In November 2023, Virgin Atlantic flew a Boeing 787 from London to New York with no paying passengers, funded by £1m of taxpayer money and powered entirely by sustainable aviation fuel. It was historic, and it raised four questions that this piece works through.
What I cover
- What SAF is. A “drop-in” replacement for jet fuel, made from renewable feedstocks such as cooking oil, waste fats and agricultural waste. Today it’s certified only as a blend of up to 50% with conventional fuel, which is why 100% flights make the news.
- Why it matters. The airline industry’s net-zero plan leans on SAF for about 65% of the reduction. It still produces emissions when burned, but over its lifecycle it cuts roughly 80% of CO2 compared with traditional jet fuel.
- The catch. SAF is still only a tiny share of the fuel aircraft burn, about 0.1%, and no SAF is cost-competitive with jet fuel yet. Scaling it depends on feedstocks, land and policy.
Where I land
SAF is the most promising near-term option for aviation, but we have to look at its full lifecycle, not just the tailpipe, to know whether it’s truly sustainable. Governments have a big role in making it affordable at scale.