ZeroAvia, Hydrogen-Electric Powertrains, and the Bet That Fuel Cells, Not Batteries, Will Electrify the Regional Airplane

ZeroAvia is building hydrogen-electric powertrains that generate electricity onboard from hydrogen fuel cells to spin an aircraft propeller, emitting only water vapor. In January 2023, the company flew a 19-seat Dornier 228 from Cotswold Airport in England with one of its two engines replaced by a hydrogen-electric system. The core bet: batteries will never carry enough energy to fly regional aircraft, but hydrogen can - if the fuel supply chain can be built.

What Is a Hydrogen-Electric Powertrain?

A hydrogen-electric powertrain does not burn anything. Despite what the word “hydrogen” suggests, there is no combustion, no rocket, no flame.

At its heart is a fuel cell. Hydrogen gas stored in a tank is brought together with oxygen from the air across a special membrane. Instead of exploding, they combine in a controlled electrochemical reaction, forcing electrons to travel around a circuit - and that flow of electrons is electricity.

The only byproduct is warm water vapor. That electricity spins an electric motor, and the motor turns a propeller.

So the propeller is electric, exactly like a battery-powered aircraft. The difference is entirely in where the electricity comes from. A battery stores electricity; a fuel cell makes it onboard, in real time, as long as hydrogen keeps flowing. A battery airplane is like a flashlight - charge it, use it, plug it back in. A hydrogen-electric airplane is like a small power plant you carry with you.

Why Not Just Use Batteries? The Energy Density Problem

The answer comes down to two words: energy density.

Compare the best modern lithium battery pack against jet fuel, pound for pound. Jet fuel holds roughly 40 to 50 times more usable energy for the same weight. That is not a gap you close with a software update - it’s physics.

It’s also the single reason every pure battery aircraft flying today is small, light, and short-legged. You cannot scale a battery up to fly 19 people 250 miles, because the battery to do it would weigh more than the airplane.

Hydrogen holds about three times the energy of jet fuel per pound - by weight, it’s the most energy-dense fuel we have. That’s what makes regional flight even conceivable.

The Catch: Hydrogen’s Volume Problem

Energy per pound is only half the equation. The other half is energy per cubic foot, and by volume, hydrogen is a disaster.

It’s the lightest element in the universe. Even compressed to 700 atmospheres, or chilled into a liquid at −420°F, hydrogen still takes up roughly four times the space of the equivalent jet fuel.

That’s the real engineering challenge. The fuel barely weighs anything, but the tanks to hold it are big, heavy, and eat cabin volume. Fuel cells themselves are well understood - we’ve flown them on spacecraft since the Gemini and Apollo eras. The hard part is everything around the fuel cell: the tanks, the plumbing, the cooling, and weight, always weight.

Who Is ZeroAvia and What Have They Flown?

ZeroAvia was founded in 2017 by Val Miftakhov, a former engineer and pilot who had previously built and sold an electric-vehicle charging company. He studied the electric aviation landscape, concluded batteries would never lift regional aircraft, and went hydrogen.

The company started small, retrofitting a six-seat Piper Malibu with a hydrogen-electric powertrain and flying it around 2020. It then scaled up to the 19-seat Dornier 228, swapping one engine for hydrogen-electric while leaving the other conventional as a safety backup. That aircraft flew more than a dozen times through 2023 under an experimental permit from the British Civil Aviation Authority.

The order book signals how serious this is. Airlines and leasing companies have placed provisional orders and reservations for roughly 2,000 powertrains. American Airlines, United, and Alaska Air Group have all backed the program.

The first engine being certified is the ZA600, a 600-kilowatt hydrogen-electric powertrain aimed at the 9-to-19-seat commuter class. A larger unit, the ZA2000, will target 40-to-80-seat regional turboprops like the ATRs and Dash 8s.

Why Hydrogen Aviation Is Harder Than the Flight Suggests

The airplane was never the hard part. Three problems stand between the demonstration and a real industry.

1. Where does the hydrogen come from? Most hydrogen produced today is gray hydrogen, made by cracking natural gas - a process that releases carbon dioxide. Fly on gray hydrogen and you haven’t solved emissions; you’ve just moved them from the airport to a chemical plant. The clean alternative, green hydrogen, is made by splitting water with renewable electricity, but it’s expensive and produced nowhere near the volume a fleet would need. Building that supply is a national-scale infrastructure project.

2. The airport. Today a typical field has a Jet A tank and a 100LL tank - a logistics chain that took a century to build. Hydrogen requires cryogenic storage at −420°F, specialized trucks, and crews trained on a fuel that leaks through gaps a normal gas can’t and burns with a flame nearly invisible in daylight. That’s why hydrogen will likely appear first on fixed routes between a small number of equipped airports.

3. Certification and the timeline. ZeroAvia has told the market it expects the ZA600 certified and entering service in the mid-2020s. Treat that with caution. There is no existing rulebook for a hydrogen fuel cell driving a propeller - the FAA and its European counterpart are writing the certification basis alongside the company, and that always runs longer than the press release suggests.

Why This Matters for Pilots

Hydrogen-electric is not vaporware. Real aircraft have flown, real money is behind it, and the physics works in a way pure batteries never will for anything larger than a light airplane. On the fundamental question - can you make clean electricity onboard and turn a propeller with it - the answer is a demonstrated yes.

But the hard part is the hydrogen itself: making it clean, making it cheap, and moving, storing, and pumping it into an aircraft at a field near you. That’s a 15-to-20-year story, not a two-year one.

If you want to track this yourself, don’t watch the next flashy test flight. Watch the boring signals: who signs the first real airport fuel-supply deal, and which regulator publishes the first actual certification basis for a fuel cell powertrain. That’s where you’ll see whether this becomes an industry or stays a very impressive science project.

Key Takeaways

ZeroAvia flew a 19-seat Dornier 228 on a hydrogen-electric powertrain in January 2023, with one engine converted and the other left conventional as a backup.
Hydrogen holds ~3x the energy of jet fuel by weight but ~4x the volume, making the fuel itself light while the tanks stay big and heavy.
Batteries carry 40–50x less energy than jet fuel per pound, which is why they can’t scale to regional aircraft - the core reason ZeroAvia chose hydrogen.
The ZA600 (600 kW) targets 9–19 seat aircraft; the larger ZA2000 targets 40–80 seat turboprops, with roughly 2,000 powertrains on provisional order and backing from American, United, and Alaska.
The real bottleneck is infrastructure, not the aircraft - green hydrogen supply, cryogenic airport handling, and a certification basis that doesn’t yet exist point to a 15-to-20-year timeline.