The German government’s Digital and Transport department is backing the new Balis 2.0 project to develop hydrogen-powered regional airliners with €9.3 million ($10 million) in funding. The program, which is led by H2Fly and Diehl Aerospace, is aiming to start ground testing 350-kilowatt fuel cells in 2025.
According to the program partners, the fuel cell technology they are working on is expected to form the basis for new hydrogen-electric powertrains in the megawatt class that could power aircraft carrying between 40 and 80 passengers. The funding announced during an event at Stuttgart Airport, where the work is being conducted, covers the rest of this year through the end of 2026. It is sourced from the federal government’s German Recovery and Resilience Plan, which is part of the European Union’s European Recovery and Resilience Facilities.
The German Aerospace Center (DLR) is supporting the two German companies by studying the coupling behavior of H2Fly’s fuel cells with an electric drive and also how the overall system can be optimized. Diehl Aerospace is responsible for the technology needed to scale the fuel cell systems and connect the various elements of the hydrogen-electric powertrain. Later this year, DLR’s new Balis test field facility at Empfingen, which is around 40 miles from Stuttgart Airport, will begin operations.
The funding announcement came just over a week after eVTOL aircraft developers Volocopter and Lilium confirmed that they now face difficulties in securing further state-backed loan guarantees. Funding has been stalled due to the refusal of Bavarian state officials to agree to their part of a commitment that would be matched by the federal authorities.
“I am very proud that Germany is playing a pioneering role in developing hydrogen fuel cell systems for commercial aviation,” commented Digital and Transport minister Volker Wissing. “This creates the technical foundation for marketable solutions for tomorrow’s carbon dioxide-neutral flying.”
For several years, H2Fly has been a key pioneer in European efforts to commercialize hydrogen propulsion for commercial aviation. In September 2023, with Textron subsidiary Pipistrel, it flew the HY4 technology demonstrator aircraft for the first time using cryogenic liquid hydrogen fuel to demonstrate its suitability for medium- and long-range sectors.
SAF is a False Hope, Says Hydrogen Pioneer
According to H2Fly co-founder and CEO Josef Kallo, the air transport industry should prioritize development of hydrogen propulsion over the use of sustainable aviation fuels (SAF), which he has described as “a false hope.” In his view, scaling up SAF production will be too expensive and will demand more renewable energy capacity than hydrogen, and so will have a more damaging environmental impact overall.
H2Fly has estimated that SAF production will take between 1.8 and 2.3 times more energy than the production and liquefaction of hydrogen. “Beyond the energy conundrum, there’s the issue of cost,” the company said in a statement released to AIN. “SAF production is expensive, and the long-term energy demand translates to high overall costs. For example, for European flights under 2,000 kilometers, investing in SAF could cost Europe €750 billion for energy provisions and €80 billion for production capacities; then, when on a global scale, the total cost balloons to €3.5 trillion.”
The company produced this analysis by identifying aviation’s past energy consumption in terms of megatons of kerosene burnt each year and then converting this into terawatt-hours. It then converted this total into what it defined as the “primary energy” needed to produce both SAF and liquid hydrogen.
According to Kallo, for now, SAF remains a viable option for long-distance flights in order to buy time for hydrogen technology to mature and for new aircraft powertrain technologies to complete certification. Acknowledging that commercializing hydrogen power isn’t without its challenges, he concluded that the long-term benefits merit high rates of investment.