Founded in 2016, Hoeller Electrolyzer has positioned itself, with Prometheus, as one of the few highly specialized expert players in the field of high-efficiency PEM electrolysis stacks. Its founder, Stefan Höller, has more than a quarter of a century’s experience of developing electrolysis technology and has already registered 14 patents connected with Prometheus. Particularly high efficiency is promised by special surface technologies for the bipolar plates which significantly reduce the use of expensive precious metals platinum and iridium as catalysts, as well as increased output pressure.

Stefan Höller, Managing Director, Hoeller Electrolyzer, said: “Our stack is going to produce hydrogen at a price not previously thought possible.”

Rolls-Royce and Hoeller Electrolyzer are united by a shared belief in the opportunity of zero-carbon energy – both for power supply and the propulsion of heavy vehicles. With decades of experience and systems expertise, Rolls-Royce is going to develop a complete electrolyzer system and has a global sales and service network, which opens up the potential for significant worldwide sales.

Matthias Kramer, CFO and Joint Managing Director, Hoeller Electrolyzer, said: “In Rolls-Royce, not only have we found an important customer for our stacks, we’ve also secured an ideal partner and supporter who shares our vision of putting stacks into full production.”

Development work on the first mtu electrolyzer using a stack from Hoeller Electrolyzer is already underway. In 2023, it will go into operation at the Validation Center in Friedrichshafen to demonstrate how an electrolyzer fits into the overall architecture of a microgrid. An initial customer project is already planned for 2024.

Armin Fürderer, who heads up the Net Zero Solutions business unit of Power Systems, said: “We’re going to launch electrolyzers with several megawatts of power right from the start. A total output of over 100 megawatts is conceivable by combining several electrolyzers.”

The equity in Hoeller Electrolyzer now held by Rolls-Royce comes from departing minority shareholders and from an increase in share capital. Financial details of the transaction are not being disclosed. Stefan Höller and Matthias Kramer will continue to lead Hoeller Electrolyzer as a standalone company, with the goal of building a leading international stack manufacturer.