Sustainable Aviation Fuel and Private Jets: What ReFuelEU Means for Charter

What SAF is, and what it is not

SAF is a drop-in fuel: it goes into the same tanks and engines as conventional Jet A-1. Under the ASTM standard it is blended rather than burned neat; the HEFA route, which turns oils and fats into jet fuel, was approved in 2011 with a 50 per cent blend limit. In practice, European SAF today is mostly waste oil. EASA reports that SAF supplied in 2025 was approximately 80% aviation biofuels, overwhelmingly derived from used cooking oil, with 85% of feedstocks imported, mainly from China (61%).

The climate benefit is counted over the fuel’s lifecycle, from feedstock to engine, rather than at the exhaust. EASA puts the 2025 saving at a weighted average of ~89% in lifecycle emissions for the SAF supplied. That is real, but it applies only to the SAF share of the blend, which is still small.

ReFuelEU: a mandate on fuel suppliers

The main European rule is ReFuelEU Aviation. It obliges fuel suppliers, not passengers, to blend SAF into fuel at Union airports, defined as airports with passenger traffic higher than 800 000 passengers or freight traffic higher than 100 000 tonnes. The minimum share is 2 % of SAF from 2025 and 6 % from 2030, rising to 70% in 2050. EASA says the 2% threshold applies at around 150 Union airports.

Business aviation is inside the definition. A commercial air transport flight is one operated for remuneration or hire, including a business aviation flight operated for commercial purposes, and the Commission confirms that maintenance, repositioning or ferry flights are included when linked to commercial activity. The operator obligations, however, apply only above a threshold: an aircraft operator is a company that operated at least 500 commercial passenger air transport flights from Union airports in the previous reporting period. Smaller operators and non-commercial flights may opt in.

What operators must actually do

For operators in scope, the obligation is about where they buy fuel, not whether it is green. EASA’s manual is explicit: operators must uplift at least 90% of the aviation fuel required (trip + taxi fuel) at Union airports each year, and are not subject to any obligation to demonstrate a minimum purchase of SAF. The rule exists to stop tankering cheaper fuel in from outside the EU.

One detail matters for small jets. EASA notes that commercial flights in aircraft with a maximum take off mass (MTOM) of less than 5.7 tonnes are in scope of ReFuelEU, even though they are excluded from EU ETS reporting. A very light jet on charter is not automatically outside the regime if its operator is in scope.

2025, the first year in numbers

The first full year beat the target. EASA’s 2026 technical report counts 39.3 million metric tons (Mt) of aviation fuel supplied, incl. 1.1 Mt of SAF (2.79%), against the 2% minimum. A year earlier SAF was 0.6% of all aviation fuel supplied.

Distribution widened too. In 2025 SAF was supplied at 121 Union airports across all 27 EU Member States, compared with 33 airports in 2024, and the Netherlands alone took 29% of all SAF reported. In 2024, Germany was one of five Member States, with France, the Netherlands, Spain and Sweden, that together accounted for 99% of supply.

What SAF costs, and what it adds to an hour

SAF is expensive. EASA’s 2025 reference prices are €1,925/t vs €640/t for conventional jet fuel, roughly three times as much. Those are neat fuel prices that, as EASA notes, do not capture downstream components such as blending, distribution and supplier margins, so the price at an FBO will be higher.

The blend dilutes the premium. By my arithmetic on those reference prices, a 2% blend costs about 4% more than fossil fuel and a 6% blend about 12% more. Take a Phenom 300E, which Duncan Aviation lists at an average fuel burn of 169 gallons per hour: that is roughly half a tonne of fuel an hour, so the 2% mandate adds something like €13 per flight hour at reference prices, and a 6% blend about €40. Against light-jet charter that Jet Supply indexes at €4,700–7,500 per block hour all-in, the mandate is not what moves a quote today. Taxes do far more, as I show in private jet taxes in Europe.

Where SAF becomes visible is a voluntary purchase above the mandate, or a higher blend. Then the premium is the full gap between €640 and €1,925 a tonne on every extra tonne, and it should appear as a separate, explained line, in the same way I insist on seeing every line of an all-in price.

The EU ETS: where carbon is priced

The EU Emissions Trading System is the other half of the picture, and it treats business aviation unevenly. Germany’s emissions trading authority, DEHSt, lists the Annex I thresholds for the trading obligation: for commercial aircraft operators 10,000 tonnes of CO2 for annual emissions or 243 flights in the three consecutive four-month periods, and for non-commercial operators 1,000 tonnes of CO2 a year. Operators that stay below them fall outside the obligation. Ireland’s EPA confirms that non-commercial operators below 1,000 tonnes are exempt until 2030.

For operators inside the ETS, SAF helps twice. It carries a zero emissions rating under the system, and the EU has set aside a maximum of 20 million ETS allowances (with an estimated value of €1.6 billion) between 2024 and 2030 to cover part or all of the price difference with fossil kerosene. Smaller charter operators below the thresholds see neither the cost nor that support.

The UK runs its own mandate

Flights out of London fall under a separate regime. The UK SAF Mandate requires suppliers to deliver 2% of the total fossil jet fuel supplied in 2025, rising to reach 10% in 2030 and 22% in 2040, with a power-to-liquid obligation from 2028. The UK’s 2030 target of 10% is well above the EU’s 6%, so the British blend should rise faster over the next few years.

What the industry says

Operators are interested but cautious. In Honeywell’s 2025 outlook, among operators taking proactive steps on sustainability, 56% are using SAF, and cost and availability of SAF continue to be the largest challenges to adoption. That matches what I see: willingness is not the constraint; price and paperwork are.

The questions I ask on a charter

When a client wants SAF on a trip, or a quote mentions it, I ask:

• Is the SAF line a pass-through of the mandated blend at that airport, or a voluntary purchase above it? Only the second is something the client is buying.
• Which airport, what quantity and what documentation? A voluntary SAF purchase should come with the volume and the supplier’s sustainability evidence, not just a percentage.
• Is it SAF or a carbon offset? They are different products and should not be described as the same thing.
• Is the aircraft right-sized? A lighter aircraft that fits the mission usually saves more fuel than any blend; see choosing between light, midsize and heavy jets.
• Is the operator in scope of ReFuelEU and the ETS? It does not change the client’s safety, but it explains how fuel and carbon costs are built into the price.

My view, briefly

SAF is now a fact of European aviation, not a marketing extra. At today’s blend levels it adds little to a private jet charter, perhaps tens of euros an hour, and it gives no one the right to call a flight carbon-neutral. The cost becomes real when a client asks for more than the mandate, and that choice deserves a clear price and proper documentation. I would rather quote that honestly than sell a green label; the same applies to every other line in what drives a charter price.

Frequently asked questions

Can a private jet fly on 100% sustainable aviation fuel? — Not under current fuel specifications. SAF is blended with conventional jet fuel; the common HEFA pathway is certified up to a 50% blend.

Does ReFuelEU apply to private jets? — The SAF obligation sits with fuel suppliers at Union airports, so its cost reaches every operator that buys fuel there. Operator obligations apply to companies with at least 500 commercial passenger flights from Union airports in the previous reporting period; others may opt in.

How much does SAF add to a charter? — At EASA’s 2025 reference prices, by my arithmetic the 2% mandate adds roughly €13 per flight hour to a Phenom 300E’s fuel bill. Voluntary purchases above the mandate cost the full premium, about three times the price of conventional fuel.

Are private jets in the EU Emissions Trading System? — Many are. The EU ETS thresholds for commercial operators are 10,000 tonnes of CO2 a year or 243 flights in three consecutive four-month periods; non-commercial operators emitting less than 1,000 tonnes a year are exempt until 2030.