Facilities for stabilizing the power grid, including gas storage caverns
Patent Information
- Application Number
- JP2024571272
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-02-21
- Filing Date
- 2023-02-21
- Publication Date
- 2025-03-07
Smart Images
Figure 2025506310000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to an arrangement for stabilizing a power grid, comprising gas storage means in the form of a cavern for storing gas. A gas generator, powered by the power grid, generates gas, in particular hydrogen, which is introduced into the cavern as a storage gas for energy, so that it can be withdrawn again when needed for the release of energy. Summary of the Invention
[0002] In the process of the energy transition towards renewable energies, the share of unstable and distributed generation is increasing, as is typical for power plants operated with renewable energies, such as wind turbines and photovoltaic systems. In addition to constant fluctuations on the load side, increasingly dynamic fluctuations occur on the generation side. Also, temporary excesses in power generation can occur, which result in the need for feed-in management measures, such as downregulation of the power plant. Such situations are common for wind turbines, which, unlike conventional power plants, have a high power gradient and can be quickly curtailed. This should be taken into account not only in terms of the stability of the power grid, but also in terms of the loss of renewable energy that comes with curtailing the power of wind turbines. It is not justified that wind turbines, which are the most desirable energy source, are underutilized and instead limited, and as a result, their forced shutdowns undermine the possibility of generating renewable energy.
[0003] For this reason, storage means are needed for the power grid to better match the variable supply of electrical energy from renewable energies to demand and to minimize the need for curtailment. Gas storage means are important, as are battery storage means, which generally only store small amounts of energy, and pumped hydro plants, which require a lot of space and whose construction significantly affects the landscape and causes major problems in terms of nature conservation. When there is an excess of electricity, gas can be generated, for example hydrogen gas by electrolysis, and stored in the gas storage means. In this way, a reserve of electricity is created that can be drawn on as needed in case of a shortage of electricity production or high demand for electricity.
[0004] Such gas storage means are not necessarily limited to one type of gas. Suitable gases are, as already mentioned, in particular hydrogen and natural gas (produced by methanation) from surplus electricity. In the case of hydrogen, hydrogen is generated from surplus electricity, for example using an electrolyser, and the hydrogen is stored in a cavern. The cavern is a large underground cavern in a suitable geological formation and is airtight. The cavern may be of natural origin or may be artificially created, for example as described in EP 2 855 306 A1. The gas (in particular hydrogen) is stored in such a cavern via a connecting pipe under high pressure, usually between 40 and 200 bar. The gas (in particular hydrogen) is stored for an indefinite period of time and is withdrawn again by the connecting pipe when required. This concept allows the storage of large volumes of gas and, accordingly, the storage of large volumes of energy. This concept has proven to be useful in particular for the operation of gas grids with relatively long storage-discharge cycles. However, this is insufficient to support power grids supplied by variable renewable energies and to meet the associated high demands for dynamic response to rapidly provide regulating energy and power.
[0005] The object of the present invention is to provide an installation for the stabilization of the power grid, which is improved in terms of dynamic response and which avoids or reduces curtailment and shutdowns, in particular of power plants operated with renewable energies, such as wind parks and wind turbines.
[0006] The inventive solution is recited with the features of the independent claims. Advantageous refinements are the subject of the dependent claims.
[0007] In an arrangement for stabilization of a power grid using energy storage means, the energy storage means comprises a gas generator for gas fuel, in particular hydrogen, and a cavern. The gas generator is powered from the power grid. The cavern has a connecting pipe leading into the cavern. The gas fuel produced by the gas generator is introduced into the cavern via the connecting pipe in order to store energy and is withdrawn from the cavern in order to extract energy. According to the invention, it is envisaged that the connecting pipe is configured as a two-way conduit leading into the cavern and in each case comprises a filling conduit and a separate withdrawal conduit.
[0008] The invention is based on the idea that the use of separate conduits for injection and withdrawal allows for parallel and continuous storage and withdrawal of gas from the storage without the need for costly switching of the conduits, in particular without reversing the flow direction in the conduits. "Parallel" in this case means that the storage and withdrawal from the storage overlap in time. Thus, a quicker switch can be made between the storage of gas (gas fuel) in the cavern and its withdrawal (discharge) from the cavern. The inventive stabilization installation thus meets high demands on dynamic response, especially for power grids with a high share of variable electricity generation from renewable energies.
[0009] The equipment of the present invention allows for simultaneous storage and withdrawal operations, which was not possible with the prior art. The present invention also allows for the withdrawal of gas at any time while gas is being injected. Thus, continuous, unbuffered gas injection is possible even while gas is being withdrawn.
[0010] The simultaneous gas injection and withdrawal allows a highly dynamic reaction to the various demands for energy intake and / or release. The inventive installation is suitable not only as a dynamic energy storage means but also for providing rapid control power, both by intake from the power grid and by discharge to it (negative and positive control power). The inventive installation is therefore suitable for providing primary control power and, thanks to the large gas storage in the caverns, also for the long-term supply of secondary control power or for the long-term supply of minute control power. The caverns can be efficiently formed in suitable geological formations or are in any case already available as a result of the prior exploitation of natural gas fields. The invention thus allows all the above-mentioned advantages to be obtained with a significantly reduced complexity compared to the case of conventional known storage technologies such as buffer batteries or pumped storage plants.
[0011] Suitably, the two-way conduit with the injection conduit is designed to continuously supply gas independent of the withdrawal and / or to continuously withdraw gas independent of the supply. This independence has many advantages. Firstly, power can be continuously drawn from the power grid, thus avoiding curtailment of the wind turbine even if there is a power surplus on the power grid. Secondly, the continuous injection of gas prevents the storage medium from running empty. Thirdly, gas can be withdrawn at all times. The cavern is thus available as a large-scale storage for reserve energy, from which power can be supplied and released at any time as required.
[0012] Below, some of the terms used will first be explained.
[0013] An electric power grid may in particular be a transmission grid and a distribution grid, and is usually operated by one or more network operators in any country. The term does not include networks within buildings.
[0014] A gas generator is a device that produces gaseous fuels electrically. Fuel, as commonly understood in the art, means a chemical that can be combusted to convert stored energy into usable energy. For example, the term includes chemical fuels such as methane, among others, and electrochemical fuels such as hydrogen for generating electricity in fuel cells.
[0015] A cave is an underground cavern. Caves are airtight and may be natural or man-made. Generally, caves are found in certain suitable geological formations.
[0016] Gas drawn from the cavern means gas (gaseous fuel) produced by a gas generator according to the present invention and stored in the cavern.
[0017] The terms "primary regulation power", "secondary regulation power" and "minute regulation power" are technical terms used by network operators, especially in the case of power grids. These terms are defined for the skilled person in the regulations applicable to the respective power grids. This may vary from country to country or from regulation area to regulation area, so there is no point in specifying the respective standards. The respective standards will be clear to the skilled person from the corresponding relevant regulations.
[0018] It is advantageous if several different use units for the gas withdrawn from the cavern are connected to the withdrawal conduit. In this way, the gas withdrawn from the cavern can be used in optionally different ways. The use units can be, apart from devices for reconverting the gas into electricity (in particular fuel cells or combined heat and power plants (CHP plants)), in particular methanation plants designed to synthesize methane with the gas fuel withdrawn from the cavern (in particular hydrogen gas) and / or transfer points to a gas grid where the withdrawn gas is directly fed to the gas grid. The gas grid is in particular a natural gas grid. However, the possibility of the gas grid being for another gas, in particular hydrogen gas, is not to be excluded.
[0019] At least one switchable gas manifold is suitably connected to the withdrawal conduit in order to be able to select between the different use units. Depending on the switching state of the gas manifold, the withdrawn gas (gas fuel) flows to one of the different use units. Here, it is advantageous if the gas manifold is also designed for switching partial flows (diversion). In this way, it is possible to use part of the withdrawn gas, for example for reconversion into electricity, while another part of the gas is supplied to another of the use units 3, for example a methanation plant. The gas manifold is preferably designed in such a way that it can be switched even during continuous withdrawal. This allows the switching to be carried out without stopping the withdrawal of gas from the cavern.
[0020] In a particularly advantageous aspect of the invention, a controller for regulation power is provided. The controller has an input for a signal of regulation power, in particular a negative regulation power. The controller is designed to operate the gas generator so as to take power from the power grid corresponding to the regulation power, in particular the negative regulation power, to produce gas that is introduced into the cavern. In this way, the installation of the invention with the cavern can contribute to the supply of regulation power. The network operator (or another superior authority in the network) sends a request signal for regulation power. This is often a request for negative regulation power. That is to say, in particular in the case of an excess of power produced by the wind turbines, it is necessary to take excess power from the grid. For this purpose, the network operator issues a control signal for negative regulation power. When this signal is sent to the controller of the installation of the invention, the controller takes the corresponding power from the grid according to the requested regulation power, generates gas from it and stores it in the cavern. In this way, it is possible to react quickly within a few seconds in the case of an excess of power in the grid, in particular when electrolysers are used as gas generators. Furthermore, the large volume of the cavern allows it to provide conditioning for a relatively long period of time, typically 60 minutes, but sometimes even longer, up to several hours.
[0021] More advantageously, the controller for regulation also acts on the device for reconversion to electricity in order to supply additional power as positive regulation to the power grid. This is essentially the reverse of the above-mentioned operation. A demand for additional power appears on the grid and the grid operator issues a target signal for supplying additional power (positive regulation). The controller acts accordingly on the device for reconversion to electricity, drawing gas from the cavern for the device (regardless of whether gas is stored at the same time). The device for reconversion to electricity further produces electricity from the gas, for example by means of a fuel cell or a combined heat and power plant (CHP plant), which is supplied to the grid (or discharged to consumers). This too can be carried out, firstly, in a very dynamic manner and, secondly, for long periods of time due to the large storage of the cavern. The CHP plant can be, for example, a hydrogen-operated gas turbine driving an electric generator.
[0022] Preferably, a switchable bypass conduit is provided. The bypass conduit is connected to the injection conduit between the gas generator and the cavern and connects them to the withdrawal conduit. This can be used to direct the gas produced by the gas generator directly to the usage unit (or one of the usage units) if necessary, without prior introduction of gas into the cavern. In this way, changes in gas demand from one of the usage units can be responded to quickly. In this way, the dynamic responsiveness of the plant can be further increased and the efficiency improved.
[0023] The cavern essentially becomes a large buffer for storing electricity. Nevertheless, it may be appropriate to additionally provide a buffer accumulator as an option. This is powered by the power grid connected to the gas generator and is also designed for particularly rapid power release and / or power intake. Thus, similar to a bypass conduit for the gas supply, it is possible to provide electrical energy particularly quickly when required, which makes it possible to improve the dynamic response of the supply of electrical energy. Furthermore, the buffer accumulator makes it possible to stabilize and smooth the electrical supply to the gas generator, in particular to the electrolyzer.
[0024] Advantageously, the inlet and outlet conduits extend in the cavern at a distance from each other. They are suitably spaced apart by at least 5 meters. This distance may depend on the dimensions (particularly the diameter) of the inlet and outlet conduits. The inlet and outlet conduits are preferably arranged adjacently. Arranged adjacently means that the distance relative to the diameter is between 3 and 30 times the diameter, in particular at least 10 times the diameter, and more preferably not more than 20 times the diameter. For this, it may be advantageous to use an average diameter. The average diameter means the average diameter of the inlet or outlet conduits. The method of averaging should be chosen by the person skilled in the art and may in particular be an arithmetic mean, a geometric mean or another type of mean. Instead of the (average) diameter, the (average) width of the respective conduit may be taken as a reference. This is particularly suitable, for example, when the inlet and / or outlet conduits have a non-circular cross section. The purpose of such a spacing of the conduits is to avoid harmful flow effects on the gas withdrawal from the inlet gas and vice versa. This allows for a better separation of the injection and withdrawal conduits and therefore minimises the risk of the injection and withdrawal conduits influencing each other, and it may be appropriate to provide separate drill shafts for the injection and withdrawal conduits, particularly if these conduits are arranged adjacent to each other.
[0025] Alternatively, a two-way conduit with an injection conduit and a separate withdrawal conduit may be arranged in a common drill shaft. In that case, the two conduits for injection and withdrawal are no longer arranged at a distance from each other, but still ensure the function of withdrawal independent of storage and the function of storage independent of withdrawal. This space-saving design is particularly suitable for caverns with a relatively narrow upper area. The combination of the two-way conduits in one drill shaft also simplifies and reduces the manufacturing complexity.
[0026] It may be appropriate for the injection conduit and the withdrawal conduit to reach different depths into the cavern, depending on their respective openings. It is preferable for the injection conduit to reach deeper. In this way, it is possible to use the third dimension, i.e. the depth of the cavern, to improve the separation between the injection conduit and the withdrawal conduit. If the opening of the withdrawal conduit is located higher in the cavern, it is easier to remove the gas in case of low gas filling.
[0027] The caverns are suitably formed in salt domes. Due to their geological characteristics, they are particularly suitable for gas-tight storage. The caverns here should be distinguished from what is called porous storage media by those skilled in the art. The caverns are pressure-resistant and suitably designed for an operating pressure of at least 40 bar, preferably up to 200 bar. In this pressure range, it has been found that a particularly advantageous operation of the caverns is possible, especially in terms of economical operating technology and geomechanical stability.
[0028] According to a further aspect that may deserve independent protection, the invention also extends to a cavern for storing gaseous fuel. According to the invention, the connecting pipes are designed as two-way conduits leading into the caverns, each of which preferably comprises an inlet conduit adjacent to each other and a separate outlet conduit. For a more detailed description of the caverns with other two-way conduits, their further configuration and operating mode, reference is also made to the above description in order to avoid repetition. [Brief description of the drawings]
[0029] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG. [Figure 1] FIG. 1 is a schematic diagram of a first embodiment. [Diagram 2] FIG. 1 is a diagram relating to the provision of adjustment power. [Diagram 3] FIG. 11 is a schematic diagram of a second embodiment. [Figure 4] FIG. 11 is a schematic diagram of a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Figure 1 shows an example of a first embodiment of the invention. The installation for stabilization of a power grid, generally designated by reference number 1, comprises as main components a gas generator 2 and a user unit 3, which are connected via a pipe connection 4 to an underground cavern 6. The cavern 6 is arranged in an underground salt dome 90. The invention is explained using the example of hydrogen as the gas produced as gas fuel by the gas generator 2 and stored in the cavern 6, but it will be clear that it is also possible to use other gas fuels, for example methane.
[0031] The stabilization installation 1 is connected to a power grid 91 via a plant transformer 10. In the illustrated example, this is the transmission grid of a network operator. The gas generator 2 is connected to the plant transformer 10 via a connecting conduit 12, which supplies the gas generator 2 with power. The gas generator 2 is designed to generate hydrogen gas using electrical power. This can be achieved in a manner known per se. The gas generator 2 is preferably designed as an electrolyser, although other hydrogen generation methods operating on electricity are also possible.
[0032] A combined heat and power plant (CHP plant) or a fuel cell 31 is also connected to the plant transformer 10 via a further connecting conduit 13. The CHP plant or the fuel cell 31 is one of the usage units 3. Electricity generated from the combined heat and power plant, for example from a generator driven by a hydrogen gas turbine or from the fuel cell 31 by reconverting hydrogen gas into electricity, can be supplied via this connecting conduit 13 to the power grid 91.
[0033] The gas generator 2 and the use unit 3 with the fuel cell 31 are connected to the cavern 6 via a pipe connection 4. According to the invention, the pipe connection 4 is designed here as a two-way conduit 5, which includes an inlet conduit 51 and an outlet conduit 52. The inlet conduit 51 is connected to the gas generator 2 and terminates at an opening 53 in the cavern. The inlet conduit 51 supplies the hydrogen gas produced in the gas generator 2 to the cavern 6. The outlet conduit 52 is designed separately from the inlet conduit 51. The outlet conduit 52 also has an opening 54 that projects into the cavern 6 and leads upwards from the cavern 6 to the use unit 3 with the fuel cell 31. In the first embodiment shown in FIG. 1, the two conduits of the two-way conduit 5, the inlet conduit 51 and the outlet conduit 52, extend into the cavern 6 at a distance from each other, but adjacent to each other. This has the advantage that effects such as flow vortices occurring at the opening 53 of the injection conduit 51 do not affect the flow characteristics of the hydrogen gas flowing out of the cavern to the opening 54 of the withdrawal conduit 52. By designing the injection conduit 51 separate from the withdrawal conduit 52, it is possible to carry out injection and withdrawal (discharge) independently. In this way, it is possible to continue to supply hydrogen gas to the cavern 6 via the injection conduit 51, regardless of whether hydrogen gas is being withdrawn through the separate withdrawal conduit 52 or not. And vice versa. It is possible to withdraw hydrogen gas through the separate withdrawal conduit 52 and supply it to the usage unit 3, regardless of whether hydrogen gas is being simultaneously introduced into the cavern 6 via the injection conduit 51 or not.
[0034] Apart from the fuel cell 31, the usage unit 3 may comprise further units for using the hydrogen gas. For example, a methanation plant 33 may be provided in which carbon dioxide (which may be taken from the air, in particular as CO2) is added to the supplied hydrogen gas to synthesize methane gas. The methane gas may be supplied to a natural gas grid 93 (shown only diagrammatically) in a manner known per se. As a further usage unit, the hydrogen gas taken from the cavern 6 via the withdrawal conduit 52 may also be supplied via a transfer point 35 to a gas grid, which may be a natural gas grid or a hydrogen gas grid (not shown). In this way, it becomes possible to directly use the stored hydrogen.
[0035] A gas manifold 30 is provided in the withdrawal conduit 52 so that the operator of the installation can select different usage modes. The gas manifold 30 is connected upstream of the usage units 3 and determines whether the hydrogen gas withdrawn from the cavern 6 by the withdrawal conduit 52 is to be supplied to one of the usage units 3, i.e. to the fuel cell 31, the methanation plant 33 or to a transfer point 35 for direct supply. The gas manifold 30 can also optionally accommodate substreaming, i.e. splitting the hydrogen gas flow from the withdrawal conduit 52 to supply hydrogen gas to several usage units 3. For example, the fuel cell 31 and the methanation plant 33 can receive the withdrawn hydrogen gas.
[0036] Also provided is a controller 8 of the installation, which is designed in particular to provide regulation power to the power grid 91. For this purpose, a setpoint input 80 is provided, into which the operator of the power grid 91 or another higher instance (not shown) can input a signal of the required regulation power. The controller 8 is further connected via a first signal conduit 81 to the fuel cell 31 and via a second signal conduit 82 to the gas generator 2, in order to influence their operation. For example, if the network operator requires positive regulation power, the controller 8 activates the fuel cell 31 via the signal conduit 81, so that the fuel cell 31 produces more electricity and correspondingly draws more hydrogen gas from the cavern 6 via the withdrawal conduit 52. This is possible at any time, thanks to the use of the two-way conduit 5, completely independently of whether the gas generator 2 is simultaneously feeding hydrogen gas to the cavern 6 via the injection conduit 51 or not. It is therefore possible to react very quickly to demands for regulation power, within a few seconds. There is no need to switch gas connections or redirect the (possibly long) connecting pipes to the cavern.
[0037] The same applies in the opposite case, i.e. when a negative regulation power is requested via the setpoint input 80. For this purpose, the controller 8 activates the gas generator 2 via the signal line 82, so that it draws more power from the power grid 91 and generates more hydrogen gas by means of the electrolyser. This hydrogen gas is led via the inlet conduit 51 to the cavern 6 and temporarily stored there. This can be done regardless of whether hydrogen gas is currently being drawn off via the outlet conduit 52 or not. Thus, in the particularly important practical case of the existence of surplus power in the power grid 91, the installation according to the invention makes it possible to quickly and effectively draw off the surplus power from the power grid 91 and store it as hydrogen gas in the cavern 6. This energy can be used again at any time in the installation, for example by converting it again into electricity by the fuel cell 31, or by using it in another way, for example by the methanation plant 33 (or by feeding it directly to the gas grid via the transfer point 35).
[0038] The installation 1 according to the invention therefore makes it possible to extract surplus power from the power grid 91 to a considerable extent and in a very dynamic way and to store the corresponding energy in the form of hydrogen gas in the cavern 6. Curtailment of the wind turbines, which in the prior art is required in such cases as a measure for stabilizing the grid, is thus thus unnecessary. In this way, it is possible to prevent a loss of renewable energy due to curtailment.
[0039] The installation of the invention is capable of providing a large amount of regulation power. Thanks to the highly dynamic response, this can be done in a matter of seconds, so that even the provision of a primary regulation power (secondary reserve) is possible. Reference is now made to FIG. 2, where the types of regulation power according to the corresponding network operator guidelines and their relationship over time are shown. Number I represents the primary regulation power, which, as a so-called secondary reserve, must be provided in its entirety within 30 seconds. The primary regulation power must usually cover a maximum of 15 minutes. Following the primary regulation power, a secondary regulation power is provided. The secondary regulation power is represented by number II in FIG. 2 and may partially overlap with the primary regulation power I. It must be provided in its entirety within 5 minutes. Following the secondary regulation power, finally, a so-called minute regulation power is provided. This is represented by number III in FIG. 2 and must be provided in its entirety within 15 minutes at the latest. After a long time, in reality close to an hour, the compensation by the balancing circuit, represented by number IV in FIG. 2, finally begins.
[0040] It is clear that the provision of primary regulation reserve I requires a highly dynamic response, while the long-term provision of secondary regulation reserve II and minute reserve III in particular requires a large capacity relative to the energy provided (power over time). Both are achieved in the inventive installation 1, because the gas generator 2 and the CHP plant or fuel cell 31 are both capable of rapid control, and the cavern 6 has a large storage volume. Thus, the inventive installation 1 can provide all kinds of regulation reserves I, II, III. Furthermore, the stored hydrogen gas can be used for other purposes, for example to produce other energy carriers such as methane, or to directly use the hydrogen gas by mixing it into the natural gas grid or into the pure hydrogen gas grid.
[0041] In order to further increase the speed of the dynamic response when supplying regulating power, it is also possible to provide a buffer accumulator 15, which is connected to the electric side of both the gas generator 2 designed as an electrolyser and the fuel cell 31, respectively, so that power or power spikes can be quickly absorbed or released, thus making the fast response properties of the inventive installation even more certain.
[0042] FIG. 3 shows a second embodiment of the installation of the invention. Components that are the same or of the same type and have the same or similar functions are provided with the same reference numerals. For further description of these components, reference is made to the above description. The second embodiment differs essentially from the first embodiment shown in FIG. 1 in that a bypass conduit 7 is arranged between the inlet conduit 51 and the outlet conduit 52. This bypass conduit 7 can be used, if necessary, to directly supply the hydrogen gas produced by the gas generator 2 to a usage unit 3, for example to supply the hydrogen gas to a methanation plant 33 of the usage unit or to directly supply the hydrogen gas to a hydrogen or natural gas grid via a transfer point 35. The bypass conduit 7 is provided with a switchable shutoff valve 71 that blocks or opens the bypass conduit 7. This shutoff valve 71 is connected to a controller 8 via a signal line (not shown). The controller 8 operates the shutoff valve 71 according to the requirements of the installation 1 of the invention in the current situation, thereby opening or closing the bypass conduit 7.
[0043] FIG. 4 shows a third embodiment of the installation of the invention. Components that are the same or of the same type and have the same or similar functions are provided with the same reference numerals. For a further description of these components, reference is made to the above description. The third embodiment differs essentially from the second embodiment in that the two-way conduit 5, including the injection conduit 51 and the separate withdrawal conduit 52, are arranged in a common pipe shaft 40 (and not arranged in separate drill shafts, as in the first and second embodiments). The basic advantage of the installation 1 of the invention, that is the possibility to supply hydrogen gas to the cavern 6 to provide a negative regulation power to the power grid 91 while at the same time withdrawing hydrogen by a separate withdrawal conduit 52 for the use unit 3, for example to produce methane by a methanation plant 33, is fully preserved in this embodiment. However, the arrangement of the two-way conduit 5 in the common pipe shaft 40 clearly simplifies the manufacture of the piping connection of the two-way conduit 5 to the cavern 6. This allows the installation 1 of the invention to be manufactured more economically.
Claims
1. An installation for stabilization of a power grid (91) using energy storage means, comprising: The energy storage means a gas generator (2) for a gas fuel, in particular hydrogen, powered from the power grid; A cave (6) and The cavern (6) has a connecting pipe (4) leading into the cavern (6), The gas fuel produced by the gas generator (2) is introduced into the cavern (6) through the connecting pipe (4) for storing energy and is taken out from the cavern (6) for extracting energy; The said connecting pipes (4) lead into said caverns (6) and are configured as two-way conduits (5) each including an inlet conduit (51) and a separate outlet conduit (52).
2. 2. Installation according to claim 1, wherein the two-way conduit (5) with the injection conduit (51) is designed for continuous gas supply independent of gas withdrawal and / or for continuous gas withdrawal independent of gas supply.
3. 3. The installation according to claim 1 or 2, wherein a number of different use units (3) for the gas fuel withdrawn from the cavern (6) are connected to the withdrawal conduit (52).
4. 4. The installation according to claim 3, wherein various usage units (3) are connected to the withdrawal conduit (52) via at least one switchable gas manifold (30), and the withdrawn gas fuel flows to one of the different usage units (3) depending on the switching state of the gas manifold (30).
5. 5. The installation according to claim 4, wherein the gas manifold (30) is also designed for switching split flows.
6. 6. The installation according to claim 4 or 5, wherein the gas manifold (30) is switchable even when the gas fuel is continuously drawn off.
7. 7. An installation according to any one of claims 4 to 6, wherein one of the usage units (3) is a device for reconverting gas into electricity, in particular a fuel cell or a combined heat and power plant (31) generating and discharging electricity into an output conduit for connection to the power grid (91) or to consumers.
8. 8. Installation according to any one of claims 4 to 7, wherein one of the use units (3) is a methanation plant (33) designed to synthesize methane by means of hydrogen.
9. 9. An installation according to any one of claims 4 to 8, wherein one of the usage units (3) is a transfer point (35) to a gas grid (93), in particular a natural gas grid, for discharging the extracted gas fuel into the gas grid (93).
10. A controller (8) for adjusting the force is provided, said controller (8) comprising: an input (80) for a signal for an adjustment force, in particular a negative adjustment force, 10. The installation according to any one of claims 1 to 9, designed to operate the gas generator (2) so as to extract electricity corresponding to a regulating power, in particular a negative regulating power, from the power grid (91) to produce the gas fuel that is introduced into the cavern (6).
11. 11. The installation according to claim 10, wherein the controller (8) for regulating power also acts on a device (31) for reconverting power into electricity in order to supply additional power as positive regulating power to the power grid (91).
12. A switchable bypass conduit (7) is provided, 12. Installation according to any one of claims 1 to 11, wherein the bypass conduit (7) is connected to the injection conduit (51) between the gas generator (2) and the cavern (6) and connects them to the withdrawal conduit (52).
13. A buffer accumulator (15) is provided, 13. The installation according to any one of claims 1 to 12, wherein the buffer accumulator (15) is powered from the power grid (91) connected to the gas generator (2) and is designed in particular for rapid supply, power release and / or power intake.
14. 14. Installation according to any one of claims 1 to 13, wherein the inlet conduit (51) and the outlet conduit (52) extend into the cavern (6) at a distance from each other.
15. 15. Installation according to any one of the preceding claims, wherein the inlet conduit (51) and the outlet conduit (52) are arranged adjacent to each other.
16. 16. Installation according to any one of the preceding claims, wherein the distance between the inlet conduit (51) and the outlet conduit (52) is between 3 times, in particular at least 10 times, and 30 times, in particular at most 20 times, its width, in particular its diameter.
17. 17. Installation according to any one of the preceding claims, wherein the injection conduit (51) and the withdrawal conduit (52) extend into the cavern (6) within a common drill shaft (40).
18. 18. Installation according to any one of the preceding claims, wherein the injection conduit (51) and the withdrawal conduit (52) reach different depths into the cavern (6) by means of their respective openings (53, 54), the injection conduit (51) preferably reaching deeper.
19. 19. The installation according to any one of claims 1 to 18, wherein the cavern (6) is formed in a salt dome (90) and / or is designed for an operating pressure of at least 40 bar, preferably up to 200 bar.