Green air travel: high fuel prices to provide some lift


Icelandair is the first airline to promise carbon-free flying on its domestic routes. That is less promising than it sounds. Guilt-free air travel has yet to achieve lift-off — although high oil and ticket prices may help a bit.

Icelandair plans to use renewable energy in battery-powered aircraft by 2030,. This is good, so far as it goes. But low-energy density batteries are heavy for the energy they carry. So the airline is tapping into a technology that is only really a potential solution for very short-haul flights.

That is a problem in an industry in which two-thirds of emissions come from journeys that are longer than 1800km, according to a Mission Possible Partnership report on aviation. Overall demand is set to grow steeply. Already, premium leisure travel has returned to pre-Covid levels, according to British Airways parent IAG. Business journeys are not far behind.

Frankly, there is no technology that can, by itself, deliver guilt-free air travel. Making planes sleeker and more efficient is a great start — and saves money — but cannot get us to “net zero”. Next up are biofuels — chemically similar to jet fuel but made from waste. Today, they account for 0.01% of aeroplane fuels, and are between 2 and 4 times more expensive according to BNEF, a consultancy. Worse, supply is limited: only so much cooking oil exists with which to make green kerosene.

For unconstrained supply, we need to turn to renewable power. Storing it as hydrogen, rather than in batteries, trades the weight problem for one of space. Even supercooled to a liquid, hydrogen holds just over a quarter of the energy as the same volume of petrol. Mixing hydrogen with CO₂ to create e-fuels sorts out both weight and space. But as the world moves towards net zero emissions, the CO₂ will need to be sucked out of the air — an energy intensive and expensive process.

The good news is that higher oil prices will help give this ponderous problem some lift. They will make newer, energy efficient aircraft more attractive, and reduce the green premium for renewable technologies. Meanwhile, fuel costs account for roughly a quarter of those expensive airline tickets. That means that an industry commitment to blend in 10% biofuels — say — would still only add £6 to the cost of a £100 ticket.

We are not quite done with flygskam — a Swedish word meaning “flight shame”. But £6 might be a reasonable sum to help assuage our consciences.

If you are a subscriber and would like to receive alerts when Lex articles are published, just click the button “Add to myFT”, which appears at the top of this page above the headline.