The MAN subsidiary Quest One, formerly H-Tec Systems, celebrated the opening of its “Gigahub” in the north of Hamburg at the end of September 2024. It wants to produce flexible PEM electrolyzers with meter-high stacks on a large scale.

It was one of those success moments of the energy transition where everyone gladly stood on stage and whose importance can be easily recognized by the number of celebrities. First and foremost, of course, was German chancellor Olaf Scholz. It was a long time since Scholz was in Hamburg-Rahlstedt, he said. As a young kid, he had gone to school there. “But back then, we didn’t yet learn that hydrogen could be used to power airplanes. This was at most a topic for researchers,” recounted Scholz in the brand new factory hall of Quest One.

From Hamburg politics, the first Bürgermeister Peter Tschentscher as well as the economy senator Melanie Leonhard made an appearance – usually no more than one of them comes to such celebrations. From Berlin came the parliamentary secretary Michael Kellner from the federal economy and climate protection ministry and Till Mansmann, green hydrogen officer of the federal ministry for education and research. From Quest One’s parent company MAN Energy Solutions and its parent company Volkswagen, the heads of the supervisory board arrived respectively, Gunnar Kilian und Hans Dieter Pötsch.

The reason for all the fuss: The company Quest One, who the day before was called H-Tec Systems, wants to start electrolyzer production on a gigawatt scale in the northeast of Hamburg.

PEM electrolysis getting big
The company story of Quest One is a story of the scaling of PEM electrolyzers. PEM electrolysis runs at moderate pressure and medium temperatures, so it offers a good compromise between efficiency and flexibility. This makes it the technology of choice when it comes to producing hydrogen using the unsteady energy sources of wind and sun. But compared to alkaline electrolysis, it has decades of industrial scaling to catch up on.

H-Tec Wasserstoff-Energie-Systeme, as Quest One was called until the end of September, began producing mini PEM electrolyzers in 1997. They were primarily intended to introduce schoolchildren to the physical principle of electrolysis. With alkaline electrolyzers powered by hydropower, at this point in time ten thousand cubic meters of hydrogen hourly was being generated in Norway and Egypt for fertilizer production. That hydrogen could seriously become a storage technology for solar and wind power was believed at the time by at most a handful of visionaries.

Since then, not only renewable energies have become significantly cheaper. PEM technology has also caught up significantly. In 2010, the northern German energy transition company GP Joule bought H-Tec. The electrolyzers grew to a few hundred kilowatts, at least suitable for small applications. In 2019, MAN Energy Solutions got aboard and H-Tec brought the first megawatt electrolyzer onto the market: nine stacks of 110 kW each, each the size of a beer crate, together with the associated peripheral systems, mounted ready for connection in a 40-foot container – a practical solution for small wind farms and individual hydrogen refueling stations.

Fig. 2: Moment of success in the energy transition: Children symbolically pressed the start button for electrolyzer production from Quest One

Gigawatt plans for green hydrogen
To supply steel mills, fertilizer manufacturers and refineries with hydrogen, this is still far from enough, nor is it enough for the target of 10 GW of electrolysis output that the former Ampel Coalition leading the federal government set for 2030. That is the dimension in which Quest One also wants to get involved. The new name should make that clear. It should not only say that climate protection is the most important of all tasks, but also that the company wants to avoid one percent of global greenhouse gas emissions with green hydrogen from its electrolyzers, explained Robin von Plettenberg, CEO of Quest One at the opening ceremony.

The approximately 800 guests applauded loudly. In general, when the “Gigahub” was officially put into operation, there was no shortage of buzzwords and emotion. Across the screen flickered images of parched soils, raging floods, burning forests, followed by an hourglass – and the shiny, metallic, donut-shaped logo of Quest One. The project is “part of something really big,” said von Plettenberg.

From handcraft to series production
So far, the production hall has primarily provided space for large plans. On the opening day, the clean room with the actual production almost completely disappeared behind the huge video screen. But innovations are not always reflected in large machines. While today you can buy turnkey solar and battery factories with little out of pocket, Quest One with each production step that runs automated and reliably in Rahlstedt has conquered a piece of new technological territory.

The research and development center, which is also located at the gigahub, helps here. Until recently, for example, employees still assembled the electrolysis cells into stacks by hand, which took hours of work. This step requires absolute precision, because the tiny hydrogen molecules can escape through the smallest gap and thus make the entire stack unusable. As Quest One celebrated its opening at the end of September, it had already succeeded in delegating this task to robots. They get the job done in a quarter of the time. Less than an hour is what it now takes to produce a stack.

Now that the automated handling is running, Quest One is also daring to speak of a new generation of megawatt stacks. Three meters high and weighing three tonnes is what they will be, it was said. The hall should be largely full by the end of 2026; then production of the megawatt stacks should begin. Such stacks could also make it easier to implement projects beyond the 100‑MW mark with PEM electrolyzers. In the course of 2026, Quest One wants to move in the direction announced in the press release – a manufacturing capacity of 5 GW annually.

A few months after the opening, everyday life has returned to Quest One. For the offices, there is still some expansion work to be done. In the clean rooms, however, series production is taking place. In the huge hall, instead of bistro tables and chairs, there are now shelves to store the stacks. They will be sent to the company’s headquarters in Augsburg, where the production of the electrolyzers is located.

For these electrolyzers to be able to produce really clean hydrogen, a lot still has to happen outside the factory. Wind and solar parks must be built and financed, as well as networks and storage for the hydrogen.

Even at the opening, the panel discussion after the ceremonial push of a button showed that those present were very aware of the challenges. “The real work is just beginning now,” concluded Jürgen Klöpffer, chief financial officer of MAN Energy.