California startup wants fuel cells to power next generation of carbon-free jet travel

Companies are racing to crack the code on emissions-free air travel. Hydrogen is key to several options, each with promises and challenges.

Beyond a splashy paint job that included a big “H” on the tail, the 40-passenger turboprop jet that took off mid-morning March 2, from a small airport in central Washington, looked like any other regional airliner.

But with that 15-minute demonstration flight, with two test pilots and one flight crew member onboard, a three-year-old startup in Hawthorne made history while providing a glimpse of a potential future with quieter, carbon-free air travel.

Universal Hydrogen, which counts Harrison Ford as a hangar neighbor at Hawthorne Municipal Airport, replaced the jet’s right turbine engine with a 1-megawatt powertrain fueled entirely by a hydrogen fuel cell. Fuel cells operate similarly to electric batteries but are much lighter, which is key for flight. And rather than needing to be recharged, fuel cells are fed energy-rich hydrogen gas to generate electricity, emitting only water vapor along the way.

The company’s March 2 test flight broke records for the largest plane to ever take to the skies and cruise primarily on hydrogen, shattering a record set in January as another California-based startup, ZeroAvia, flew a 19-passenger airliner over England.

As bigger and bigger planes operate off such systems, hydrogen fuel cells increasingly are looking like feasible options to help the aviation sector clean up its act.

“This technology has the potential to be a game-changer on the industry’s path to zero-emission flight,” said Derek Kerr, financial chief for American Airlines, which — along with Airbus Ventures, GE Aviation and Toyota Ventures — is an early investor in Universal Hydrogen.

Aviation is responsible for more than 2% of the world’s annual carbon emissions, with air travel projected to grow significantly over coming years. While sectors that produce more carbon, such as road travel, are on track to make tremendous strides in emissions reductions, technical and safety hurdles have so far prevented some of the same solutions from translating to air travel. And if aviation doesn’t crack that code, Arnaud Namer, chief operating officer for Universal Hydrogen, said the industry will eventually account for much more than 2% of global emissions “and therefore be much more visible.”

There are still a number of hurdles for Universal Hydrogen and its competitors to overcome before commercial passengers might start riding in flights fueled entirely by hydrogen fuel cells, and multiple other options are still in the mix.

If things go as planned, though, Namer said they hope to get the OK to retrofit their first regional airliners to start running on green hydrogen by 2025, with orders already in hand for 247 conversions from 16 customers around the world. The company hopes to make hydrogen fuel cell systems to power specially designed single-aisle jets by 2035 and to power jumbo jets of the future perhaps in the mid-2040s.

It’s an ambitious timeline for the notoriously slow-moving aviation sector. But Namer said it’s necessary if we want to have a chance at meeting the Paris Agreement goal of keeping warming below 1.5 degrees Celusius and for the aviation sector to reach its goal of net-zero emissions by 2050.

“It’s not a question of being optimistic,” Namer said. “It is a question of not having another choice.”

Why hydrogen fuel cells?

Innovators are pursuing a handful of options to replace traditional jet fuel, which emits high levels of atmosphere-warming carbon dioxide while producing soot and other particulates that are harmful to respiratory health. But each alternative has its own set of advantages and challenges.

For many environmentalists, the most appealing alternative to making flights carbon neutral is fully electric jets, which would emit no carbon or other pollutants. But with current technology, batteries needed to power jets over any distance would be too heavy to be practical. So unless that technology changes dramatically, only small planes are likely good fits to become fully electric, with the potential for hybrid models in larger planes.

Three other options all involve hydrogen.

Companies including Airbus are making plans for planes that can run on liquid hydrogen fuel. Planes would need an estimated four times the volume of hydrogen fuel than jet fuel, which means airliners must be redesigned to fit that payload.

If those redesigns are successful, there’s the question of how that liquid hydrogen will get to the airport. Namer cited estimates that it would take trillions of dollars of infrastructure, happening at airports around the world at the same time, for the sector to pivot to managing hydrogen the way it currently handles jet fuel.

Another option is sustainable aviation fuel, or SAF. Paramount-based World Energy, just 12 miles east of Hawthorne airport, is pioneering production of SAF, where hydrogen is used to turn old cooking oil, plant materials and other feedstocks into “drop-in ready” fuel that can replace traditional jet fuel in existing engines. But along with the high cost of SAF and lack of infrastructure to manufacture and transport that fuel, even World Energy estimates that there’s only enough feedstock to make SAF for perhaps 20% of jets operating today. So the company is looking at ways to make a new version of SAF, using carbon scrubbed from the air through capture and removal operations, which are just getting off the ground with mixed results.

That’s why Namer said he only sees SAF as a “bridge solution,” while his company is banking on hydrogen fuel cells as the “end point.”

“We’re not betting on research and technology that may mature or may not mature,” he said. “We’re adapting existing technologies,” with hydrogen fuel cells already powering vehicles such as the Toyota Mirai. Now, he said, it’s just a matter of converting those technologies to the aerospace market.

Cracking the code

To make planes powered entirely by clean hydrogen fuel cells a reality, Namer said his company needed to crack the code on three key hurdles.

The first — and this applies to all methods that involve hydrogen — is that the fuel needs to be genuinely clean.

Pure hydrogen doesn’t exist in nature. Instead, it occurs in compounds such as water and methane, meaning that before you can use hydrogen as an energy source you’ve got to separate it out from some other molecule. Currently, the process of doing that almost always means burning fossil fuels, which eliminates any emissions gains at the tailpipe.

But Universal Hydrogen has committed to use only truly green hydrogen, where renewable energy provides electricity that splits water molecules, leaving pure hydrogen behind. Namer’s company has partnered with several others to source green hydrogen, for now largely from hydro-electric power in the Northeast United States and Europe. And with so much money being thrown at green hydrogen development, he’s confident the market will grow rapidly, bringing the price down so that it’s comparable to jet fuel prices within a couple years.

The second hurdle is to design aircraft that can handle hydrogen fuel cell systems. Overcoming that challenge is where most of Universal Hydrogen’s proprietary work comes into play.

With help from a team at the company’s Toulouse, France location, where about half of their 100 employees work, Universal Hydrogen crews developed a way to retrofit existing planes that can carry up to 50 people to run entirely on hydrogen fuel cells. The success of that operation was demonstrated in the March 2 flight out of Washington using a converted De Havilland Canada Dash 8-300.

Those systems do take up substantial space, which means airlines need to remove a few rows of seats — and potentially lose some profits along the way. But, while he declined to give an exact figure, Namer said the price to convert the planes isn’t that much more than an airline’s cost to do typical overhaul and maintenance work. And once the conversion is done, much like with electric vehicles, Namer said the maintenance costs for fuel cell planes are lower, since they’re not burning fuel or dealing with as many moving parts.

As for planes bigger than 50 passengers, Namer said they will need to be redesigned to accommodate fuel cell systems. They hope to see such narrow-body planes hit the market in 2035, which account for 60% of current industry emissions. Then redesign of wide-body jets might be another decade behind that.

The third hurdle has been to figure out how to get hydrogen from where it’s produced to airports.

Hydrogen is used either in compressed gas form, which takes up lots of space and is prone to leaks, or in liquid form, where it needs to be kept at around minus 423 degrees Fahrenheit. Either way, Namer said asking airports and airlines to develop infrastructure to handle those supplies without interrupting operations would be “inconceivable.”

So rather than pursue pipelines or other traditional options, Universal Hydrogen developed secure modules, which look like small trailers. These lightweight pods can be sent via truck, rail or boat filled with liquid hydrogen, which doesn’t need any special temperature control for at least 96 hours. Those modules then are loaded onto the plane via existing cargo handling equipment, where they’re rigged to turn liquid hydrogen to compressed gas as they connect to waiting fuel cell systems.

“This means that there’s no need for new infrastructure to be developed to be able to get the hydrogen from the production site to the airport,” Namer said, making “every airport hydrogen ready immediately.”

Challenges remain

With planned solutions for those three major hurdles in place, Universal Hydrogen still has several challenges to overcome.

The first is to get certification from the Federal Aviation Administration in the U.S. (and similar aviation regulators in other countries) to clear their powertrain conversion kit to retrofit existing regional aircraft.

Along with needing additional capital, the company also needs partners to ramp up production of green hydrogen, while its team kicks up production of its modules to store and transport that hydrogen and conversion kits to retrofit regional airliners. To that point, the company is designing a manufacturing and distribution hub on 50 acres in New Mexico.

Then there are environmental and safety issues to still consider.

All hydrogen companies have to contend with both real concerns and public perception around safety issues, with thoughts of the Hindenburg still lingering nearly nine decades later. Namer noted the safety record of hydrogen fuel cells in Toyota Mirais. He also said their systems have built-in leak detection and venting systems, so any leaked hydrogen would be filtered out before it could accumulate.

There also is some concern about how water vapor emitted by planes in the form of contrails can act as a greenhouse gas, trapping heat in the atmosphere. Research so far suggests that’s still a far better option than carbon, which stays in the atmosphere for a century rather than around nine days like water vapor.

But contrails also don’t form at the altitudes that regional airliners, like the ones Universal Hydrogen plans to launch with, must fly, company spokeswoman Leia Espericueta said. Even for higher-flying planes, she noted that early research shows water from a fuel cell is less likely to form contrails than water emitted by planes burning jet fuel.

Since the plan now calls for moving hydrogen modules around by truck, rail or boat, Namer said they’re also looking at ways to lower the carbon footprint of that network, including prioritizing transport by other fuel cell-powered modes of transport. But he said they’re also counting on each of those industries to do their part.

“We can’t solve the world’s problems,” he said. But, he added, “everything that we can convert to hydrogen will be a significant step forward towards the 2050 Paris Agreement.”