Just switch over?

Just switch over?

Hydrogen in the existing natural gas network

Whether hydrogen contributes to the clean heating transition will also depend on how easily existing natural gas networks can be converted. This is what Gasnetz Hamburg wants to find out in the project H2Switch100. For this, the company is looking at a very ordinary section of its existing network.


There’s nothing special about the small grid section in the southern district of Hamburg – exactly why the grid operator Gasnetz Hamburg chose it. In total 16 connections, including 14 normal households, a business park and a sports club. In the residential buildings, natural gas heating systems are installed. The business park and sports club operate a combined heat and power plant with natural gas. There are in the partial network new PE (polyethylene) pipes as well as old steel pipes and house connections from various decades. “The network section is representative for Hamburg’s gas grid,” said Sebastian Esser, project leader at Gasnetz Hamburg.

The aim is to find out whether other ordinary network sections could also be converted to hydrogen. The mix of materials and designs distinguishes H₂-SWITCH100 from the longer-running project H2Direkt of the company Thüga in Hohenwart. There, already in winter 2023/24, ten households and one commercial customer are to be supplied with pure hydrogen. However, only PE pipes, known to be suitable for hydrogen, are installed there (see p. 30).


Feasibility study with laboratory trials

In Hamburg, meanwhile, preliminary investigations are still pending. Together with the partners TÜV Süd and DBI Gas- und Umwelttechnik, Gasnetz Hamburg wants to demonstrate in a feasibility study within twelve months the integrity of the network for hydrogen. In the first step, samples from the original network will be sent to the lab. “For each component type that occurs in the network, we will examine at least one specimen,” said Esser.

In particular, these are individual gate valves and ball valves, but also entire service laterals and pieces of piping. In the laboratories of partner organizations, the components should then demonstrate that they are suitable for employment in a hydrogen network. Is there any embrittlement of the steel parts? Do the pressure regulators work? Are the shut-off devices tight? Answers to these questions are to be provided in the feasibility study running until August and funded by the investment bank IFB Hamburg (Hamburgische Investitions- und Förderbank).

“We’re very confident about the old components and the pipes themselves, as gas with about 50 percent hydrogen content was flowing through the pipes until the 1980s. Some components, however, were added later,” said Esser. The cost for this first project phase, according to Gasnetz Hamburg, lies “in the low six-figure range.”

Replace meter and burner

If the laboratory tests turn out positive, step 2 will follow: the actual conversion of the network. At issue will not be merely feasibility but also costs. Because even if the network is suitable for hydrogen, at the least the burner nozzles and the meters will probably have to be replaced. Lastly, the standard volume of gas must increase by a factor of three to compensate for the lower calorific value of hydrogen compared to natural gas.

“In the pipes themselves, this is no problem. Firstly, the hydrogen has a lower viscosity and therefore flows faster; secondly, we can slightly increase the pressure if necessary; and thirdly, the pipe diameters in the Hamburg gas grid are sufficiently dimensioned to accommodate the higher throughput,” erklärt Esser.

Many manufacturers already have up their sleeves heaters that can be operated with pure hydrogen, for the coming years. “As far as the combined heat and power plants are concerned, manufacturers have already announced their intention to make devices available for testing,” according to Esser. The additional costs incurred as a result of the pilot test will be borne by Gasnetz Hamburg. Thanks to this pledge, the supplier is being met with wide-open customer doors. “Even some neighbors who do not yet have a natural gas connection have now expressed an interest in hydrogen,” Esser recounted.

Hydrogen from planned industrial network

While the pipes and other components are very normal, the location of the network section is very special. It lies almost directly along the route for the already planned hydrogen network for the Hamburg industry with project name HH-WIN. Already in 2024, Gasnetz Hamburg wants to have built large parts of HH-WIN. In year 2027, the company intends to be able to supply the first hydrogen volumes. The confirmation that this will be an IPCEI (Important Project of Common European Interest), which is eligible for a particularly high level of funding, was still pending at the time of going to press.

“Compared to the needs of industry, the hydrogen requirement for the pilot project is minimal,” said Esser. The hydrogen for the industrial network is to come from three sources, which according to current announcements should all stand ready to be put into operation. On the one hand, there is the 100-megawatt electrolyzer that should appear directly in the industrial area at the site of the former coal-fired plant Kohlekraftwerk Moorburg. After some unrest within the project consortium, Hamburger Energiewerke wants to implement the project now together with asset manager Luxcara as majority shareholder. Commissioning is still targeted for 2026.

Secondly, hydrogen is to come to Hamburg via an ammonia terminal that Mabanft and Air Products announced at the start of 2022. By now, the project has undergone a nautical risk analysis, and the companies are in the process of compiling the documents for the approval procedure. As target year for commissioning Mabanaft still named 2026.

And thirdly, there is the European hydrogen core network of the grid operators. Both with the Netherlands and with Wilhelmshaven, Hamburg is connected by existing long-distance lines that are to be converted to hydrogen in the first project phase (see p. 30).

How low-CO2 the production of hydrogen will be in each case is difficult to say, as the regulations as well as the energy production and conversion are massively in motion.

Role of hydrogen in the heating transition unclear

If it turns out that the pipeline network could be easily repurposed, this does not make hydrogen the first choice for Hamburg’s heating transition. After all, in contrast to industry, there are many other options for heating buildings with significantly lower conversion losses. This consideration was once also the basis of the Wasserstoff-Roadmap (hydrogen roadmap), which prioritized – initially still scarce – green hydrogen for sectors that are difficult to decarbonize, including first and foremost industry. The environmental and energy office of Hamburg (BUKEA) also is following this strategy.

The Hanseatic city started collecting data for a heating register much earlier than most other large cities, and intends to present a complete heating plan already by 2024. In the city center, this will probably mainly be district heating, while heat pumps are popular in the peripheral areas.

“Certainly, converting the natural gas pipelines to pure hydrogen operation is not a solution for the whole of Hamburg,” acknowledged Michael Dammann, the technical managing director of Gasnetz Hamburg. “However, the further use of an already existing infrastructure with the green gas can be a sensible supplement to options like expansion of district heating and heat pumps in certain building structures and locations. With H₂-SWITCH100, we want to find out specifically what effort and costs are associated with such a changeover and whether there are technical hurdles.”

Author: Eva Augsten

Pilot plant for coating bipolar plates

Pilot plant for coating bipolar plates

At Fraunhofer FEP (Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik), a pilot plant for the coating of metal sheets and strips is being used for the efficient coating of bipolar plates for electrolyzers and fuel cells. The institute, according to its own statements, is a leader in the development of electron beam and plasma technologies. This expertise could also advance hydrogen technology in the future.

One example of this would be plasma-activated electron beam evaporation. This is a vacuum coating process that enables both high throughput and high coating quality. Exactly this combination is crucial for the coating of bipolar plates for electrolyzers and fuel cells. Because these have to function for a long time, stably, in a chemically aggressive environment. For this, they must receive coatings that reliably protect the plates and at the same time guarantee electrical conductivity.


Using electron beam evaporation, coatings to form a certain shape can be applied to the metal strip before these are stamped into bipolar plates, stated Burkhard Zimmermann, division manager for electron beam technologies at Fraunhofer FEP. The coating of the material is a crucial step for scaling the production with a roll-to-roll process. The challenge here is the formability of the coating. To ensure this, a dense macrostructure of the coating with the largest possible crystallites is required. Exactly these layer properties can be realized by the developed processes.

H2 production by photocatalysis

H2 production by photocatalysis

The direct generation of hydrogen from sunlight has long been considered the most elegant solution for H2 production, if then scalable. Until now, there has still been a deficit of suitable materials and large-scale system solutions. Researchers at the University of Cambridge in England have now found an approach that from salt or waste water, directly with the help of solar energy, can produce drinking water and hydrogen.

For this, chemist Chanon Pornrungroj has combined a solar vapor generator (SVG) with a photocatalyst (PC). Normally, pure water is required for photocatalysis. In order to be able to use dirty water as well, he designed a water evaporator powered by solar heat, which removes impurities. This condensed water can then (after mineral addition) be used for drinking and cooking, and also for subsequent H2 production.


The research group of Erwin Reisner deposited a photocatalyst for this on a nanostructured carbon mesh that absorbs both light and heat and generates water vapor. The photocatalyst then uses this water vapor to generate H2. Especially in regions without access to clean water could this be an important advancement.

Stracke other H2Now managing director

Stracke other H2Now managing director

BMV Energy GmbH is entering the market as another player in hydrogen refueling stations. The owner-managed, medium-sized company together with Score founded H2Now GmbH in August 2023 and appointed Stefan Schwarzer as managing director to advance the establishment of refueling stations with green hydrogen, particularly for commercial vehicles. In November 2023, the Berlin-based company announced that the company will be co-represented with second managing director Andrew Stracke in April 2024. Stracke was prior to this a member of the executive board at Westfalen AG.

H2Now was brought to life jointly by the petroleum company BMV and Score, a gas station operator with headquarters in Emden, to bundle the synergies of the medium-sized companies. To the BMV corporation belongs a gas station network with 145 stations of the brands Sprint and Go. According to the management, there are “already established locations suitable for the addition of a hydrogen refueling station with the help of H2NOW, to become part of the Germany-wide hydrogen station network and be supported with extensive know-how in project planning, funding, realization and operation.”

Starting points for a comprehensive hydrogen ramp-up

Starting points for a comprehensive hydrogen ramp-up

Industry congress GAT 2023 in Cologne

To establish a functioning hydrogen economy, the entire value chain must be addressed. It is important to keep in view the market and regulatory aspects as well as the technical aspects (standardization). At the event GAT 2023 in September in Cologne, it could be seen how intensively the industry is working on the implementation. Exciting here are, among other things, the conversion plans of the gas grid operators towards climate-neutral gases. The second phase of the GTP also shows the great interest on the part of municipalities and the industrial sector.

Dr. Kirsten Westphal made clear how the German association for energy and water economy (Bundesverband der Energie- und Wasserwirtschaft, BDEW) see the heating market of the future: “Instead of natural gas, in the future especially hydrogen and its derivatives will be employed,” said the member of top management at the event in Cologne. The hydrogen will come from domestic production as well as a considerable portion from imports. The BDEW is not worried that it will come to a deficit situation. “The studies show that sufficient quantities of hydrogen will be able to be made available,” stated Westphal.


However, the ramp-up of hydrogen production requires the right framework conditions. Regarding this, the BDEW representative counts in addition to the acceleration and strengthening of the expansion of renewable energies in Germany also the quick notification of IPCEI projects (Important Projects of Common European Interest) for hydrogen production by the EU, which will then actually occur at the end of the year (see p. 20), as well as other supplementary funding programs to reach the electrolysis capacity target of 10 GW in year 2030.

On the import side, Westphal is calling on politicians to present an import strategy in the short term. Furthermore, the financing of import projects should also be flanked by measures such as Hermes cover (export credit guarantees) or capital subsidies.


Establishment of a functioning H2 trading market

One aspect of particular importance, however, is to embed the ramp-up of hydrogen production in the development of a market. In each of the various phases in this, different political instruments are needed: to begin, more steering and support; later, a growing market and less support. The visualized goal is a functioning trading market in which hydrogen volumes are efficiently distributed according to market-based mechanisms.

But what characterizes the image of the targeted steady-state hydrogen market? In Cologne, the BDEW expert named a whole bundle of criteria:

  • Production and trade of hydrogen and its derivatives in Germany, the EU and globally in sufficient quantities
  • The combination of long-term contracts (particularly at import level) with competitive prices that reflect current market conditions as well as increasing spot deliveries
  • The trading of guarantees of origin, certificates and commodities on a uniform, standardized European market that includes an international connection
  • Competition for access to end customers as well as transparent price signals and sufficient market liquidity on the supplier side
  • A fully functional and comprehensive network infrastructure. Non-discriminatory grid access for all competitive players on the hydrogen market. H2 grid access is essentially based on the entry-exit system.
  • Climate-neutral hydrogen is used wherever there is demand. Demand is based on the market price.
  • Storage options ensure security of supply for hydrogen and derivatives and open up various ways to make the hydrogen market flexible. There is decentralized generation and purchase as well as central storage.

In all these projects are, according to Westphal, a transparent and reliable standardization as well as certification needed, to also create acceptance for hydrogen and its derivatives, which also needs a stable regulatory framework.

Standardization of particular importance

The establishing of standards is also the means of choice from the view of Dr. Thomas Gößmann. According to the Thyssengas chairman, it should be borne in mind that the approval offices have had little contact with the topic of hydrogen until now and therefore have no experience in most cases.

For Germany as an export country, the agreement on international standards is of particular importance, stated Oda Keppler, ministerial director at the German ministry for education and research (BMBF), at GAT. This applies, among other things, for the quality criteria for the product hydrogen, as otherwise the international trading of it could not be done.

For the success of the hydrogen economy, it is crucial, according to Gößmann, to involve the people. “If the country of engineers succeeds in taking the people with it, then we will also succeed,” the Thyssengas chairman is certain. It is also important not to focus too much on the color principle of the hydrogen. This is hardly comprehensible for many people anyway. “We are colorblind. We’re setting up the highway. It doesn’t matter to us who drives on it,” said the grid operator.

Dr. Frank Reiners is certain that the hydrogen economy will only really take off when the entire value chain is populated. According to the member of the management board of Open Grid Europe, however, pipeline construction is of particular importance. Germany as a hub has a special role and responsibility here, as many gas pipelines come on land or come together here. “We cannot afford to do nothing,” stated Reiners in Cologne.

Prof. Gerald Linke, chairman of the DVGW, said at the opening of the industry event GAT in Cologne, “The backbone network must provide all regions in Germany with access to climate-neutral hydrogen.”

H2 core network for all regions

The German association for gas and water standards (Deutscher Verein des Gas- und Wasserfaches, DVGW) welcomes the federal government’s initiative, in an amendment to the energy industry act (Energiewirtschaftsgesetz), to establish a legal framework for the rapid approval and construction of a hydrogen core network. However, to the DVGW, this approach does not go far enough. “The backbone network must provide all regions in Germany with access to climate-neutral hydrogen, as otherwise an exiting of entire economy sectors is imminent, especially the small and medium enterprises,” said the DVGW chairman Prof. Gerald Linke at the industry event.

In a second step, transformation regulation for gas distribution grids is therefore also needed. Without an extensive conversion of the existing gas distribution infrastructure, it will not be possible to transform the connections of 1.8 million industrial and commercial customers toward climate neutrality, stressed Linke.

The basis for the transport to end customers has been laid out in the so-termed Gasnetzgebietstransformationsplan (gas grid area transformation plan, GTP) by the DVGW together with the initiative H2vorOrt. In the current second planning year, 241 gas distribution system operators have participated, a significant increase compared to the 180 companies in the previous year. Currently, the GTP covers pipelines with a total length of 415,000 km (258,000 mi) and reaches 381 of the total 401 regional districts of Germany.

The planning process with the GTP is deliberately designed to be open-ended and includes the conversion, decommissioning and partial new construction of pipelines. Considered are all new, climate-neutral gases, so in addition to hydrogen also for example biomethane. The aim of the GTP is to accelerate the transformation at the distribution grid level and, by the individual planning of the grid operators in coordination with the other stages of the supply chain, to create a coherent vision for the whole of Germany. As part of the GTP planning, the grid operators are analyzing on the basis of their specific situations on site the demands of their customers, the decentralized feed-in situation, the development of hydrogen availability by upstream network operators and the technical suitability of their networks for hydrogen.

For the first time in Germany, the conversion of a long-distance gas pipeline to transport hydrogen has begun at OGE Verdichterstation Emsbüren

Municipalities and industry are planning with hydrogen

Part of the GTP is also a survey of end customers by the respective network operators. This revealed a clear preference for the use of climate-neutral gases. Only five percent of the nearly 1,000 surveyed municipalities see no need in the long term for the use of climate-neutral gases. Of the nearly 2,000 major industrial customers who responded, more than three quarters are relying on hydrogen in the future. And 29 percent already see the use of hydrogen as an option by 2030, while a further 30 percent expect this in the coming decade.

Some current projects show that these visions are already currently being implemented. For example, mid-October at Verdichterstation Emsbüren, a compressor station of grid operator OGE in Niedersachsen, was the start of the conversion of the first long-distance pipeline to transport hydrogen (see Fig. 3). As part of the project GET H2 Nukleus, this is to establish the core for a nationwide hydrogen infrastructure. With the changeover, the participating network operators want to enable customers from industry and SMEs to connect to the hydrogen supply.

Most of the municipalities surveyed, according to the DVGW poll, are counting on climate-neutral gases in the long term

Another project started at the beginning of November in Energiepark Bad Lauchstädt with the start of the second phase of the conversion of a natural gas pipeline for the transport of hydrogen. For the technically seamless operation of the grid of the future of transmission system operator Ontras Gastransport, a pig launcher was placed in position. The following months will be preparation for putting into operation the hydrogen pipeline. For this, the construction of a transfer station as well as setting up a system for purifying and drying the gas are necessary. Once Energiepark Bad Lauchstädt is fully operational in year 2025, test transfers of hydrogen will follow, scientifically accompanied by DBI-GTI (DBI Gastechnologisches Institut gGmbH Freiberg), an independent laboratory of the DVGW.

Such projects help to increasingly address the locational advantages of the continent. At GAT in Cologne, Prof. Thomas Thiemann of Siemens Energy summed up the situation as follows: “With its large pipeline network and storage facilities, Europe has a huge asset compared to other areas. We must exploit this advantage.”

Out of the surveyed industrial customers, 76 percent are interested in hydrogen

Study: Green hydrogen not more expensive than gas in the long term

End customer prices for green hydrogen in the medium and long term could be in the range of natural gas or the current subsidization threshold of natural gas of 12 euro-cents per kWh (Gaspreisbremse). That is what the study by Frontier Economics on behalf of the DVGW determined. If total costs are compared – so costs for acquisition, building renovation and operation, – then the cost for both single-family and multi-family houses with a gas boiler powered by hydrogen, depending on building type and efficiency class, lie at a similar level to an electrically run heat pump. In the study, the total costs of various energy carriers for households as well as for exemplary heat supply solutions were compared with each other.

For the cost comparison, indicative end customer prices based on production costs were used. In addition to the prices for gaseous energy sources, the DVGW study also compares the total costs that households may incur depending on the heat supply solution. Because if the goal is to meet the climate targets, heat generation for buildings in Germany must be fundamentally changed, according to the DVGW.

The aim of the investigation is, on the one hand, to put the end customer prices of green hydrogen in relation to alternative energy sources for households in the years 2035 and 2045. On the other hand, the analysis focuses on the total costs of different heat supply solutions for two selected building types in the efficiency classes B and D. Considered are green gas boilers based on biomethane and climate-neutral hydrogen as well as heat pumps.

Overall, the comparison shows that the cost ratios of the energy sources change over the period under review. While end customer prices for climate-neutral hydrogen in Germany are expected to remain above those for natural gas and biomethane until 2035, they could reach a comparable level by 2045.

Households in Germany would therefore have to pay between 12 and 17 euro-cents per kWh for hydrogen in 2035. The price of natural gas, on the other hand, taking rising CO2 prices into account, would be between 9 and 11 euro-cents per kWh, and that for biomethane just above, at around 10 to 13 euro-cents per kWh, depending on the biomass used in its production.

After 2035, end customer prices for hydrogen could fall and approach those of natural gas. The main drivers for this include the degression of costs for H2 production and rising CO2 prices in the context of emissions trading. In year 2045, according to the study, purchase prices for hydrogen could then lower to around 11 to 15 euro-cents per kWh.

Author: Michael Nallinger

The industry highpoint in autumn

The industry highpoint in autumn

Hydrogen Technology Expo total success

In autumn 2023 as well, the Hydrogen Technology Expo was again the event you had to be at. For the third time in a row, the British organizer Trans-Global Events Ltd was able to dramatically increase the number of exhibitors as well as visitors – which is why the trade fair halls of the Hanseatic city on the Weser (Bremen) will no longer be sufficient in 2024. The move to Hamburg this year is therefore inevitable and had been predicted early on by H2-international (see H2-international Feb. 2023).

The trend is unmistakable: More and more companies from the mechanical engineering, electrical and chemical industries are flooding the hydrogen market. Accordingly, a large number of completely new exhibitors could be found in the four trade fair halls in Bremen. Among them were numerous unknown names, but also heavyweights such as Saudi Aramco, ExxonMobil or ITM Power.


After 180 exhibitors in the first and 350 in the second year, this time there were over 550 – in 2024, there should be at least 100 more. The number of visitors increased from 5,000 in the previous year to over 10,000.

Moving towards mass production


Companies like the chemicals corporation Gore had explicitly “chosen this trade show in Europe” because “Europe is furthest along.” Nouchine Humbert, Global Marketing Director of W.L. Gore, told H2-international, “This is a market where we expect strong growth.” Referred to is particularly the electrolysis sector, because in comparison fuel cells need “many more square meters than electrolyzers.”

Sufficient production capacity is available to the North American company – in Japan. The production lines there are enough for another five years, asserted Rainer Enggruber, director of the division PEM/water/electrolysis products. Gigawatt announcements are therefore not a challenge for the membrane manufacturer, it was confidently stated.

New tubular reactor

An innovation was shown by the Hebmüller Group. Sales director Marc Hebmüller presented the prototype of the HydroGenMHD (see Fig. 1), an H2 generation device from One Scientific of Johnson City, Tennessee. The company Hebmüller is the European licensee of the US system developer that developed this compact tubular catalyst, in whose magnetohydrodynamic chamber hydrogen is generated upon splitting off of oxygen from water vapor.

Marc Hebmüller explained: “This innovative technology employs a unique system where superheated steam is subjected to a catalyst and intense magnetic fields generated through the MHD process. These magnetic fields induce controlled plasma dynamics within the feedstock, facilitating the dissociation of molecules into hydrogen gas and oxygen gas.”

Stack based on circuit boards

A completely new concept for the production of fuel cells was presented by Bramble Energy: a fuel cell stack based on printed circuit board technology. The British company founded in 2017 relies here on the plastic FR4, which provides the necessary stability, and copper as a heat as well as electricity conductor. Between two circuit boards is one membrane each, which means that bipolar plates can be dispensed with entirely. Instead, a monopolar plate constitutes a single cell, of which several are then stacked.

The technology readiness level Carsten Pohlmann, director for business development (see Fig. 2), puts at TRL 9, and the price per kilowatt at 100 USD. First tests in a Renault demonstrator and with a 100 kW system for a double-decker bus are already underway.

Carsten Pohlmann presented in Bremen for the first time the circuit board cell from Bramble

The next Hydrogen Technology Expo Europe will take place October 23 and 24, 2024 on the fairgrounds of Messe Hamburg. It therefore will overlap by one day with WindEnergy.