Hydrogen production: the search for the missing molecule

Hydrogen is abundant, but rarely free. It is stuck in molecules such as water (H₂O) and must first be extracted - a task for electrolysers. They split water into hydrogen (H₂) and oxygen (O). The hydrogen obtained can power fuel cells or be replaced in blast furnaces. So far, however, such systems have been manufactured in Germany in small quantities and at high cost.

This is set to change. The "H2 Giga" flagship project has been researching production on a gigawatt scale since 2021. A goal that marks the transition from manufacturing to industrial production, so to speak.

Robots take over production of electrolyzers

Until now, electrolysers have mainly been assembled by hand. In Braak, Schleswig-Holstein, something has now been created that can be seen as the opposite: an automated production line.

In the "PEP.IN" sub-project, scientists have worked with industry to set up a system in which robots carry out stacking - the precise layering of electrodes and membranes.

"The robots need one second to place one component on top of the other," says Nicolas Mandry from Fraunhofer IPA.

One second - a speed that would be unattainable in manual work. The team developed the grippers themselves. Quality assurance is also carried out using cameras and image processing. They sort out what is faulty and tolerate what remains uncritical.

The result is a factory on a gigawatt scale.

"The electrolysers produced here within a year therefore have an accumulated nominal output of at least one gigawatt - a multiple of what was achieved when electrolysers were still manufactured using a lot of manual labor,"
says Mandry.

Digital twin: a digital image

Industrialization needs an overview. In the FRHY sub-project, researchers are therefore working on a networked production IT system that collects data from all production modules in real time - a digital twin that makes errors visible and enables optimization.

But despite all the ambition, not everything stayed on schedule.

"Shortly before the end of the research project, not all of the production facilities, which are spread across a total of five Fraunhofer Institutes, have been completed or put into operation,"
says Henry Himmelstoß.

Supply bottlenecks have delayed the construction. For the time being, emulators are simulating what machines will later take over. It looks like a makeshift solution - but one that nurtures hope for a follow-up project.

Iridium: The scarce element

Few details demonstrate the technology's dependence on global raw materials markets as clearly as the anode of PEM electrolysers. It is coated with iridium, one of the rarest elements of all. Around 0.67 grams are required per kilowatt.