ZeroAvia and the hydrogen-electric powertrain that wants to eliminate jet fuel from regional aviation

ZeroAvia is building a hydrogen-electric powertrain designed to replace conventional turboprop engines on regional aircraft with nine to eighty seats. The system uses proton exchange membrane fuel cells to convert compressed hydrogen into electricity, producing only water as a byproduct. With over $150 million in funding from investors including Breakthrough Energy Ventures, United Airlines, and Alaska Air Group, it represents the most flight-tested hydrogen fuel cell propulsion program in commercial aviation — though significant certification and infrastructure challenges stand between demonstration flights and fare-paying passengers.

How Does ZeroAvia’s Hydrogen-Electric Powertrain Work?

The system feeds compressed hydrogen gas into a proton exchange membrane (PEM) fuel cell, which converts hydrogen into electricity through an electrochemical reaction — no combustion involved. That electricity drives an electric motor, which turns a propeller. The only byproduct is water.

This approach differs fundamentally from companies exploring hydrogen combustion in modified turbines. Fuel cells are significantly more efficient: a conventional turbine converts roughly 30 to 40 percent of fuel energy into useful work, while a fuel cell can achieve 50 to 60 percent efficiency. That efficiency advantage partially offsets hydrogen’s storage challenges.

The company was founded in 2017 by Val Miftakhov, a physicist and serial entrepreneur who concluded that batteries alone would never have the energy density for meaningful commercial flights. The math supports that conclusion. Lithium-ion batteries store approximately 250 watt-hours per kilogram. Jet fuel stores about 12,000 watt-hours per kilogram. Even with electric motors’ superior efficiency, batteries can’t compete beyond roughly 100 nautical miles with useful payload.

Hydrogen stores approximately 33,000 watt-hours per kilogram — nearly three times the energy density of jet fuel by mass and the highest of any fuel in existence.

Why Is Hydrogen Storage the Biggest Engineering Challenge?

Hydrogen is extraordinarily energy-dense by weight but extremely energy-sparse by volume. At standard atmospheric pressure, one kilogram of hydrogen occupies about 11 cubic meters — a cube roughly seven feet per side. That’s obviously unusable in an aircraft.

ZeroAvia uses compressed gaseous hydrogen at 300 to 700 bar (300 to 700 times atmospheric pressure). At 700 bar, density reaches about 40 grams per liter, which is workable but demands tanks far larger and heavier than conventional kerosene tanks carrying equivalent energy.

Current compressed hydrogen tanks at 700 bar achieve roughly 5 to 6 percent gravimetric efficiency, meaning the hydrogen itself constitutes only 5 to 6 percent of the total tank system weight. The rest is carbon fiber composite pressure vessel, liner, valves, and regulators. For 50 kilograms of usable hydrogen, the complete tank system weighs 800 to 1,000 kilograms.

Liquid hydrogen offers better density at about 71 grams per liter, but requires storage at minus 253 degrees Celsius — just 20 degrees above absolute zero. The cryogenic systems and boil-off management make this impractical for regional aircraft. Airbus is exploring liquid hydrogen for large airliners through its ZEROe program, but for ZeroAvia’s target aircraft, compressed gas is the viable near-term path.

What Has ZeroAvia Actually Flown?

In September 2020, ZeroAvia flew a modified Piper M-class (six-seat aircraft) powered by their hydrogen-electric powertrain at Cranfield Airport in England. It was a short flight — a few pattern circuits — but it was the largest hydrogen fuel cell aircraft to fly at that time.

In January 2023, they flew a 19-seat Dornier 228 twin-engine commuter aircraft with one engine replaced by their ZA-600 powertrain at Cotswold Airport in Gloucestershire. The left engine ran on a combination of hydrogen fuel cell and battery power, while the right engine remained a conventional turboprop for safety. The flight lasted approximately 10 minutes and reached about 2,500 feet.

The Dornier 228 flight was the more significant milestone. The Dornier is a real commuter aircraft used by airlines worldwide, not a proof-of-concept demonstrator.

What Are ZeroAvia’s Products and Timeline?

ZeroAvia has announced two main powertrains:

• ZA-600: Targeting 600 kilowatts (~800 horsepower) for 9 to 19 seat aircraft with approximately 300 nautical miles of range
• ZA-2000: Targeting 2 to 5 megawatts for 40 to 80 seat regional aircraft with similar range

The ZA-600 is the nearer-term product. Partner aircraft include the Dornier 228 and potentially the De Havilland Canada Dash 8. The ZA-2000 targets the ATR 72, one of the most common regional turboprops in the world with over 1,000 in service.

ZeroAvia is pursuing a supplemental type certificate (STC) pathway — modifying existing aircraft types rather than certifying entirely new airframes. This avoids the decade-long, billion-dollar process of clean-sheet aircraft certification.

As of early 2026, type certification has not yet been achieved. The original target of commercial service by 2025 has slipped. A more realistic timeline is 2028 to 2030 for the ZA-600 on a 19-seat aircraft, assuming certification, manufacturing scale-up, and hydrogen infrastructure all proceed on schedule.

How Do the Operating Economics Compare to Jet Fuel?

A conventional Dornier 228 with two Honeywell TPE331 turboprops burns roughly 350 to 400 pounds of jet fuel per hour. ZeroAvia’s hydrogen system would require approximately 40 to 50 kilograms of hydrogen per hour for equivalent performance.

ZeroAvia projects roughly 50 percent lower fuel costs compared to jet fuel and significantly reduced maintenance costs. The maintenance argument is compelling: fuel cells involve no combustion, no hot section inspections, and no turbine blade replacements. Electric motors have one moving part. A Pratt & Whitney PT6A turboprop goes to overhaul every 3,500 to 5,000 hours. An electric motor could theoretically operate tens of thousands of hours between major service events.

However, fuel cell durability in aviation remains unproven at scale. Automotive fuel cells like those in the Toyota Mirai are designed for 5,000 to 8,000 hours in relatively benign conditions. Aviation fuel cells face altitude changes, pressure variations, temperature extremes, vibration, and absolute reliability requirements. The long-term degradation curve of a PEM fuel cell in an aviation environment has not been characterized over tens of thousands of hours.

Is 300 Nautical Miles of Range Enough?

Three hundred nautical miles is significantly less than a conventional turboprop’s 600 to 800 nautical mile range. But actual regional airline route data tells a different story.

A large percentage of commercial flights on aircraft with fewer than 19 seats operate legs of 200 nautical miles or less: island hopping in Hawaii, inter-city routes in Scandinavia, Scottish Highlands services, and Caribbean island pairs. For these missions, 300 nautical miles provides adequate range, and the operating cost advantages could be transformative.

What About the Hydrogen Infrastructure Problem?

The most elegant powertrain is useless without fuel at the airport. Today’s hydrogen production landscape presents a challenge:

• Gray hydrogen (from steam methane reforming of natural gas): $1–2 per kilogram, but releases CO₂ — merely shifting emissions upstream
• Green hydrogen (from electrolysis using renewable electricity): $4–8 per kilogram, but truly zero-emission

The industry projects green hydrogen reaching cost parity with gray hydrogen around 2030, driven by falling electrolyzer costs and cheaper renewable energy.

ZeroAvia is pursuing vertical integration, developing its own airport hydrogen refueling infrastructure. The concept involves on-site electrolyzers powered by grid renewables or dedicated solar and wind installations, producing hydrogen where aircraft need it — no trucking or pipelines required. They’ve partnered with several UK airports on modular production and storage systems.

What’s Driving Regulatory Urgency?

The European Union’s Fit for 55 package and the UK’s Jet Zero strategy are imposing increasingly aggressive aviation decarbonization targets. Emissions trading schemes are raising the cost of carbon for airlines. Norway has declared a goal of all short-haul flights being zero-emission by 2040.

For operators in these markets, hydrogen propulsion is shifting from an environmental aspiration to a regulatory imperative. ZeroAvia has secured letters of intent for over 1,500 engines — not firm orders with deposits, but a signal of serious market interest from operators facing carbon regulations and fuel price volatility.

Who Are the Major Investors and Partners?

ZeroAvia’s investor roster is notably heavy on companies that actually operate aircraft:

• Breakthrough Energy Ventures (Bill Gates)
• Amazon Climate Pledge Fund
• IAG (British Airways parent company)
• United Airlines Ventures
• Alaska Air Group

These are not speculative venture investors. They are organizations that have examined the engineering and concluded the approach has a credible path forward.

How Does ZeroAvia Compare to Competitors?

Airbus ZEROe is targeting large commercial aircraft using both hydrogen combustion and fuel cells, but with an entry-into-service date no earlier than 2035. H2FLY in Germany has flown a fuel cell Dornier 228 and set altitude records for hydrogen-electric flight. Heart Aerospace is pursuing a hybrid approach with the ES-30, combining batteries and turbogenerators.

ZeroAvia’s primary advantage is being further along in flight-testing a fuel cell system at commercially relevant scale than nearly any competitor. Its primary disadvantage is attempting to certify a fundamentally new propulsion technology while simultaneously building the fuel infrastructure to support it — two enormous challenges running in parallel.

What Does This Mean for General Aviation?

The ZA-600’s 600 kilowatts (approximately 800 horsepower) falls within the range of a large turboprop single or light twin. If hydrogen storage weight and volume decrease, and green hydrogen becomes affordable and widely available, a hydrogen-electric equivalent of the Cessna Caravan or King Air is conceivable within 15 to 20 years.

A hydrogen Caravan with 300 nautical miles of range and dramatically lower fuel and maintenance costs would be transformative for operators in Alaska, the Pacific Islands, sub-Saharan Africa, and other regions where the Caravan currently dominates short-haul utility flying.

Key Takeaways

• ZeroAvia’s hydrogen fuel cell powertrain produces only electricity and water — no combustion, no carbon emissions — and has been flight-tested on both a 6-seat Piper M-class and a 19-seat Dornier 228
• Hydrogen offers nearly 3x the energy density of jet fuel by mass, but storage tanks at 700 bar are heavy, limiting practical range to roughly 300 nautical miles for near-term applications
• Commercial service on 19-seat aircraft is realistically expected between 2028 and 2030, pending certification and infrastructure development
• The retrofit strategy — swapping engines on existing airframes rather than designing new aircraft — is the most certifiable path to getting hydrogen propulsion into revenue service
• Green hydrogen cost parity with conventional hydrogen is projected around 2030, which aligns with ZeroAvia’s commercial timeline but adds economic uncertainty

Sources: ZeroAvia published flight test data, Royal Aeronautical Society hydrogen aviation reports, International Council on Clean Transportation analysis, UK Aerospace Technology Institute hydrogen infrastructure requirements report.