As an industry, we believe that sustainable aviation fuels (SAFs) provide a viable, long-term alternative to traditional jet fuel, with the potential to make air travel cleaner and greener than ever. It is already possible to make SAFs from a wide variety of easily accessible sources, ranging from used cooking oil, to everyday household waste, crops, and even algae.
Powering your plane with food waste may sound like science-fiction, but SAFs are compatible with most modern engines and are used to power hundreds of thousands of flights globally every year. So, what are sustainable aviation fuels, when can we expect them to be in regular use, and what difference will they make to emissions?
WHAT ARE SUSTAINABLE AVIATION FUELS?
Sustainable aviation fuels are exactly that – fuels made from sustainable and renewable sources that produce huge CO2 reductions compared with fossil jet fuels. You may have heard ‘sustainable aviation fuels’ and ‘biofuels’ used interchangeably, but there are some important distinctions. ‘Biofuels’ generally refers to any fuel produced from plant or animal material, regardless of whether it has been produced sustainably or not. For example, biofuels made using unsustainably-produced palm oil or crops requiring deforestation, could actually be bad for the environment.
In contrast, SAFs have to meet strict sustainability criteria, including limited use of fresh water, no competition with food production and no deforestation. No palm oil, for example, is used in SAFs.
WHEN WILL SAFs BE WIDELY ADOPTED?
While SAFs are already compatible with most modern engines, they usually need to be blended with conventional jet fuels (up to 50%). This is because components of conventional jet fuel, like sulphur, allow seals to swell in older engines and prevent fuel leaks. However, new engines don’t have this problem, and SAFs have been tested at 100% in new aircraft – which means that the first 100% SAF-powered commercial flights may not be far away.
WHY AREN’T SAFs ALREADY WIDELY USED?
Many of the world’s leading airlines are already making arrangements to buy SAFs, and are supporting their development through test flights and other research. However, there is still work to be done before SAFs become the norm for powering commercial flights. Scaling-up the use of SAFs for use worldwide is extremely challenging and requires substantial investment. The industry is providing most of this investment, but has also called for government assistance and for the oil companies to step up.
WHAT DIFFERENCE WILL SAFs MAKE TO EMISSIONS?
Even when the emissions created in the production of SAFs are taken into account, their use can reduce CO2 emissions by up to an impressive 80% compared with fossil fuels.