_H2News: Dr. Kundler, what was the main objective of the_H2Gigahydrogen flagship project?

Dr. Isabel Kundler:_H2Gigawas launched in 2021 as one of three flagship hydrogen projects funded by what is now the Federal Ministry of Research, Technology, and Space (BMFTR). The flagship project conducted research on technologies for the industrialization and upscaling of water electrolysis—a prerequisite for the production of green hydrogen on a gigawatt scale. Approximately 130 partners in 30 independent projects conducted research on these topics and made significant progress across all four electrolysis technologies.

_H2News: To what extent was the goal achieved?

Kundler: They have certainly achieved their main objective: Even while the project was still underway, some manufacturers had already incorporated the technologies researched in_H2Gigainto their production lines—which were not part of the flagship project—such as Siemens Energy AG at its Gigafactory in Berlin and Quest One GmbH at its Gigahub in Hamburg.

The participating universities and research institutes have also achieved important results. They have established test infrastructures for large stacks or modules and, through their research, have gained important insights into the operation of stacks on a large scale. For example, Forschungszentrum Jülich GmbH set up a module test bed for PEM electrolysis on the MW scale, and Clausthal University of Technology established a test field for alkaline electrolysis stacks and conducted research there.

_H2News:_H2Gigahas aimed to make the transition from artisanal production to automated, mass production of electrolysers. How was this achieved?

Kundler: The mass production of electrolysis stacks sounds easier than it is. For example, during stack assembly, robots must grasp mechanically diverse materials—especially soft or fragile ones—and position them precisely before releasing them. The partners have researched and developed production technology specifically tailored to these requirements. These are specialized technologies for first-of-their-kind systems. This was achieved through close collaboration between academia and industry, bringing together fundamental understanding and a focus on industrial relevance.

_H2News: To what extent has the entire project benefited from the collaboration among the 130 partners from academia and industry?

Kundler: The exchange between the partners has brought the community closer together. Thanks to regular meetings on_H2Giga’score topics—as well as on broader issues—the partners’ level of knowledge at the end of the project was certainly higher than it would have been if everyone had worked in isolation on their own projects.

The electrolysis technology platform within the flagship project also invited external speakers and partners from the other flagship projects,_H2Mareand TransHyDE, to provide information on cross-cutting topics, which benefited everyone. This exchange of information made it possible to work more quickly and efficiently in numerous areas.

_H2News: Dr. Ausfelder, let’s take a look at the competition. How do you assess the current international competitive landscape in electrolyzer production?

Dr. Florian Ausfelder: We have strong players in Germany for all four electrolysis technologies. They are also at the forefront in terms of key technical parameters, key performance indicators (KPIs), their systems, and manufacturing capacity. Nevertheless, we are all aware of the massive price pressure coming from the Far East. In particular, excess capacity, lower raw material costs, lower labor costs, and government subsidies in the relevant countries—especially in China—are intensifying this pressure. This means that we absolutely cannot “rest on our laurels” regarding our strong technological position, and support—including funding—remains crucial for the next steps.

However, I would like to emphasize as a positive aspect that there are other factors influencing a purchasing decision besides just the lowest price—such as the reliability of the technology, service, knowledgeable representatives, or trust in the supplier. This strengthens German manufacturers’ position in the international market. Overall, though, the situation is definitely challenging.

_H2News: What role do electricity costs play in the current cost structure of green hydrogen?

Ausfelder: Electricity costs account for a significant portion of the costs associated with green hydrogen. We see the greatest potential for cost reduction in the selection of a site that can provide large amounts of solar or wind power. It is desirable for the electrolyzer—as a major consumer—to operate in a way that supports the grid and the power system, but I don’t think we should expect miracles in the cost structure as a result. After all, the electrolyzer is only economically viable if it can be operated at high load for a significant portion of the time. In addition, the gradual increase in conversion efficiency and a longer service life resulting from improvements in the stack and power electronics can lead to cost savings.

_H2News: Let’s turn our attention to Germany for a moment; why is the hydrogen ramp-up proceeding more slowly here than originally expected?

Ausfelder: Expectations for the ramp-up were very high and were based primarily on hopes and wishes. There are now successful implementation projects, but we have also seen projects where a final investment decision (FID) was never reached or that were abandoned. A major issue here is the cost of green hydrogen, which is still significantly higher than that of hydrogen produced by natural gas reforming. As a result, it is currently difficult to find users for green hydrogen. Consequently, all research and development activities that can help reduce costs are particularly important right now.

_H2News: What specific steps could help accelerate the ramp-up of green hydrogen again?

Ausfelder: From a regulatory perspective, it would be desirable to rethink the stringent RFNBO* criteria—that is, the criteria that define when hydrogen is considered “green”—and adapt them to ensure feasibility. In particular, the currently required simultaneity and additionality in the generation of the renewable electricity used are potential levers here.

From a technical standpoint, every step that helps reduce costs is important. This includes the aforementioned conversion efficiency of the electrolyzer, as well as concepts and international partnerships for hydrogen production at locations with affordable renewable energy. Overall, we must overcome the challenges of scaling up green hydrogen production in Germany, while at the same time having strong players who market their electrolysis technology on the global market and thus remain competitive in the race to develop cost-effective sites worldwide.

(*Renewable Fuels of Non-Biological Origin)

_H2News: Speaking of the global market—Dr. Kundler, how significant are single-source dependencies at present?

Kundler: There are a few single-source dependencies in the field of electrolysis, such as the diaphragm material used in alkaline electrolysis. There are also only a few suppliers of membranes and ionomers for polymer electrolyte membrane (PEM) electrolysis. As long as these single-source suppliers deliver regularly, this isn’t a problem, but it is a risk. As production ramps up, this risk increases, so it is essential to address this issue and establish additional suppliers.

_H2News: Let’s move on to the technology roadmap for the further development of water electrolysis on a gigawatt scale. How did the idea for this come about?

Kundler: We wanted to summarize the state of the art both in general and across the flagship projects, and to outline the next steps. The large electrolysis community from_H2Gigaoffered a unique opportunity here to thoroughly assess the research needs for the phase following the hydrogen flagship projects and to consolidate them with core teams. In this way, we identified gaps and highlighted topics that build on the results of the flagship projects and contribute to the ramp-up of hydrogen with a time horizon of 2030 and 2045. The core teams prioritized topics, identified open issues, and proposed concrete measures.

_H2News: In the roadmap, you mention “de-risking.” What exactly does that mean?

Kundler: That’s an important point when moving from a small scale to large systems—including in the field of research. De-risking means minimizing the risk of failure. Technically, this involves researching and understanding the failure mechanisms so that they can be reliably avoided. You could even say that I’ve only truly understood and brought a failure mechanism under control when I can turn it on or off at will at any time. But de-risking also exists in non-technical areas, such as securing supply chains or mitigating risks arising from changes in the regulatory framework. The closer we get to full-scale operation, the more important it is to minimize such risks, because they can result in high costs.

_H2News: Electrolysis encompasses four technologies: alkaline electrolysis (AEL), PEM electrolysis, high-temperature electrolysis (HTEL), and anion-exchange membrane electrolysis (AEM). Why do AEL and PEM, in particular, play a central role in the current ramp-up?

Kundler: This is primarily because these two technologies are the most advanced—though that does not mean there is no longer a need for research. For a ramp-up to the three-digit MW range or beyond—within the next five to ten years—a technology must already be capable of operating reliably today in (individual) large-scale systems. This is the case with PEM electrolysis and alkaline electrolysis.

But there is also potential for the two newer technologies: HTEL is particularly well-suited for specific locations where high-temperature waste heat is available. AEM electrolysis is a particularly innovative technology that must first demonstrate its long-term stability in larger systems. Ideally, it combines the advantages of PEM technology—the polymer membrane—with those of alkaline electrolysis, meaning it uses few or no precious metals.

_H2News: In your opinion, what are the most important next steps in terms of research and development for the various electrolysis technologies?

Kundler: In PEM electrolysis and alkaline electrolysis, it is important to investigate and understand the influence of operating conditions and interactions with interfering parameters, even in large stacks and systems. This knowledge can be used to increase operational stability and reduce degradation. Through long-term tests supported by AI, predictive maintenance models can be developed, thereby optimizing maintenance and repair strategies. Materials research, particularly for catalyst layers, also holds potential for higher conversion efficiency and/or longer service life. In the case of HTEL and AEM electrolysis, materials research takes on even greater importance, as do improvements in long-term stability and the upscaling of cell sizes and systems.

_H2News: Which results or developments from the_{H2Giga project}surprised or impressed you the most personally?

Kundler: For a good four years at DECHEMA, our electrolysis technology platform allowed us to provide the_{H2Giga partners}with a space for scientific exchange and interaction between academia and industry. The community has grown closer together, and the strong commitment of all partners to their projects has led to tremendous progress in electrolysis technology.

We would like to extend our heartfelt thanks to all_{H2Giga partners}for this wonderful collaboration! And, on behalf of all partners, we would like to thank the BMFTR for its funding of the flagship hydrogen projects.

_H2News: And we'd like to thank you both for the interview, Dr. Kundler and Dr. Ausfelder!