Green hydrogen today: These five electrolysis plants are already in operation

Nobian site in Bitterfeld-Wolfen

In the hydrogen industry, much revolves around announcements, agreements, planning, and approvals. Occasionally, ground is broken for a new plant, but electrolyzers actually producing green hydrogen in Germany are still a rarity. However, some plants are already in operation today. This is interesting for manufacturers of industrial valves and seals, as it shows that green hydrogen need not remain a dream. If the German government has its way, many projects will follow - the potential for the valve market is obvious. Here, therefore, are five of the most powerful hydrogen plants in the Federal Republic.

© Hamburg Authority for Environment, Climate, Energy and Agriculture

H&R Ölwerke Schindler GmbH has been producing the hydrogen needed for its refinery since November 2017

5th Place: 5 MW electrolyzer of H&R Schindler GmbH at the Hamburg refinery site

At its refinery site in Hamburg-Neuhof, H&R Ölwerke Schindler GmbH has been operating a 5-megawatt electrolyzer since the end of 2017. The installation of the hydrogen plant was part of the "Green Refinery" concept, as H&R also operates it with electricity from renewable sources. The hydrogen produced is then used in the manufacture of specialty products from mineral oil. Provided by Siemens Energy, the plant is based on PEM (Proton Exchange Membrane) technology and is expected to produce several hundred tons of hydrogen annually. According to the company, the investment costs were around 10 million euros.

A special feature of the plant: It operates "flexibly regulated", meaning it can use excess electricity from wind or solar energy for hydrogen production and thus serve as a buffer storage. This helps the electrolyzer stabilize the power grid during peak load times and prevents power loss during overproduction.

In the long term, H&R wants to replace its fossil raw materials with renewable and synthesized, CO2-neutrally produced products. The company sees itself as an innovation leader in sector coupling, as it links the electricity sector with the material use of hydrogen on an industrial scale.

Energiepark Mainz: Electrolysis hall with recoolers, hydrogen tanks and compressor container

4th Place: 6 MW electrolyzer of Mainzer Stadtwerke and Linde Group in Energiepark Mainz

Since 2015, Mainzer Stadtwerke, together with the Linde Group, has been operating a PEM electrolysis with a total output of 6 megawatts at the Energiepark in Mainz. At its commissioning about ten years ago, it was, according to the companies, the largest of its kind worldwide. The hydrogen from the Mainz Energy Park is also partly green, as it can use excess electricity from wind turbines in the area. Thus, it also plays a role in stabilizing the Mainz power grid.

The core of the plant consists of three PEM electrolyzers from Siemens, each with a peak output of 2 megawatts. The PEM technology enables particularly flexible operation, which is advantageous for the use of volatile renewable energies such as wind power. Therefore, it is often used in electrolyzers already running today.

The process is based on acidic electrolysis with a polymeric solid electrolyte, where water is split into oxygen and hydrogen. An "ionic compressor" developed by Linde compresses the produced hydrogen for storage and transport.

Energiepark Wunsiedel with the hydrogen plant in white at the bottom left

3rd Place: 8.75 MW electrolyzer of WUN H2 GmbH in Energiepark Wunsiedel

The joint venture WUN H2 GmbH was founded in 2021 by Rießner-Gase GmbH, Siemens Project Ventures GmbH and Stadtwerke Wunsiedel. The companies' goal was to construct and operate one of Bavaria's largest energy storage facilities. In September 2022, the PEM plant built by Siemens AG went into operation. Since then, it has been one of the largest of its kind not only in Germany but throughout Europe.

Due to its high production capacity, the plant produces up to 175 kg of hydrogen per hour, according to WUN H2 GmbH. The operators state the possible annual production as 1,350 tons of green hydrogen. The required electricity comes exclusively from regional and supra-regional solar and wind power plants. And not in small amounts: The operators estimate the annual energy requirement at up to 60,000 MWh.

After production, the hydrogen is compressed to up to 500 bar and stored directly on site in tanks. As its purity after appropriate treatment is up to 99.999%, it can be used in mobile fuel cells or the transport sector, among other applications. In addition, WUN H2 sells the hydrogen to local industrial companies.

The Refhyne electrolyzer in Wesseling

2nd Place: 10 MW electrolyzer from Shell in the Shell Energy and Chemicals Park Wesseling

The Shell Energy and Chemicals Park Rheinland in Wesseling near Cologne is home to probably the second-largest electrolyzer in Germany. It was commissioned in the summer of 2021 by the Dutch oil giant Shell. At the time, the company stated that it was the largest PEM electrolysis in Europe. It was built by the British manufacturer ITM Power in Sheffield, with individual components coming from Sweden, Spain, and Germany.

The construction of the 10 MW plant, called "Refhyne", was funded by the EU Fuels Cells and Hydrogen Joint Undertaking. It is expected to produce up to 1,300 tons of green hydrogen annually. Shell is already planning to build a second plant at the site, which would be ten times larger with 100 MW capacity: Refhyne II. However, construction has been postponed so far; it was originally scheduled to begin in 2022.

Shell is one of the five largest oil companies worldwide. However, the Dutch company aims to reduce its CO2 emissions to zero by 2050. In the Rhineland, Shell plans to produce sustainable chemical and energy products, using hydrogen, circular waste materials, and biomass as raw materials.

Nobian site in Bitterfeld-Wolfen

1st Place: ~16 MW chlor-alkali electrolyzer from Nobian in the Bitterfeld-Wolfen Chemical Park

In November 2021, the chemical producer Nobian began production and delivery of green hydrogen for an international customer at the Bitterfeld-Wolfen Chemical Park. This makes it the largest electrolysis site in Germany - according to the company, the electrolyzers require 28 MW of electricity, with the total plant's power requirement even amounting to 32 MW.

The chlor-alkali membrane electrolysis simultaneously splits an aqueous sodium chloride solution with renewable energy into chlorine, caustic soda, and green hydrogen. The CO2 footprint is reduced by 90% compared to conventional hydrogen from fossil fuels. The product meets the TÜV Süd CMS 70 standard. The company also plans to certify all its sites for green hydrogen production. The certification follows strict rules and is intended to ensure that only green electricity is used in production. At the Bitterfeld site, Nobian can produce up to 2,700 tons of green hydrogen annually, according to its own information.

Conclusion

The first plants in Germany are already producing, and many more are set to follow. On July 15, Federal Minister of Economics Robert Habeck, along with the economics ministers from 10 participating federal states, handed over the funding notices for 23 large hydrogen projects.

A total of 4.6 billion euros will flow into the IPCEI projects, with a further 3.3 billion euros in private investments to follow. The money will be used to create, among other things, 1.4 GW of electrolysis capacity and 2,000 kilometers of H2 pipelines. So the money is there, and plans for projects are too - all that's missing are the orders to manufacturers of hydrogen-capable valves.

If you want to learn more about the topic, visit wire & Tube 2026 in Düsseldorf. The production of hydrogen is one of the main themes here.