Hydrogen aviation is ready for take-off

While hydrogen use in the aviation industry cannot yet be said to have taken off, it is hurtling down the runway at great speed and about to nudge its nose into the air.

Technical advancements have been coming thick and fast in recent weeks, with some of the biggest players in the industry, including Rolls-Royce and Airbus, announcing major developments.

Rolls-Royce, manufacturer of engines for the world’s largest aircraft, revealed on Nov. 28 the successful test of a regional aircraft engine powered by hydrogen. The Rolls-Royce AE 2100-A was fuelled by hydrogen produced from wind and tidal power at the European Marine Energy Centre in the Orkney Islands.

A few days later, Airbus said it’s developing a hydrogen fuel-cell engine for aircraft. Unlike the Rolls-Royce engine, which burns hydrogen to produce power, it would generate electricity in much the same way as a fuel-cell car or bus.

Rolls-Royce, manufacturer of engines for the world’s largest aircraft, revealed on Nov. 28 the successful test of a regional aircraft engine powered by hydrogen.

Airbus plans to test the engine by the middle of the decade on a modified A380 MSN1, but it is likely to be deployed on smaller commercial aircraft able to carry up to 100 passengers about 1,150 miles.

Airbus has been a leader among investors in hydrogen aviation technologies and in September 2020 revealed three ZEROe concept aircraft, all powered by hydrogen. The “blended-wing body” design looks like a flying V, while the turbofan and turboprop designs have longer bodies to store the hydrogen fuel in the rear and have longer wings.

While hydrogen has an energy density almost three times greater than diesel or gasoline, it needs to be chilled to minus 253 degrees centigrade to keep it liquid, creating some technical challenges for aircraft designers.

However, another piece of the hydrogen aviation puzzle fell into place in November announced it had completed a prototype cryogenic hydrogen fuel tanks. Following testing with nitrogen, Airbus is aiming for a fully functional hydrogen tank in 2023 with flight testing expected to begin between 2026 and 2028.

Emissions from aviation account for 2% of the global total. If aviation is serious about achieving net zero emissions, hydrogen is currently the only option.

Sustainable aviation fuels (SAFs), while favoured by some because they can be dropped into existing aircraft with few modifications, only reduce carbon emissions by 80% while hydrogen produced with renewable energy creates negligible CO2 and none while being burned or used in a fuel cell.

Emissions from aviation account for 2% of the global total. If aviation is serious about achieving net zero emissions, hydrogen is currently the only option.

SAF is also expensive – produced from biological resources it is between two and six times more expensive than traditional jet fuel – and there isn’t much of it about – it currently covers less than 0.1% of the aviation industry’s needs.

Hydrogen fuel could make up 32% of the market by 2050 if it becomes commercially available by 2035, according to a study from climate think-tank Energy Transition Commission.

FlyZero, the UK study into zero-carbon emission commercial air travel, concluded that green hydrogen is the optimum fuel for zero-carbon emission flight and could power a midsize aircraft with 280 passengers from London to San Francisco directly, or from London to Auckland with just one stop.

The economics look good too. In January, U.S. non-profit, the International Council on Clean Transportation, published a study that found green hydrogen would be a cheaper aviation fuel than e-kerosene for trips of up to 3,400 km.

Airbus expects to achieve “mature technology readiness” for a hydrogen-combustion propulsion system by 2025 and to have a commercial hydrogen plane in service by 2035.

While Airbus has been leading the charge among larger aircraft manufacturers on the investment in hydrogen, there are numerous start-ups and other smaller players making progress as well.

Airbus has been a leader among investors in hydrogen aviation technologies and in September 2020 revealed three ZEROe concept aircraft, all powered by hydrogen. The “blended-wing body” design looks like a flying V, while the turbofan and turboprop designs have longer bodies to store the hydrogen fuel in the rear and have longer wings.

U.S. and U.K.-based ZeroAvia has targeted 2025 to launch the 600-kW ZA600 powertrain, designed to retrofit aircraft with up to 19 seats with a range of up to 300 miles. By 2027, it aims to have launched the 2- to 5-MW ZA2000, enabling emissions-free flight for up to 80 passengers for 685 miles.

ZeroAvia is working with partners, including Mitsubishi Heavy Industries and RJ Aviation Group to certify a system for even larger, regional jets by 2030.

GKN Aerospace, a UK-based hydrogen aviation contender with considerable pedigree in traditional aviation, is also seeking to scale up its technology after successful early tests. After initially targeting a 19-passenger aircraft solution with its H2GEAR Programme, it is now looking at 96-passenger aircraft and beyond.

U.S. and U.K.-based ZeroAvia has targeted 2025 to launch the 600-kW ZA600 powertrain, designed to retrofit aircraft with up to 19 seats with a range of up to 300 miles. By 2027, it aims to have launched the 2- to 5-MW ZA2000, enabling emissions-free flight for up to 80 passengers for 685 miles.

Cranfield Aerospace Solutions (CAeS) has been developing its hydrogen propulsion system since 2019 under the name Project Fresson. It recently announced an addition to its deal to supply fuel-cell conversion kits for the Britten-Norman BN2 Islander to Germany’s Evia Aero and to develop a solution for a larger, 19-seater aircraft.

Fasten your seat belts. Hydrogen aviation will soon be airborne.

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