What is sustainable aviation fuel (SAF)?

Sustainable aviation fuel (SAF) is a drop-in replacement for conventional Jet A-1 aviation fuel produced from non-fossil feedstocks. SAF is chemically compatible with existing aircraft engines and infrastructure when blended with conventional jet fuel (up to 50% SAF blend in most approved pathways; 100% SAF certification is under development). SAF can reduce lifecycle CO2 emissions by 50–94% compared to conventional jet fuel, depending on the production pathway and feedstock. Main production pathways: (1) HEFA (Hydroprocessed Esters and Fatty Acids) — the dominant pathway; uses waste fats/oils/greases, UCO (used cooking oil), animal fats; most commercially mature; (2) ATJ (Alcohol-to-Jet) — converts ethanol or isobutanol to jet fuel; (3) Power-to-liquid (e-SAF/e-Fuel) — green hydrogen + captured CO2 via Fischer-Tropsch synthesis; theoretically near-zero carbon but currently very expensive.

What is the EU ReFuelEU Aviation mandate?

ReFuelEU Aviation is an EU regulation (effective from 2025) setting minimum SAF blending mandates for aviation fuel supplied at EU airports. Blending requirements: 2% SAF minimum from 2025; 6% from 2030; 20% from 2035; 34% from 2040; 42% from 2045; 70% by 2050. Within the overall SAF mandate, synthetic fuels (e-SAF/PtL) have a specific sub-mandate: 0.7% from 2030; 5% from 2035; 35% by 2050. Fuel suppliers (not airlines) are responsible for compliance; non-compliant suppliers face penalties. The regulation applies to all fuel uplifts at EU airports, including for non-EU carriers. ReFuelEU is the primary regulatory driver for SAF adoption across European aviation.

How much does SAF cost compared to conventional jet fuel?

SAF is significantly more expensive than conventional Jet A-1 in 2026. Typical prices: HEFA-SAF (from waste fats/UCO) — approximately $1,500–2,200/tonne ($1.90–2.80/gallon), vs conventional Jet A-1 at ~$600–900/tonne ($0.76–1.14/gallon) — a premium of approximately 2–3x. ATJ-SAF is similarly priced. E-SAF (power-to-liquid) remains at $3,000–5,000+/tonne in early commercial projects — 4–6x conventional jet fuel. At current SAF prices, a 2% SAF blend increases airline fuel costs by approximately 2–5% depending on the conventional/SAF price gap. CORSIA (ICAO's carbon offsetting scheme) and EU ETS costs for aviation partially offset the green premium economics. SAF costs are expected to fall as scale increases; BNEF projects HEFA-SAF at ~$800–1,200/tonne by 2030.

Sustainable Aviation Fuel (SAF) 2026

Published 1 October 2026 · Updated 22 October 2026

Aviation accounts for approximately 2.5% of global CO2 emissions — and unlike road transport, has no near-term battery electrification pathway for long-haul flights. Sustainable aviation fuel (SAF) is the primary decarbonisation tool for aviation, with the EU's ReFuelEU mandate now in force (2% SAF blend from 2025), CORSIA applying internationally, and major airlines committing to 10–30% SAF use by 2030. In 2026, SAF remains significantly more expensive than conventional Jet A-1, but production capacity is expanding rapidly.

For conventional jet fuel pricing context, see our jet fuel prices 2026. For the aviation fuel guide, see our aviation fuel guide. For shipping's parallel decarbonisation challenge, see our shipping decarbonisation 2026. For the carbon pricing framework, see our carbon credit glossary entry.

SAF production pathways

Pathway	Feedstock	CO2 reduction (lifecycle)	Maturity	Cost (2026)
HEFA (Hydroprocessed Esters & Fatty Acids)	UCO, animal fats, plant oils	~65–80%	Commercial (dominant)	$1,500–2,200/t
ATJ (Alcohol-to-Jet)	Ethanol, isobutanol	~50–70%	Early commercial	$1,800–2,500/t
FT-SPK (Fischer-Tropsch from biomass)	Woody biomass, agricultural residues	~70–95%	Pre-commercial / pilot	$2,500–4,000/t
Power-to-Liquid (e-SAF)	Green H₂ + captured CO₂	~85–99%	Early demonstration	$3,000–6,000/t
SIP (Synthesised Iso-Paraffins)	Sugars (fermentation route)	~50–85%	Limited commercial	$2,000–3,500/t

HEFA dominates current SAF production due to its commercial maturity — major producers include Neste (Finland; world's largest SAF producer), World Energy (USA), SkyNRG (Netherlands), and several major oil refineries adding SAF production streams (Shell, TotalEnergies, Repsol). HEFA feedstock is constrained by the availability of sustainable waste fats and UCO; the IEA estimates HEFA cannot alone supply the volumes needed for 2030+ mandates.

ReFuelEU Aviation and global mandates

Jurisdiction	Mandate/Target	SAF blend level (key years)
EU (ReFuelEU Aviation)	Regulation; binding on fuel suppliers	2% (2025), 6% (2030), 20% (2035), 70% (2050)
UK (Jet Zero SAF mandate)	UK SAF mandate from 2025	2% (2025), 10% (2030), 22% (2040), 10% by 2050 (different metric)
USA (SAF Grand Challenge)	Voluntary + IRA tax credit incentive	Goal: 3bn gallons/year by 2030 (vs ~100m gallons today)
ICAO CORSIA	Carbon offsetting + SAF credit system	SAF generates CORSIA credits; mandatory for international aviation 2027+
Singapore (SAF levy)	Singapore Changi SAF levy from 2026	1% blend (2026); rising to 3–5% by 2030

SAF prices vs conventional Jet A-1

The "green premium" — the additional cost of SAF vs conventional jet fuel — is the primary commercial barrier to rapid SAF adoption:

Conventional Jet A-1 (2026): ~$600–900/tonne ($0.76–1.14/gallon)
HEFA-SAF (2026): ~$1,500–2,200/tonne ($1.90–2.80/gallon) — a 2–3x premium
At a 2% blend (ReFuelEU 2025 minimum), SAF adds approximately 2–4% to airline fuel costs — manageable
At a 6% blend (2030 target), SAF adds approximately 7–15% to fuel costs — significant; airlines are beginning to pass this as "SAF surcharge" to passengers
Cost reduction trajectory: HEFA-SAF projected at ~$800–1,200/tonne by 2030 as scale increases; e-SAF at ~$1,500–2,500/tonne by 2035 with green H2 cost reductions

Global SAF production capacity 2026

Global SAF production in 2026 is estimated at approximately 2–3 million tonnes per year (Mt/year) — up from ~300,000 tonnes in 2022 but still only ~1–1.5% of total global jet fuel consumption (~280 Mt/year):

Neste (Finland): ~1.5 Mt/year SAF capacity across Rotterdam, Singapore, and Porvoo refineries; world's largest SAF producer
World Energy (USA): ~500,000 tonnes/year at Paramount, CA facility
TotalEnergies: La Mède refinery (France) converted to SAF/biofuels; expanding capacity
LanzaJet (ATJ): First commercial ATJ-SAF plant operational in Freedom Pines, Georgia, USA (2023)
HIF Global (e-SAF): Haru Oni facility (Chile) — world's first commercial e-SAF plant; ~130,000 litres/year at early stage; scaling planned

SAF book-and-claim accounting
Most SAF is not physically blended into the jet fuel used on a specific flight. Instead, SAF is blended into the fuel at a refinery or airport tank farm, and airlines purchase "SAF certificates" (book-and-claim system) that credit them with the CO2 reduction regardless of which aircraft physically burned the SAF molecules. This system — analogous to renewable electricity certificates — allows airlines to claim SAF benefits even when operating in regions without SAF production. CORSIA's SAF scheme uses a similar certificate-based accounting. The book-and-claim approach reduces logistics complexity but has faced scrutiny over additionality — whether the SAF certificate genuinely represents additional decarbonisation or merely redistributes credit for existing production. Standards bodies (ISCC, RSB) certify SAF to ensure sustainability criteria are met. For parallel certificate markets in carbon, see our carbon credit glossary entry.

Frequently asked questions

What is sustainable aviation fuel (SAF)? SAF is a drop-in jet fuel replacement produced from non-fossil feedstocks (waste fats, biomass, green H₂ + CO₂) that reduces lifecycle CO2 by 50–99% vs conventional Jet A-1. It's chemically compatible with existing aircraft engines (up to 50% blend approved). HEFA (from waste fats/UCO) is the dominant commercial pathway. Global SAF production reached ~2–3 Mt/year in 2026 vs ~280 Mt/year total jet fuel consumption.: SAF is a drop-in jet fuel replacement produced from non-fossil feedstocks (waste fats, biomass, green H₂ + CO₂) that reduces lifecycle CO2 by 50–99% vs conventional Jet A-1. It's chemically compatible with existing aircraft engines (up to 50% blend approved). HEFA (from waste fats/UCO) is the dominant commercial pathway. Global SAF production reached ~2–3 Mt/year in 2026 vs ~280 Mt/year total jet fuel consumption.
What is the EU ReFuelEU Aviation mandate? ReFuelEU Aviation requires minimum SAF blending at EU airports: 2% from 2025, 6% from 2030, 20% from 2035, 70% by 2050. Fuel suppliers (not airlines) bear the compliance obligation. An e-SAF sub-mandate (0.7% from 2030) drives power-to-liquid development. Non-compliance faces penalties. The UK has a parallel SAF mandate (2% from 2025, 10% by 2030).: ReFuelEU Aviation requires minimum SAF blending at EU airports: 2% from 2025, 6% from 2030, 20% from 2035, 70% by 2050. Fuel suppliers (not airlines) bear the compliance obligation. An e-SAF sub-mandate (0.7% from 2030) drives power-to-liquid development. Non-compliance faces penalties. The UK has a parallel SAF mandate (2% from 2025, 10% by 2030).
How much does SAF cost compared to conventional jet fuel? HEFA-SAF costs ~$1,500–2,200/tonne in 2026 vs conventional Jet A-1 at ~$600–900/tonne — a 2–3x premium. At 2% blend (2025 EU mandate), this adds ~2–4% to airline fuel costs; at 6% (2030), ~7–15%. E-SAF (power-to-liquid) costs $3,000–6,000/tonne currently. SAF costs projected to fall as scale increases: HEFA ~$800–1,200/t by 2030.: HEFA-SAF costs ~$1,500–2,200/tonne in 2026 vs conventional Jet A-1 at ~$600–900/tonne — a 2–3x premium. At 2% blend (2025 EU mandate), this adds ~2–4% to airline fuel costs; at 6% (2030), ~7–15%. E-SAF (power-to-liquid) costs $3,000–6,000/tonne currently. SAF costs projected to fall as scale increases: HEFA ~$800–1,200/t by 2030.