Brazilian aircraft designer Embraer has unveiled a 30-seat hydrogen fuel-cell powered plane concept, but its previously announced plans for an H2 jet engine aircraft will take a back seat while it focuses on the products it can bring to market first, the company has told Hydrogen Insight.
The 30-seater H2 fuel cell aircraft design (E30-H2FC) was revealed yesterday alongside an updated version of the 19-seat design (E19-H2FC), first unveiled in November 2021, as well as new 19- and 30-seat hybrid electric concepts (E19-HE and E30-HE).
The H2 fuel cell concept has a range of 200 miles with zero emissions at the exhaust, although the lifecycle emissions would depend on whether it uses green hydrogen made with renewable energy or fossil-based green or grey hydrogen.
The electric hybrid model, which has a range of 500 miles, uses an electric engine in conjunction with aircraft fuel, either conventional fuel (Jet A-1) or sustainable aviation fuels (SAFs). Emissions are reduced by 30% when the electric engines are used with Jet A-1 and by 90% when used with SAFs, Embraer claims.
The hydrogen fuel cell and electric hybrid plane concepts were originally launched in November 2021 as 19-seaters and nine-seaters, respectively, as part of a wider launch of its Energia sustainability initiative, which also included an all-electric model as well as a hydrogen jet engine design for 35-50 passengers (E50-H2GT).
The decision to bulk out the hydrogen fuel cell and hybrid electric concepts came after the company’s conversations with customers, executives told Flight Global, a specialist aviation title. None of the plane concepts are part of a committed development programme, but are being evaluated, they added.
The electric hybrid model could be commercialised by 2030, said Embraer, with the hydrogen fuel-cell model following after 2035.
But the company is still aiming to bring the 50-seater hydrogen jet engine plane to market by 2040 as planned, Embraer told Hydrogen Insight — although it is not a priority in the short-term.
“We are just focusing now on the options we believe we can bring to service earlier: HE [hybrid electric] in 2030 and FC [hydrogen fuel cell] in 2035,” a spokesman for the company said.
Critics point out that hydrogen is an expensive fuel option for aviation, and more difficult to handle and store than Jet A-1, which they say compromises safety and makes aviation more expensive.
Hydrogen-fuelled gas turbine planes would likely need use liquid hydrogen (LH2) due to its superior volumetric energy density compared to compressed hydrogen, therefore reducing the size of the on-board fuel tanks, but LH2 has to be kept at temperatures of minus 253℃, which would add to the running costs. However, because LH2 has a volumetric energy density of 8.5 megajoules per litre (MJ/l), compared to 34.7MK/l for A-1, its fuel tanks would need to be four times larger than on existing planes to carry the same amount of energy.
The all-electric model was also absent from the line up of advanced Energia concepts this week, highlighting the difficulties faced by this technology for anything but the shortest flights. Batteries are heavy and not as energy dense by weight or volume as hydrocarbon-based fuels.
Embraer specialises in smaller aircraft for regional journeys, which its executives claim give it a technological edge.
“As new propulsion technologies will be first applied on smaller aircraft, Embraer is in a unique position,” said Luis Carlos Affonso, Embraer’s vice president of engineering. “The 19- and 30-seaters are sensible starting points for focused studies since they are likely to present earlier technical and economical readiness.”
But the company faces stiff competition from other aircraft makers and engineering firms.
Airbus is developing a suite of hydrogen-powered planes, three based around hydrogen jet engines, with a fourth powered by a hydrogen fuel cell.
The French company unveiled the architecture for its H2 fuel cell engine last week.
The Airbus hydrogen-fuelled jet engine planes, which it claims will be on the market by 2035, are being designed to carry 100-200 passengers at a range of 1,000-2,000 miles (1,609-3,218km).
And Easyjet has already taken the plunge and invested in a hydrogen-powered engine, putting millions of dollars into a Rolls Royce H2 engine design, saying it is the “best choice for a short-haul airline”.
