On a scheduled KLM Cityhopper service from Amsterdam to Hamburg, flight KL 1755, the tanks held synthetic kerosene produced by eFuel Alliance member INERATEC at the Höchst industrial park in Frankfurt. Delivery to Hamburg and blending with conventional jet fuel were organised together with MB Energy, also an eFuel Alliance member. The detail that matters is not the route but the origin: the fuel came from a scalable industrial plant, not a laboratory or a small pilot rig.
It also passed through the entire standard aviation supply chain — production, treatment, blending, logistics and fuelling at Hamburg airport — while meeting all the quality, safety and certification requirements of international aviation. In other words: no special case, no exemption, no separate infrastructure. That is precisely what makes it interesting.
The technology flies. The price still does not.
Shortly before the international aerospace exhibition in Berlin, the European Commission published the price differences that apply for 2025 between fossil kerosene and sustainable aviation fuels. These figures are not a market observation but a regulatory instrument: they determine how many free EU ETS allowances are allocated under the Emissions Trading Directive.
The Commission sets fossil kerosene at €640 per tonne. RFNBOs are valued at €8,272 per tonne and renewable hydrogen at €8,476 per tonne. On that basis, direct ETS support reaches up to €7,030 per tonne of RFNBO, €5,322 for renewable hydrogen, €2,542 for synthetic low-carbon fuels, €1,515 for advanced biogenic aviation fuels and €526 for conventional bio-jet.
Read the first two numbers together and the scale of the problem becomes visible: a renewable molecule that does exactly the same job in exactly the same engine is priced at roughly thirteen times the fossil reference. ETS support closes most of that gap — but not all of it. On these figures, some €600 per tonne is still left uncovered, and that residue has to be carried by someone in a market where the competing product is untaxed at the point of combustion.
Why offtake, not chemistry, is the binding constraint
The production side has just gained a new option. With ASTM International certifying the methanol-to-jet route as a production pathway for sustainable aviation fuel, a central investment barrier has fallen. It matters because methanol is a platform fuel: according to a joint study by the eFuel Alliance and Porsche Consulting, around 80 per cent of the renewable fuel production planned worldwide up to 2030 is eMethanol. A certified path from that molecule to jet fuel widens the feedstock base considerably.
The volumes required are substantial. To meet international climate targets, global SAF production would have to rise from around 40,000 barrels per day in 2025 to roughly 400,000 barrels per day by 2035. In the EU, eSAF is meant to reach 5 per cent of kerosene consumption by 2035 and 35 per cent by 2050 — and between a final investment decision and the start of production, three to five years typically pass.
The eFuel Alliance describes the ASTM decision as the regulatory breakthrough the sector had been waiting for, while pointing to what still has to follow in Europe. Offtake agreements remain rare, chiefly because production costs are high. One of the main cost drivers is regulatory: the delegated acts under the Renewable Energy Directive define the conditions under which a renewable fuel can be counted as eSAF at all. What matters now is whether the European legal framework converts the tailwind from the methanol-to-jet approval into investment-friendly conditions.
What this means for Switzerland
Switzerland is well represented on the technology side of exactly this chain. The aerobrew plant opened at PSI in Villigen runs the whole methanol-to-jet process under one roof, and Swiss engineering sits in electrolysers, catalysts and synthesis units across Europe. What Switzerland cannot solve alone is the other half of the equation: the price gap, and the contracts that would bridge it.
That is why the Commission’s price table is more than accounting detail. It is the clearest official statement yet of how far apart fossil and renewable aviation fuel still stand, and therefore of how strong purchase incentives have to be if long-term offtake contracts are to become viable and trigger investment in new capacity. A plant that no one has agreed to buy from does not get built, however elegant its process diagram.
One condition remains non-negotiable from a Power-to-X perspective: e-SAF only makes climate sense when the carbon it contains is recycled CO₂ from biogenic, atmospheric or industrial sources, and when that recycling displaces fossil carbon instead of providing a reason to burn more of it. On that basis, the fossil emissions from flying drop to near zero. Perhaps a little less flying — definitely fossil-free flying.
Source: eFuel Alliance, eFuel Bulletin, Edition II 2026.
🤖 AI transparency: This text and its visual were created using AI, reviewed and approved by a human.
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