Siemens Energy has announced plans to build a “multi-gigawatt” PEM electrolyser factory in Berlin, with the first 1GW up and running in 2023.

The “highly automated” facility will be built at an existing production hall at a location already used by the company to produce gas turbines capable of burning hydrogen blends.

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Giga-scale electrolyser factories have already been announced by Germany’s Thyssenkrupp (5GW), Australia’s Fortescue Future Industries (2GW, in conjunction with Plug Power), the UK’s ITM Power (5GW), France’s McPhy (1GW), Plug Power (1GW in the US and 1GW in South Korea), US manufacturer Cummins (two 1GW plants, one in conjunction with Iberdrola and the other with Chinese oil giant Sinopec) and India’s Ohmium (500MW, but “expandable to 2GW”).

Siemens Energy says it will produce the electrolyser cells and stacks at the Berlin plant — which will be powered entirely by renewable electricity — but will then transport these 540km by truck to a facility in the city of Mülheim for assembly into “larger process-based units”.

The company — which was spun off from conglomerate Siemens’ gas and power division in 2020 — already builds PEM (proton exchange membrane) electrolysers, and will move its existing manufacturing capacity to the Berlin site.

“For us, hydrogen is an important component of the future energy world. For this to be economically viable, the manufacturing costs for electrolyzers must be significantly reduced. With our new production facility, we are helping to make hydrogen competitive sooner,” said CEO Christian Bruch.

Siemens Energy declined to tell Recharge how much cheaper the company's electrolysers would be once mass production in Berlin begins.

PEM machines are said to be more expensive than traditional alkaline electrolysers, but better able to deal with the ups and downs of variable renewable energy — although a report this week by the International Renewable Energy Agency said: “The flexibility of alkaline and proton-exchange membrane stacks [inside electrolysers] is sufficient to follow fluctuations in wind and solar.”