• 04 Jan 2022 10:18 AM
• 2

The H2eVTOL Council's Pioneering Year

By Danielle C. McLean, H2eVTOL Council Founder & Co-Chair

Vertiflite, Jan/Feb 2022

In April 2020, at the US Air Force’s Agility Prime Launch, a number of VFS members discussed the progression of hydrogen fuel cell technology and that it appeared to be at a tipping point for applications on electric vertical takeoff and landing (eVTOL) aircraft. A series of planning and educational web meetings were held, led by Danielle McLean (Happy Takeoff) and Dr. Anubhav Datta (University of Maryland), as the chair of the VFS Electric VTOL Technical Committee, and supported by Jim Sherman, VFS Director of Strategic Development.

The H2eVTOL Council is now comprised of almost 200 senior engineers and leaders from eVTOL developers, professional societies, universities and government agencies, with the goal to help mobilize the global aerospace community and adjacent industries toward the transformation of air mobility, powered by hydrogen. In January 2021, Michael Dyment (NEXA Capital Partners) joined the group and helped establish a charter for the VFS Hydrogen eVTOL Council, with Dyment and McLean elected as co-chairs (see “VFS Forms Councils on eVTOL Flight Testing and Hydrogen,” Vertiflite, March/April 2021). There was enough interest and momentum that more than 100 members signed up in the first month.

A Gamechanger

Most eVTOL aircraft designers view hydrogen fuel cells as a future capability, while some are working with H2 system developers to bring it to maturity as a nearer-term solution (see “Future Fuel: HyPoint’s Hydrogen Revolution,” Vertiflite, Sept/Oct 2021).

Hydrogen has a much higher specific energy than batteries, translating to either longer flights or heavier payloads. The drawback with fuel cells is that they have low specific power; they can’t deliver a lot of power in a short time, an imperative for power-hungry vertical takeoffs and landings. In contrast, batteries have high specific power for vertical takeoff and landing, but their specific energy is low, so they can’t fly for very long.

Combining the high specific energy of fuel cells with the high specific power of batteries offers the benefits of both technologies. Batteries can provide power for vertical takeoffs and landings; hydrogen can provide power during cruise. The fuel cells can even charge the battery packs during cruise. This could result in all-electric VTOL flights capable of flight ranges of 200–300 miles (320–480 km) or more.

Hydrogen fuel cells have been tested and flown on several multirotor and fixed-wing drones, successfully demonstrating flights over 10 hours. For larger heavier eVTOL aircraft that require more power than a drone for takeoff, the combination of batteries and fuel cells could achieve zero-emission, all-electric, long-range flights.

Despite the clear advantages of utilizing hydrogen, it still hasn’t been adopted in aviation at large. Both gaseous and liquid hydrogen are difficult to store. Other impediments like the lack of infrastructure, transporting hydrogen and high costs are all results of hydrogen storage intricacies. It’s certainly possible to store hydrogen at scale. Companies like Plug Power have been storing and transporting hydrogen to supply forklifts for decades. Unconventional partnerships between forklift fuel suppliers and aerospace companies may be exactly what the H2eVTOL industry needs. Other companies, such as Element 1 and Universal Hydrogen, are developing other novel approaches for storage and transportation.

Although multiple hydrogen councils, consortia and government bodies have published white papers and roadmaps with useful information, they rarely mention aviation. The Council is engaging with the government, industry and academic organizations to ensure that H2 for eVTOL is not forgotten — because aviation has been the slowest transportation industry to decarbonize and stands to benefit the most from hydrogen.

Setting the Stage

VFS formed the H2eVTOL Council to tackle these tough challenges by bringing the world’s hydrogen and aviation experts together. In a series of presentations, members of the H2eVTOL Council gained a wealth of knowledge throughout 2021. Guest presenters discussed hydrogen highways and existing ecosystems in the fuel cell forklift industry that can be used for eVTOL. Members learned about different fuel cell stack cooling methods, such as Intelligent Energy’s evaporative cooling and HyPoint’s air cooling, as well as HyMARC’s cutting-edge metal hydride research, Universal Hydrogen’s storage tanks and their innovative ways of transporting hydrogen through capsules.

Element 1 is developing onboard methanol reformers that produce hydrogen for the fuel cells. Methanol can store more hydrogen than liquid hydrogen and may be able to use existing infrastructure because it behaves like gasoline and doesn’t have to be compressed. However, challenges to acceptance remain, such as whether methanol production is truly renewable and how an onboard reformer compares in cost, weight, and balance-of-plant to liquid hydrogen.

The Council learned that production at scale of green hydrogen (from renewable sources) for air mobility is under development and could be coming to the US in the next decade. US planning and investing in hydrogen infrastructure for hydrogen fuel cell (HFC) cars has paled in comparison to other global leaders. In 2020, Japan had more than 160 hydrogen refueling stations, Europe (primarily Germany) had over 150, and China had over 100. At the end of 2021, the US still has fewer than 100 hydrogen refueling stations, only 48 of which are commercialized (all located in California). By 2030, Japan plans to have 900 hydrogen refueling stations. China and the US share a goal of 1,000 stations. Europe plans to dominate with sights set on 3,700 stations by 2030. This is with respect to the automotive industry and does not include forklift refueling stations.

Funding for hydrogen refueling stations was also discussed in presentations to the H2eVTOL Council. Perhaps one of the most important takeaways for the entire eVTOL industry was that building a network of stations is four times cheaper per mass of H2 and doubles (on average) the capacity of hydrogen, verses funding one station at a time.

The year came to a climactic close with a presentation by Elevate Government Affairs who debriefed the council on the US government’s recently passed “Infrastructure Investment and Jobs Act” (see “Is Hydrogen Aviation’s Clean Fuel for the Near Future?”). This $1.2T infrastructure bill includes $62B directed to the US Department of Energy for clean energy. One third of this — $21B — is for clean energy demonstration projects, with more than one-third ($8B) going towards hydrogen. Another $1.5B is going to hydrogen manufacturing and supply chain needs.

This is an exciting development. With the plans for hydrogen research and developments by the European Union and members states that were announced in 2020, there is increasing momentum in hydrogen transportation technology, creating a tipping point for aviation in general, and eVTOL specifically.