German Aerospace Center Achieves Historic Megawatt Milestone in Hydrogen Fuel Cell Aviation Technology

The German Aerospace Center (DLR) has reached a pivotal moment in Hydrogen aviation development by successfully operating fuel cell systems and electric motors at power outputs exceeding one megawatt each through their BALIS test infrastructure. This achievement marks a critical breakthrough in scaling hydrogen fuel cell technology for aviation, validating integrated propulsion systems at power levels necessary for commercial flight. The milestone comes as the global hydrogen aircraft market experiences rapid growth, positioning Germany at the forefront of zero-emission aviation innovation.

This technical success is underpinned by significant government investment and a unique, modular test facility capable of evaluating megawatt-class fuel cell systems for multiple transportation domains. The BALIS project, along with its follow-up BALIS 2.0 initiative, demonstrates sustained commitment to advancing hydrogen Propulsion technologies that could transform aviation, shipping, and heavy-duty vehicles. As the industry seeks sustainable solutions, the DLR’s achievement signals a new era for clean, high-power mobility.

Historical Foundation and Project Evolution

The BALIS project originated from Germany’s strategic focus on hydrogen-powered mobility as part of national climate goals. Launched in 2021 with support from the Federal Ministry of Transport and Digital Infrastructure, the initiative aimed to develop and test megawatt-class fuel cell propulsion systems for aviation and other sectors. The facility, located at the Empfingen Innovation Campus, was designed for modular, flexible testing, with 26 million euros in initial funding and subsequent expansions for infrastructure and research.

BALIS’s infrastructure was developed in collaboration with AVL and other partners, ensuring comprehensive capabilities for system and component validation. The project’s evolution continued with BALIS 2.0, a targeted initiative focused on developing a 350 kW fuel cell module as a scalable building block for larger systems. This follow-up, led by H2FLY and Diehl Aerospace, received 9.3 million euros in funding and reflects a shift towards aviation-specific applications and Certification requirements.

These efforts are embedded in Germany’s broader National Innovation Programme Hydrogen and Fuel Cell Technology, which coordinates funding and research across the hydrogen value chain. As DLR’s leadership notes, the step from ground-based validation to flight certification is complex and time-consuming, and large-scale testbeds like BALIS are essential for de-risking this transition.

Technical Achievement and Engineering Significance

The recent DLR milestone stands out for integrating and operating both fuel cell systems and electric motors above the one megawatt threshold, levels not yet available commercially. The BALIS team electrically coupled twelve fuel cell modules, each with over 400 individual cells, creating a sophisticated, modular system. This approach addresses the current market limitation, where the largest mobile fuel cells offer only several hundred kilowatts.

Project leader Cornelie Bänsch described the accomplishment as a major milestone in setting up and commissioning the facility’s first-generation fuel cell test system. The technical challenge extended beyond mere power scaling to achieving stable, coordinated operation across all modules. Advanced operating strategies were developed to manage this complexity, with plans to further increase output and run dynamic load profiles that simulate real-world aviation conditions.

The BALIS system’s capacity extends to 1.5 megawatts, suitable for applications in ships, heavy-duty vehicles, and aviation. Its modular design allows for detailed investigations of individual components as well as complete powertrain systems, including refueling infrastructure and control technology. This level of integration provides crucial validation for the aviation industry’s shift toward hydrogen-powered flight.

“This is an important milestone in the set-up and commissioning of the test facility and the first generation of the fuel cell test system. Systems of this power class are not yet available on the market, the technical challenge lies in developing and integrating all the components so that they operate stably at high outputs of one megawatt or more.”

, Cornelie Bänsch, DLR Institute of Engineering Thermodynamics

Infrastructure Architecture and Testing Capabilities

The BALIS test facility is unique worldwide for its ability to develop and test megawatt-class fuel cell propulsion systems. Located at the E2U Empfingen Development Centre, its modular container-based architecture enables flexible, scalable evaluation of both individual components and integrated powertrains. Researchers can simulate various load cases and operational scenarios, mirroring actual aircraft mission requirements from ground operations to cruise flight.

Core facility components include fuel cell systems, liquid hydrogen tanks, high-performance electric motors, batteries, and advanced control and regulation technology. DLR is also building a test tank and refueling infrastructure for liquid hydrogen, addressing the critical challenge of high-density storage required in aviation. This infrastructure supports realistic operational testing, such as simulating taxi, takeoff, climb, and cruise with sustained high power output.

The facility’s comprehensive capabilities make it a preferred location for collaboration with aeronautics institutes and industry partners. Its ability to accommodate full-scale system integration and dynamic testing bridges the gap between laboratory research and commercial aviation applications, accelerating technology development and de-risking future deployment.

Economic Context and Market Dynamics

The hydrogen aviation sector is experiencing rapid expansion, with the global hydrogen aircraft market valued at $826 million in 2023 and projected to reach $4.8 billion by 2034. The broader aircraft fuel cells market is expected to grow from $2.82 billion in 2025 to $24.63 billion by 2035. This growth is driven by increased adoption of sustainable aviation fuels, regulatory pressure to reduce emissions, and substantial public and private investment.

Government funding has been instrumental in enabling BALIS achievements, with 29 million euros allocated to the original facility and 9.3 million euros for BALIS 2.0. These investments are part of coordinated national and European strategies to support hydrogen research and infrastructure. Private sector engagement is also increasing, as major aerospace firms and Startups invest in hydrogen-powered aircraft development.

Cost competitiveness remains a key challenge. Green hydrogen production costs are currently higher than conventional fuels, but government incentives and economies of scale are expected to narrow this gap. The development of supply chains, refueling infrastructure, and certification standards will be critical for commercial viability and widespread adoption.

Aviation Applications and Commercial Potential

The demonstration of megawatt-class fuel cell systems unlocks significant potential for hydrogen-powered aviation, especially for regional aircraft with 40 to 80 passengers and ranges up to 1,000 kilometers. The BALIS systems’ scalability and modularity enable applications across different aircraft types, from small commuter planes to larger commercial jets as technology matures.

Certification and integration present technical hurdles, with aviation requiring the highest safety standards (Design Assurance Level A). BALIS 2.0 is addressing these through component development, system design, and verification testing. Initial ground tests of the 350 kW module are planned for 2025, forming the basis for future flight certification and operational deployment.

International competition is intensifying, with Airbus’s ZEROe project and American, Asian, and UK initiatives all targeting hydrogen aviation. Regulatory frameworks, such as the FAA’s Hydrogen-Fueled Aircraft Safety and Certification Roadmap and the UK CAA’s Hydrogen Sandbox Challenge, are evolving to support certification and market introduction, though commercial deployment is expected in the second half of the 2030s.

“Federal funding for BALIS 2.0 demonstrates the growing significance of hydrogen fuel cell systems as a viable solution for clean aviation. The project insights will propel the development of megawatt-class powertrains, significantly accelerating the transition to sustainable, zero-emission flight.”

, Professor Josef Kallo, H2FLY

Safety, Environmental Impact, and Regulatory Framework

Safety is paramount in hydrogen aviation, with comprehensive protocols for handling, storage, and system integration. The BALIS facility incorporates multiple safety barriers, monitoring systems, and modular isolation to minimize risk during testing. Aviation-specific standards require extensive validation and redundancy, with regulatory authorities developing new frameworks for hydrogen certification.

Environmentally, hydrogen fuel cell aviation offers the promise of zero-carbon flight, especially when using green hydrogen produced from renewables. The aviation sector currently accounts for 2-3% of global CO2 emissions, and hydrogen-powered regional aircraft could deliver meaningful reductions. Life-cycle benefits depend on the hydrogen source, and infrastructure impacts must be considered in sustainability assessments.

Regulatory harmonization is underway, with the FAA, EASA, and UK CAA collaborating on standards, certification, and safety research. The development of international standards and certification pathways is essential for global market adoption, with ground-based validation and special conditions paving the way for future commercial operations.

Conclusion

The DLR’s achievement of operating megawatt-class fuel cell systems marks a watershed moment in the evolution of hydrogen aviation technology. The BALIS test facility’s unique capabilities have validated the feasibility of scaling hydrogen propulsion to commercial aviation power levels, providing a foundation for zero-emission flight and cross-sector applications in shipping and heavy vehicles.

As the market, regulatory, and technological landscapes evolve, Germany’s leadership through BALIS positions it at the forefront of sustainable aviation innovation. The path to commercial deployment will require sustained investment, international collaboration, and continued technical progress, but the groundwork laid by BALIS offers a compelling blueprint for the future of clean, high-power transportation.

FAQ

What is the BALIS project?
BALIS is a test infrastructure developed by the German Aerospace Center (DLR) to develop and validate megawatt-class hydrogen fuel cell propulsion systems for aviation and other transportation sectors.

Why is the megawatt threshold significant?
Exceeding one megawatt in integrated fuel cell and electric motor operation demonstrates the scalability of hydrogen technology for commercial aviation, where high power outputs are essential for practical application.

When will hydrogen-powered aircraft be commercially available?
While ground testing and system validation are underway, commercial deployment is expected in the second half of the 2030s, pending further technical development and regulatory certification.

What are the main challenges for hydrogen aviation?
Key challenges include achieving power density suitable for flight, developing safe and efficient hydrogen storage, integrating complex systems, and meeting stringent certification standards.

How is the environmental impact addressed?
Hydrogen fuel cell aviation can offer zero-emission flight, especially when using green hydrogen. The environmental benefits depend on the hydrogen production method and the development of supporting infrastructure.

Sources:
DLR: BALIS test system components cross megawatt threshold for the first time