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

First commercial green hydrogen production

First commercial green hydrogen production

Solar Global operates electrolyzer plant in Czech Republic

An electrolyzer in the town of Napajedla in southeastern Czech Republic has produced the country’s first green hydrogen from solar power. The industrial green hydrogen production facility is run by Solar Global, one of the leading companies in the Czech renewables sector.


This hydrogen plant should be seen primarily as a pioneering initiative since its capacity of 230 kilowatts is relatively low. It can consume up to 246 megawatt-hours per year of electricity. The power is sourced from a photovoltaic plant with a peak capacity of 611 kW. Battery storage is used to buffer the discrepancies between generation and consumption. In line with the Czech hydrogen strategy, most of the hydrogen ends up as fuel.

“Green hydrogen produced in this way can be used at the refueling station in Napajedla to fill up not just trucks and buses, but also cars with environmentally friendly hydrogen propulsion,” explained Vítězslav Skopal, owner of Solar Global Group. According to Solar Global, the plant can supply around 8 metric tons (8.8 US tons) of green hydrogen. This is enough to enable a car to travel 800,000 kilometers (500,000 miles) and a hydrogen bus to travel 80,000 kilometers (50,000 miles).

Covering the entire value chain

Hydrogen production is expected to develop gradually into a major area of industry in the Czech Republic. As this happens, the Solar Global Group foresees an entire value chain developing alongside it. In addition to hydrogen production, the company has its sights set on the operation of vehicles equipped with fuel cells. Ultimately, the corporation also wants to get involved in the supply of hydrogen via refueling stations. “Of course all this depends on the building of other requisite technologies, in other words hydrogen compression, storage and refueling stations, and these are the next stages of our pilot project,” said Skopal.

The production of the country’s first kilogram of hydrogen was funded by the State Environmental Fund of the Czech Republic or SEF CR, which has been in existence since 1992. So far the environment ministry has financially supported four electrolyzers from the environment fund. “Two further projects are under examination,” stated Lucie Früblingová, spokeswoman for the state environment fund. The schemes under which hydrogen projects can receive support are currently being widened. The number of assisted projects and the amount distributed in subsidies are set to rise in the future.

Traditional producers look to green hydrogen

Among those due to receive funding is Orlen Unipetrol, the Czech Republic’s largest producer of “gray,” fossil-based hydrogen. The company, which is part of Polish petroleum giant Orlen, intends to install an electrolyzer in conjunction with a solar power plant in Litvínov. Groundwork will begin sometime between 2024 and 2025, with the production of green hydrogen slated to start at the end of 2028. However, Unipetrol is well aware that its own production can only cover a fraction of its hydrogen demand and is already considering hydrogen imports.

Another electrolyzer being aided by the environment fund belongs to the Sev.en Energy Group. The mining company operates what was once the extensive opencast brown coal mine in Most, Komořany, which will soon be exhausted, as well as the associated coal power plants. Sev.en is planning a massive expansion in solar power plants totaling 120 MW. The proposals include a 17.5-MW electrolyzer that will manufacture 360 metric tons (400 US tons) of green hydrogen a year starting in 2027. The costs for the hydrogen system, according to Sev.en’s head of transformation Pavel Farkač, run to around CZK 700 million, which equates to EUR 28.5 million, a substantial proportion of which is to be covered by subsidies from the environment fund.

In October 2023, the Czech government presented the draft of an energy and climate plan for the years leading up to 2030. The press release from the environment ministry stated that the use of hydrogen would increase within industry and the mobility sector by the end of the decade. The plan also foresees that electricity derived from brown coal will no longer be exported.

Author: Aleksandra Fedorska

National hydrogen strategy for the Czech Republic:

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

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

A new energy infrastructure is emerging

A new energy infrastructure is emerging

“Green” and “blue” ammonia from other continents to come to Europe

Ammonia produced from electrolysis-generated hydrogen is to become the green energy carrier and sustainable basic chemical of the future. The infrastructure for the import is being created at lightning speed. In Hamburg and Brunsbüttel, new terminals are to start operation in 2026.


In the hydrogen sector, Japan has often been ahead of its time. In 2014, the Japanese government adopted its fourth strategic energy plan. Hydrogen and fuel cells were already high on the list back then. At the same time, various import options were to be investigated. One of them was ammonia.

Ammonia consists, as the chemical formula NH3 reveals, of nitrogen and hydrogen. If produced from hydrogen obtained electrolytically using renewable energies as well as nitrogen from the ambient air, it could become a climate-friendly energy source of the future. In contrast to pure hydrogen, it is comparatively easy to transport: Ammonia becomes liquid under ambient pressure “already” at ‑33 °C or at 20 °C with just under 9 bar. Additionally, the energy density of liquid ammonia lies with 11.4 GJ/m3 substantially over that of liquid hydrogen with 8.52 GJ/m3.

Cracking eats up energy

With so-termed crackers, the ammonia can basically be broken down into hydrogen and nitrogen again. However, this involves an endothermic process. The Fraunhofer Institute for system and innovation research (Fraunhofer ISI) therefore warns in a metastudy on hydrogen import against high conversion losses and high costs when ammonia is used as a carrier to get hydrogen again in the end.

But this is not necessary for all applications, since ammonia can also be used directly as a fuel. Especially in ship transport could ammonia be a promising fuel. Japan wants to use the pungent-smelling gas primarily in coal-fired power plants. There has already been a test run. Starting 2021, the companies JERA and IHI have substituted 20 percent of the fuel in a gigawatt-level coal-fired plant with ammonia. Now, the first commercial terminals are being built. A consortium around Mitsubishi wants to convert a terminal in the port of Namikata to ammonia, and the duo IHI and Vopak are checking where in Japan further import terminals could be built.

Europe setting the pace

Since the energy crisis, Europe has also been flooring it. For this, it is convenient that there are already commercial shipping routes for ammonia. Around 20 million tonnes are transported by ship annually, mainly for the production of fertilizers. That the fertilizer giant Yara International with 15 ships and access to 18 ammonia terminals operates, according to its own information, the largest shipping and logistics network for this is therefore no surprise. But if ammonia is to become an energy source, its transport will need to be able to increase significantly.

At the beginning of 2024, the Dutch Institute for Sustainable Process Technology (ISPT) published a “Clean Ammonia Roadmap.” Following this, alone in industry cluster Antwerp-Rotterdam-Rhine-Ruhr could up to 25 million tonnes of “clean” ammonia be generated and imported. The Port of Rotterdam could develop into a central transshipment and storage site. According to the ISPT study, up to three million tonnes annually could be further transported from the Netherlands and Belgium to Germany.

New and retrofitted terminals

To bring ammonia directly to Germany, several terminals are to be built or expanded. In Hamburg, October 2022, the port company HHLA test-imported ammonia in a shipping container from Abu Dhabi, with which the copper producer Aurubis was able to test the substitution of natural gas – an action that seems rather symbolic. For the real use, the energy company Mabanaft plans an import capacity of 600,000 tonnes per year, which is to be available starting 2026.

On the Blumensand Tank Terminal operated by Mabanaft’s subsidiary Oiltanking Deutschland, a tank for the storage of liquid ammonia is to appear. A cracker is to be able to split the ammonia into nitrogen and hydrogen. In preparation for the approval procedure, a so-termed scoping meeting has now taken place with the environmental authority, at which, together with directly affected neighbors, environmental groups and other specialists, the scope of the voluntary environmental impact assessment was discussed.

Via the new terminal in Brunsbüttel, RWE wants to import around 300,000 tonnes of green ammonia annually. Here, too, 2026 is targeted as the starting year. Not really that much when you compare it with the planned LNG terminal, through which 8 billion cubic meters of liquefied natural gas are to be transported to Germany every year. Comparing the energy content, that’s about 1,560 GWh of ammonia and 80,000 GWh of LNG.

RWE also announced plans to build a cracker to break down some of the ammonia back into hydrogen and nitrogen. Through the energy loss, the relationship between ammonia and LNG drifts further apart. RWE stressed, however, that a retrofit of the LNG terminal for ammonia is to be later possible.

Fewer headlines than the planned new construction have been made by both existing terminals of Yara in Brunsbüttel and Rostock, Germany, in contrast, which the company has so far only used for its own needs. Already about 600,000 tonnes of ammonia arrive in Rostock annually. In total, according to the company’s information, Yara has the ability to deliver 3 million tonnes of clean ammonia, if the demand is available.

Distribution by rail or pipeline

One of the first customers of Yara could be the Leipzig-based natural gas company VNG. The two companies signed a corresponding cooperation agreement in spring 2023. Also Mabanaft in Hamburg has already named the process gas producer Air Products as an anchor customer. RWE is currently examining whether and how ammonia can be further transported by rail in Germany. Also on board is the rail transport company VTG.

The transport of ammonia by rail is not new, but it carries a higher risk than by sea. After all, ammonia not only smells unpleasant, it also attacks the respiratory tract. In the past, accidents involving injuries or even fatalities have repeatedly occurred during transport by train and truck through busy areas, including in Serbia in December 2022 and in the US state of Iowa September 2023. The Bulgarian fertilizer company Agropolychim, after the accident, is now investing in a new fleet of ammonia tankers.

According to a study by Dutch think tank ISPT, pipelines could make the transport of ammonia over land much safer. There are so far around 7,600 kilometers of ammonia pipelines worldwide. In the past 50 years, there have only been eleven accidents, none of which resulting in fatalities.

Fig. 2: Starting 2030, LOTTE Chemical, Mitsubishi and RWE want to produce ammonia in Texas together, Source: RWE

Where does green ammonia come from?

Before the ammonia can be imported to Germany, however, it must first be produced. A hotspot for this is expected to be Namibia with its H2 megaproject Hyphen Hydrogen Energy. With the German company Enertrag as shareholder, the path to hydrogen is practically paved out. The megaproject is set to supply one million tonnes of ammonia, generated using wind and solar energy. Of this, RWE has already reserved 300,000 tonnes by means of a letter of intent. But looking at the quantities cited by ISPT, the currently targeted production in Namibia will not suffice.

RWE therefore has also reported a partnership with the Korean LOTTE Chemical and the Japanese Mitsubishi Group. Together, the companies are investigating the establishment of production of up to 10 million metric tons of ammonia per year in the US state of Texas. Involved are both “blue” and “green” ammonia, and production is to start in 2030. With this, RWE is equally fulfilling a recommendation of Fraunhofer ISI: Join forces with other future importing nations instead of creating a competitive situation.

Author: Eva Augsten

Fuel cell systems for grid hardening

Fuel cell systems for grid hardening

Interview with Christian Leu and Benedikt Eska from Axiosus

An important but often neglected area of application for H2 technology is the uninterrupted supply of power. To prevent flickering lights and even more so blackouts, so-termed UPS (uninterruptible power supply) systems are indispensable. In the best-case scenario, when the network is stable, they will not be used, but their presence is nevertheless of central importance. H2-international spoke about this to Benedikt Eska and Christian Leu, the managing directors of Axiosus Energy GmbH, as well as about the company itself and the technology platform Clean Power Net (CPN).


Fig.: Christian Leu

H2-international: Let’s start with your FC and hydrogen CV. You have both been in the H2 business for some time already. Since when and where or as what?

Leu: It all started when I started working as a development engineer for fuel cell technology at the Berlin start-up Heliocentris in 1998. Most recently, I was responsible for the stationary fuel cell power supply product line there and during this time involved in the first commercial roll-outs for FC grid replacement systems at the radio communications service BOS in Germany.

Eska: My first serious contact with the subject of fuel cells was over 25 years ago already. In 2001, I then started at Proton Motor and was one of the people responsible for the IPO in London in 2006. In 2009, I founded my consulting company with focus on fuel cells and hydrogen.

Mr. Leu, after this long time at Heliocentris, you were initially active alone in Berlin. Why then did you join forces with Mr. Eska?

Leu: Following the insolvency of Heliocentris in 2017, I took over a position at the firm ITK Engineering, a company within the Bosch Group, for the development of expertise and business in the field of hydrogen and fuel cell technology. Over time, I developed the desire not only to support developers, but above all to help users successfully bring finished developments into commercial use in the long term. As this was not compatible with the business model of ITK, I was looking for opportunities for my own business. In Benedikt, I found an ideal partner – like-minded and complementary in experiences and strengths.

Mr. Eska, after these years of working independently – what prompted you to found your own company with Mr. Leu??

Eska: There were more and more requests in my consulting company asking if I could also help with implementation. For this reason, I had been thinking about changing my legal form for some time and putting my business on a broader footing. Then, something of a coincidence conspired, as I phoned Christian at the right moment. After having already worked together on other occasions, we had an intensive exchange and saw common ground. Admittedly, before COVID and the learning curve with online meetings, we probably wouldn’t have founded the company together in this form a few years ago.

When exactly did you start working together?

Eska: We founded the company together in 2022, but we actually already knew each other from the VDMA (German association for mechanical engineers) working group on fuel cells, or really – for those who know it – from the predecessor AK Berta. That must have been around 2003 or 2004.

Before we come to your services: What does Axiosus stand for?

Leu: We often get this question, of course. Axiosus is a made-up word and already has our field of activity in its name. Axiosus is composed of the Greek axiópistos for “reliable” and the English “sustainability.” Axiosus Energy therefore stands for reliable, sustainable energy supply solutions.

I see. What exactly do you offer then?

Eska: We see ourselves strongly at the interface between system providers and users. The suppliers want to focus on their standard products, and the users are looking for an optimal solution for themselves. We bring both sides together. This starts with the technical conception and site planning through to implementation on site with the various builders. For this, we rely on our partners, for example from the electrical and civil engineering industry. From the user’s point of view, we can also act as a general contractor for suitable projects. We act manufacturer-neutral and open to all technologies.

In summary, there are two pillars: consulting and project development. Our hardware projects are currently mainly in the area of emergency power supply for critical infrastructure. We also provide consulting services in the fields of electrolysis, hydrogen supply and strategic-technological corporate development.

Can you please give us an insight into how big the market for this is – here in Germany alone?

Leu: Without taking into account other applications from other areas of critical infrastructure, 3,800 base stations are in operation in the BOS radio network alone, with power requirements of less than 5 kW. In the service range, we tend to assume more than 10,000 applications with high availability requirements.

You look after, for example, the BOS digital radio in Brandenburg. Can you briefly discuss what you’re doing there with respect to this project?

Eska: In Brandenburg, we are are working as subcontractors of the fuel cell manufacturer Advent Technologies from Denmark. We coordinate all necessary planning and installation work for emergency power systems. We are also the first point of contact for technical questions for the operator. In the next phase, we will also take care of the maintenance and service work.

There’s this great term “grid hardening.” What does that mean?

Leu: The aim of grid hardening is to secure the entire BOS radio network for 72 hours. For this purpose, the existing battery UPS systems are usually supplemented by stationary emergency power systems. Many of the German states rely on fuel cell solutions for this.

Axiosus was at a CPN workshop in 2022, but isn’t, according to the website, a partner of Clean Power Net (CPN). This alliance has been very quiet in recent years. This was once one of the lighthouse projects (Leuchturmprojekt) of the German administrative agency for hydrogen and fuel cell technology (NOW). Is anything still happening there?

Eska: We see CPN as a valuable alliance of manufacturers and suppliers. As we are not members ourselves, we cannot comment on current CPN activities. As guests at the 2022 workshop, we were able to report on our operating experience in Brandenburg.

What is your latest project?

Leu: In our latest project, we are currently helping a big company with the design and procurement of hydrogen storage systems along with the associated logistics concept. We are also continuing to build up our company. First of all, we need to recruit more staff this year in order to meet demand. If all inquiries materialize, we will be able to provide larger power supply services and other orders as a general contractor.

Last question: Are you actually also internationally active?

Eska: Even though we have not been operating for long under Axiosus Energy, we already have customers from both EU and non-EU countries. Our collaboration with the Danish Advent Technologies A/S we’ve already mentioned.

Thank you very much for your answers to the questions.

Interviewer: Sven Geitmann