- Stargate Hydrogen partners with Repsol, securing additional investment to strengthen its green hydrogen innovation
- Repsol proactively diversifies beyond fossil fuels, targeting net-zero through renewable energy
- Meanwhile, Stargate Hydrogen expanded manufacturing in Tallinn with modular growth strategy and gigawatt-scale potential
- Joint R&D on ceramic-based electrolysers has the potential to make green hydrogen significantly more accessible globally
This July, Stargate Hydrogen, the well-known Estonian innovator in next-generation alkaline electrolysers for cost-effective green hydrogen, formed an alliance with Repsol, Spanish-based global energy leader. Through its Corporate Venture arm, Repsol acquired a minority stake, reinforcing Stargate’s technological leadership and competitiveness in the international renewable hydrogen sector.
The Background of the Parties
Repsol is a globally established integrated energy company headquartered in Spain, operating across the entire energy value chain, from oil and gas exploration to refining, chemicals, and retail. Traditionally rooted in fossil fuels, it remains one of Europe’s largest producers and distributors of hydrocarbons.
In recent years, Repsol has committed to transforming its business model by investing heavily in low-carbon technologies, renewable energy, and green hydrogen. It was the first major oil and gas company to announce a net-zero emissions target by 2050, positioning itself as a leader in the energy transition.
Particularly, Repsol Corporate Venturing is constantly seeking out transformative technologies that can accelerate the energy transition. Their investment in Stargate Hydrogen is a significant step aligned with Repsol’s ambition to lead the deployment of renewable hydrogen across Europe and beyond.
Founded in 2021, Stargate Hydrogen is a Tallinn-based cleantech company developing next-generation alkaline electrolysers designed to produce green hydrogen more efficiently and at lower cost. Its core innovation lies in advanced ceramic-based materials that enhance electrolyser performance and durability. By scaling manufacturing and R&D, Stargate Hydrogen aims to accelerate the global adoption of renewable hydrogen.
‘Stargate Hydrogen has demonstrated exceptional technological leadership in the development of next-generation alkaline electrolysers, which are crucial for reducing the cost of renewable hydrogen production. Their ceramic-based catalyst technology and proprietary stack design offer a compelling path toward scalable, efficient, and economically viable hydrogen solutions,’ Repsol’s Director of Corporate Venturing, Technological Busness Development, and Open Innovation Gema García González comments.
Scaling Up Across Europe and Beyond
Marko Virkebau, Co-Founder and CEO at Stargate Hydrogen
Earlier this year, Stargate Hydrogen raised an EUR 11M Series A round and inaugurated its new factory. On the system side, the company’s pilot project at the Utilitas power plant in Tallinn has been successfully commissioned. Pure hydrogen is now being produced, and its quality has been validated by an independent third party.
According to Stargate Hydrogen’s CEO Marko Virkebau, there’s a steady advancement with the manufacturing of the 1 MW Gateway system for the Finnish state energy company Fortum, which remains on track for delivery by the end of 2025.
On the stack side, Stargate Hydrogen is also moving ahead rapidly. In addition to ongoing sales for an undisclosed client in Germany, it established a new partnership for stack integration in India, expanding its footprint beyond Europe.
A Smart Approach to Manufacturing Growth
Moving to its new facility in Tallinn, the Stargate Hydrogen team made a conscious decision not to launch an oversized electrolyser plant operating below capacity. Instead, they adopted a future-oriented, modular growth strategy—scaling production as demand increases, avoiding unnecessary upfront costs for stakeholders. That’s why a brownfield site with a highly flexible floor plan was selected, allowing us to optimise space and scale efficiently.
According to the team, the facility can produce up to 140 MW of electrolysers per year in its current configuration, with the potential to expand to gigawatt-scale output with only modest additional investment. The site also enables Stargate Hydrogen to build larger stacks, and the plan is to scale from the current 0.5 MW units to 5 MW stacks, serving the needs of large industrial projects.
Stargate Hydrogen is also expanding its testing capabilities with plans to commission a new in-house test bench, enabling the company to evaluate its products without relying on third parties. According to Stargate Hydrogen’s CTO Dr Rainer Küngas, this will not only reduce costs but also allow for extended, continuous testing, yielding more accurate performance data and accelerating product validation.
Stardust and the Next R&D Frontier
Dr Rainer Küngas, Co-Founder and CTO at Stargate Hydrogen
‘Our ceramic coating technology, Stardust, remains under active development and continues to deliver promising results. While some optimization work remains, we are now setting up the first commercial-scale production line for small stacks that incorporate electrodes with ceramic coatings. This marks an important step towards full commercial deployment,’ Dr Küngas shares.
As for Stargate Hydrogen’s top R&D priorities, they are about reducing the Levelized Cost of Hydrogen (LCOH):
- ELECTROLIFE Project – advancing knowledge on degradation mechanisms and improving cell performance.
- EXOTHyC Project – developing and validating a next-generation alkaline electrolyser short-stack prototype with a novel cell design.
- ENDURE Project – increasing current density and stability to bring alkaline electrolyser performance and durability to a new level.
These efforts are designed to accelerate both technological breakthroughs and commercial competitiveness in the green hydrogen market.
Validation from Industry Leaders
‘Besides the commercial developments, we have significantly boosted our manufacturing capacity with the launch of our new production facility in Tallinn. On the funding front, we secured a strategic investment from Repsol—further validation that our technology is trusted by major industry players,’ Mr Virkebau adds.
Salome Mikadze, Knight-Hennessy Scholar at Stanford University, Co-Founder of Movadex
Specifically, the new alliance with Repsol provides Stargate Hydrogen with the capital to expand its production capacity but more importantly with strategic opportunities to establish a presence in the Iberian Peninsula. From an R&D standpoint, the Stargate Hydrogen team notes Repsol’s strong interest in the development of Stardust and integrating innovative technologies into their operational and commercial projects.
‘In today’s world, such cooperation can be perceived as a strategic step for both parties, with benefits and challenges that inevitably accompany the transformation of the energy landscape. Such partnerships are often a springboard for breakthrough technologies that require not only engineering excellence, but also stable support to enter big markets,’ Movadex’ co-founder and Knight-Hennessy scholar at Stanford Salome Mikadze comments.
Beyond Capital: A Shared Vision for Net-Zero
‘This collaboration goes beyond financial support; it is a start for joint technical initiatives and potential integration of our solutions into Repsol’s own hydrogen value chain. Discussions are ongoing regarding the extent of our access to Repsol’s operational data and industrial sites. These talks are progressing, and we see considerable potential for such collaboration to strengthen our technology validation and scale-up efforts,’ Mr Virkebau tells ITKeyMedia.
Gema García González, Director of Corporate Venturing, Technology Business Development, and Open Innovation at Repsol
‘As Spain’s largest producer and consumer of hydrogen, Repsol brings deep operational expertise to this partnership. We see Stargate Hydrogen not only as a promising innovator but also as a valuable ally in our roadmap to decarbonize heavy industry and achieve net-zero emissions by 2050. This collaboration will allow us to work together across R&D, product development, and commercial deployment, helping to strengthen Europe’s energy independence and technological competitiveness in the hydrogen sector,’ Ms González concludes.
The involvement of major energy players like Repsol is vital for accelerating green innovation, as their resources and expertise help scale breakthrough technologies like Stargate Hydrogen’s electrolysers. By bridging entrepreneurial innovation with industrial strength, such alliances empower both major companies and innovative startups to lower costs and speed up deployment. Building such synergies is key to advancing the global transition to a sustainable, net-zero future.
Kostiantyn is a freelance writer from Crimea but based in Lviv. He loves writing about IT and high tech because those topics are always upbeat and he’s an inherent optimist!
