(CNN) — Last month, a navy blue, six-seater aircraft took off at Cranfield Airport in England. Usually, a 15-minute, 20-mile flight wouldn't be noteworthy -- but this was the world's first hydrogen fuel-cell-powered flight for a commercial-size aircraft.
The plane's powertrain -- the mechanism which drives the plane, including fuel tanks and engine -- was built by ZeroAvia, a US and UK-based company developing hydrogen-electric engines. Using liquid hydrogen to feed fuel cells, the technology eliminates carbon emissions during the flight.
A conventional flight today produces half the CO2 generated by flights in 1990, largely thanks to an increase in fuel efficiency. However, due to record traffic growth, driven by increasing passenger numbers and trade volume, the aviation industry is creating more emissions than ever before -- accounting for 2% of global manmade carbon emissions. This percentage is set to increase says Bobby Sethi, a senior lecturer in aviation at Cranfield University: other industries, like road transport, are "decarbonizing at a faster rate" he says, while aviation is lagging behind.
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Some companies are pushing ahead with climate-friendly solutions in a bid to catch up. The Electric Aviation Group's 70-seat hybrid-electric aircraft aims to reduce CO2 emissions by 75% and is expected to enter service in 2028, while Airbus recently announced that it aims to manufacture three hydrogen aircraft, sitting up to 200 passengers, by 2035.
But there is a long wait until these models come to market and aviation needs a solution now, says ZeroAvia founder and CEO Val Miftakhov.
With funding from UK government-backed bodies including the Aerospace Technology Institute and Innovate UK, ZeroAvia wants to plug the gap as aviation technology develops, and provide a sustainable solution for short and medium haul flights.
Miftakhov, who piloted ZeroAvia's test flight, says the company's technology is designed to be retrofitted into existing aircraft. He claims that ZeroAvia will have hydrogen-powered commercial planes taking to the sky in just three years.
Airbus unveiled its ZEROe zero-emission concept in September 2020, and claims it will be commerically available by 2035.
Airbus
An energy-dense fuel
While the spotlight has been on electric aviation for the past decade, the limitations of current battery technology restricts its expansion. Currently, lithium ion batteries are around 48 times less energy dense than kerosene, says Sethi.
This means scaling up is a problem for electric aviation. The largest electric plane flown to date is the 9-seater eCaravan. It has a range of only 100 miles -- for which it requires a battery weighing 2,000 pounds.
Sethi highlights that in larger planes, like a Boeing 747, the battery would far exceed the plane's maximum take-off weight. "It's just not possible unless battery technology improves significantly, which is why hydrogen is a more viable option to fuel aircraft in the future," he says.
Having previously worked with electric car batteries, Mifta
