Energy system and methods for operating an energy system

Abstract

The present invention relates to an energy system (2) and a method for operating it. The energy system (2) comprises: an energy generation device (3) or an interface to an energy generation device (3), which is provided for generating electrical energy and which is configured in particular as a photovoltaic device (3a); a first subsystem (10), comprising an electrolysis device (13), which is provided for generating hydrogen, and a battery device (12), which is provided for the short-term storage and provision of electrical energy; a second subsystem (20), comprising a first storage device (21), in particular a high-pressure storage device, which is provided for storing the hydrogen generated by the electrolysis device (13).To ensure that as many components of the energy system (2) as possible contribute to its extended function and can be optimally controlled and integrated into the energy system (2) for efficient operation via an optimized control system, at least one compressor unit (30, 40) designed as a hydride compressor unit (31, 41) is provided, which is designed to compress the generated hydrogen before it is stored in the first storage unit (21). A control unit (60) is provided for controlling the energy system (2), which includes an intelligent, preferably predictive, energy management unit (61).

Description

[0001] The present invention relates firstly to an energy system according to the preamble of claim 1. Furthermore, the invention also relates to a method for operating such an energy system.

[0002] Energy systems of this type are known in the prior art in a variety of forms. Such energy systems are typically used to generate and supply energy for a wide range of applications. In one embodiment, the energy system is a building energy system that generates and supplies energy for a building.

[0003] In a solution known from the prior art, such an energy system, in its simplest case, comprises a device for generating electrical energy, which is, for example, a photovoltaic system. Electrically energy-consuming components of the energy system are connected to the electrical energy-generating device via an electrical system.

[0004] The electrical energy that is not directly consumed is stored in a battery. If the electrical energy supplied by the electrical energy generation device is insufficient, the energy-consuming components of the energy system are powered by electrical energy from the battery.

[0005] To utilize the energy system as comprehensively as possible, further developments have enabled the use of excess energy produced by the electrical power generation device to produce hydrogen via an electrolysis unit, particularly when the battery is fully charged. The electrolysis unit then uses the remaining excess energy to produce hydrogen and stores it in a storage unit. To maximize hydrogen storage capacity, the storage unit is designed, for example, as a high-pressure storage system. In such a case, a piston compressor is installed upstream of the storage unit to compress the produced hydrogen to high pressures.

[0006] If the electrical energy generation device and the battery system alone are no longer sufficient, the hydrogen storage tank comes into play. Electrical energy is generated from it to compensate for the missing power. This is done via a fuel cell unit within the energy system. The fuel cell unit generates electrical energy from the hydrogen.

[0007] The aforementioned processes generate waste heat at various points, which can now also be used in further developments of the energy system, for example to heat individual components of the energy system, to heat rooms, to heat water, and the like.

[0008] In operating such a complex energy system, it is therefore necessary to control the individual components of the energy system in a targeted manner and to implement efficient energy management. A known energy system with a corresponding control device, from which the present invention is based, is disclosed and described in EP 3 381 102 B1 of the applicant.

[0009] The present invention is based on the objective of further optimizing an energy system of the type mentioned above, in such a way that as many components of the energy system as possible can contribute to the extended function of the energy system, and that the individual components of the energy system can be optimally controlled and integrated into the energy system for efficient operation via an optimized control system.

[0010] This problem is solved according to the invention by the energy system with the features according to independent claim 1, which represents the first aspect of the invention, by the method with the features according to independent claim 13, which represents the second aspect of the invention, and by the computer program product with the features according to independent claim 17, which represents the third aspect of the invention.

[0011] Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings. Features and details disclosed in connection with the first aspect of the invention also apply in full to the second and third aspects of the invention, and vice versa, so that the disclosure of one aspect of the invention always includes full reference to and acknowledgments of the other aspects. In particular, the process of the method according to the invention is also explained in connection with the description of the energy system, so that the disclosure of the method also refers to the disclosure of the apparatus aspect.

[0012] The invention is situated in the field of energy systems. The energy system in question is, for example, a system for generating or providing energy, preferably electrical energy and optionally also thermal energy. In principle, the invention is not limited to specific types of energy systems. Several preferred embodiments are described below.

[0013] In a preferred embodiment, the energy system is a building energy system. Building energy systems are generally known from the prior art and serve to supply buildings, for example, low-energy buildings, passive buildings, or zero-energy buildings, with energy in the form of heat and, in particular, in the form of electricity, for example, electricity from renewable energy sources such as photovoltaic (PV) generators or small wind turbines. Of course, other types of renewable energy sources are also applicable. Such a building energy system creates the basis for a building's energy demand, with regard to both electricity and heat, to be completely covered by renewable energy sources, thus ensuring complete CO2 neutrality in operation.At least, the electricity demand of a building can be almost completely covered by renewable energy sources, in particular by means of a PV generator and / or a small wind turbine, in order to achieve a desired increase in self-consumption.

[0014] Such a building energy system is disclosed and described, for example, in the applicant's patent applications WO 2017 / 089468 A1 and WO 2017 / 089469 A1, the content of which is included in the description of the present patent application.

[0015] According to a preferred embodiment, a building energy system of the type mentioned has the following basic features: - a DC power supply point, preferably configured for a nominal voltage of 48 volts or for a nominal voltage between 200 and 1000 volts and / or an AC power supply point, preferably configured for a voltage of 230 volts or 110 volts or a 3-phase supply at 230 volts or 110 volts per phase, wherein the DC power supply point and / or the AC power supply point is connected at least temporarily during operation to an electrical load that has a power consumption capacity, - a PV generator electrically connected to the DC feed-in point, at least temporarily, to generate electrical PV power, - a fuel cell unit electrically connected to the DC or AC power input point, at least temporarily, for generating electrical fuel cell power, - an electrolysis unit electrically connected to the DC feed-in point or to the AC feed-in point at least temporarily for producing hydrogen to be consumed by the fuel cell unit, wherein the electrolysis unit is supplied with an electrical electrolysis input power during operation, - a hydrogen tank, in particular as a long-term energy storage device, which is at least temporarily fluidly connected to the fuel cell unit and the electrolysis unit and is designed to store hydrogen to be produced by the electrolysis unit and consumed by the fuel cell unit, - a storage battery unit, in particular as a short-term energy storage device, which is electrically connected or can be connected at least temporarily to the DC feed-in point or, preferably, to the AC feed-in point via a bidirectional inverter, so that electrical PV power and electrical fuel cell power can be stored in the storage battery unit and electrical electrolysis input power and consumption power can be drawn from the storage battery unit; and - a control module for controlling the building's energy system.

[0016] A fundamental concept of the present invention is the compression of the hydrogen produced in the electrolysis unit from approximately 20-30 bar to up to 700 bar in the high-pressure storage unit via a specially designed compressor unit. Process characteristics occurring during the operation of the compressor unit, such as waste heat, can be utilized for the overall operation of the energy system and integrated into its energy management. Furthermore, intelligent, and in particular predictive, energy management is provided.

[0017] According to the first aspect of the invention, an energy system is provided which has the features of independent claim 1. In a preferred embodiment, the energy system is designed as a building energy system. This serves to provide energy to a building.

[0018] First, an energy generation device is provided, which serves to generate and supply electrical energy. The energy generation device is specifically designed to generate electrical energy based on renewable energy sources. According to one embodiment, the energy generation device is designed as a photovoltaic (PV) system. According to another embodiment, the energy generation device is designed as a wind turbine, particularly a small wind turbine. However, the energy generation device can also be implemented as a differently designed energy source. For the sake of clarity, the invention is described below using an energy generation device in the form of a photovoltaic system, without limiting the invention to this specific embodiment.

[0019] In one embodiment, the energy generation device is part of the energy system. In another embodiment, the energy generation device is a component independent of the energy system. In this case, the energy system has an interface with the energy generation device.

[0020] The following section describes a number of components of the energy system. The focus is on those components that are directly related to the present invention. Of course, the energy system may include other components as well.

[0021] The individual components are connected to each other via a connecting pipe system consisting of several different pipe sections. Depending on requirements, various media can be transported via this system, such as fluids, gases, electrical energy, and the like. The connecting pipe system is adapted accordingly in each case.

[0022] The energy system initially comprises a first subsystem. According to one embodiment, this is an indoor system, which is located, for example, within the building. The individual components of the indoor system can, for example, be housed in a system cabinet.

[0023] The first component of the first subsystem is an electrolysis unit, which is used to produce hydrogen. "Electrolysis" refers specifically to the splitting of a chemical compound using electric current. Through electrolysis, the substances contained in the compound are separated from one another. The electrolysis process takes place in the electrolysis unit. For example, the energy system uses surplus electricity from the power generation unit, such as in summer, to produce hydrogen in the electrolysis unit. If the electrical energy generated by the power generation unit is insufficient, such as in winter, electrical energy is generated from the hydrogen.

[0024] Furthermore, the energy system includes a battery storage system for the short-term storage and provision of electrical energy. This is a short-term storage system, for example, for day / night operation, for the electrical energy generated by the energy generation device. The electrical energy generated by the photovoltaic system during the day, for example, is stored in the battery storage system and made available for use in the evening. At least a portion of the energy generated by the energy generation device is stored in the battery storage system.

[0025] The energy system also has a second subsystem. According to one embodiment, this is an external system, which is located, for example, outside the building.

[0026] The second subsystem includes a first storage device for storing the hydrogen produced by the electrolysis unit. The hydrogen produced by the electrolysis unit is stored in the first storage device until it is needed at a later time, for example, in winter. In contrast to the battery, which provides short-term storage, the first storage device is specifically designed for long-term storage. Preferably, the first storage device is a high-pressure storage device in which hydrogen can be stored at pressures up to 700 bar, for example, up to 300 bar. The aim is to make the first storage device as compact as possible while simultaneously maximizing its hydrogen storage capacity.

[0027] According to the present invention, the energy system is characterized in that at least one compressor device is provided, by means of which the hydrogen produced by the electrolysis device is compressed to the desired high pressure before being stored in the first storage device.

[0028] Up to now, these hydrogen compressor systems have been used in the form of piston compressors, which, particularly in the case of directly electrically driven, multi-stage piston compressors with intercooling, can achieve a relatively high overall efficiency. However, mechanical compressor systems are expensive to purchase and noisy during operation. This is a particular disadvantage in buildings, for example, at night. Another disadvantage of a mechanical compressor is the wear and tear on the moving parts, which limits its lifespan and can lead to high maintenance costs. The alternative of increasing the pressure of hydrogen via electrochemical compression is not yet ready for mass production and faces significant challenges in process engineering, mechanics, safety, and cost.

[0029] According to the invention, the at least one compressor device is now designed as a hydride compressor device, which is provided for compressing the generated hydrogen before storage in the first storage device, for example to up to 700 bar.

[0030] Hydride storage devices, in which hydrogen is stored in a compressed form, are already known. An example of this is described in EP 3 722 653 A1.

[0031] According to the invention, it has now been found that such a hydride storage device can also be used as a compressor device for the energy system and thus functions as a hydride compressor device. A hydride compressor device is a special type of compressor device. It utilizes the ability of certain materials that can reversibly bind hydrogen via absorption or adsorption to adsorb and release hydrogen under specific conditions. These materials are hereinafter referred to as hydride materials. The hydride materials are located within the hydride compressor device. According to one embodiment, the hydride compressor device is a metal hydride compressor, and the hydrogen-binding material is a metal hydride material, hereinafter referred to simply as hydride or metal hydride. The hydride compressor device typically operates in a cyclic process.During the charging phase, hydrogen is fed into a receiving vessel containing a hydride material. The hydride material adsorbs the hydrogen. Once the hydride material is fully charged, the receiving vessel is heated. This is done, for example, using a heating device, such as an electric heater. Increasing the temperature reduces the hydride material's capacity to hold hydrogen, and the hydrogen is released, thus increasing the gas pressure in the enclosed space. This process is called desorption. The higher the temperature to which the receiving vessel is heated, the more hydrogen is released in gaseous form and the higher the hydrogen pressure in the receiving vessel. The hydride compressor system, and in particular the receiving vessel, is heated until the desired pressure is reached, for example, 300 bar at 170°C.The released hydrogen is at a higher pressure than originally supplied. Desorption is an endothermic process. During the discharge phase, additional heat energy is added at a high temperature level, and the released hydrogen is directed to a storage device or directly to an application. The discharge phase preferably begins as soon as the pressure in the hydride compressor unit slightly exceeds the pressure in the high-pressure storage tank. This has the advantage that, with only a partially charged high-pressure storage tank, the hydride compressor unit does not experience the maximum pressure and temperature fluctuations that significantly affect its cycle stability. By further increasing the temperature, particularly beyond the temperature at which the tank pressure is reached, the residual hydrogen content in the hydride can be further reduced, and the desorption rate accelerated.Once the hydride material is discharged, the storage container is cooled again, and the cycle begins anew. Cooling can be achieved, for example, using an electrically driven fan that draws cooling air from the ambient air. Cooling must occur below a critical temperature, a mean temperature within the hydride storage material, which is determined primarily by the type and quantity of hydride material and the required hydrogen uptake rate during operation. The duration of the cooling process therefore also depends significantly on the difference between the ambient temperature and the target temperature, as well as on the heat transfer characteristics of the hydraulic compressor.

[0032] During operation, the hydride compressor unit is therefore charged and subsequently regenerated. In light of this description, the term "regeneration" encompasses, in particular, the following: heating to the desorption temperature; desorbing the hydrogen at an elevated temperature by supplying desorption energy, for example, via heating; and finally, preferably forced, cooling of the hydride compressor unit, for example, via forced convection / ventilation. Experience has shown that the typical time required for regeneration with a well-designed unit, as described below, is between 3 and 10 hours. This generally allows for a complete charging and regeneration cycle per day.

[0033] A typical daily cycle begins with the start-up of the electrolysis unit and thus the start of the charging of the hydride compressor unit, which has preferably cooled down overnight. In typical system applications, the timing for stopping the electrolysis process and starting regeneration should be chosen so that the energy-intensive heating and desorption phases can still be carried out almost entirely with excess PV energy.

[0034] According to one embodiment, the hydride compressor device comprises one or more receiving containers. The number of receiving containers depends on the size and capacity of the hydride compressor device. Each receiving container holds a hydride material. The hydrogen is stored in the receiving containers. A heating device, preferably electric, is provided for heating and the desorption process. The heating device can preferably be an electric heater in direct thermal contact with the receiving containers, or, similar to a convection oven, an air heater with recirculation. Heating via condensation, for example of water vapor, or via a liquid heat transfer medium is also possible. The invention is not limited to specific types of heating devices.The heating device obtains the necessary electrical energy, for example, via the device for generating electrical energy.

[0035] A blower unit serves to cool the hydride compressor unit as needed, supplying it with cooling air, preferably fresh air drawn from the environment. The blower unit obtains the necessary electrical energy, for example, from a power generator.

[0036] The hydride compressor devices known from the prior art are currently used in a similar design as metal hydride hydrogen tanks, which can be used, for example, in vehicles. To circumvent the disadvantages of mechanical compression, the inventors have now demonstrated new ways in which the operating principles of a hydride compressor device can also be mastered in the energy system that is the subject of the invention. As already explained, these energy systems are very complex in their structure, properties, and operation, so that the mechanical compressor devices used in energy systems to date cannot simply be replaced by a hydride compressor device. Rather, a series of adaptation steps are required.The inventors have also discovered that waste heat generated during the operation of the hydride compressor unit can be used for other processes within the energy system. To achieve this, the hydride compressor unit must be integrated into the energy system, which is not a trivial task. Furthermore, sophisticated energy and power management is required to realize this. The goal is to produce as much hydrogen as possible while minimizing electrical energy consumption and simultaneously maximizing the operating time of the electrolysis unit. Since the thermal energy for heating and desorption in this application must be generated electrically and therefore directly reduces the available electrical energy for consumers and for hydrogen production via electrolysis, these measures must preferably include minimizing the mass of the hydride compressor unit.An increase in the dynamics of the regeneration phase is also desirable. The inventors have discovered that this is possible when using a hydride compressor device. The present invention also provides such an energy management device. This will be explained in detail later in the description using exemplary embodiments.

[0037] According to one embodiment, the energy system has a single hydride compressor unit. This places particular demands on the control of the energy system, especially on energy management, and depends in particular on the daily changing electrical consumption profiles, the amount of PV energy available daily (which results from data on the PV installation and the daily varying solar irradiance), and the size of the available battery storage, collectively referred to below as "energy boundary conditions." With only one hydride compressor unit, electrolysis operation and regeneration of the hydride compressor unit cannot usually be carried out simultaneously.This limits the daily operating time of the electrolysis unit and, due to its limited power consumption, also its hydrogen production rate, thus limiting the amount of hydrogen that can be produced daily. Extending the operating time using energy from the battery allows for a larger annual storage quantity of hydrogen for a given electrolysis capacity, provided there is a sufficiently high daily surplus of PV energy. However, it must be ensured that, despite potentially drawing a larger amount of energy from the battery to regenerate the hydride compressor, electrical self-sufficiency is not jeopardized, that excessive discharge of the battery during the day is avoided, and, in particular, that no increased reliance on electricity from the grid becomes necessary.With the present invention, in particular the energy management, it is possible to use only a single hydride compressor device for a wide range of energy boundary conditions.

[0038] The design of a single hydride compressor system, aimed at optimized hydrogen harvesting throughout the year, is based on available energy, such as solar energy, particularly in summer, which can reach up to 16 hours of sunshine per day. This results in a large hydride compressor system with long cycle times and high energy requirements for regeneration, typically at the end of the day, when energy from the battery system is needed.

[0039] Therefore, it is advantageous to control the individual components, and in particular the electrolysis unit and the hydride compressor unit, efficiently. Preferably, a sophisticated control system, described in detail below, also prevents regeneration of the hydride compressor unit in a partially loaded state. In such a case, the poorly recoverable heating energy and heat losses would be high, as these are almost independent of the integral loading state of the hydride material. The present invention makes it possible to operate the energy system with only one hydride compressor unit.

[0040] According to another embodiment, the energy system comprises at least two hydride compressor units, for example, two, three, or more hydride compressor units. Preferably, the individual hydride compressor units are independent of one another and thus can be operated independently. In a preferred embodiment, the energy system comprises two hydride compressor units.

[0041] According to one embodiment, the at least two hydride compressor units are of the same dimensions. According to another embodiment, the at least two hydride compressor units are of different dimensions.

[0042] According to one embodiment, the same hydride material is found in each of the hydride compressor units. According to another embodiment, different hydride materials are found in each of the hydride compressor units. The different hydride materials differ, in particular, in type and / or properties. According to a further embodiment, at least one of the other hydride compressor units, with otherwise similar design features, can use a different type of metal hydride material, which, for example, allows loading at higher ambient temperatures and desorbing at lower temperatures and pressures, as long as the tank pressure is not yet too high.

[0043] According to one embodiment, the two or more hydride compressor units are provided in the energy system and can be operated independently of one another. In this case, each hydride compressor unit performs the entire necessary pressure stroke. According to another embodiment, the two or more hydride compressor units are connected in parallel.

[0044] Using at least two hydride compressor units offers several advantages compared to a solution with only one. With only one hydride compressor unit, electrolysis and the hydride compressor unit typically cannot operate simultaneously. This limits the daily operating time of the electrolyzer and, consequently, the amount of hydrogen that can be produced daily.Extending the operating time via energy from the battery system is possible through intelligent operation with optimized energy management, as explained in more detail below, but in some cases it is only feasible to a limited extent and can only fulfill partial aspects of the present task, in particular not the maximum possible miniaturization of the hydride compressor system and not the simultaneous operation of electrolysis and regeneration of the hydride compressor system with direct use of available high photovoltaic power on sunny days.

[0045] The use of two or more hydride compressor units enables maximum utilization of directly available electrical energy from the renewable source, for example, solar energy, for electrolysis and hydrogen compression, while minimizing reliance on the battery storage system. The invention is not limited to a specific number of hydride compressor units. According to one embodiment, the energy system comprises two hydride compressor units. However, three or more hydride compressor units can also be implemented.

[0046] Small hydride compressor units with short cycle times are preferred. The cost of a hydride compressor unit increases almost linearly with the active hydride mass. This, in turn, is a direct measure of the amount of hydrogen that can be stored and compressed per charge / discharge cycle under nominal conditions. Using multiple hydride compressor units with short cycle times allows for the use of smaller hydride compressor units compared to single units, offering the aforementioned advantages.

[0047] This can be illustrated with an example. The design of a single compressor is based, for instance, on the available solar energy in summer – up to 16 hours of sunshine per day. Such a compressor is clearly oversized when daily solar energy is limited, for example, from February to April, or from September to November. The entire thermal mass of the large compressor must be heated to the high desorption temperature, even with a partial load. This significantly increases the energy required per unit of hydrogen during the regeneration phase. Particularly on days with, for example, less than four hours of sunshine, operation with a single, large compressor would be uneconomical in some cases. For instance, the operating time of the electrolysis unit would be reduced to 1-2 hours, with a further regeneration time of more than 3 hours.

[0048] According to one embodiment with two hydride compressor units, the hydride compressor units are of different sizes. In one embodiment, the capacity of the larger hydride compressor unit, that is, in particular the amount of hydride material in the hydride compressor unit, is 100% to 500%, preferably up to 250%, of the capacity of the smaller hydride compressor unit. If more than two hydride compressor units are used, their energy recovery from waste heat is improved. However, the overall costs increase. When using two or more differently sized hydride compressor units, however, less mass of hydride material and less mass of receiving container are required compared to a single hydride compressor unit, which can offset the additional costs of multiple hydride compressor units.

[0049] The operation of one, two, or more hydride compressor units is controlled by a control unit that features intelligent energy management. This is explained in detail below. Furthermore, the waste heat from the hydride compressor unit(s) can be utilized in the operation of the energy system.

[0050] In addition to the components already described, the energy system may have further components, some of which are named below.

[0051] According to one embodiment, the energy system includes a fuel cell unit. The hydrogen produced by the electrolysis unit and stored in the first storage unit is converted back into electrical energy by the fuel cell unit as needed, for example, in winter. The heat generated during the production of electrical energy from hydrogen can be used to supplement the building's heating system. The fuel cell unit is specifically part of the first subsystem of the energy system. When hydrogen is expanded from the first storage unit into the at least one hydride compressor unit, releasing the heat of absorption, and subsequently used to slowly generate electrical energy in the fuel cell unit, the resulting waste heat can be used for other processes, such as ventilation, heating, and the like.

[0052] According to one embodiment, the energy system includes a heat pump device, or an interface to a heat pump device.

[0053] According to one embodiment, the energy system includes a hot water generation device or an interface to a hot water generation device.

[0054] According to one embodiment, the energy system includes a second storage device for storing hydrogen. This second storage device is specifically part of the second subsystem of the energy system. According to one embodiment, the second storage device is designed as a medium-pressure storage device, for example, for storing hydrogen up to 30 bar. According to another embodiment, the second storage device is used for intermediate storage of the generated hydrogen.

[0055] By using an additional storage device, for example a medium-pressure gas storage tank, which may optionally be filled with a suitable storage material with preferably different absorption / desorption characteristics than those of the hydride compressor device, such as a metal hydride or MOF or carbon nanofibre / nanotube or zeolite, or the like, hydrogen produced by the electrolysis device can be temporarily stored at certain times, for example on days with a small surplus of solar energy, optionally in addition to partially charging the hydride compressor device, and at a later time, on the next or the day after, conveyed via the hydride compressor device into the first storage device designed as a high-pressure storage device.On days with a high surplus of electrical energy, for example, on days with a very high surplus of solar energy, and / or when the capacity of the hydride compressor unit(s) and / or the hydrogen adsorption capacity of the hydride compressor unit(s) is exceeded, a portion of the hydrogen mass flow from the electrolysis unit can also be temporarily stored. This can be done either in parallel with the charging of the hydride compressor unit(s) or sequentially with the charging process.

[0056] This will be illustrated with an example. For instance, a hydride compressor unit can be designed to be smaller and more cost-effective. On days with a very high surplus of solar energy and long hours of sunshine, a rapid, possibly only partial, intermediate desorption cycle of the hydride compressor unit can be carried out, and during this time the generated hydrogen can be temporarily stored in the second storage unit. A pressure stroke of 15 bar and a volume of 150 l in a pure pressure storage tank as the second storage unit, for example, allows for the intermediate storage of 2.25 Nm³. 3Hydrogen is added. This corresponds, for example, to an electrolysis runtime of 4.5–6 hours for a relatively small electrolysis unit, depending on the electrolysis capacity. Preferably, after regeneration and at low ambient temperatures, such as at the end of the night or in the early morning when the pressure in the hydride compressor unit is particularly low, the unit is pre-charged from the intermediate storage unit in the form of the second storage unit. The compressor unit can then be directly charged by electrolysis, reaching a higher charge level in a shorter time and allowing for earlier and / or more energy-efficient regeneration.

[0057] The following example illustrates the functionality of the second storage unit, which is specifically designed as a medium-pressure storage unit for the intermediate storage of hydrogen. Preferably, the second storage unit is filled via electrolysis operation after the hydride compressor unit stops charging, for example, up to 30 bar. If sufficient excess PV power is expected, the regeneration process can be started simultaneously. In this case, higher PV power can be used directly for both parallel processes, even if only one hydride compressor unit is present. The cooling phase of the hydride compressor unit can take place overnight, and the entire regeneration phase can be controlled so that the temperature and pressure in the hydride storage unit are low the following morning, for example, 15 bar at 15°C.This allows a large portion of the hydrogen temporarily stored in the second storage unit to be absorbed even before the electrolysis unit starts up. For this purpose, a valve between the second storage unit and the hydride compressor unit is opened, and hydrogen flows into the hydride compressor unit. During this process, the cooling system for the hydride compressor unit must be activated to keep the temperature and pressure in the active material low during absorption. Once the usable portion of the contents of the second storage unit has flowed into the hydride compressor unit, the overflow valve can be closed.The second energy storage unit is then ready to receive hydrogen from the electrolysis process, preferably when the hydride compressor unit's regeneration phase is restarted on the same or a subsequent day, or if the hydride compressor unit's capacity is limited by excessively high ambient temperatures and sufficient energy is still available to continue operating the electrolysis unit. In any case, this is controlled by the energy management system. The electrolysis unit can be started later, also controlled by the energy management system. This operating mode allows for the direct use of more PV energy when the electrolysis unit and the hydride compressor unit are operating in parallel.Secondly, with two or more hydride compressor units, the charging time, and thus the cycle time, of one of the compressor units can be shortened, with the aim of charging and regenerating that unit a second time on the same day. Through these measures, more hydrogen can be produced on a very productive day by cleverly controlling the system. On a less productive day, a hydride compressor unit can be brought to a higher charge level by discharging the second hydrogen storage unit in addition to electrolysis, and then regenerated more efficiently.

[0058] When using such a second storage device, the energy system can then, for example, only have a single hydride compressor device.

[0059] The operation of at least one hydride compressor unit in conjunction with the second hydrogen storage unit is supported by a control unit which, in particular, features intelligent energy management and which is described in greater detail below.

[0060] Another component of the energy system can be a drying unit for the generated hydrogen. In particular, traces of water vapor, but also of oxygen, contained in the hydrogen lead to irreversible damage to the metal hydride in the hydride compressor unit. A hydrogen purity of grade 4.5, preferably better than 5.0, must be ensured. The hydrogen generated in the electrolysis unit is usually still moist and must therefore be dried before entering the hydride compressor unit to ensure that the water vapor content does not exceed approximately 10 ppm. This is done in the drying unit, which, according to one embodiment, is located downstream of the electrolysis unit in the direction of hydrogen flow.The dryer unit can, for example, be operated in pressure / temperature alternating mode and be filled with dryer substances, such as zeolitic dryer substances.

[0061] According to one embodiment, the energy system includes a pressure-maintaining valve. One objective is to achieve more effective drying and water separation at a higher pressure, preferably between 20 and 30 bar. In one embodiment, this valve is positioned in the flow direction of the generated hydrogen between the electrolysis unit and the hydride compressor unit, preferably between the dryer unit and the hydride compressor unit. The pressure in the hydride compressor unit during charging is highly dependent on the ambient temperature and the state of the charge. Efficient drying with extended service intervals is greatly enhanced when the electrolysis unit and the dryer unit operate at maximum pressure. This is ensured by the pressure-maintaining valve.

[0062] According to one embodiment, the energy system includes a recombinator device, which is located downstream of the electrolysis unit, particularly upstream of the dryer, in the direction of flow of the generated hydrogen. The water produced during recombination is thus also removed in the subsequent drying stage. The recombinator device is preferably heated to ensure that the catalysts used therein, particularly precious metal catalysts of the platinum group, preferably Pt or Pd, become sufficiently active to efficiently and almost completely convert the typically low oxygen concentrations (e.g., < 0.1%) present at the recombinator inlet.

[0063] According to one embodiment, the energy system can include a ventilation device or an interface to a ventilation device. Waste heat generated in the energy system can then be supplied to the ventilation device.

[0064] According to one embodiment, at least one hydride compressor unit has a heat dissipation system that is thermally connected to another component of the energy system for heat exchange. The heat dissipation system consists, in particular, of hot exhaust air from the hydride compressor unit. The heat generated in the hydride compressor unit can be dissipated via the heat dissipation system and subsequently supplied to another component of the energy system. Such a component is preferably one that requires heat for its operation or for whose operation heat is advantageous, for example, another hydride compressor unit and / or the ventilation unit and / or the heat pump unit and / or the dryer unit and / or the hot water generation unit.

[0065] Regarding the utilization of waste heat, some application examples are given below. Both air and other heat transfer media can be used for heating and cooling. The following considerations can be applied to different heat transfer media, if necessary by transferring the thermal energy from one medium to another via a heat exchanger. If air is used as the heat transfer medium for cooling and / or heating the hydride compressor unit, then after the desorption phase, i.e., during the cooling phase of the hydride compressor unit, exhaust air is available, initially at up to approximately 200°C, and at the end of the cooling process at approximately ambient temperature. The waste heat can, for example, be transferred directly from the exhaust air of the hydride compressor unit into the intake air of an air-to-water heat pump, thereby increasing its COP.The waste heat can also be used via an air-to-water heat exchanger to superheat the hot water supply of a heat pump or a domestic hot water system. The waste heat can be distributed into the building, for example, via a ventilation system. The waste heat can also be used to regenerate / heat a hydrogen dryer. When using two or more hydride compressor units, the heated exhaust air during the cooling phase can also be used for preheating, i.e., for at least partially heating another hydride compressor unit during the heating phase, and subsequently used in another way described above.

[0066] The waste heat can be generated and dissipated, for example, in the following operating modes of the hydride compressor unit(s): During cooling after desorption in regular hydrogen production, the hydride compressor unit is typically cooled rapidly, for example from approximately 170°C to < 30°C. The superheated cooling air can be supplied to other components, as described in various places in this application.

[0067] In another embodiment, which can be particularly advantageous in winter, hydrogen can be expanded from the first storage device, the high-pressure storage device, into the hydride compressor device. During this process, hydrogen is re-adsorbed in the hydride compressor device, and the heat of adsorption is released in the metal hydride. The hydride compressor device will heat up as a result. Similar uses are conceivable here, analogous to the utilization of waste heat during the cooling phase of the hydride compressor device after the regeneration phase. Preferably, this method is applied in a building energy system during the winter months, when the fuel cell device is also preferably operated and when the waste heat is even more needed for heating the building.The amount of hydrogen stored from the high-pressure device controls the adsorption energy released and thus the temperature increase of the hydride compressor unit. This method is particularly advantageous for providing heat at a controllable temperature level for, for example, 0.5 to 2 hours. During fuel cell operation, which preferably does not fall within the timeframe of this process, the hydrogen is then extracted at a preferably low rate, for example, 0.5 Nm³. 3The hydrogen is extracted per hour. The energy for this slow desorption process at low pressure, for example 3-10 bar, can also be drawn from the environment at low ambient temperatures. In this case, a control system takes over the task of controlling and monitoring these processes and ensuring that the fuel cell has sufficient hydrogen pressure available at very low temperatures, where the pressure in the hydride compressor unit falls below the minimum threshold. This can be achieved, for example, by adding more hydrogen from the first hydrogen storage unit, the high-pressure storage unit, or by electrically heating the hydride compressor unit, or by directly connecting the high-pressure storage unit and the fuel cell unit via a pressure reducer.In a preferred embodiment and operating mode, the pressure reducer between the high-pressure storage device and the fuel cell device can be designed for a significantly lower inlet pressure.

[0068] According to one embodiment, each assembly comprising the electrolysis unit, the fuel cell unit, the at least one hydride compressor unit, the first hydrogen storage unit, and / or the second hydrogen storage unit is assigned a valve assembly, in particular a shut-off valve assembly. If two or more hydride compressor units are used, according to one embodiment, each hydride compressor unit is assigned a valve assembly. Depending on the operating mode, the corresponding assembly can then be completely switched on or off. The valve assembly can, for example, be a solenoid valve assembly, although the invention is not limited to this specific example.

[0069] According to one embodiment, the energy system includes a control unit configured to control at least individual components of the energy system. In particular, the control unit has interfaces and signal connections to the individual components of the energy system, which can be wireless or wired.

[0070] The control unit is, in particular, the entirety of all components that influence the energy system. The control unit can be designed as hardware components, software components, or a combination thereof. In particular, the control unit comprises a processor in which at least parts of the inventive method for controlling the operation of the energy system according to the second aspect of the invention take place, or in which a computer program product according to the third aspect of the invention is implemented. Depending on the configuration, the control unit is at least partially an integral part of the energy system. Alternatively, the control unit may be an external component that is then at least temporarily connected to and communicates with the energy system via interfaces and signal connections.

[0071] According to one embodiment, the control unit includes an energy management unit configured to control at least individual components of the energy system. Either the energy management unit generates commands that cause the control unit to control the individual components of the energy system, or the energy management unit itself controls the individual components of the energy system based on signals and commands it generates. In particular, the "energy management unit" as defined in the present invention determines, analyzes, and / or predicts the current energy consumption and / or energy generated by individual components, especially during a defined observation period. Examples of this are described in more detail below, particularly within the context of the method according to the invention.The energy management system serves, in particular, the systematic recording and communication of energy flows and essential operating parameters, and especially the automatic control of energy system components to optimize and improve energy efficiency. The energy management system makes it possible, in particular, to improve the operation of the energy system and the efficiency, especially of individual components, through procedural and technical measures. The energy management system may, for example, consist of electronic components, software, logic modules, and the like, or a combination thereof, which are, in particular, components of a computer or processor system. For example, a computer program product according to the third aspect of the invention may be implemented and / or run within the energy management system.

[0072] The control unit and / or the energy management unit enable, in particular, intelligent, predictive energy management. This will be further clarified below in connection with the method according to the invention.

[0073] The following are some examples of how the control unit and / or energy management unit works: In particular, the control unit and / or the energy management unit controls the energy system in such a way as to ensure a secure energy supply with as little energy as possible drawn from an electrical supply network, especially little temporary draw which could in principle be balanced again within a few hours, and as little hydrogen consumption as possible, especially in the winter months.

[0074] In particular, the control unit and / or the energy management unit controls both the operation of the electrolysis unit and the operation, especially the compression and regeneration phases, of the at least one hydride compressor unit, particularly with all available parameters. A number of examples are described below.

[0075] For example, the control unit, in particular the energy management unit, controls and / or monitors the timing and sequence of the activation and charging of one or more hydride compressor units. It can also be advantageous to charge both hydride compressor units simultaneously, for instance, on very hot days when the hydrogen flow rates are too high for a single hydride compressor unit, but the temperature and / or loading level of the storage material limits the absorption rate. For example, the control unit, in particular the energy management unit, controls and / or monitors the timing of the start of hydride compressor unit regeneration for each hydride compressor unit and controls the heating, desorption, and cooling processes.For example, the control unit, in particular the energy management unit, controls and / or checks whether the hydride compressor unit(s) is / are ready to receive hydrogen. This is done, for example, by measuring or determining the operating temperature and pressure, possibly supported by the estimated hydrogen charge at the start of the charging process and the amount of hydrogen stored since then. For example, the control unit, in particular the energy management unit, controls and / or checks the start time of the hydride compressor unit regeneration and controls the regeneration / heating process. For example, the control unit, in particular the energy management unit, controls and / or checks the regeneration of the hydride compressor unit after each charging, even with only partial charging, especially without significantly burdening the battery system.For example, the control unit, in particular the energy management unit, controls and / or checks a postponement of the regeneration of a hydride compressor unit to a later time, for example to the following day, in order to then use available PV surplus power directly.

[0076] For example, the control unit, in particular the energy management unit, controls and / or monitors whether and when the electrolysis unit is switched on and off and, if necessary, reduces the power output of the electrolysis unit, for example, as soon as the hydride compressor unit can no longer accept the nominal flow rate, for example, at higher temperatures and higher charge levels. For example, the control unit, in particular the energy management unit, controls and / or monitors the maximization of the daily electrolysis runtime and thus the amount of hydrogen produced, which is one of the main objectives of the operational management.

[0077] For example, the control unit, in particular the energy management unit, controls and / or monitors the charging and discharging of the second storage unit. An example is described below in which the second storage unit interacts with at least one hydride compressor unit.

[0078] At the end of desorption, a high pressure of, for example, up to 300 bar still prevails in the hydride compressor unit. This means that a significant amount of gaseous hydrogen remains in the hydride compressor unit. If cooling then occurs in the closed hydride compressor chamber, hydrogen is immediately reabsorbed into the hydride material. This increases the charge level of the hydride, even before the next electrolysis cycle begins, and delays cooling, as heat is released. If a second storage device is used, which can be activated at will, particularly via a valve, the following procedure can be taken to avoid or at least reduce the aforementioned effects: After the desorption phase, at least one hydride compressor unit is depressurized into the second storage unit, which may then reach a pressure exceeding 30 bar, depending on the size of the second storage unit, the free gas volume in the hydride compressor unit, and the gas pressure of the second storage unit. During the expansion and subsequent cooling, not only does a large portion of the gaseous hydrogen flow into the second storage device; it also further desorbs hydrogen from the hydride, thereby cooling it down. The hydride compressor unit therefore cools down faster, which is advantageous because the cooling time is the longest part of the cycle and should be as short as possible, especially with two hydride compressor units; The hydride compressor unit then has a lower starting charge, can absorb more hydrogen before the next regeneration, and can even absorb hydrogen again at a higher hydride temperature if necessary. This is advantageous, for example, when the outside temperature is high and there is hardly any driving temperature gradient towards the end of the cooling phase. The second storage unit must be controlled appropriately by the energy management system and emptied again at precisely the right time via a hydride compressor unit, for example at the beginning of the day, which then reduces the filling time of one of the hydride compressor units. Ideally, both the filling time and the cooling time can therefore be significantly reduced.

[0079] For example, the control unit, in particular the energy management unit, controls and / or monitors the use of battery energy from the battery unit for electrolysis and / or the regeneration of the hydride compressor unit. For example, the control unit, in particular the energy management unit, controls and / or monitors the state of charge of the battery unit until the end of a given period. For example, the control unit, in particular the energy management unit, generates a forecast of the battery state of charge over a given period.

[0080] For example, the control unit, in particular the energy management unit, checks the energy surplus of the electrical energy generation device, especially the expected surplus, such as the solar energy surplus generated as electrical energy in the PV system, and its progression until the end of a given period, for example, until the end of the day. For example, the control unit, especially the energy management unit, checks any energy surplus of the energy generation device, particularly the expected surplus, from generated electrical energy and the consumption of electrical energy by consumers that are part of the energy system and / or connected to the energy system.For example, the control unit, in particular the energy management unit, checks the battery charge level, especially the expected state of charge until the end of a given period, for the operating scenarios of the energy system under consideration, taking into account the expected electrical energy consumption of the building and its occupants. For example, the control unit, in particular the energy management unit, checks whether and how much battery energy is available for electrolysis. For example, the control unit, in particular the energy management unit, checks whether and how much battery energy is available for regenerating the hydride compressor unit. In doing so, the control unit, in particular the energy management unit, prioritizes a sufficiently high battery charge level that can buffer unexpected consumption during the period under consideration or reduced PV energy yields.

[0081] For example, the control unit, in particular the energy management unit, switches the components of the energy system for optimized heat extraction and / or the operating state of the energy system for heat extraction.

[0082] According to one embodiment, the energy management device is configured—that is, assembled from individual elements—to determine operating parameters for the energy system component to be controlled based on determined, predetermined, or predicted data that is generated, stored, or received by the energy management device. The device then controls the component based on these operating parameters. This is described in greater detail below in connection with the method according to the invention, and reference is made to the corresponding explanations below. An "operating parameter" is, in particular, a factor or boundary condition that influences the operation and function of a component of the energy system or of the entire energy system.This includes, for example, the load profile of the components, the operating behavior of the components, the operating and environmental conditions, and the like. The operating conditions are characterized in particular by the numerical values ​​of the individual quantities that occur at a specific operating state of a component or the energy system. These quantities can change during operation. Examples of this are explained further below in connection with the method according to the invention.

[0083] According to one embodiment, the energy management device is configured to determine the operating parameters for the component to be controlled, and to monitor, record, or predict any energy surplus of the energy generation device and its course over a defined observation period, which is determined or specified. This is described in greater detail below in connection with the method according to the invention, so reference is made here to the corresponding explanations below.

[0084] According to one embodiment, the energy management device is configured to monitor, record, or predict the state of charge of the battery device and its progression over a defined observation period, which is determined or specified. This is described in greater detail below in connection with the method according to the invention, so reference is made here to the corresponding explanations below.

[0085] According to one embodiment, the energy management device is configured to calculate a predicted usable capacity of the battery system over a predetermined period, particularly predictively and / or on a rolling basis, taking into account a predicted energy surplus from the energy generation device and a predicted total energy consumption of the energy system and the external consumers to be supplied and / or those components that are connected to and supplied with energy via the energy system. A "rolling" calculation means, in particular, that it changes periodically according to a specific system. This is described in greater detail below in connection with the method according to the invention, so reference is made here to the corresponding explanations below.

[0086] According to one embodiment, the control unit of the energy system, in particular its energy management unit, is configured to control the individual components of the energy system, either individually or in any combination.The following are controlled in particular: the electrolysis unit and / or the battery unit and / or the at least one hydride compressor unit and / or the first storage unit, in particular a shut-off valve unit assigned to the first storage unit being controlled, i.e., opened or closed, and / or the second storage unit, in particular a shut-off valve unit assigned to the second storage unit being controlled, i.e., opened or closed, and / or the fuel cell unit, and / or the heat pump unit, and / or the hot water generation unit and / or the waste heat removal of the hydride compressor unit, and / or the dryer unit, and / or the pressure holding valve unit, and / or the recombinator unit, and / or the ventilation unit.

[0087] During fuel cell operation of the energy system, for example in the colder months, hydrogen can be expanded from the first storage unit into the hydride compressor unit. This process releases heat, specifically the heat of absorption, which is similar to the heat released during desorption. The hydride compressor unit heats up. This heat can be dissipated and utilized. The process can be controlled, particularly via the control unit, such as the energy management unit, by adjusting parameters like the amount of hydrogen per recharge, the hydrogen flow rate during discharge in fuel cell operation, and the heat dissipation. The recharge / inflow is controlled, for example, by a throttle valve and / or a valve, such as a solenoid valve.Preferably, the system is charged quickly so that the temperature increases and the heat can then be used more effectively; and then discharged more slowly to absorb energy from the environment, especially at temperatures below 20°C with a lower heat output.

[0088] According to one embodiment, the at least one hydride compressor unit is part of the first subsystem. It is therefore located indoors. This has several advantages. For example, the waste heat from the hydride compressor unit(s) can be dissipated much more effectively and efficiently into the building and / or a hot water storage tank. A disadvantage of indoor installation is that there are then areas with high hydrogen pressure in the building, and that a larger quantity of hydrogen is present in the building, namely in the hydride compressor unit. This can lead to significantly increased complexity in the safety technology.

[0089] According to a preferred embodiment, the at least one hydride compressor unit is therefore part of the second subsystem, i.e., the external system.

[0090] According to the second aspect of the invention, a method is provided which has the features of independent claim 13.

[0091] The method is carried out in an energy system according to the first aspect of the invention. To avoid repetition, reference is made here in full to the general description of the invention above and to the explanations of the energy system according to the first aspect of the invention. This applies in particular to the functioning of the method. Individual process steps have already been described in connection with the energy system and its components, as well as the interaction of the individual components of the energy system.

[0092] The procedure is characterized by the following steps: Electrical energy is generated, at least temporarily, by means of an energy generation device. In this case, the energy generation device is part of the energy system. Alternatively, electrical energy is obtained, at least temporarily, from an energy generation device. In this case, the energy generation device is not necessarily part of the energy system.

[0093] The electrical energy is at least partially and / or temporarily stored in a battery system.

[0094] The electrical energy provided by the power generation device and / or the electrical energy provided by the battery system is used, at least temporarily, to operate an electrolysis unit. Hydrogen is produced in this unit.

[0095] The hydrogen is stored in a first storage facility, in particular a high-pressure storage facility.

[0096] With regard to these process steps, particular reference is made to the explanations concerning the energy system according to the first aspect of the invention above.

[0097] According to the invention, the method is characterized in that the hydrogen is compressed in at least one compressor device designed as a hydride compressor device before being stored in the first storage device.

[0098] The hydride compressor unit, particularly in conjunction with the energy system utilizing renewable energy, preferably photovoltaic energy, is a complex component that requires control at various points and times during its operation. Furthermore, the hydride compressor unit interacts with other components of the energy system, such as the electrolysis unit. During operation, the hydride compressor unit generates waste heat that can be used for other components and subprocesses within the energy system. Therefore, the hydride compressor unit also interacts with such components. This interaction has already been described in connection with the energy system according to the first aspect of the invention, and reference is made here to the corresponding explanations above.

[0099] The control of the at least one hydride compressor unit, as well as the control of the various components of the energy system, is preferably carried out via a control unit. For this purpose, the control unit includes an energy management unit. The control unit and / or energy management unit are configured to control at least individual components of the energy system. Both components are also described in connection with the energy system according to the first aspect of the invention, so reference is made here to the corresponding descriptions above. In particular, the energy management unit is provided as a device for intelligent, predictive energy management, which is described in more detail below.

[0100] According to one embodiment, the method is further characterized by the following steps, in particular those carried out by the energy management device: a) Defining operating parameters for the energy system component to be controlled. "Defining" in this context means, in particular, that the operating parameters are generated, determined, prescribed, calculated, and the like. An "operating parameter" is, in particular, a factor or boundary condition that influences the operation and function of a component of the energy system or the entire energy system. This includes, for example, the load profile and / or the state of charge of the components, the operating behavior of the components, the operating conditions, and the like. The operating conditions are characterized, in particular, by the numerical values ​​of the individual quantities that occur at a specific operating state of a component or the energy system. These quantities can change during operation. The operating parameters can be generated either in the control unit and / or in the energy management unit.Or they can be received as specifications from the control unit and / or the energy management unit. b) Generating a control signal based on the defined operating parameters and transmitting the control signal to the component to be controlled. This is preferably done via a suitable signal connection between the control unit and / or the energy management unit and the component to be controlled. c) Controlling the component based on the control signal received by the component.

[0101] A number of exemplary implementations are described below.

[0102] According to one embodiment, the determination of operating parameters for the component of the energy system to be controlled is based on determined, specified, or predicted data that are generated in the energy management device, and / or received by the energy management device, and / or stored in the energy management device.

[0103] According to one embodiment, the operating parameters for the component to be controlled are determined over a defined observation period, which is either determined or specified. This observation period can, for example, be a few hours, until sunset, a day, or several days. The invention is not limited to specific time periods in this respect. Some examples are described below.

[0104] According to one embodiment, the operating parameters for the component to be controlled are determined by identifying, checking, recording, or forecasting in the energy management device an energy surplus from the electrical energy generated by the energy generation device and the electrical energy consumed in the components of the energy system and / or the electrical consumers connected to the energy system, and its course over a defined observation period that is determined or specified.

[0105] According to one embodiment, the operating parameters for the component to be controlled are determined by checking, recording, or predicting the state of charge of the battery device and its course over a defined observation period, which is determined or specified, in the energy management device.

[0106] According to one embodiment, the control unit and / or the energy management unit calculates a usable capacity of the battery system, particularly a predicted one, taking into account a predicted energy surplus of the energy generation device and a predicted total energy consumption of the energy system and / or the energy consumption of those components connected to and supplied with energy via the energy system, over a predetermined period, particularly predictively and / or continuously. As a result, according to one embodiment, control signals are generated for the component to be controlled and transmitted to it.

[0107] The aforementioned measures can be carried out either individually or in any combination.

[0108] The following is a concrete example to illustrate the connections.

[0109] According to one embodiment, the usable capacity of the energy system's battery is calculated predictively over a defined period, for example, at least two days, particularly on a rolling basis, taking into account the expected PV energy and the expected total energy consumption of the electrical loads supplied by the energy system and / or the energy system itself. This calculation is performed in the control unit and / or the energy management unit. As a result, control signals are generated and transmitted to the electrolysis unit and / or the at least one hydride compressor unit.For example, the operating time of the electrolysis unit can be adjusted, for instance, increased so that the regeneration of at least one hydride compressor unit and the operating time of the electrolysis unit can continue partially in the evening or after sunset without compromising the energy system's self-sufficiency. In this case, electrical energy is drawn from the battery. This also includes, in particular, starting the electrolysis process with a significant energy component from the battery before a PV energy surplus is expected and / or before the battery has reached a high state of charge again.

[0110] It is also very energy-efficient to desorb / regenerate a hydride compressor unit, whose capacity is designed to absorb a large amount of hydrogen, corresponding to a sunny summer day with more than 12 hours of sunshine, only every 2nd or 3rd day on days with limited solar energy, for example preferably from February to April and September to November.

[0111] According to one embodiment, the energy system comprises only a single hydride compressor unit. As already described in connection with the energy system according to the first aspect of the invention, this places special demands on the control of the energy system, particularly on the energy management, for example, in terms of minimizing energy consumption for the regeneration of the hydride compressor unit.

[0112] According to another embodiment, the energy system comprises two or more hydride compressor units. As already described in connection with the energy system according to the first aspect of the invention, this also places special demands on the control of the energy system, in particular on the energy management, for example so that the same or a larger quantity of hydrogen can be compressed daily with minimal use of expensive metal hydride material and increased use of direct PV surplus energy.

[0113] According to one embodiment, the control unit and / or the energy management unit control both the operation of the electrolysis unit and the compression and regeneration phase of the hydride compressor unit(s) with all available parameters.

[0114] The following are some examples of suitable control systems.

[0115] According to one embodiment, over a defined observation period, for example over two to three days, a budget of the expected solar energy yield, the expected consumer-side energy demand and the state of charge of the battery system is calculated in the control unit and / or in the energy management unit.

[0116] Furthermore, according to one embodiment, current, local weather data is received and taken into account in the control unit and / or in the energy generation unit. Based on such current, local weather data, predicted data, such as sunshine duration, solar energy input, and outdoor temperature profile over time, are generated and / or queried in the control unit and / or in the energy management unit.

[0117] According to one embodiment, the aforementioned data are compared with the storage states of the battery device and the consumer-side energy demand, which can be referred to as the load profile.

[0118] According to one embodiment, budgeting is carried out over the defined observation period. For example, budgeting is performed at least daily and also considers a further period, for example, at least the following two to three days, including the current day. This is done on a rolling basis. Further parameters for budgeting include the size and type of any existing second hydrogen storage facility in the form of an intermediate storage unit, as well as its operating characteristics.

[0119] On consecutive days with high solar energy yield, the regeneration steps of the hydride compressor unit(s) and, if necessary, even the operating time of the electrolysis unit can be postponed to a later time, for example, to the evening and night hours. Excessive discharge of the battery system, and thus a temporary loss of the energy system's operational readiness, can be avoided thanks to budgeting and the predictive data used in the energy management system.

[0120] According to one embodiment, based on the determined, specified or predicted data, the hydride compressor unit(s) are controlled by the control unit and / or the energy management unit in such a way that the time and sequence of switching on and loading of the at least one hydride compressor unit are determined.

[0121] According to one embodiment, based on the determined, specified, or predicted data, the hydride compressor unit(s) are controlled by the control unit and / or the energy management unit in such a way as to determine whether two or more hydride compressor units are charged simultaneously when the energy system has two or more hydride compressor units.

[0122] According to one embodiment, based on the determined, specified, or predicted data, the control unit and / or the energy management unit controls the hydride compressor unit(s) in such a way that the start time of the hydride compressor unit regeneration is determined for each hydride compressor unit, and the regeneration / heating process is controlled. If one of the hydride compressor units is equipped with metal hydrides with different physical properties, this is also taken into account in the control of the hydride compressor units.

[0123] For example, the control unit, in particular the energy management unit, controls and / or checks whether the hydride compressor unit(s) is / are ready to accept hydrogen. This is done, for example, by measuring or determining the operating temperature and pressure, optionally also supported by determining the state of charge.

[0124] For example, the control unit, in particular the energy management unit, controls and / or checks the regeneration of the hydride compressor unit after each loading, even in the case of only partial loading, in particular with the aim of minimizing the load on the battery unit.

[0125] For example, the control unit, in particular the energy management unit, controls and / or checks a postponement of the regeneration of a hydride compressor unit to a later time, for example to the following day.

[0126] According to one embodiment, waste heat is extracted from at least one hydride compressor unit via a waste heat extraction system and made available for heat exchange with another component of the energy system, in particular another hydride compressor unit and / or the ventilation unit and / or the heat pump unit and / or the dryer unit and / or the fuel cell unit.

[0127] In particular, this enables the use of waste heat during the cooling phase of the at least one hydride compressor unit after desorption. For example, the heated cooling air from the blower unit can be used to heat other components of the energy system during the cooling phase of the hydride compressor unit(s). Examples of this are already described above in connection with the energy system according to the invention.

[0128] According to one embodiment, the electrolysis device and / or the battery device and / or the first storage device and / or the second storage device and / or the at least one hydride compressor device and / or the fuel cell device and / or the heat pump device and / or the waste heat dissipation of the compressor device and / or the dryer device and / or the pressure holding valve and / or the recombinator device and / or the ventilation device and / or a hot water generation device are controlled via the control signals generated by the control device and / or the energy management device.

[0129] Some application examples are given below.

[0130] For example, the control signals generated by the control unit and / or the energy management unit control: when electrolysis is started; the power output of the electrolysis unit during the entire charging process of the at least one hydride compressor unit; when the electrolysis unit is stopped; whether regeneration of the at least one hydride compressor unit is carried out on the same day; the temperature and duration of the desorption phase of the at least one hydride compressor unit; when hydrogen is stored in and released from a second storage unit; in the case of several hydride compressor units with different dimensions and / or with metal hydrides with different physical properties, which hydride compressor unit is started first – the larger or the smaller one; and whether another hydride compressor unit is started at all.How long a hydride compressor unit is charged; in the case of multiple hydride compressor units, when the next hydride compressor unit is started; how long and at what temperature desorption takes place; when the electrolysis unit is switched on and off; what power the electrolysis unit operates at to optimize hydrogen harvesting and compression; whether and to what extent, especially at high ambient temperatures and when at least one hydride compressor unit has already reached a higher charge level, the power of the electrolysis unit is reduced to introduce even more hydrogen into the hydride compressor unit for the current charging cycle.

[0131] According to the third aspect of the invention, a computer program product is provided which has the features of independent claim 17.

[0132] The computer program product comprises instructions that, when executed by a computer system, cause it to perform the steps of the method according to the second aspect of the invention. In this regard, explicit reference is made here to the corresponding explanations relating to the first and second aspects of the invention, as well as to the general description of the invention. The computer system is, in particular, a component of, or interacts with, the control unit or the energy management unit. The computer program product is, in particular, software or an algorithm that can be loaded into a computer system, for example, its memory, transmitted over a network, or distributed on a data carrier.The computer program product causes the control unit, in particular the power management unit, to initiate and / or execute an action based on commands.

[0133] The present invention, in accordance with the aforementioned aspects, offers a number of advantages. For example, more hydrogen can be produced and compressed annually using smaller and potentially more cost-effective compressor systems. Furthermore, over the course of a year, this results in a significantly reduced energy input per unit of hydrogen and improved heat utilization. If the device for generating electrical energy is a photovoltaic system, significantly better use of directly available solar energy for electrolysis and compression can be achieved.

[0134] When two or more hydride compressor units are used, the modular system allows for a wide range of customer requirements to be met with only a few different sizes of individual compressor units.

[0135] The invention will now be explained in more detail with reference to various exemplary embodiments and the accompanying drawings. These show... Fig. 1 in schematic view a basic sketch of an energy system according to the invention; Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6 different embodiments of a first design variant of the energy system; and Fig. 7, Fig. 8 to Fig. 9 different examples of a second embodiment of the energy system.

[0136] The figures depict various embodiments and implementation variants of an energy system. These embodiments share some similarities, with identical components being assigned identical reference numerals. Therefore, a component with a specific reference numeral described in connection with one figure is also considered to be fully described in connection with the other figures and embodiments, even if it is not explicitly mentioned in the descriptions there.

[0137] In Fig. 1. First, the basic structure of the energy system 2, in which the present invention is implemented, is briefly described. The energy system 2 is provided in a building 1. The energy system 2 has a first subsystem 10, which is designed as an indoor system and is located within the building 1. The first subsystem 10 has a number of system components. In Fig. Figure 1 shows, by way of example, a battery system 12 and an electrolysis system 13. Furthermore, the energy system 2 has a second subsystem 20, which is designed as an external system and is located outside the building 1. For the generation of electrical energy, the energy system 2 has a device 3 for generating electrical energy, which in the example shown is designed as a photovoltaic system 3a. The aforementioned components of the energy system 2 are connected to electrical consumers 4a located in the building 1 via an electrical system 4. The basic operating principle of the energy system 2 is as follows: Energy system 2 converts the direct current from the photovoltaic system 3a into alternating current, which powers the electrical consumers 4a. The electrical energy that is not used directly is stored in the battery system 12. Once the battery is full, the electrolysis system 13 uses the remaining excess energy to produce hydrogen and stores it, particularly for winter use, in the second subsystem 20.

[0138] In a particularly preferred configuration, the primary objective is to supply all electrical energy consumers in the building throughout the year, utilizing renewable energy sources and minimizing reliance on electricity drawn from the grid. Feeding surplus electricity into the external grid is permitted, but should be minimized in favor of internal consumption.

[0139] On cloudy days, during twilight and at night, the electrical consumers 4a are powered by electrical energy from the battery system 12. On sunny days, and especially in summer, the photovoltaic system 3a generates more electrical energy than is consumed in building 1. This surplus energy is used to produce hydrogen by means of the electrolysis system 13 and to store this hydrogen in a preferably seasonal storage facility located in the second subsystem 20.

[0140] Especially during the winter months, when the days are shorter and the sun is much less strong than in summer, and when the photovoltaic system 3a may be covered in snow, the hydrogen storage comes into play. Since the battery system 12 can no longer be charged solely by solar power, it draws on the hydrogen produced and stored during the summer. This hydrogen is then used to generate electrical energy, compensating for the lack of solar radiation. This is done via a fuel cell system in energy system 2. The fuel cell system generates electrical energy from the hydrogen.

[0141] The aforementioned processes generate waste heat at various points, which can be used additionally, for example for heating rooms, heating water, and the like.

[0142] To make energy system 2 as efficient as possible, the individual system components must be coordinated so that they can be used optimally. The interaction of the individual components is anything but trivial and therefore requires sophisticated energy management.

[0143] This will be explained below using the following examples. Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8 to Fig. 9 describes a series of exemplary implementations.

[0144] The in the Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8 to Fig. The 9 energy systems shown each represent a sub-area of ​​a total building energy system, which is an electrically self-sufficient and entirely renewable energy-based multi-hybrid building energy storage system, and which is very greatly simplified in Fig. 1 is shown.

[0145] The multi-hybrid building energy storage system makes it possible to distribute the electrical energy generated by a photovoltaic (PV) system, a small wind turbine, or similar devices throughout the year, according to demand. The system operates virtually as an off-grid system, largely independent of the electrical grid. Rather, the system is designed to ensure the building's electrical self-sufficiency, so that little or no electrical energy needs to be drawn from the grid throughout the year.

[0146] The primary task of a building energy system is to make the electrical energy generated by photovoltaic (PV) modules or similar systems available to the building's consumers. Secondarily, excess electrical energy can be temporarily stored in a battery during periods of low demand or high solar irradiance. Tertiarily, the electrical energy can be stored as gaseous hydrogen in a hydrogen long-term storage system for periods of low solar irradiance, such as at night or in winter, and then made available again as needed via a fuel cell. Finally, excess energy can also be fed into the electricity grid.

[0147] In addition to energy-related tasks, the system also functions as controlled residential ventilation through an integrated ventilation unit.

[0148] The hydrogen produced in the electrolysis unit flows via the hydrogen line into the externally located pressure storage system.

[0149] If there is no or insufficient PV energy, energy is drawn from the battery to cover the consumer load. If the energy stored in the short-term storage unit is insufficient, the fuel cell system can cover the additional electrical energy demand. During fuel cell operation, hydrogen flows from the pressure storage system to the fuel cell system via the hydrogen line.

[0150] The entire system is centrally operated via an Energy Manager with predictive energy management.

[0151] The second subsystem is primarily intended for outdoor operation, but under certain conditions it can also be installed and operated wholly or partially within a specific area of ​​the house.

[0152] In the Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. Figure 6 initially shows a first implementation variant for energy system 2, where the Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. Six different embodiments of this first embodiment variant are shown.

[0153] The basic structure of energy system 2 according to the first design variant is in Fig. 2 shown. Fig. Figure 2 shows the design of a basic system. As can be seen from... Fig. As can be seen in Figure 2, energy system 2 has a first subsystem 10, which is designed as an internal system. In the case of the Fig. In the embodiment shown in Figure 2, only a single sub-subsystem 10a of subsystem 10 is implemented. The first subsystem 10 is located inside the building. In the example shown, the individual components of the first subsystem 10 are housed in a system cabinet 11. Additionally, energy system 2 has a second subsystem 20 in the form of an external system. This means that the second subsystem 20 is located outside the building. Both systems are connected via electrical and hydraulic lines in the form of a connecting line assembly 50, as well as via a common, higher-level control system, which includes a control unit 60 or is configured as such.

[0154] For the generation of electrical energy, a device 3 for the generation of electrical energy in the form of a photovoltaic system 3a is provided.

[0155] The first subsystem 10 includes a battery unit 12, which functions as a short-term storage device and in which electrical energy generated by the electrical energy generation device 3 is at least partially stored. Furthermore, the first subsystem 10 includes an electrolysis unit 13 for the production of hydrogen. For operation, the electrolysis unit 13 is supplied with electrical energy from the electrical energy generation device 3 and / or from the battery unit 12 via a supply 52. ​​The first subsystem 10 also includes a fuel cell unit 18. The first subsystem 10 is connected to the building and the electrical energy generation device via an electrical system, a ventilation system, and optionally via hydraulic heat extraction.

[0156] The second subsystem 20 has a first storage device 21 in the form of a high-pressure storage device. In the first storage device 21, the hydrogen produced in the electrolysis device 13 is stored at high pressures of, for example, 300 bar up to 700 bar.

[0157] The individual components of the energy system 2 are connected to each other via the connecting line device 50, which consists of a number of different line sections.

[0158] In a first operating mode of the energy system 2, the hydrogen produced in the electrolysis unit 13 leaves the electrolysis unit 13 in the flow direction 50a via a section of the connecting line assembly 50, in which, in the flow direction of the produced hydrogen, for example, a recombinator unit 14, followed by a dryer unit 15, and optionally a pressure-maintaining valve unit 16 are located. These components are explained in detail above in the general description of the invention, so reference is made here to the corresponding descriptions above. The electrolysis section can be isolated from the rest of the energy system 2, if necessary, by means of a valve assembly 17a, which is designed in the form of a shut-off valve assembly.

[0159] From the optional pressure-holding valve device 16, the generated hydrogen flows in the flow direction 50a via further pipe sections of the connecting pipe device 50 into the second subsystem 20.

[0160] The generated hydrogen flows via a valve assembly 23a, designed as a shut-off valve assembly, in a first direction of a bidirectional flow direction 51a, via a valve assembly 23b, also designed as a shut-off valve assembly, into a compressor assembly 30, which is designed as a hydride compressor assembly 31, here a metal hydride compressor assembly. In this first embodiment, only a single compressor assembly is provided. The hydride compressor assembly 31 has a number of parallel receiving containers 32a, 32b, 32c, each containing a hydride material 33, here a metal hydride material. In the illustrated embodiment, three such receiving containers are shown, although the invention is naturally not limited to a specific number of receiving containers. A valve assembly 36 in the form of a slide valve assembly serves for installation and service purposes.The charging / discharging of the hydride compressor unit 31 can be controlled via valve assembly 23b. A third valve assembly 23c, in the form of a shut-off valve assembly, completes the valve group. The valve assemblies are designed, for example, as solenoid valve assemblies. Other valve types with a similar function can, of course, also be implemented. This applies in particular to all valve assemblies of the energy system 2. During operation, the hydride compressor unit 31 is connected to the hydrogen-carrying connecting line assembly 50, which comes from the electrolysis unit 13, via valve assembly 23b for charging and discharging the hydride compressor unit 31. In this case, valve assemblies 23a and 23b are open, and valve assembly 23c is closed. The hydrogen is stored in the receiving containers 32a, 32b, and 32c.For regeneration, the hydride compressor unit 31 is switched off by actuating the valve unit 23a. An electric heating unit 34 is provided for the heating and subsequent desorption process. The heating unit 34 obtains the electrical energy required for its operation via a supply 53a from the electrical energy generation device 3 and / or from the battery unit 12. A blower unit 35 serves to improve convective heat transfer during indirect heating via circulating air and for subsequent cooling of the hydride compressor unit 31. Cooling air can be supplied to the hydride compressor unit 31 via an air supply 54a as needed. The waste heat generated during the operation of the hydride compressor unit 31 can be used for further processes and is dissipated via a waste heat exhaust 55a.The operating principle of the hydride compressor device 31 is explained in detail above in the general description of the invention, so reference is made here to the corresponding explanations above.

[0161] After the hydrogen has been compressed in the hydride compressor unit 31 during the heating process, the compressed hydrogen leaves the hydride compressor unit 31 in the immediately following desorption phase via the connecting line unit 50 in a second direction of the bidirectional flow direction 51a and flows in flow direction 50b via the now also open valve unit 23c in a first direction of a bidirectional flow direction 51b to the first storage unit 21, into which the hydrogen is stored at the increased pressure of up to 700 bar. For this purpose, a valve unit 23d in the form of a shut-off valve unit is assigned to the first storage unit 21, which is opened for the duration of the storage process.

[0162] The hydrogen stored in the first storage unit 21 is used to operate the fuel cell unit 18. The fuel cell unit 18 operates in a second operating mode of the energy system 2. In this second operating mode, the hydrogen is drawn from the first storage unit 21, passed in a second direction of the bidirectional flow direction 51b through the valve unit 23d and the connecting line unit 50, and depressurized via a pressure reducer 24 (with an optional upstream valve unit, not shown) before entering the fuel cell unit 18 via the connecting line unit 50 in the flow direction 50c. The pressure reducer 24 serves to reduce the pressure of the hydrogen to a level suitable for fuel cell operation.An optional buffer storage device 19 is located in front of the fuel cell device 18. On the outlet side of the fuel cell device 18, a valve device 17b in the form of a shut-off valve device, which in particular is a purge valve, is located for protection, pressure maintenance and purging purposes.

[0163] Exhaust air or building exhaust air 56a generated during the operation of energy system 2 can be routed through the first subsystem 10 to sufficiently dilute any unwanted hydrogen that might escape through leaks. This exhaust air can then be discharged as building exhaust air 56b.

[0164] A control unit 60 is provided for controlling the energy system 2. This control unit includes at least one energy management unit 61 and a storage unit 62 for storing data. The structure and operation of the control unit and the energy management unit are explained in detail in the general description above, so reference is made here to the corresponding explanations above. The control unit 60 is connected to the electrical energy generation unit 3 via a signal connection 63a, to the battery unit 12 via a signal connection 63b, to the electrolysis unit 13 via a signal connection 63c, to the hydride compressor unit 31 via a signal connection 63d, and to the first storage unit 21 via a signal connection 63e. The operation of the control unit 60 is explained in more detail below. This explanation applies equally to all implementation examples.

[0165] The in Fig. The embodiment shown in 3 differs from the one in Fig. In the embodiment shown in Figure 2, the waste heat from the hydride compressor unit 31 is used to heat a heat pump unit 25 or an air-to-domestic hot water heat exchanger, which is coupled to the building's heating circuit 57. For this purpose, the waste heat from the hydride compressor unit 31 is supplied to the heat pump unit 25 or the air-to-domestic hot water heat exchanger via a waste heat discharge 55b.

[0166] The in Fig. The embodiment shown in section 4 is based on the one described in Fig. 3. It differs from the embodiment shown in Fig. The embodiment shown in Figure 3 is distinguished by the provision of a second storage device 26 for hydrogen in the form of a medium-pressure storage device, which serves for the intermediate storage of the hydrogen. The operation of the second storage device 26 is described in detail above in the general description of the invention, so reference is made here to the corresponding explanations above.

[0167] The second storage unit 26 can be switched on and off as needed via a valve assembly 23e in the form of a shut-off valve assembly. The hydrogen coming from the electrolysis unit 13 and / or the hydride compressor assembly 31 can be stored in and released from the second storage unit 26 in a bidirectional flow direction 51c via the connecting line assembly 50 and the valve assembly 23e. Since the hydrogen in the second storage unit 26 is stored at a significantly lower pressure compared to the first storage unit 21, the hydrogen stored in the second storage unit 26 is used either to feed into the fuel cell assembly 18 or, if required, in a bidirectional flow direction 51d into the hydride storage unit 31. The second storage unit 26 is connected to the control unit 60 via a signal connection 63f.

[0168] Fig. Figure 5 shows an embodiment of the energy system 2 according to Fig. 4, wherein the internal system 10, in addition to the first sub-subsystem 10a described above, also has a second sub-subsystem 10b. The hydride compressor unit 31 with its associated components and elements is located in the second sub-subsystem 10b. Although the example shown depicts two sub-subsystems 10a and 10b, these two sub-subsystems 10a and 10b can, of course, also be combined into a single, common subsystem 10. In the Fig. In the embodiment shown in Figure 5, the hydride compressor unit 31 is no longer part of the outdoor system, but rather a component of the indoor system. This has several advantages. For example, the hot exhaust air from the hydride compressor unit 31 can be used for thermal purposes. A portion of the hot exhaust air can be supplied to the building via the waste heat extraction system 55a, for instance to a ventilation system, or to a system as described in Figure 5. Fig. 4. The heat pump unit shown or an air-to-domestic hot water heat exchanger. The latter two components are included in the [unclear text]. Fig. Although not explicitly shown in the embodiment illustrated in Figure 5, the waste heat extraction system can be connected to the waste heat extraction system 55a. The waste heat from the hydride compressor unit 31 can also be used to heat the dryer unit 15, thereby regenerating the dryer unit 15. For this purpose, the waste heat from the hydride compressor unit 31 is supplied to the dryer unit 15 via a waste heat extraction system 55c.

[0169] Fig. Figure 6 finally shows an embodiment of the energy system 2 according to Fig. 4, wherein the indoor system 10, in addition to the first sub-subsystem 10a described above, has a second sub-subsystem 10b. The hydride compressor unit 31 with its associated components and elements, as well as the heat pump unit 25 or the air-to-domestic hot water heat exchanger, are located in the second sub-subsystem 10b. Although two sub-subsystems 10a and 10b are shown in the illustrated example, these two sub-subsystems 10a and 10b can, of course, be combined into a single, common subsystem 10. Building exhaust air 56c can be used for the blower unit 35.

[0170] In the Fig. 7, Fig. 8 to Fig. Figure 9 shows a second implementation variant for energy system 2, where the Fig. 7, Fig. 8 to Fig. Nine different embodiments of this second design variant are presented.

[0171] The basic structure of energy system 2 according to the second design variant is in Fig. 7 shown. Fig. Figure 7 shows the design of a basic system. As can be seen from... Fig. As can be seen in Figure 7, energy system 2 has a first subsystem 10, which is designed as an internal system. In the Fig. In the embodiment shown in Figure 7, only a single sub-subsystem 10a of subsystem 10 is implemented. The first subsystem 10 is located inside the building. In the example shown, the individual components of the first subsystem 10 are housed in a system cabinet 11. Additionally, the energy system 2 has a second subsystem 20 in the form of an external system. This means that the second subsystem 20 is located outside the building. Both systems are connected via electrical and hydraulic lines in the form of a connecting line assembly 50, as well as via a common, higher-level control system, which includes a control unit 60 or is configured as such.

[0172] For the generation of electrical energy, a device 3 for the generation of electrical energy in the form of a photovoltaic system 3a is provided.

[0173] The first subsystem 10 includes a battery unit 12, which functions as a short-term storage device and stores electrical energy generated by the electrical energy generation device 3. Furthermore, the first subsystem 10 includes an electrolysis unit 13 for hydrogen production. For operation, the electrolysis unit 13 is supplied with electrical energy from the electrical energy generation device 3 and / or from the battery unit 12 via a supply 52. ​​The first subsystem 10 also includes a fuel cell unit 18. The first subsystem 10 is connected to the building and the electrical energy generation device via an electrical system, a ventilation system, and optionally via hydraulic heat extraction.

[0174] The second subsystem 20 has a first storage device 21 in the form of a high-pressure storage device. In the first storage device 21, the hydrogen produced in the electrolysis device 13 is stored at high pressures of, for example, 300 bar up to 700 bar.

[0175] The individual components of the energy system 2 are connected to each other via the connecting line device 50, which consists of a number of different line sections.

[0176] In a first operating mode of the energy system 2, the hydrogen produced in the electrolysis unit 13 leaves the electrolysis unit 13 in the flow direction 50a via a section of the connecting line assembly 50, in which, in the flow direction of the produced hydrogen, for example, a recombinator unit 14, followed by a dryer unit 15, and optionally a pressure-maintaining valve unit 16 are located. These components are explained in detail above in the general description of the invention, so reference is made here to the corresponding descriptions above. The electrolysis section can be isolated from the rest of the energy system 2, if necessary, by means of a valve assembly 17a, which is designed in the form of a shut-off valve assembly.

[0177] From the optional pressure-holding valve device 16, the generated hydrogen flows in the flow direction 50a via further pipe sections of the connecting pipe device 50 into the second subsystem 20.

[0178] The generated hydrogen then enters either a first compressor unit 30 and / or optionally a second compressor unit 40. In a preferred embodiment, the first compressor unit 30 and the second compressor unit 40 are of different dimensions, but they can also be the same. In another embodiment, the two compressor units can optionally be equipped with metal hydrides with different operating characteristics. In one embodiment, the capacity of the first compressor unit is 100% to 250% of that of the second compressor unit 40. In this exemplary embodiment, the energy system has two compressor units, although, of course, more than two compressor units can also be implemented.

[0179] In an operating state of the energy system, the generated hydrogen flows via a valve assembly 23a, configured as a shut-off valve assembly, in a first direction of a bidirectional flow direction 51a via a valve assembly 23b, also configured as a shut-off valve assembly, into the compressor assembly 30, which is configured as a hydride compressor assembly 31, here a metal hydride compressor assembly. The hydride compressor assembly 31 has a number of parallel receiving containers 32a, 32b, 32c, each containing a hydride material 33, here a metal hydride material. In the illustrated embodiment, three such receiving containers are shown, although the invention is naturally not limited to a specific number of receiving containers. A valve assembly 36 in the form of a slide valve assembly serves for installation and service purposes.The charging / discharging of the hydride compressor unit 31 can be controlled via valve assembly 23b. A third, optional valve assembly 23c, in the form of a shut-off valve assembly, completes the valve group. The valve assemblies are designed, for example, as solenoid valve assemblies. Other valve types with a similar function can, of course, also be implemented. This applies in particular to all valve assemblies of the energy system 2. During operation, the hydride compressor unit 31 is connected to the hydrogen-carrying connecting line assembly 50, which comes from the electrolysis unit 13, via valve assembly 23b for charging and discharging the hydride compressor unit 31. In this case, valve assemblies 23a and 23b are open, and valve assembly 23c is closed. The hydrogen is stored in the receiving containers 32a, 32b, and 32c.For regeneration, the hydride compressor unit 31 is switched off by actuating the valve unit 23a. An electric heating unit 34 is provided for the heating and subsequent desorption process. The heating unit 34 obtains the electrical energy required for its operation via a supply 53a from the electrical energy generation device 3 and / or from the battery unit 12. A blower unit 35 serves to improve convective heat transfer during indirect heating via circulating air and for subsequent cooling of the hydride compressor unit 31. Cooling air can be supplied to the hydride compressor unit 31 via an air supply 54a as needed. The waste heat generated during the operation of the hydride compressor unit 31 can be used for further processes and is dissipated via a waste heat exhaust 55a.The operating principle of the hydride compressor device 31 is explained in detail above in the general description of the invention, so reference is made here to the corresponding explanations above.

[0180] After the hydrogen has been compressed in the hydride compressor unit 31 during the heating process, the compressed hydrogen leaves the hydride compressor unit 31 in the immediately following desorption phase via the connecting line unit 50 in a second direction of the bidirectional flow direction 51a and flows in flow direction 50b via the now also open valve unit 23c in a first direction of a bidirectional flow direction 51b to the first storage unit 21, into which the hydrogen is stored at the increased pressure of up to 700 bar. For this purpose, a valve unit 23d in the form of a shut-off valve unit is assigned to the first storage unit 21, which is opened for the duration of the storage process.

[0181] In another operating state of the energy system, the generated hydrogen flows via a valve assembly 23f, designed as a shut-off valve assembly, in a first direction of a bidirectional flow direction 51e via a valve assembly 23g, also designed as a shut-off valve assembly, into the compressor assembly 40, which is likewise designed as a hydride compressor assembly 41, here as a metal hydride compressor assembly. The hydride compressor assembly 41 also has a number of parallel receiving containers 42a, 42b, 42c, each containing a hydride material 43, here a metal hydride material. In the illustrated embodiment, three such receiving containers are shown, although the invention is naturally not limited to a specific number of receiving containers. A valve assembly 46 in the form of a slide valve assembly serves for installation and service purposes.The charging / discharging of the hydride compressor unit 41 can be controlled via valve assembly 23g. A third optional valve assembly 23h, in the form of a shut-off valve assembly, completes the valve group. The valve assemblies are designed, for example, as solenoid valve assemblies. Other valve types with similar functions can, of course, also be implemented. This applies in particular to all valve assemblies of the energy system 2. During operation, the hydride compressor unit 41 is connected to the hydrogen-carrying connecting line assembly 50, which comes from the electrolysis unit 13, via valve assembly 23g for charging and discharging the hydride compressor unit 41. In this case, valve assemblies 23f and 23g are open, and valve assembly 23h is closed. The hydrogen is stored in the receiving containers 42a, 42b, and 42c.For regeneration, the hydride compressor unit 41 is switched off by actuating the valve unit 23f. An electric heating unit 44 is provided for the heating and subsequent desorption process. The heating unit 44 obtains the electrical energy required for its operation via a supply 53b from the electrical energy generation device 3 and / or from the battery unit 12. A blower unit 45 serves to improve convective heat transfer during indirect heating via circulating air and for subsequent cooling of the hydride compressor unit 41. Cooling air can be supplied to the hydride compressor unit 41 via an air supply 54b as needed. The waste heat generated during the operation of the hydride compressor unit 41 can be used for further processes and is dissipated via a waste heat exhaust 55d.The operation of the hydride compressor device 41 corresponds to the operation of the hydride compressor device 31 and is explained in detail above in the general description of the invention, so that reference is made here to the corresponding explanations above.

[0182] After the hydrogen has been compressed in the hydride compressor unit 41 during the heating process, the compressed hydrogen leaves the hydride compressor unit 41 in the immediately following desorption phase via the connecting line unit 50 in a second direction of the bidirectional flow direction 51e and flows in flow direction 50d via the now also open valve unit 23h in a first direction of a bidirectional flow direction 51b to the first storage unit 21, into which the hydrogen is stored at the increased pressure of up to 700 bar. The valve unit 23d is assigned to the first storage unit 21 for this purpose.

[0183] The two hydride compressor devices 31, 41 can be used alternately or simultaneously, depending on the operating mode of the energy system 2. Examples of this are explained above in the general description of the invention.

[0184] The hydrogen stored in the first storage unit 21 is used to operate the fuel cell unit 18. The fuel cell unit 18 operates in a second operating mode of the energy system 2. In this second operating mode, the hydrogen is drawn from the first storage unit 21, passed in a second direction of the bidirectional flow 51b through the valve unit 23d and the connecting line unit 50, and, with an optional upstream valve unit (not shown), is depressurized via a pressure reducer 24 before entering the fuel cell unit 18 via the connecting line unit 50 in the flow direction 50c. The pressure reducer 24 serves to reduce the pressure of the hydrogen to a level suitable for fuel cell operation.An optional buffer storage device 19 is located in front of the fuel cell device 18. On the outlet side of the fuel cell device 18, a valve device 17b in the form of a shut-off valve device, which in particular is a purge valve, is located for protection, pressure maintenance and purging purposes.

[0185] Exhaust air or building exhaust air 56a generated during the operation of energy system 2 can be routed through the first subsystem 10 to sufficiently dilute any unwanted hydrogen that might escape through leaks. This exhaust air can then be discharged as building exhaust air 56b.

[0186] A control unit 60 is provided for controlling the energy system 2. This control unit includes at least one energy management unit 61 and a storage unit 62 for storing data. The structure and operation of the control unit and the energy management unit are explained in detail in the general description above, so reference is made here to the corresponding explanations above. The control unit 60 is connected via a signal connection 63a to the electrical energy generation unit 3, via a signal connection 63b to the battery unit 12, via a signal connection 63c to the electrolysis unit 13, via a signal connection 63d to the hydride compressor unit 31 of the first compressor unit 30, via a signal connection 63e to the first storage unit, and via a signal connection 63g to the hydride compressor unit 41 of the second compressor unit 40.

[0187] The in Fig. The embodiment shown in section 8 differs from the one in Fig. In the embodiment shown in Figure 7, the waste heat from the hydride compressor unit 31 of the first compressor unit 30 and the waste heat from the hydride compressor unit 41 of the second compressor unit 40 are used to heat a heat pump unit 25 or an air-to-water heat exchanger, which is coupled to the heating circuit 57 of the building. For this purpose, the waste heat from the first hydride compressor unit 31 is supplied to the heat pump unit 25 or the heat exchanger via a waste heat discharge 55b, and the waste heat from the second hydride compressor unit 41 is supplied to the heat pump unit 25 or the heat exchanger via a waste heat discharge 55e.

[0188] Furthermore, the in Fig. Figure 8 illustrates a second storage device 26 for hydrogen in the form of a medium-pressure storage device, which serves for the intermediate storage of the hydrogen. The operation of the second storage device 26 is described in detail above in the general description of the invention, so reference is made here to the corresponding explanations above.

[0189] The second storage unit 26 can be switched on and off as needed via a valve assembly 23e in the form of a shut-off valve assembly. The hydrogen coming from the electrolysis unit 13 and / or the first hydride compressor assembly 31 and / or the second hydride compressor assembly 41 can be stored in and released from the second storage unit 26 in a bidirectional flow direction 51c via the connecting line assembly 50 and the valve assembly 23e.Since the hydrogen in the second storage unit 26 is stored at a significantly lower pressure compared to the first storage unit 21, the hydrogen stored in the second storage unit 26 is used either to feed into the fuel cell unit 18, or, if required, in a bidirectional flow direction 51d into the first hydride compressor unit 31 and / or in a bidirectional flow direction 51f into the second hydride compressor unit 41. The second storage unit 26 is connected to the control unit 60 via a signal connection 63f.

[0190] At the in Fig. 9 illustrated embodiment, which is based on the Fig. Based on the embodiment shown in Figure 8, the internal system 10 comprises, in addition to the first sub-subsystem 10a described above, a second sub-subsystem 10b. The hydride compressor unit 31 and the hydrocompressor unit 41, with their associated components and elements, are located in the second sub-subsystem 10b. Although two sub-subsystems 10a and 10b are shown in the illustrated example, these two sub-subsystems 10a and 10b can, of course, also be combined into a single, common subsystem 10. In the example shown in Figure 8, the sub-subsystems 10a and 10b are combined into a single, common subsystem 10. Fig.In the embodiment shown in Figure 9, the hydride compressor units 31 and 41 are no longer part of the external system, but rather part of the internal system. This offers several advantages. For example, the hot exhaust air from the first hydride compressor unit 31, and optionally also from the second hydride compressor unit 41, can be used for thermal purposes. For instance, the waste heat from the hydride compressor unit 31 can be used to heat the dryer unit 15, thereby regenerating the dryer unit 15. For this purpose, the waste heat from the hydride compressor unit 31 is supplied to the dryer unit 15 via a heat exhaust duct 55c. The second hydride compressor unit 41 can be used in the same way.

[0191] The function of the control unit 60 with the energy management unit 61, by which the method according to the invention is carried out, will now be described in more detail. The control unit 60 and / or the energy management unit 61 enable, in particular, intelligent, predictive energy management.

[0192] For example, in the energy management unit 61, the usable capacity of the battery unit 12 is calculated over a predetermined period, in particular predictively and / or on a rolling basis, taking into account the energy surplus of the energy generation unit 3 and a forecasted total energy consumption of the energy system 2 and / or an energy consumption of the connected components that are supplied with electrical energy by the energy system 2. As a result, control signals are generated for the component to be controlled and transmitted to it via the signal connections.

[0193] As already explained in the general description, the control unit 60 is connected to individual components of the energy system 2. The control unit 60 controls these components via control signals. For example, individual components are grouped into assemblies. For example, valve devices, particularly in the form of shut-off valves, are assigned to individual components or assemblies. The control unit 60 then controls these valve devices, for example, by opening, partially opening, closing, or partially closing them based on control signals. This allows individual components or assemblies to be switched on or off as needed.

[0194] For example, the following are controlled via the control signals generated by the control unit 60 and / or the energy management unit 61: when the electrolysis is started; the power output of the electrolysis unit 13 during the entire charging process of the at least one hydride compressor unit 31, 41; when the electrolysis unit 13 is stopped; whether regeneration of the at least one hydride compressor unit 31, 41 is carried out on the same day; at what temperature and for how long the desorption phase of the at least one hydride compressor unit 31, 41 is operated; when hydrogen is stored in and removed from a second storage unit 26; in the case of several hydride compressor units 31, 41, in particular with different dimensions and / or filling with different hydride materials, which hydride compressor unit is started first; whether another hydride compressor unit is started at all;How long a hydride compressor unit 31, 41 is charged; In the case of multiple hydride compressor units 31, 41, when the next hydride compressor unit is started; How long and at what temperature desorption takes place; When the electrolysis unit 13 is switched on and off; What power the electrolysis unit 13 operates at to optimize hydrogen harvesting and compression; Whether and to what extent, especially at high ambient temperatures and when a higher loading state has already been reached in at least one hydride compressor unit 31, 41, the power of the electrolysis unit 13 is reduced in order to introduce even more hydrogen into the hydride compressor unit 31, 41 for the current charging cycle.

[0195] In summary, the present invention relates in particular to an energy system 2 and a method for operating it. The energy system 2 comprises: an energy generation device 3 or an interface to an energy generation device 3, which is provided for generating electrical energy and which is in particular configured as a photovoltaic device 3a; a first subsystem 10, comprising an electrolysis device 13, which is provided for generating hydrogen, and a battery device 12, which is provided for the short-term storage and provision of electrical energy; a second subsystem 20, comprising a first storage device 21, in particular a high-pressure storage device, which is provided for storing the hydrogen generated by the electrolysis device 13.To ensure that as many components as possible of the energy system 2 contribute to its extended function and can be optimally controlled and integrated into the energy system 2 via an optimized control system for efficient operation, at least one compressor unit 30, 40, designed as a hydride compressor unit 31, 41, is provided. This compressor unit is designed to compress the generated hydrogen before it is stored in the first storage unit 21. A control unit 60 is provided for controlling the energy system 2. This control unit includes an intelligent, preferably predictive, energy management unit 61. Reference symbol list 1 building 2 Energy system 3 Device for generating electrical energy 3a Photovoltaics (PV) - Setup 4 Electrical System 4a Electrical consumer 10 First subsystem (internal system) 10a First subsystem 10b Second subsystem 11 System cabinet 12 Battery system 13 Electrolysis unit 14 Recombinator device 15 Dryer unit 16 Pressure holding valve device 17a Valve assembly (shut-off valve assembly) 17b Valve assembly (shut-off valve assembly) 18 Fuel cell equipment 19 Buffer storage device 20 Second subsystem (external system) 21 First storage device (high-pressure storage device) 23a Valve assembly (shut-off valve assembly) 23b Valve assembly (shut-off valve assembly) 23c Valve assembly (shut-off valve assembly) 23d Valve assembly (shut-off valve assembly) 23e Valve assembly (shut-off valve assembly) 23f Valve assembly (shut-off valve assembly) 23g valve assembly (shut-off valve assembly) 23h Valve assembly (shut-off valve assembly) 24 Pressure relief device (pressure reducer) 25 Heat pump system 26 Second storage device (medium pressure storage device) 30 Compressor unit (First compressor unit) 31 Hydride compressor unit (metal hydride compressor unit) 32a Receiving container 32b Receiving container 32c Receiving container 33 hydride material (metal hydride material) 34 Heating system 35 Blower unit 36 Valve assembly (gate assembly) 40 Compressor unit (Second compressor unit) 41 Hydride compressor unit (metal hydride compressor unit) 42a Receiving container 42b Receiving container 42c Receiving container 43 hydride material (metal hydride material) 44 Heating system 45 Blower unit 46 Valve assembly (gate assembly) 50 Connecting line device 50a Flow direction of hydrogen (unidirectional) 50b Flow direction of hydrogen (unidirectional) 50c Flow direction hydrogen (unidirectional) 50d Flow direction hydrogen (unidirectional) 51a Flow direction of hydrogen (bidirectional) 51b Flow direction of hydrogen (bidirectional) 51c Flow direction of hydrogen (bidirectional) 51d Flow direction of hydrogen (bidirectional) 51e Flow direction of hydrogen (bidirectional) 51f Flow direction of hydrogen (bidirectional) 52 Supply of electrical energy 53a Supply of electrical energy 53b Supply of electrical energy 54a Air supply 54b Air supply 55a Waste heat removal 55b Waste heat removal 55c Waste heat removal 55d Waste heat removal 55e Waste heat removal 56a Building exhaust air 56b Building exhaust air 56c Building exhaust air 57 Heating circuit (building) 60 Control unit 61 Energy management facility 62 Storage device 63a Signal connection 63b Signal connection 63c Signal connection 63d signal connection 63e Signal connection 63f Signal connection 63g signal connection QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 3 381 102 B1

[0008] WO 2017 / 089468 A1

[0014] WO 2017 / 089469 A1

[0014] EP 3 722 653 A1

[0030]

Claims

[1] Energy system (2), in particular building energy system, comprising an energy generating device (3) or an interface to an energy generating device (3) which is provided for the generation of electrical energy and which is in particular designed as a photovoltaic device (3a), a first subsystem (10), comprising an electrolysis unit (13) provided for the production of hydrogen, and a battery unit (12) provided for the short-term storage and provision of electrical energy, a second subsystem (20), comprising a first storage device (21), in particular a high-pressure storage device, which is provided for storing the hydrogen produced by the electrolysis device (13), characterized by at least one compressor unit (30, 40) designed as a hydride compressor unit (31, 41), which is provided for compressing the generated hydrogen before storage in the first storage unit (21). [2] Energy system according to claim 1, characterized by , that the energy system (2) has a single hydride compressor unit (31). [3] Energy system according to claim 1, characterized by that the energy system (2) has two or more hydride compressor devices (31, 41). [4] Energy system according to claim 3, characterized by , that the hydride compressor devices (31, 41) have different hydride materials. [5] Energy system according to any one of claims 1 to 4, characterized by , that at least one hydride compressor unit (31, 41) is part of the second subsystem (20), or that at least one hydride compressor unit (31, 41) is part of the first subsystem (10). [6] Energy system according to any one of claims 1 to 5, characterized by , that the energy system (2) has at least one or more additional components consisting of: a fuel cell device (18); a heat pump device (25); a second storage device (26), which is in particular designed as a medium-pressure storage device and which is provided for intermediate storage of the produced hydrogen; a dryer device (15) for the produced hydrogen, which is provided downstream of the electrolysis device (13) in the direction of flow (50a) of the produced hydrogen; a pressure-maintaining valve device (16), which is provided downstream of the electrolysis device (13) and the hydride compressor device (31, 41) in the direction of flow (50a) of the produced hydrogen; a recombiner device (14), which is provided downstream of the electrolysis device (13) in the direction of flow (50a) of the produced hydrogen; a ventilation device; a hot water generation device. [7] Energy system according to any one of claims 1 to 6, characterized by, that at least one hydride compressor unit (31, 41) has a waste heat removal system (55a, 55d) which is thermally connected for heat exchange with another hydride compressor unit (41, 31) and / or the ventilation unit and / or the heat pump unit (25) and / or the hot water generation unit and / or the dryer unit (15) and / or the fuel cell unit (18). [8] Energy system according to any one of claims 1 to 7, characterized by , that the energy system (2) has a control unit (60) with an energy management unit (61) which is configured to control at least some of the components of the energy system (2). [9] Energy system according to claim 8, characterized by, that the energy management device (61) is configured to determine operating parameters for the component of the energy system (2) to be controlled based on determined, specified or predicted data that are generated or stored in or received by the energy management device (61) and to control the component on the basis of the operating parameters. [10] Energy system according to claim 9, characterized by, that the energy management device (61) is configured to determine the operating parameters for the component to be controlled, to check, record or predict an energy surplus of the energy generation device (3) from generated electrical energy and consumption of electrical energy and its course in a defined observation period which is determined or specified, and / or to check, record or predict the state of charge of the battery device (12) and its course in a defined observation period which is determined or specified. [11] Energy system according to claim 9 or 10, characterized by, that the energy management device (61) is configured to calculate a predicted usable capacity of the battery device (12) taking into account a predicted energy surplus of the energy generation device (3) and a predicted total energy consumption of the energy system (2) and / or those components which are connected to and supplied with energy via the energy system (2), over a specified observation period, in particular in a forward-looking and / or rolling manner. [12] Energy system according to any one of claims 8 to 11, characterized by, that the energy management device (61) is configured to control the electrolysis device (13) and / or the battery device (12) and / or the at least one hydride compressor device (31, 41) and / or the first storage device (21) and / or the second storage device (26) and / or the fuel cell device (18) and / or the heat pump device (25) and / or the waste heat removal (55a, 55d) of the hydride compressor device (31, 41) and / or the dryer device (15) and / or the pressure holding valve device (16) and / or the recombiner device (14) and / or the ventilation device and / or the hot water generation device. [13] A method for operating an energy system (2) according to any one of claims 1 to 12, in which electrical energy is generated at least temporarily by means of an energy generation device (3), or electrical energy is obtained at least temporarily from an energy generation device (3); at least a part of the electrical energy is temporarily stored in a battery device (12); an electrolysis device (13) is operated at least temporarily with the electrical energy from the energy generation device (3) and / or the battery device (12), in which hydrogen is produced and the hydrogen is stored in a first storage device (21), in particular a high-pressure storage device, characterized by , that the hydrogen is compressed in at least one compressor unit (30, 40) designed as a hydride compressor unit (31, 41) before being stored in the first storage unit (21). [14] Method according to claim 13, wherein the energy system (2) comprises a control unit (60) with an energy management unit (61) configured to control at least individual components of the energy system (2), further characterized by The following steps, in particular those carried out by the energy management entity (61): a) Determining operating parameters for the component of the energy system to be controlled (2); b) Generating a control signal based on the specified operating parameters and transmitting the control signal to the component to be controlled; c) Controlling the component based on the control signal. [15] Method according to one of claims 13 or 14, characterized by, that waste heat is extracted from at least one hydride compressor unit (31, 41) via a waste heat extraction system (55a, 55d) and made available for heat exchange with another component of the energy system (2), in particular another hydride compressor unit (31, 41) and / or the ventilation unit and / or the heat pump unit (25) and / or the dryer unit (15) and / or the hot water generation unit and / or the fuel cell unit (18). [16] Method according to any one of claims 13 to 15, characterized by, that the electrolysis device (13) and / or the battery device (12) and / or the first storage device (21) and / or the second storage device (26) and / or the at least one hydride compressor device (31, 41) and / or the ventilation device and / or the hot water generation device and / or the fuel cell device (18) and / or the heat pump device (25) and / or the waste heat removal (55a, 55d) of the at least one hydride compressor device (31, 41) and / or the dryer device (15) and / or the pressure holding valve device (16) and / or the recombinator device (14) is controlled via the control signals generated by the energy management device (61). [17] Computer program product comprising instructions which, when executed by a computer device, cause the computer program product to perform the steps of the method according to any one of claims 13 to 16.

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