On Tuesday morning, November 28th, the first trans-Atlantic flight by an airliner powered by 100% green fuel took off. Virgin Atlantic operated the flight from London Heathrow to New York’s John F. Kennedy Airport with a Boeing 787 Dreamliner.

Virgin founder Richard Branson, British Transport Secretary Mark Harper, and Virgin Atlantic chief executive Shai Weiss were among the passengers on the flight, which did not carry fare-paying travelers.

‘Flight100’

The Civil Aviation Authority reviewed various aspects of the flight before granting an operating permit, including analyzing ground tests with an engine running on 100% sustainable aviation fuel. Virgin Atlantic was awarded up to £1 million by the Government in December last year to plan and operate the flight, called ‘Flight100’, to demonstrate the effectiveness of sustainable aviation fuel.

Sustainable Aviation Fuel (SAF) is vital to reducing the aviation industry’s carbon emissions. However, supply is insufficient, and the product is still much more expensive than conventional jet fuel. It makes up only about 0,1% of aviation fuel used globally.

Sustainable sources

SAF looks, smells, and performs just like normal aviation fuel and can be dropped in normal engines without needing modification. It is made from sustainable sources, such as agricultural waste and used cooking oil, meaning its production uses about 70% less carbon. It can be used in jet engines to a maximum blend of 50% with kerosene without any modifications.

However, a flight powered by ‘green’ fuel is not 100% emission-free, but rather ‘net zero’, with the airline’s combustion process offsetting carbon emissions during the journey. Plus, the process of making SAF uses lots of energy, and SAF critics argue there simply isn’t enough raw material or ‘feedstock’ to produce it.

Combustion process

SAF is not a fossil fuel, like diesel, but it still has to go through the combustion process in the aircraft’s engine. And thanks to the combustion process, SAF can be used by existing aircraft. For other technologies, like hydrogen, aircraft need to be completely redesigned. Today, SAF is probably the best mid-term solution to helping make a decent dent in decarbonizing aviation while other greener technologies, like hydrogen, are developed.

The International Air Transport Association expects the number of passengers to nearly double by 2036, and many environmentalists say the best way to save the planet is to drastically reduce our air miles.

Guilt-free flyning?

The first ‘green’ long-haul flight was a success, but, according to the campaign group Aviation Environment Federation (AEF), “the idea that it will get us closer to guilt-free flying is a joke”. “SAF only represents about 0,1% of aviation fuel globally, and will be very hard to scale up sustainably. For now, the only way to cut CO2 from aviation is to fly less.”