World’s one-of-a-kind H2 test lab

World’s one-of-a-kind H2 test lab

Electrolyzers on the test bench

In Hydrogen Lab Bremerhaven, manufacturers and operators of electrolyzers can put their systems to the test. The fluctuating feed-in of wind power is, in contrast to the steady mode of operation, a challenge. How the associated complex processes can be optimized engineers are now testing in real operation.


A gray, windy day in Bremerhaven – a city near the North Sea in Germany. The engineer Kevin Schalk from research institute Fraunhofer IWES showed me the Hydrogen Lab Bremerhaven (HLB) – an extensive open-air test site. It is located next to a blue-painted hangar at the former airport Luneort and contains the most important building blocks for a climate-neutral energy system: a PEM electrolyzer, an alkaline electrolyzer, three compressors, low-pressure and high-pressure storage vessels for hydrogen (up to 40 bar or up to 425 bar), fuel cells and a hydrogen-capable combined heat-and-power plant.

“Our Hydrogen Lab is modular and designed for maximum flexibility,” says Kevin Schalk. All components of the test field are connected to each other by trench routes in which the power and data cables as well as the hydrogen lines run. The pipes for water and wastewater are laid underground. Uniting the installations is the control room, in which all the information comes together and from where the components are monitored and controlled.

Between the plants, there are free spaces where manufacturers or operators can have their own electrolyzers tested. This means that each test specimen can be investigated independently of tests in other parts of the laboratory, states Schalk. If needed, the opposite is also possible: The test specimen can be operated together with other parts of the hydrogen laboratory.

Around the H2 test site, meadows stretch as far as the horizon, dotted with wind turbines. At eight megawatts, the most impressive plant of this kind is located directly next to the open-air laboratory; a gray giant whose rotors turn leisurely in the wind. “When the AD8-180 went into operation in 2016, it was the largest wind turbine in the world” says Kevin Schalk, who is director of Hydrogen Lab Bremerhaven (HLB). The elongated rotor blades indicate that the prototype was actually intended for use at sea. Now, the plant will soon be used to test the production of hydrogen from wind power under real conditions. Up to one tonne of green gas is to be produced there every day.

Direct comparison of different electrolyzers

The team around Kevin Schalk will address the question of how different types of electrolyzers interact with a wind energy plant on a real scale. On the one hand, there is the 1-megawatt PEM electrolyzer that splits distilled water into hydrogen and oxygen. This type of water splitting takes place in an acidic environment, in contrast to alkaline electrolysis in an alkaline milieu. Potassium hydroxide solution (KOH) in a concentration of 20 to 40 percent is used as the electrolyte.

An alkaline electrolyzer (AEL) possesses an anion exchange membrane, thus allowing the OH ions to pass through. It is cheaper to purchase and distinguishes itself by long-term stability. The most expensive components of an electrolyzer are the stacks as well as the power electronics, so the rectifier and transformer. The question of efficiency, according to Schalk, can hardly be given a blanket answer – at least for complete systems.

If an electrolyzer is operated with fluctuating electricity from renewable energies instead of continuously as in normal operation, this is a challenge for various reasons: A dynamic driving mode puts more strain on the materials, and it can come to a gas contamination in partial load operation, which ultimately leads to shut-down of the system. In the HLB, various operating states are to be compared with each other, so full load or partial load; in addition to the start times from cold or warm standby.

“We can set, for example, the operating mode of an electrolyzer to the seven-day forecast of the wind turbine and then test this operating mode,” explains the engineer. “Together, our electrolyzers can absorb a maximum of 2.3 megawatts. So far, there is generally little data and knowledge about how megawatt electrolyzers behave with fluctuating wind power. The available data are mostly simulations and studies based on measured data in smaller systems and then extrapolated,” he adds.

Unique selling point of the H2 research laboratory

A few hundred meters away from the test laboratory is the Dynamic Nacelle Testing Laboratory (DyNaLab) of Fraunhofer IWES, a large nacelle test stand with a virtual 44‑MVA medium-voltage grid. To this, the Hydrogen Lab is also connected, which allows the electrical integration of the systems into the power grid to be tested. “Dynamic changes in grid frequency or voltage dips can be simulated in this way in order to investigate the effects on an electrolyzer, for example,” says Kevin Schalk. This is a unique selling point and enables researchers to test what will become increasingly important in the future: electrolysis in grid-stabilizing operation. This also includes the two technical options for reconversion to electricity: the hydrogen-capable combined heat-and-power plant and the fuel cell systems.

Fig. 2: Shipping container solution with various hydrogen storage vessels (left) and combined heat-and-power plant

A layman can hardly imagine how difficult it is to set up such a highly complex system in one location. The electrolyzers alone require more than just a water connection from which the water is first sent to a treatment unit so that it is ultra-pure before it can be fed into the electrolyzer stack, explains Kevin Schalk. The hydrogen that is then generated must also be treated and the remaining water removed, which occurs in a drying unit. In addition, the oxygen released during water splitting must be collected and stored safely. Ideally, the oxygen could be used for further applications, for example in an industrial or commercial operation or in a sewage treatment plant.

“And that was just the water; now comes the electricity side,” continues Kevin Schalk. “We have the connection to the public power grid, so we may still have to transform it to achieve the right voltage level. This is followed by the inverter to switch from AC to DC voltage. Then, the current goes into the stacks of the water splitting unit. Whenever the grid “twitches,” so the frequency or voltage changes beyond a certain level, the electrolyzer after it must be able to cope with it. And if the power electronics are not set correctly, the system switches off,” he adds.

In addition, the thermal side of the system must be taken into account. “Initially, the electrolyzer must be heated,” explains Kevin Schalk. “Later, when it is running constantly, it usually needs to be cooled in order to maintain the optimum operating point in each case. This is inevitably accompanied by energy losses,” he adds. That’s it for the PEM electrolyzer. With alkaline electrolysis, the potassium hydroxide solution still has to be removed and recycled.

Getting fit for offshore use

Another key topic for the research lab is taking place as part of the government-supported pioneer project (Wasserstoff-Leitprojekt) H2Mare. Involved is a 100-cubic-meter (3,531-cubic-foot) seawater basin as well as a desalination plant, for which the waste heat from the electrolyzers will be used. This is based on the realization that, in densely populated Germany, larger quantities of green hydrogen are most likely to be produced at sea. Therefore, the electrochemical process for splitting water must be suitable for use on the high seas, because in future electrolyzers will also be connected directly to offshore wind turbines. This in turn requires coupling with a seawater desalination plant, and this combination is energetically favorable because the waste heat from the electrolyzer can be used for the desalination.

Engineer Schalk points out that he and his colleagues adhere to the German or European regulations in all their investigations, such as the EU sustainability certification for compliance with RED II (Renewable Energy Directive). It specifies the conditions under which hydrogen can be certified as “green,” and that is exactly what they want to produce here. “The customers need guaranteed green hydrogen, for example for public transit buses,” he says. An H2 refueling station for commercial vehicles has been built in the bus hub of Bremerhaven. In addition to public transit, there are other potential customers in the region: for example, a shipping company that wants to operate its ship in Cuxhaven with gaseous hydrogen. Or the public mobility company Eisenbahnen und Verkehrsbetriebe Elbe-Weser (EVB) as operator of the hydrogen trains for the regional railroad in Niedersachsen.

Hydrogen Lab Bremerhaven is cooperating with Norddeutsches Reallabor, a large-scale research project funded by the German economy ministry in which several German states are advancing sector coupling based on hydrogen. HLB receives funding totaling around 16 million euros from the European Development Fund as well as the German state of Bremen. In May of this year, the HLB will go from trial to normal operation and will initially produce a good 100 metric tons of hydrogen per year. In the second phase, Kevin Schalk expects over 200 tonnes. “We will be the first large-scale production facility for green H2 in northern Germany,” he says.

Fig. 3: View over the HLB with free working spaces – the control center on the left

Mechatronic H2 pressure regulator

Mechatronic H2 pressure regulator

Up until now, Italian company Landi Renzo has been mainly known for its conversion sets for gas engines. Now the automotive supplier, which employs more than 1,200 staff globally, is venturing into the hydrogen sector and developing an advanced electronic pressure regulator for medium- and heavy-duty vehicles with H2 combustion engines.

The Cavriago-based company has joined forces with German group Bosch to help it broaden its range beyond components for natural gas, biomethane or LPG. Its aim is to produce and market hydrogen-based fuel systems with next-generation mechatronic pressure regulators before the end of 2024. In doing so, Landi Renzo hopes to become an enabler of carbon-neutral commercial vehicle operation and thus play a part in accelerating the decarbonization of the mobility and transport sector.


Damiano Micelli, head of technology, commented: “This mechatronic hydrogen pressure regulator is an important milestone in technological advancement which we are able to offer to the rapidly evolving mobility and transportation market. […] This is a highly innovative solution that will be available shortly for medium- and heavy-duty applications.”

Pressure regulators are a key element in conversion kits since they help to balance out large pressure differences and, if needed, change the state of a particular fuel. According to Landi Renzo, “a simple and robust mechanical regulator” was previously sufficient to fulfill this function. However, mechatronic pressure regulators such as the EM-H can also control and calibrate the hydrogen delivery pressure in line with vehicle requirements. In a two-stage process, the inlet pressure is initially reduced mechanically from high to medium. The pressure is then lowered entirely electronically to the desired value.

Landi Renzo has over 70 years of experience in the automotive and energy sectors and its facilities include an H2 center of excellence in Bologna which has a well-equipped, modular Class 8 clean room.

Establishment of a metrological infrastructure

Establishment of a metrological infrastructure

Flow measurement of high-pressure gas and liquid hydrogen

In the field of flow measurement, the use of hydrogen, especially regeneratively produced hydrogen, as a process gas and energy carrier has become a focal point in many applications. Due to the need to use storage capacity efficiently, hydrogen must be stored under high pressure or in liquid state. Metrologically verified quantity measurement is needed for the low to high pressure range of gaseous and liquefied hydrogen applications. In addition, appropriate traceability chains to the SI system need to be established for the wide range of operating conditions in order to make valid statements about the measurement accuracy and stability of the flow meters used. The EMPIR project 20IND11 MetHyInfra addresses these challenges by providing reliable data, metrological infrastructure, validated procedures and normative support.


Critical Flow Venturi Nozzles (CFVN) are widely used today and represent a standardised and accepted method of flow measurement. The main details of the shape and theoretical model are defined in the ISO 9300 standard. CFVNs are used in legal metrology and are recognised as a reliable standard with high long-term stability. The low cost and low maintenance CFVNs provide stable, reproducible measurements with a well-defined geometry and are only dependent on the gases used. The ISO 9300 standard describes two nozzle shapes, cylindrical and toroidal. In reality, however, the nozzle contours manufactured to this standard deviate from these ideal shapes. In most cases, the actual shape is between the two ideal shapes.

The achievable measurement uncertainty is also limited by the quality of the models of the thermophysical properties of the gases to be measured. The current reference Equation of State (EoS) for normal hydrogen (n-H2) was developed by Leachman et al [1]. Due to the limited thermodynamic measurement data available for n-H2 with comparatively high measurement uncertainties, the uncertainties for the various properties are generally an order of magnitude higher than for other gases.

Therefore, in this project, new Speed of Sound (SoS) measurements were performed at temperatures from 273 to 323 K and pressures up to 100 MPa. The data obtained were used to develop a new EoS for n-H2 optimised for gas-phase calculations [2]. The measurements made it possible to significantly reduce the uncertainties of the SoS calculated from the EoS in the investigated temperature and pressure range.

Extensive Computational Fluid Dynamics (CFD) simulations were carried out in the project to gain further insight into the flow physics in the nozzle. For this purpose, a numerical model for high-pressure hydrogen flows in the CFVN was developed in OpenFOAM, taking into account various relevant gas effects such as compressibility effects, boundary layer effects and transition effects. The results obtained are in much better agreement with the experimental data than previously available implementations.

In order to be able to evaluate and compare the flow behaviour of non-ideal nozzle contours, CFD simulations were also carried out for the ideal nozzles investigated experimentally in this project, as well as for parameterised nozzles. The flow coefficient of these non-ideal nozzles can be predicted very well using the proposed nozzle shape characterisation. The implementations developed in the project are freely available [3].

Figure 2: Mobile HRS flow standard

As there is currently no test facility with traceable standards available, that can be used to calibrate CFVNs directly with high pressure hydrogen, an alternative method had to be developed. The chosen approach is to calibrate a Coriolis flow meter (CFM) under high pressure conditions (range 10 MPa to 90 MPa) with a traceable gravimetric primary standard, so that it can later be used as a reference for the nozzle calibration.

The H2 test filling station (Hydrogen Refuelling Station, HRS) at the Centre for Fuel Cell Technology (ZBT) in Duisburg was selected for the calibration of the reference meter. For the measurements, a Rheonik RHM04 CFM was installed as a reference flow meter in the “warm zone” of the HRS, i.e. upstream of the heat exchanger and the pressure control valve. In this area, the temperature is always close to the ambient temperature and the pressure is constantly high, typically around 90 MPa. A mobile HRS primary flow standard was used for the calibration, which was connected directly to the HRS and thus took the role of a vehicle.

In the final step, the results of the CFVN measurement campaign will be compared with those of the CFD simulations. The newly developed EoS will be used in both the measurement campaign and the CFD simulations in order to compare both results in the best possible way.

Measurement method for liquid hydrogen

In addition to gaseous hydrogen, the project focuses on liquefied hydrogen (LH2). There are currently no primary or transfer standards for the measurement of LH2. The uncertainty associated with using a flow meter to measure the quantity of LH2 is unknown and unquantified as there is no direct traceability to calibrations using LH2 as the calibration liquid. The lack of calibration facilities means that meters used with LH2 must be calibrated with alternative liquids such as water, liquid nitrogen (LN2) or liquefied natural gas (LNG).

The project has therefore developed three approaches based on completely independent traceability chains for LH2 flow measurement. The first two approaches are applicable to flow rates during loading and unloading of LH2 tankers (flow rates up to 3,000 kg/h for a DN25 cross-section at pressures up to about 1 MPa), the third for smaller flow rates (4 kg/h for a DN3 cross-section at pressures up to about 0.2 MPa).

The first approach is based on the evaluation of the transferability of water and LNG calibrations to LH2 conditions. The study will identify and analyse potential uncertainty contributions for cryogenic CFMs. The experimental and theoretical analysis will serve as a basis for guidelines for the design and selection of CFMs suitable for SI traceable LH2 flow measurements. CFMs are a well-accepted technology for direct measurement of mass flow and density of liquids and are typically used in cryogenic custody transfer for transport fuel applications.

The literature review identified several temperature correction models applicable to LH2 flow measurement, i.e. how the LH2 flow measurement should be corrected due to temperature effects affecting the CFM measurement. Numerical finite element methods (FEM) for U-shaped, arc-shaped and straight pipe designs have been used to predict the temperature sensitivity of CFMs for LH2 flow measurement [4]. Finally, FEM can also be used to estimate the achievable measurement uncertainty using the current state of the art for LH2 flow measurement.

The second approach is based on cryogenic Laser Doppler Velocimetry (LDV) and is referred to as “Référence en Débitmétrie Cryogénique Laser” (RDCL). Traceability is ensured by velocity measurements and it can be used either as a primary standard or as a secondary standard for flow measurements of LH2. Its in-situ calibration uncertainty in cryogenic flows (i.e. LN2, LNG) has been estimated to be 0.6% (k = 2) [5]. Since the RDCL can be installed in any LNG plant, it has the advantage that a representative calibration can be performed directly in the plant under process conditions.

Figure 3: LDV standard for traceable cryogenic flow measurement

The third approach is known as the vaporisation method. Traceability to SI units is ensured in the gas phase by calibrated Laminar Flow Elements (LFE) after the liquefied gas has been evaporated. The LFEs are traceable to the Physikalisch-Technische Bundesanstalt (PTB). As with the first approach, the transferability of alternative liquid calibrations using water, LN2 and liquefied helium (LHe) must be evaluated, as the calibration rig is not suitable for direct use of LH2 for safety reasons. The lower flow range and the fact that non-explosive gases are used are operational advantages of the evaporation method. Another benefit is the use of LHe (boiling point about 4 K) so that the uncertainty of the alternative liquid calibration is based on interpolation rather than extrapolation.

An important aspect to consider in the vaporisation method is the conversion of para hydrogen (para-H2) to normal hydrogen (n-H2), which has been studied in detail by Günz [6]. At low temperatures, para-H2 is present almost exclusively; at room temperature, the ratio changes to 25% para-H2 and 75% ortho-hydrogen (n-H2). Para-H2 and ortho-hydrogen differ significantly in certain physical properties such as thermal conductivity, heat capacity or SoS. These can strongly influence the gas flow measurement, depending on the measuring principle of the flow meter. LFEs used to measure gas flow at ambient conditions are not affected by this as density and viscosity show negligible differences, particularly in the temperature range of interest here.

In summary, the results of the project will increase the confidence of end users and consumers. The methods presented will ensure reliable measurement data, which is important for increasing the share of hydrogen in total energy consumption.

This project (20IND11 MetHyInfra) has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.


[1] Leachman, J. W.; Jacobsen, R. T.; etc., Fundamental Equations of State for Parahydrogen, Normal Hydrogen, and Orthohydrogen, J. Phys. Chem. Ref. Data 38(3): 721-748 (2009)

[2] Nguyen, T.-T.-G.; Wedler, C., etc., Experimental Speed-of-Sound Data and a Fundamental Equation of State for Normal Hydrogen Optimized for Flow Measurements. International Journal of Hydrogen Energy, 2024.

[3] Weiss, S. (2023). Derivation and validation of a reference data-based real gas model for hydrogen (V1.0) [Data set].

[4] Schakel, M. D.; Gugole, F.; etc., Establish traceability for liquefied hydrogen flow measurements, FLOMEKO, Chongqing, 2022

[5] Maury, R., Strzelecki, A., etc., Cryogenic flow rate measurement with a laser Doppler velocimetry standard, Measurement Science and Technology, vol. 29, no. 3, p. 034009, 2018

[6] Günz, C., Good practice guide to ensure complete conversion from para to normal hydrogen of vaporized liquified hydrogen,

Authors: Oliver Büker, RISE Research Institutes of Sweden, Borås, Sweden, Benjamin Böckler, PTB Physikalisch-Technische Bundesanstalt, Braunschweig, Germany

FRHY Stack, first of its kind!

FRHY Stack, first of its kind!

Technology platform for high-rate electrolyzer production

The cooperative FRHY project, which forms part of the German flagship hydrogen initiative H2Giga, is aimed at scaling up electrolyzer manufacturing. Increasing electrolyzer production rates requires new technical solutions. To facilitate the development of these essential technologies a model stack was created as a point of reference. Named the FRHY Stack, it is a high-efficiency electrolyzer with the potential for industrial mass production which also supports knowledge and technology transfer.


The ten cells that in total make up the FRHY Stack each consist of two formed and joined plates referred to as bipolar plates or BPPs. These two half plates are initially stamped in a high-speed rolling process on a system newly developed by the Fraunhofer Institute for Machine Tools and Forming Technology IWU. They are then joined together in a welding process that has been adapted to take account of the high processing speed.

FRHY – the reference stack

Another key component is the proton exchange membrane or PEM which belongs to the membrane electrode assembly, otherwise known as the MEA. The membrane is fabricated in a new inkjet printing process devised by Fraunhofer ENAS. The BPP and MEA are embedded into a stiff film framework, the subgasket, to which various seals are added as well as the porous transport layer (PTL), more commonly known as the gas diffusion layer or GDL. The result is a cell design that is suitable for industrial mass manufacturing.

Within the stack, which consists of several cells, the medium and the hydrogen are conveyed through channels on the edge of each cell. Two gold-coated contact plates at the end of the stack supply the stack with energy.

The FRHY reference stack is suitable for a variety of application scenarios and has a high level of efficiency. It is the first time that the model hydrogen factory Referenzfabrik.H2 has made a platform available which will enable a number of sectors and organizations to perform technical and economic assessments of individual components, develop their own business model and position themselves in the supply chain.

Fig. 1: FRHY reference stack, Source: Referenzfabrik.H2

In the initial development phase, a design portfolio was created to define the main parameters for creating cell or stack components and provide a means of contrasting different designs. This allowed two very functional designs to be configured that enable cells to be produced in large numbers. Version M is the type used for the FRHY Stack; its manufacturing potential is based on metal BPPs.

Version K was also developed. This features a newly created intelligent plastic frame that can be made in large numbers in an automated production process. Based on these designs, engineers were able to produce components and bring them together in the FRHY Stack.

As a result of the stack, there is now a valuable frame of reference for the development of the next high-rate generation of electrolyzers. Even electrolyzers in the (price-sensitive) kilowatt range are scarcely marketable without high-rate production processes. If, however, the sale prices are reasonable, a huge market would open up just to meet the energy storage needs of wind farms or residential buildings. What’s more, the stack could be used for application scenarios in the megawatt range. The coupling of stacks would allow plants to produce large quantities of hydrogen, for example in order to supply the manufacturing and raw materials industries.

Direction of FRHY project

FRHY is taking a technology-neutral approach to developing new modules for highly scalable electrolyzer production and to the configuration of digital twins. The objective is to create a portfolio of essential production steps for technical and economic assessment to help industry select the right production processes while considering key parameters, in particular scalability, quality and cost. For instance, production options can be calculated and possible manufacturing strategies can be analyzed, e.g., taking account of automation or integrative continuous process management. This approach not only allows capital costs to be quantified but also return on investment to be deduced in relation to the planned production quantity.

The FRHY methodology also enables production lines to be linked up into one overall value system. This creates transparency and supports the building of supply chains. In addition, it makes it easier to plan factories and make decisions about effective vertical integration.

The unbiased FRHY approach gives an enormous boost to production and testing processes for electrolyzers and ensures a high degree of technology readiness. A key focus here is on furnishing proof of robust and scalable processes. This will additionally benefit the quality and longevity of the product. This is because stable processes also ensure the economic mass production of high-quality electrolyzers and support the further advancement of both production and the product itself.

H2Giga and FRHY

The German education and research ministry is supporting Germany’s entry into the hydrogen economy through its backing of the H2Giga flagship hydrogen project. Over the course of the four-year initiative which runs until March 2025, the project will seek to overcome existing obstacles to the series production of large-scale water electrolyzers. FRHY is a joint project involving six Fraunhofer institutes: IWU, ENAS, IPT, IPA, IMWS and IWES. The decentralized structure means the project is able to incorporate regional partners and networks in Baden-Württemberg, Nordrhein-Westfalen and central Germany.


FRHY links up physical and virtual solutions and consequently has an enormous impact in terms of innovation on electrolyzer production. This approach has resulted in ambitious plans that will smooth the path toward electrolyzer mass production.

The development of new, configurable production and testing modules for key process steps in stack manufacture will lower production costs by at least 50 percent and improve product quality by 20 percent while also considerably extending the life of complete electrolyzer systems.

The research questions that need to be resolved primarily entail expanding the technological limits of electrolyzer production. Parallel to this, it is expected that the scientific findings will boost the development of a production-optimized next generation of electrolyzers. The FRHY project, and the FRHY Stack especially, have laid the necessary foundations to bring this about.

Digitally mapped production and testing modules are integrated into a technology portfolio for stack production. This toolkit combines the results from physical and digital analyses. For the first time this lets industry deduce urgently needed quantifiable information about output volumes, costs and areas of operation depending on the production method employed.


The FRHY reference stack is the first example of a solution being created to provide a platform for the industrial mass production of electrolyzer components. Deploying continuous roll-to-roll manufacturing technologies is not the only way to increase production volumes. New processes, too, that are consciously designed to make sparing use of critical materials, e.g., platinum, iridium and titanium, as well as in-situ testing technologies bring about a substantial decrease in production costs.

The result is a genuine point of reference and a technological “diamond in the rough” that companies can implement in an industrial setting. The reference stack therefore lays important groundwork for the future availability of hydrogen systems at affordable prices – and ultimately for a hydrogen retail price that is economically viable.

Fig. 2: Rotary stamping of bipolar plates: The structure of the bipolar plate is stamped by a pair of rollers. The main advantage of this method is the high processing speed that leads to a substantial increase in output figures, scaling effects and finally to a significant reduction in cost.


The overall coordination for the FRHY project is undertaken by the model hydrogen factory Referenzfabrik.H2 developed by Fraunhofer IWU. The objective of Referenzfabrik.H2 is to be a pacemaker for the industrial mass production of electrolyzers and fuel cells. The project brings together science and industry as part of a value-creation community that works in collaboration to swiftly ramp up the efficient, scalable production of hydrogen systems.

The factory is underpinned by Fraunhofer IWU’s research and development projects. Solutions that arise from these projects provide the basic structure for manufacturing. This is where industrial corporations are able to contribute their expertise and develop this further together with the participating Fraunhofer institutes and other industrial enterprises. Only through the close cooperation of academia and industry will it be possible to produce high-performance systems for mass deployment more rapidly and at more affordable cost.

Author: Dr. Ulrike Beyer, Referenzfabrik.H2 at Fraunhofer IWU

HySupply – German-Australian hydrogen bridge

HySupply – German-Australian hydrogen bridge

Acatech and BDI show what’s feasible

Defossilizing the energy system is an important goal of the clean energy transition – importing green hydrogen a possible option for this. The cooperation project HySupply from the national academy Acatech and the national association Bundesverband der deutschen Industrie (BDI) has therefore examined the feasibility of a German-Australian hydrogen bridge. The result: The production and transport of hydrogen and hydrogen derivatives from Australia to Germany are technically, economically and legally possible. A crucial question here: How could domestic imports be distributed in an economically and technically sensible way?


Energy imports are a constant staple for the German energy supply. While they have largely concentrated on energy sources of fossil origin such as natural gas and crude oil, they could soon be expanded to include an alternative energy source: green hydrogen. According to the target picture contained in the update of the German hydrogen strategy, the total hydrogen demand in Germany in 2030 will be between 95 and 130 TWh and can only be covered by imports. Within the next ten years, Australian hydrogen could therefore play a role in the German energy system. But why is Australia, of all places, 14,000 kilometers away, being considered for this?

Making the energy supply stable and resilient
All the preconditions speak in favor: Renewable energies for the production of green hydrogen are abundant in Australia. In addition, the conditions are ideal with regard to a future-proof and reliable supply: “An Australian-German hydrogen bridge promises a stable and mutually beneficial trade relationship between two democratic countries,” states Acatech president Jan Wörner regarding preconditions. “We now have the opportunity to help shape the future hydrogen market and make our innovation location more resilient to dependencies. For this, we need a decided, joint establishment of infrastructures and framework conditions,” he adds.

However, the technology for transporting liquid hydrogen will probably not be available within the next 20 years, stated Robert Schlögl recently in an interview with Deutschlandfunk. He is president of the foundation Alexander von Humboldt-Stiftung and an Acatech member. As co-project manager, he has accompanied HySupply since its start in November 2020. These and other challenges in the transportation of liquid hydrogen are the reason why the HySupply feasibility study deals with the import possibilities of H2 derivatives, so ammonia, synthetic natural gas, methanol, Fischer-Tropsch products and LOHCs.

HySupply investigated from the end of 2020 to January 2024 under which technical, economic and legal conditions a German-Australian hydrogen bridge is feasible. The feasibility study funded by the German education ministry (BMBF) was conducted by Acatech (Deutsche Akademie der Technikwissenschaften) and the BDI (Bundesverband der deutschen Industrie). The University of New South Wales (UNSW) led the Australian consortium. This was sponsored by the Department of Foreign Affairs and Trade (DFAT). Together, the two sides united a unique network of experts from academia and industry to examine the entire value chain.

Transportation and supply routes

Studies in the past have already focused on various aspects of hydrogen imports. What’s special about the present study compiled by the research institute Fraunhofer IEG for HySupply: For the first time, a publication deals explicitly with the last mile, which usually poses the greatest challenges regarding infrastructure – both the technical and economic nature. Robert Schlögl states on the matter: “This study analyzes, evaluates and compares comprehensively and for the first time all major hydrogen derivatives and transport options, from the import hub to the end consumer.”

In total, there are 543 demand locations in Germany that went into this analysis. They were classified according to various use cases and investigated regarding the supply possibilities with hydrogen and its derivatives. Use cases – those are the production of ammonia, steel, petrochemical basic chemicals and synthetic jet fuels. In addition to that are the preparation of process heat in metal production and processing, the manufacture of glass and ceramics and in the paper industry. As transport modes, the study considers inland ship transport, the rail network, the hydrogen core grid and pipelines for other products. For each use case, the study lists the economic advantages and disadvantages of the respective options.

Fig. 2: Overview of the analyzed supply network and distribution of the demand locations, Source: Fraunhofer IEG

Flexibility determines the H2 ramp-up
The H2 core grid plays an important role in supplying industry. The study indicates that all identified locations of potential large-scale hydrogen consumers will be reached by the hydrogen core network in 2035. However: In many cases, the transport of hydrogen (or derivatives) by barge or rail represents a possible alternative or supplement to pipeline-based site supply.

Around eleven percent of the sites lie at a demand of over 500 gigawatt-hours of hydrogen equivalents (GWhHeq). For the most part, they entail uses like the production of basic chemicals and steel and the employment of ammonia and synthetic jet fuels. And 85 percent of the investigated 543 demand locations, in contrast, claim an annual demand of less than 150 GWhHeq. For these cases, the recommended alternative to pipeline-based supply is the provision by barge or rail.

Final study focuses on the year 2035
The national hydrogen strategy includes the installation of a hydrogen core network over 9,000 kilometers long by year 2032. It is intended to connect the major hydrogen feeders with all major consumers. The first phase of the market ramp-up, until 2035, requires the ability to offer answer options to the most important logistics questions. This applies in particular to the distribution options for the imported hydrogen and hydrogen derivatives that are required for the market ramp-up. The final study presented at the end of the project HySupply with the title “Wasserstoff Verteiloptionen 2035” (hydrogen distribution options 2035) therefore focuses precisely on this crucial period up to 2035 and provides an additional outlook for the following ten years up to 2045.

Fig. 3: Cost-optimized supply chains, Source: Fraunhofer IEG

Domestic transport costs only a small proportion of total costs

Between 3,400 and 16,000 euros per tonne of hydrogen equivalent (EUR/tH₂eq): This is how far the range of provisioning costs found in the study extends between the different use cases. In this, the import costs, with a range of 41 to 100 percent, make up the majority, whereas the costs for domestic redistribution, averaging five percent of costs, comes out comparatively low. In the economic evaluation were included the costs for the provision of hydrogen and its derivatives. The specific transport and conversion costs were additionally included.

Fig. 4: Cost model for evaluating the supply chains, Source: Fraunhofer IEG

Karen Pittel, Acatech presidium member and director of the IFO Institute’s center for energy, climate and resources (IFO Zentrum für Energie, Klima und Ressourcen), advocates flexibility in the distribution options: “These alternative distribution options play an important role in supplying the locations with comparatively low demand. They carry the necessary flexibility to come into implementation in the first phase of the market ramp-up. To be able to guarantee this, we should secure and expand the efficiency of the alternative distribution options.”

Nevertheless, the consistent expansion of the hydrogen core grid will play a central role, especially for locations with high demand. The parallel expansion of the various distribution options Robert Schlögl therefore also sees as crucial: “The completion of the hydrogen core network must be vigorously pursued. At the same time, we must also get implemented other tasks such as the expansion of the rail network or the development of CO2 infrastructure.”

Fig. 5: Categories of the modeled supply chain characteristics, Source: Fraunhofer IEG

Recommendations for action regarding hydrogen distribution options by 2035

  • The hydrogen grid must be further expanded. Storage options should be taken into account in the planning process.
  • The existing rail network must be expanded and new routes added.
  • The hydrogen import strategy should soon be published.
  • In the market ramp-up phase, hydrogen derivatives should initially be used as a material and only later as a hydrogen carrier.
  • Pipelines for product transmission should be used in the long term to support the distribution of hydrogen derivatives.
  • Sustainability criteria for the import of carbon-containing hydrogen derivatives should be guaranteed through the establishment of international certification systems.
  • Hydrogen and CO2 infrastructures must be planned together and built taking into account mutual interactions.

Spillmann, T.; Nolden, C.; Ragwitz, M.; Pieton, N.; Sander, P.; Rublack, L. (2024): Wasserstoff-Verteiloptionen 2035. Versorgungsmöglichkeiten von Verbrauchsstandorten in Deutschland mit importiertem Wasserstoff. Cottbus: Fraunhofer-Einrichtung für Energieinfrastrukturen und Geothermie IEG

Iryna Nesterenko, Philipp Stöcker
Both from Acatech – Deutsche Akademie der Technikwissenschaften