier from the viewpoint of preventing a reduction in surface area due to aggregation of the fine particle catalyst. When the catalyst is supported on the carrier, the method for supporting is not particularly limited, and for example, a coprecipitation method, a thermal decomposition method, an electroless plating method, or the like can be used. The type of carrier is not particularly limited, and for example, in addition to carbon materials such as activated carbon, carbon nanotubes, and graphite, alumina silicate such as silica, alumina, and zeolite can be used. One type of carrier may be used, or two or more types may be used in any ratio and combination.

  The hydrogenation reaction conditions for unsaturated hydrocarbons in the hydrogenation apparatus 4 are not particularly limited and may be set arbitrarily. For example, hydrogen can be added even at a reaction temperature of room temperature (about 25 ° C.), but it is preferable to add hydrogen at a temperature of about 100 ° C. to 400 ° C. from the viewpoint of shortening the reaction time.

  In addition, although the reaction pressure during the addition reaction is not particularly limited, the pressure during hydrogen addition is 1 to 50 atm (gauge pressure) from the viewpoint of increasing the efficiency of the addition reaction and shortening the reaction time. That is, the pressure is preferably 0.1 MPa or more and 5 MPa or less. Therefore, in order to increase the pressure at the time of hydrogenation, the pressure regulator 19 shown in FIG. 6 can be provided between the buffer tank 3 and the hydrogenation device 4.

  As described above, hydrogen can be added to the unsaturated hydrocarbon, and a saturated hydrocarbon is obtained. The obtained saturated hydrocarbon (so-called organic hydride) is stored in a saturated hydrocarbon storage tank 10 described later.

  The hydrogen production string 5 has a configuration in which a plurality of hydrogen production apparatuses 2 are electrically connected in series via the switching means 7. The hydrogen production array 6 has a configuration in which a plurality of the hydrogen production strings 5 are electrically connected in parallel via the switching means 7.

  The switching means 7 is a switch element that has a function of energizing or shutting off the power generated by the power generation device 1 to the hydrogen production device 2 and that can control the driving state by an external signal, and the specification matches the power of the power generation means. For example, a conventional switching element may be used without any particular limitation. For example, a relay element, a semiconductor element, etc. are mentioned.

  Based on the device configuration determined by the signal processing unit 17 according to the power generation amount of the renewable energy power generation device 1, the electrical characteristics of the hydrogen production device 2, and the charging status of the power storage device 12, the control device 8 The device is not particularly limited as long as it is a device that transmits an energization or shutoff signal. Depending on the situation, there may be a configuration in which a plurality of hydrogen production apparatuses 2 are connected in series, that is, one hydrogen production string configuration or a plurality of one hydrogen production apparatus 2 connected in parallel. The control device 8 is connected to the switching means 7 for transmitting an energization or shut-off signal to the switching means 7 and to the signal processing unit 17 via an electric signal line in order to exchange electric signals.

  The backflow prevention mechanism 9 serves to prevent hydrogen gas produced by the hydrogen production apparatus 2 in operation from flowing into the hydrogen production apparatus 2 that is not in operation through the gas pipe. This leads to prevention of failure or deterioration of the hydrogen production apparatus, in other words, an effect of highly efficient use of renewable energy can be expected. The backflow prevention mechanism 9 is not limited in specification as long as the above purpose can be achieved, but examples thereof include a check valve and an on-off valve. Further, when the pressure is increased by the reaction pressure inside the hydrogen production apparatus, the internal pressure of the buffer tank 3, or the pressure regulator shown in FIG.

  The backflow prevention mechanism 9 is preferably installed before the connection point of the pipe into which the hydrogen gas flows toward the connection point between the hydrogen gas pipes, and is installed in the pipe on the side where the hydrogen gas is to flow from the connection point. You don't have to. However, as long as it has a configuration and structure in which hydrogen gas does not flow into the non-operating hydrogen production device 2 by switching the hydrogen production device 2, it is not limited to the above. For example, when the same number of buffer tanks 3 as the plurality of hydrogen production apparatuses 2 are connected in a one-to-one relationship, a backflow prevention mechanism may be provided in a pipe until hydrogen gas is supplied to the hydrogenation apparatus 4. Conceivable. In addition, when the hydrogen production apparatus 2 and the buffer tank 3 are connected in a plurality of relationship, a backflow prevention mechanism may be provided in each pipe or at the connection point of the buffer tank 3. Since the pipe length can be long, there is a concern that the cost will increase.

<Operation>
As described above, the renewable energy storage system 100 according to the first embodiment has the above-described configuration. Next, the operation of each means when storing renewable energy by the renewable energy storage system 100 will be described with reference to FIG.

  First, using renewable energy such as sunlight, the power generation device 1 (for example, a solar cell) generates electric power. The generated electric power is supplied to the hydrogen production array 6.

  The hydrogen production array 6 was supplied while switching the electrical connection configuration of the number of series of hydrogen production devices 2 and / or the number of parallel production of hydrogen production strings 5 according to the generated power and the electrical characteristics of the hydrogen production device 2. In accordance with the generated power, water electrolysis starts and hydrogen is generated.

  The hydrogen produced in the hydrogen production array 6 is supplied to the buffer tank 3, and after purification such as moisture removal, the hydrogen is purified and supplied to the hydrogenation device 4.

  Here, the control device 8 and the switching means 7 are switched to the connection form of the number of water electrolysis means for obtaining the maximum hydrogen gas amount and the number of strings. At this time, since the hydrogen gas produced by the hydrogen production apparatus 2 in operation is not operating or does not flow into another hydrogen production apparatus, a backflow prevention mechanism is provided before the connection point of the pipe flowing into each gas pipe connection point. It is necessary to provide it.

  The environment in which the series of operations are performed is not particularly limited, and can be performed in any environment as long as the above-described problem can be solved. In addition, it is not always necessary that all the means be installed at the same place. For example, the hydrogen production apparatus 2 can be arbitrarily installed indoors, and the hydrogenation apparatus 4 can be installed outdoors.

<Summary>
As described above, according to the renewable energy system 100 according to the first embodiment, it is possible to cope with fluctuations in the supply amount of renewable energy and to improve the efficiency of adding hydrogen to unsaturated hydrocarbons. Renewable energy can be stored without waste. And since the stored renewable energy is converted into hydrogen and stably stored as a compound containing the hydrogen, it can be freely used whenever necessary.

[2. Second Embodiment]
Next, a renewable energy storage system 200 according to the second embodiment will be described with reference to FIG. 2 that are denoted by the same reference numerals as those in FIG. 1 represent the same means, and detailed descriptions thereof are omitted.

  In the renewable energy storage system 200, a saturated hydrocarbon storage tank 10 and an unsaturated hydrocarbon storage tank 11 are configured with respect to FIG.

  The saturated hydrocarbon produced by adding hydrogen is stored in the saturated hydrocarbon storage tank 10 as described above. Then, the saturated hydrocarbons stored in the saturated hydrocarbon storage tank 10 are shipped in the liquid state to which the generated hydrogen is added. After shipment, hydrogen is desorbed from the saturated hydrocarbon, and the desorbed hydrogen is used as fuel or the like. Note that the unsaturated hydrocarbon generated by desorption of hydrogen is stored again in the unsaturated hydrocarbon storage tank 11.

  The saturated hydrocarbon storage tank 10 stores the saturated hydrocarbon generated in the hydrogenation device 4. Therefore, the saturated hydrocarbon storage tank 10 is connected to the hydrogenation device 4 by a liquid pipe. Moreover, between the saturated hydrocarbon storage tank 10 and the hydrogenation apparatus 4, for example, a flow rate adjusting valve, a flow meter, etc. for controlling the supply amount of saturated hydrocarbons to the saturated hydrocarbon storage tank 10 may be provided. .

  The unsaturated hydrocarbon storage tank 11 stores unsaturated hydrocarbons supplied to the hydrogenation device 4. The unsaturated hydrocarbon storage tank 11 is connected to the hydrogenation device 4 by a liquid pipe. Further, for example, a flow rate adjusting valve, a flow meter or the like for controlling the supply amount from the unsaturated hydrocarbon storage tank 10 to the hydrogenation device 4 may be provided.

  Thus, also in the renewable energy storage system which concerns on 2nd Embodiment, the system which stores renewable energy with high efficiency can be provided.

[3. Third Embodiment]
Next, a renewable energy storage system 300 according to the third embodiment will be described with reference to FIG. 3, the same reference numerals as those in FIG. 2 denote the same means, and detailed description thereof is omitted.

  When electric power is supplied to the hydrogen production array 6, electrolysis of water is started and hydrogen is generated. However, electrolysis may not be performed only with the electric power from the power generator 1. In such a case, the power storage device 12 can be provided.

  The power storage device 12 stores the power generated by the power generation device 1. The power storage device 12 is electrically connected to the power generation device 1 and the hydrogen production device 2 so that the power stored in the power storage device 12 can be supplied to the hydrogen production device 2 as necessary. In addition, the power storage device 12 is connected to the charging voltage measuring instrument 14 by an electric signal line.

  The specific configuration of power storage device 12 is not particularly limited, and any known storage battery (secondary battery) and charge / discharge control system can be used. However, the storage battery is preferably a cycle storage battery manufactured exclusively for repeated use, in which the battery is discharged from a fully charged state and charged again after a certain discharge. Specifically, examples of the storage battery include a sodium sulfur battery and a lead storage battery, and among them, a lead storage battery that is excellent in electrical performance, compact, and inexpensive is preferable. In addition, a storage battery may be comprised by one storage battery, and may comprise two or more storage batteries arbitrarily, and may be comprised as a storage battery group. A conventional charge / discharge control system such as a battery charger can be applied to the charge / discharge control system, and there is no particular limitation.

  By installing the power storage device 12 as described above in the renewable energy storage system configuration, the power from the power storage device 12 can be used together, or the power from the power generation device 1 is not used. You may use only. For example, since sufficient sunshine can be ensured during a clear daytime, the power storage device 12 is charged with a sufficient amount of power, and the hydrogenation device 4 is driven with the surplus power. On the other hand, since the solar power generation cannot be performed during the night time, the hydrogenation device 4 is operated using the power charged in the power storage device 12 during the daytime. By doing in this way, renewable energy can be utilized without waste.

  Thus, the renewable energy storage system according to the third embodiment can also provide a system capable of storing renewable energy with high efficiency.

[4. Fourth Embodiment]
Next, a renewable energy storage system 400 according to the fourth embodiment will be described with reference to FIG. 4, the same reference numerals as those in FIG. 1 denote the same means, and detailed description thereof is omitted.

  A renewable energy storage system 400 shown in FIG. 4 is similar to the renewable energy storage system 300 shown in FIG. 3 except that the output measuring instrument 13, the charging voltage measuring instrument 14, the current measuring instrument 15, the temperature measuring instrument 16, the signal processing apparatus 17, and the like. It is the structure which added. Even if the renewable energy storage system is configured in this manner, the problem of the present invention can be solved.

  The output measuring instrument 13 is connected to the power generation device 1, the signal processing unit 17, and an electric signal line, and includes means for measuring an output voltage value and an output current value of renewable energy power generation, and via the electric signal line. There is no limitation as long as the signal processing unit has a function of giving a measurement value.

  The charging voltage measuring instrument 14 is connected to the charging device 12, the signal processing unit 17, and an electric signal line, and includes means for measuring the charging voltage of the storage battery. For example, there is no particular limitation as long as it has a function of supplying the signal processing unit 17 with a charging voltage signal of a charging / discharging control system in the charging device 12.

  The current measuring device 15 is a device that measures the value of the current flowing into the hydrogen production string 5 and is not particularly limited as long as it has a function of giving a signal to the signal processing unit 17 connected by an electric signal line. Further, for example, a method of measuring with a device such as a clamp meter without being incorporated in the electric circuit of the renewable energy power generation is conceivable.

  The temperature measuring device 16 is a device that measures the reaction temperature inside the hydrogen production apparatus 2, has a function of giving a signal to the signal processing unit 17 connected by an electric signal line, and is expected as a reaction temperature of the hydrogen production apparatus 2. A material having high measurement sensitivity of about −50 ° C. to 100 ° C. is preferable.

  The signal processing unit 17 is connected to the output measuring instrument 13, the charging voltage measuring instrument 14, the current measuring instrument 15, the temperature measuring instrument 16, and the control device 8 through electric signal lines, and the output measuring instrument 13 and the charging voltage measuring instrument 14. In accordance with the signal amounts obtained by the current measuring device 15 and the temperature measuring device 16, the renewable energy storage system can be operated efficiently based on the control program stored in the internal memory, that is, the maximum hydrogen amount is obtained. There is no particular limitation as long as it has a function of estimating (calculating) a hydrogen production array connection configuration to be transmitted and transmitting a control signal to the control device 8.

  In the apparatus configuration estimation (calculation), the output measuring instrument 13, the charging voltage measuring instrument 14, the current measuring instrument 15, and the temperature measuring instrument 16 signals are obtained in consideration of the electrical characteristics of the hydrogen production apparatus, particularly the rated operation value and the upper limit value. It is desirable to determine the connection configuration to be obtained and system operation capable of producing hydrogen with high energy efficiency. However, frequent connection switching, such as when the input power fluctuation is severe, can cause failure and deterioration of the hydrogen production equipment, so avoid it as much as possible, switch to a more flexible connection configuration, and absorb more renewable energy fluctuations to regenerate more. Possible energy storage system can be operated with high efficiency.

[5. Fifth Embodiment]
Next, a renewable energy storage system 500 according to the fifth embodiment will be described with reference to FIG. In FIG. 5, the same reference numerals as those in FIG. 4 denote the same means, and detailed description thereof will be omitted.

  A renewable energy storage system 500 shown in FIG. 5 is obtained by adding a power regulator to the renewable energy storage system 400 shown in FIG. Even if the renewable energy storage system is configured in this manner, the problem of the present invention can be solved.

  Depending on the type of renewable energy, the electric power obtained may be direct current or alternating current. For example, direct-current power can be obtained by solar power generation, and alternating-current power can be obtained by wind power generation. In addition, in solar power generation, output fluctuations associated with changes in solar radiation intensity are seen, and even DC power becomes fluctuating power accompanying changes over time. In wind power generation, the propeller rotates and the generator body rotates to output AC power. Since the power signals obtained by these power generation means are different, there are cases where a DC-DC converter converter or the like is provided in solar power generation, and in the case where an AC-DC converter or the like that converts AC power into DC power is provided in wind power generation. There is.

  Therefore, in the renewable energy storage system 500, the power adjustment device 18 having these functions is provided. Note that the renewable energy storage system 500 may be connected to the grid power via the power adjustment device 18. Even if the renewable energy storage system is configured in this manner, the problem of the present invention can be solved. Furthermore, since the power adjustment device 13 is provided, power can be supplied relatively stably, and renewable energy can be stored without imposing an excessive burden on the power storage device 12 and the hydrogen production device 2.

[6. Sixth Embodiment]
Next, a renewable energy storage system 600 according to the sixth embodiment will be described with reference to FIG. In FIG. 6, the same reference numerals as those in FIG. 5 denote the same means, and detailed description thereof will be omitted.

  A renewable energy storage system 600 shown in FIG. 6 is obtained by adding a pressure regulator 19 to the renewable energy storage system 500 shown in FIG. Even if the renewable energy storage system is configured in this manner, the problem of the present invention can be solved.

  The pressure adjusting device 19 can be connected between the buffer tank 3 and the hydrogenation device 4 via a fuel pipe. The pressure adjusting device 19 can increase the reaction efficiency of imparting hydrogen to the unsaturated hydrocarbon by increasing the pressure of the hydrogen gas purified in the buffer tank 3. In this way, the renewable energy storage system 600 can be operated with high efficiency.

  The pressure adjusting device 19 is not particularly limited as long as the gas obtained from the buffer tank 3 can be supplied to the hydrogenation device 4 at a constant pressure. For example, a method of enclosing hydrogen gas at a constant pressure can be mentioned. Further, as a method for controlling the pressure, for example, a hydrogen pressure control means such as a pressure regulator may be provided, or a known compressor may be used. By providing such a hydrogen pressure control means, the generated hydrogen pressure can be appropriately controlled.

[7. Others]
In addition, although the apparatus structure was added and demonstrated sequentially on the basis of the renewable energy storage system 100, for example, only the electric power adjustment device 18 may be added to the renewable energy storage system 100, or only the pressure adjustment device 19 is used. May be added, and can be similarly applied to other embodiments.

  Further, in the configuration of the hydrogen production string 5 of FIGS. 1 to 6 in the present invention, that is, the serial connection method of the hydrogenous s-image device 2, hydrogen that is energized and driven by a frequently used hydrogen production device and switching means. There may be a difference in the frequency of use with manufacturing equipment, which may cause failure and premature deterioration. For this reason, the present invention is not limited to the drawings of the present invention, and can be solved by a connection method and switching control in consideration of the usage frequency.

  Further, the renewable energy storage system in the present invention does not necessarily have a one-to-one relationship with the renewable energy power generation means. In other words, it may be incorporated into a power distribution network such as a smart grid, and high-efficiency use of renewable energy can be provided by converting surplus power and fluctuation power in the grid into saturated hydrocarbons.

  Although not shown in FIGS. 1 to 6, the power regulator and the storage battery are controlled so that the fluctuation power is leveled, the fluctuation-absorbed renewable energy is efficiently produced, and the saturated hydrocarbon is generated. Highly efficient operation of a renewable energy storage system can be realized.

DESCRIPTION OF SYMBOLS 1 Renewable energy power generation means 2 Hydrogen production means 3 Buffer tank 4 Hydrogenation device 5 Hydrogen production string 6 Hydrogen production array 7 Switching means 8 Control device 9 Backflow prevention mechanism 10 Saturated hydrocarbon storage tank 11 Unsaturated hydrocarbon storage tank 12 Power storage Device 13 Output voltage measuring device 14 Charging voltage measuring device 15 Current measuring device 16 Temperature measuring device 17 Signal processing device 18 Power adjusting device 19 Pressure adjusting device

Claims (7)

A renewable energy storage system for storing renewable energy comprising:
Power generation means for converting the renewable energy into electrical energy;
Hydrogen production means comprising a plurality of hydrogen production apparatuses for producing hydrogen gas using electrical energy obtained by the power generation means;
A buffer tank for purifying the hydrogen gas produced by the hydrogen production means;
Hydrogenation means for adding hydrogen gas flowing out of the buffer tank to the unsaturated hydrocarbon;
Switching means for switching the connection configuration of the hydrogen production apparatus;
A control device for controlling the switching means,
A plurality of the hydrogen production apparatuses and the buffer tank are connected by a pipe having a backflow prevention mechanism,
A renewable energy storage system, wherein the backflow prevention mechanism prevents hydrogen gas produced by the hydrogen production apparatus from flowing into another hydrogen production apparatus through a pipe. A renewable energy storage system for storing renewable energy comprising:
Power generation means for converting the renewable energy into electrical energy;
A hydrogen production string comprising a plurality of hydrogen production apparatuses that produce hydrogen gas using electrical energy obtained by the power generation means, a plurality of hydrogen production strings in which a plurality of the hydrogen production apparatuses are electrically connected in series, and a plurality of rows of the hydrogen production strings Hydrogen production means comprising a hydrogen production array electrically connected in parallel;
A buffer tank for purifying the hydrogen gas produced by the hydrogen production means;
Hydrogenation means for adding hydrogen gas flowing out of the buffer tank to the unsaturated hydrocarbon;
Switching means for switching the number of serially connected hydrogen production apparatuses constituting the hydrogen production string and the number of parallel connection of hydrogen production strings constituting the hydrogen production array;
A control device for controlling the switching means,
A plurality of the hydrogen production apparatuses and the buffer tank are connected by a pipe having a backflow prevention mechanism,
A renewable energy storage system, wherein the backflow prevention mechanism prevents hydrogen gas produced by the hydrogen production apparatus from flowing into another hydrogen production apparatus through a pipe. In Claim 2, the saturated hydrocarbon storage means which stores the saturated hydrocarbon produced | generated by adding the said hydrogen to the said unsaturated hydrocarbon,
An unsaturated hydrocarbon storage means for storing the unsaturated hydrocarbon;
A renewable energy storage system comprising:   The renewable energy storage system according to claim 1, comprising a configuration for storing electric power obtained by the power generation means in a power storage device. In claim 4,
Output measuring means for detecting an output value of the power generation means;
Charging voltage measuring means for detecting a charging voltage value of the power storage means;
Current measuring means for detecting the amount of current supplied to the hydrogen production means;
Temperature measuring means for detecting a production part temperature of the hydrogen producing means;
With
A renewable energy storage system comprising a signal processing unit that measures the detected output voltage value, the charging voltage value, the current amount, and the temperature signal, and transmits each signal to a control device. In claim 4,
Power control means for controlling the output of power obtained by the power generation means,
The renewable energy storage system, wherein the power control means adjusts the amount of power supplied to the power storage means and the hydrogen production apparatus. In claim 2,
A renewable energy storage system comprising a pressure adjusting device that adjusts the pressure of hydrogen gas that has passed through the buffer tank and sends the pressure to the hydrogenation device.