Photo caption: Bob Tanner, executive director of Aerospace Partnerships at Parallax Advanced Research and the Ohio Aerospace Institute
The evolution of unmanned aerial systems (UAS) in military and commercial sectors has been rapid and innovative. Lessons learned from these advancements are now shaping the development of electric vertical takeoff and landing (eVTOL) vehicles, which are poised to support cargo and passenger operations. Even the vision of eVTOLs as people-movers for the 2026 World Cup in Texas and the 2028 Los Angeles Olympics underscores the promise of advanced air mobility (AAM). However, achieving this vision requires overcoming some significant challenges.
AAM represents a paradigm shift in air transportation, encompassing a broad range of technologies, including traditionally piloted, semi-autonomous, and fully autonomous aircraft. These vehicles promise to democratize air travel and delivery services through greater accessibility and affordability. UAS in addition to AAM systems are already revolutionizing several industries. From UAS used in logistics to healthcare, first responder services to infrastructure inspection, these aerial systems are demonstrating efficiencies that will in time fundamentally change how goods and services are purchased and delivered. Among these transformative opportunities is the integration of hydrogen as an alternative fuel, which could enable longer flight durations, reduce emissions, and support a more sustainable aviation industry.
Hydrogen’s Potential for AAM
Hydrogen offers a compelling solution to many challenges facing AAM. While electric propulsion faces limitations in battery weight, cold-weather performance, and grid capacity, hydrogen offers a pathway to longer-duration flights and greater scalability. As well as efforts to achieve zero emissions in aviation are driving renewed focus on hydrogen’s viability as a power propulsion system.
Canada, for example, is investing heavily in liquid hydrogen and hydrogen propulsion systems, conducting demonstrations and advancing the technology for aviation applications. Hydrogen’s higher energy density compared to batteries allows for extended range, which is essential for eVTOLs transitioning from short-hop flights to more complex, long-distance operations. Parallax Advanced Research and the Ohio Aerospace Institute (OAI) collaborate with partners like Aero Montreal and the Great Lakes Aviation and Space Technology Alliance (GLASTA) to drive hydrogen-focused AAM innovations across the U.S.-Canada corridor, fostering cross-border advancements in technology and operations. Read about our efforts here: https://clevelandmagazine.com/cleader/business/articles/ohio-aerospace-institute-expands-opportunities-for-advanced-air-mobility
Lessons from UAS Informing Hydrogen Adoption
The UAS industry’s experience highlights the importance of endurance in advanced propulsion systems. Battery technology limits flight duration, but hydrogen-powered systems can enable significant operational advancements. For example, Parallax and OAI are already working with companies, like NEOEx Systems of Amherst, Ohio, to provide on-board liquid hydrogen energy storage and fuel cell power system integration services to unmanned aerial vehicle (UAV) manufacturers, with the aim of achieving 1,000-mile flight paths for small UAS using hydrogen.
These insights emphasize the need for robust infrastructure to support hydrogen production, storage, and distribution. Developing airport-based hydrogen hubs, as outlined by the Vertical Flight Society’s 2023 roadmap, is a critical step. These hubs can begin with ground vehicle fueling stations and expand to support aviation applications. Parallax and OAI are actively contributing to this effort by collaborating with industry and academic partners to drive research, demonstrations, and the development of hydrogen infrastructure tailored for AAM. Through these initiatives, our enterprise is helping lay the groundwork for scalable hydrogen solutions across key regions, including the U.S.-Canada corridor as I mentioned above.
Addressing Technical and Infrastructure Challenges
Despite its promise, hydrogen-powered eVTOLs face technical hurdles, including energy density, range, and safety. Dr. Andrew Gyekenyesi, director of Research and chief scientist at OAI, who is currently working on efforts for developing the educational curricula required for the coming hydrogen economy in partnership with the University of Toledo and other Ohio and Michigan academic institutes as well as overseeing technical projects related to hydrogen embrittlement of metals and model based optimization of fuel cell systems, provided his insights on what technical infrastructure challenges exist and how we may address them.
He said, “Hydrogen in liquid form will provide the most capacity in terms of energy density, although it will require advanced storage solutions, such as pressurized, well-insulated cryogenic tanks. These systems are more complex and costly than storage tanks for typical hydrocarbon fuels. In addition, they add considerable weight and volume penalties when used on AAM vehicles. The ground-based infrastructure challenges include the need for a network of hydrogen refueling stations and pipelines, as well as green production methods, such as electrolysis powered by renewable energy to achieve a truly green status.”
Even so, hydrogen is a frontrunner in the race to decarbonize aviation. While biofuels and battery-based systems have roles to play, hydrogen’s zero-emission potential and energy density make it a key contender for sustainable aviation. However, milestones such as regulatory approval, improved fuel cell efficiency, and cost-competitive production must be achieved to realize widespread adoption. Dr. Gyekenyesi also pointed out that multiple large-scale efforts are underway to address these challenges and that localized hydrogen production using solar power and other renewable sources could enable large-scale, self-contained, on-site fueling stations at airports. Additionally, leveraging mature industrial processes from sectors like ammonia production and space exploration provides a foundation for scaling hydrogen infrastructure in aviation.
Building a Roadmap for Public-Private Acceptance of Hydrogen-Powered AAM
Public-private collaboration is also essential to accelerating hydrogen innovation. Programs like the Air Force’s Agility Prime, which has fostered partnerships to advance AAM technologies, highlight the importance of such efforts. The APEX program, a Department of the Air Force Program managed by Parallax, has played an important role in this by helping small businesses secure non-dilutive funding through Agility Prime that has enabled the development and advancement of cutting-edge technologies that support the integration of hydrogen solutions into the AAM ecosystem. Read here about how NEOEx Systems, Inc., partnered with the Ohio State University on developing hydrogen energy and power systems for unmanned aerial vehicles (UAVs), a collaboration facilitated by the APEX program.
Similar initiatives are needed to drive hydrogen research, infrastructure development, and demonstration projects. Parallax has also had the privilege of working with NASA and the State of Ohio on the Advanced Air Mobility Community Integration Considerations Playbook, designed to help communities understand the challenges and opportunities of advanced air mobility. Together, these efforts underscore the importance of continued collaboration between governments, academia, and industry to create incentives for hydrogen adoption. Without a doubt, policy and research must go hand in hand, and demonstrating real-world implementation is key to gaining public confidence and scaling the technology.
Everything considered, hydrogen’s integration into AAM represents a bold step toward sustainable, scalable aviation, but we’ll need to address the technical challenges, build robust infrastructure, and continue fostering collaboration between government, industry, and academia to fully unlock hydrogen’s transformative potential. As the industry evolves, Parallax and OAI will remain at the forefront, championing innovation and laying the groundwork for a cleaner, more connected future in aviation.
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About Parallax Advanced Research & The Ohio Aerospace Institute
Parallax Advanced Research is a 501(c)(3) private nonprofit research institute that tackles global challenges through strategic partnerships with government, industry, and academia. It accelerates innovation, addresses critical global issues, and develops groundbreaking ideas with its partners. With offices in Ohio and Virginia, Parallax aims to deliver new solutions and speed them to market. In 2023, Parallax and the Ohio Aerospace Institute formed a collaborative affiliation to drive innovation and technological advancements in Ohio and for the nation. The Ohio Aerospace Institute plays a pivotal role in advancing the aerospace industry in Ohio and the nation by fostering collaborations between universities, aerospace industries, and government organizations, and managing aerospace research, education, and workforce development projects. More information on both organizations can be found at Parallax and OAI websites.