Viewpoint: Why Hydrogen Aviation Isn’t Taking Off Yet

Hydrogen has long been hailed as the game-changing fuel that will herald a new era in greener commercial and business aviation. 

It’s hard to deny the appeal of hydrogen’s clean burning properties and high energy density by weight. But the real question isn’t whether this fuel can power aviation. It’s why the vision of widespread, hydrogen-powered flight keeps slipping further into the future.

For instance, while British-American aircraft developer ZeroAvia recently announced plans to open a hydrogen powertrain manufacturing facility in Scotland, Airbus rowed back on promises to develop hydrogen-powered commercial aircraft by the mid-2030s, citing slower-than-expected technological development. Despite the promise of hydrogen, widespread adoption in aviation may be decades away, with technological, safety, and cost challenges all complicating the picture.

Hydrogen holds several advantages over existing fuels. It’s an excellent fuel source, with the highest energy content of any fuel by mass, and it burns cleanly with water vapor its primary byproduct. These attributes, theoretically, make hydrogen the perfect clean fuel for aviation.

Despite the advantages of hydrogen’s high energy content by mass, it’s extremely low energy content by volume creates significant storage challenges. To be viable for aircraft, hydrogen must be liquefied either through supercooling, similar to LNG; or using liquid ammonia, which is 70% hydrogen. It can also be stored in a metal hydrate, but this increases its weight, which makes it counterproductive for aviation.

Cost remains one of the biggest obstacles to hydrogen adoption in aviation. Most hydrogen today is a byproduct of oil refining. Wind, solar, and hydropower are unlikely to produce power at the scale needed for low-cost hydrogen, except in limited instances with favorable geography and weather. Because it can be derived from water, large-scale nuclear-powered processing of water into hydrogen or ammonia could bring costs down dramatically. Unfortunately, the West lags behind in creating the right nuclear infrastructure, making large-scale hydrogen production more likely in countries like China, where expansion is rapid, or the UAE, where nuclear already supplies a quarter of the country’s electricity. Even when low-cost hydrogen becomes available, it could be challenging to meet the demand as air, land, and sea-based transportation compete for limited supply.

In aviation, the demands of safety will always dictate the pace of innovation. Hydrogen ignites easily – sometimes too easily, as the 1937 Hindenburg disaster proved. Aviation safety standards mean that any hydrogen-powered airliner must undergo an extensive process, and timelines for new engine and aircraft technologies to become pervasive take decades. History shows that this industry evolves incrementally: the Boeing 777X and its engines are derived from existing designs, and although work began in 2012, the model isn’t expected to enter airline fleets before 2026. A hydrogen-powered commercial aircraft will require far more testing and certification.

Once the storage, cost, and safety challenges are resolved, hydrogen-powered aircraft will be a real possibility. Then, the industry will encounter the biggest obstacle of all: infrastructure. To make hydrogen aviation viable, it won’t be enough to build a few hubs with fueling capacity. No airline will buy a plane that can only operate between a few city pairs. This mirrors the development of the automobile. Though cars were invented in the 1890s, it took half a century for the automobile to fully displace horses because drivers needed a gas station every 20 miles on every major road. Without robust, global infrastructure, hydrogen-powered aviation cannot achieve sufficient scale to be commercially viable.

Like sustainable aviation fuel (SAF), hydrogen will someday be an important component in reducing the carbon footprint of commercial and business aviation. However, many of the current goals and regulatory mandates are overly optimistic given the scale of challenges the aviation industry needs to overcome. For example, governments are pushing to advance multiple SAF pathways simultaneously to meet ambitious targets, but each option adds infrastructure complexity. Given new technology in aviation can take decades to become pervasive, a more effective approach could enable innovation via incentives or investments in enabling technologies and infrastructure over broad mandates. This could allow hydrogen-fueled aviation the time it needs to mature and roll out with enough infrastructure in place to ensure viable flight operations.

While the promise of flying on a hydrogen-powered aircraft may still be decades away, steady progress grounded in realistic expectations will be the approach that brings the vision to life.

Richard Murphy is ION Commodities lead for Global Liquids Portfolio.