tThe runway temperature reached 50C at the Farnborough air show this week. Officials checked for tarmac between the aerospace industry showing off its wares, with flights by passenger jets including the Boeing 777X and Airbus A350, various military jets and flypasts by the Red Arrows display team.
Monday’s heat was yet another reminder, if needed, of the urgency of decarbonising aviation, which is responsible for about 3% of global emissions. The threat of a climate crisis has taken the shine off an industry that was once the height of glamour, and zero-emission flights pose a technical challenge far greater than decarbonising most other parts of the economy.
Air passenger numbers are rising again after pandemic lockdowns, even on slower-recovering long-haul routes, but aerospace executives are putting increasing emphasis on their investments in technologies that will deliver carbon-free flights, while governments are turning their attention too late to aviation emissions.
Boris Johnson confused executives with a rambunctious opening speech — “an audition for his future career in the after-dinner circuit,” a senior industry insider wryly noted — but the UK government also used the show to promise 2019 would be the record year. for aviation emissions.
The key measure – in addition to aiming to have zero-emission flights in some parts of the UK by 2030 – was a mandate that 10% of all aviation fuel used in the UK be so-called “sustainable” aviation fuel (SAF) by 2030. , the EU’s dual objective. This is driven by the ambition to have at least five commercial-scale SAF plants under construction in the UK by 2025.
Environmental groups said the strategy was not aimed at reducing air traffic — a dirty word at an industry event known for its barrage of orders for new jets that produce more than 800,000 tons of carbon dioxide equivalent over their lifetimes. .
Alethea Warrington, a campaigner at the climate charity Possible, said: “They rely heavily on undeveloped, extremely expensive or unworkable technologies, but the strategy fails crucially by omitting a policy to reasonably reduce the demand for flights, such as a frequent flyer- charge.”
Asked about the policy change that could come with a change in prime minister, Warren East, the CEO of Rolls-Royce, said he hoped the UK government would remain committed to reducing aviation emissions.
“The energy transition and the need for carbon-free energy are beyond any change in government,” he said.
Some Airbus and Boeing suppliers face less existential risk than engine manufacturers. Collins announced that it is developing high-voltage wiring that can be used in hybrid engines that combine electricity and fossil fuels. The US company’s Solihull plant in the West Midlands has also produced a working prototype electric motor for the Airlander airship, which will be fully electric by 2030.
Henry Brooks, president of Power and Controls at Collins, said hybrid propulsion could ultimately save up to 30% of a passenger plane’s emissions. “The hybrid electric part is very real,” he said.
For net zero flights, however, Farnborough’s message was that the industry is pinning its hopes on SAF first and then on unproven hydrogen technologies.
SAF can be made from plants or smart chemistry. Still, many analysts doubt it can live up to its name without using large amounts of arable land for the feedstock or massive amounts of energy in chemical reactions.
East said he sees “several decades” of demand for SAF, after an initial net zero flight in 2023.
The industry’s second big hope is hydrogen. Hydrogen is an attractive fuel because water, rather than carbon dioxide, is the only output when it oxidizes.
EasyJet and Rolls-Royce announced on the show that they would jointly invest in hydrogen-powered gas turbine engines, while Airbus said this week it would study the effects of steam contrails in the atmosphere produced by the use of hydrogen. Airbus has already announced work on hydrogen propulsion with CFM, a motor joint venture of General Electric and Safran, in stark contrast to Boeing whose hydrogen efforts were limited to testing a storage tank.
“Hydrogen builds up like a bit of a panacea,” East said, but he expects it will take between 15 and 25 years for a two-aisle widebody jet to run purely on gas.
Even then, it could still rely on combustion rather than generating electrical energy on board with fuel cells. A combustion scenario could provide engine manufacturers with cover to continue making profitable but polluting gas turbines (theoretically capable of burning either kerosene or hydrogen) for longer.
Val Miftakhov, chief executive of hydrogen fuel cell aircraft startup ZeroAvia, said his goal is a “true zero” flight with hydrogen produced from renewable energy — not net zero, which relies on re-emitting carbon previously out of the atmosphere. caught.
The company aims to certify a 19-seat aircraft by 2024 and a 90-seat aircraft by 2028. can’t tell you exactly how.”
Battery electric flight on passenger planes that can carry more than 100 people is further away. East said it would “probably be on a pretty small plane in my lifetime – but I’ll be very old”. A battery-powered transatlantic flight will likely be seen only by his grandchildren, he added.
In the meantime, the industry is hedging its bets to fly zero-emissions. But the high volume of orders for fossil fuel aircraft suggests that, despite all the talk in Farnborough about abatement technologies, the airline industry is counting on the jet fuel era to continue for decades to come.