Rolls-Royce has acquired a 54 per cent controlling ownership in electrolysis stack expert Hoeller Electrolyzer, whose cutting-edge technology will serve as the foundation for a new line of mtu electrolyzer products from its Power Systems division.

Hoeller Electrolyzer, based in Wismar, Germany, is an early-stage technological business producing polymer electrolyte membrane (PEM) stacks for the cost-effective production of hydrogen under the brand name Prometheus.

Hydrogen is becoming an increasingly appealing energy source to fuel the green energy transition, and the demand for "green" hydrogen – whose production does not produce CO2 – is anticipated to increase substantially. 

It is required for fuel cells and hydrogen engines, the manufacture of synthetic "drop-in" fuels, and industrial operations that currently utilise hydrogen that is not produced in a carbon-neutral manner. Therefore, high-performance electrolyzers are an integral part of any hydrogen system.

Dr Otto Preiss, COO and Chief Technology Officer, Rolls-Royce Power Systems, said: 

“By developing our mtu electrolyzers and by taking a majority stake in Hoeller Electrolyzers, we are methodically growing our hydrogen portfolio and securing access to this fascinating technology, which is not a pipe dream but has great market potential. 

"This will enable us to supply complete hydrogen solutions and make a significant contribution to protecting the climate. Our complete hydrogen solutions will enable customers to store renewably produced energy in the form of hydrogen for use as and when required, or for further processing or onward sale.”

In hydrogen electrolysis, water is exposed to a direct current, resulting in the formation of hydrogen at the negative pole and oxygen at the positive pole. 

Using electricity from renewable sources such as solar or wind, it is possible to manufacture carbon-neutral hydrogen in this manner. 

In a cell, the electrochemical reaction occurs between plate-shaped electrodes that are separated by membranes. The 'stack', the heart of an electrolyzer, is composed of hundreds of cells arranged vertically and squeezed together.

With Prometheus, Hoeller Electrolyzer has positioned itself as one of the few highly specialised specialist players in high-efficiency PEM electrolysis stacks. Hoeller Electrolyzer was founded in 2016. Stefan Holler, the company's creator, has over a quarter-century of experience developing electrolysis technology and has already registered 14 patents related to Prometheus. 

Special surface technologies for the bipolar plates, which reduce the need for the costly precious metals platinum and iridium as catalysts, as well as enhanced output pressure, offer a very high level of efficiency.

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 share a belief in the viability of carbon-free energy for both power generation and the propulsion of large vehicles. 

Rolls-Royce will design a comprehensive electrolyzer system utilising its decades of experience and systems expertise, as well as its global sales and service network, which has the potential for considerable worldwide sales.

Already under development is the first mtu electrolyzer utilising a Hoeller Electrolyzer stack. In 2023, it will be operational at the Validation Center in Friedrichshafen to illustrate how an electrolyzer fits into the microgrid's overall architecture. A customer project is scheduled to begin in 2024.

Power Systems' Net Zero Solutions business unit leader Armin Fürderer stated, "We will introduce electrolyzers with many megawatts of power from the beginning. Combining multiple electrolyzers might produce a total output of more than 100 megawatts."

Rolls-Royce now has equity in Hoeller Electrolyzer due to the departure of minority shareholders and an increase in share capital.

Stefan Holler and Matthias Kramer will continue to lead Hoeller Electrolyzer as a separate entity, to become the world's leading maker of stacks.

Source: Travel News Asia

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