How EU Aviation Fuel Rules Could Undermine The Energy Transition
As Europe accelerates its push toward decarbonized aviation, a new study from Chalmers University of Technology suggests the European Union’s regulatory framework may be steering the industry toward a more expensive and energy-intensive path than necessary.
At the center of the debate is sustainable aviation fuel, or SAF, which has become one of the aviation sector’s most critical tools for reducing emissions. Under the EU’s ReFuelEU Aviation mandate, airports across the bloc are now required to blend sustainable fuel into conventional jet fuel, beginning at 2 percent and scaling to at least 70 percent by 2050. Half of that future supply must come from Renewable Fuels of Non-Biological Origin, better known as RFNBOs, a category that includes synthetic fuels produced using renewable electricity, hydrogen, and captured carbon dioxide.
The ambition is clear: reduce dependence on fossil fuels while stimulating investment in renewable energy infrastructure. Yet according to researchers at Chalmers, the current regulatory structure may unintentionally reward inefficiency.
The study, published in the journal Fuel, examined three different pathways for producing synthetic methanol, a key intermediary molecule that can later be refined into aviation fuel. While each pathway can yield the same end product using biomass-derived carbon, the differences in energy demand and production cost are substantial.
Researchers found that biomass gasification — a process that converts biomass directly into synthesis gas containing both hydrogen and carbon — delivered the strongest performance metrics. Compared to combustion-based pathways favored under current EU classifications, gasification reduced production costs by as much as 46 percent while lowering electricity demand by approximately 30 percent.
That distinction matters because sustainable aviation fuel production is expected to scale dramatically over the next two decades, requiring enormous industrial investment and long-term infrastructure commitments.
“The regulatory framework does not account sufficiently for how efficiently different systems use energy and resources,” said Henrik Thunman, Professor of Energy Technology at Chalmers and co-author of the study.
What complicates the equation is the EU’s RFNBO classification itself. Under current rules, fuels created from captured carbon dioxide generated through biomass combustion qualify within the RFNBO framework. But fuels produced through direct biomass gasification are only partially eligible because the process relies more directly on biogenic carbon inputs.
In practice, this creates a paradox: pathways that consume more electricity and generate larger energy losses are receiving stronger regulatory incentives than systems researchers argue are materially more resource efficient.
The implications extend beyond aviation. Europe’s clean energy transition increasingly hinges on how effectively limited renewable resources — particularly biomass and green electricity — are allocated across industries. If regulations encourage inefficient conversion processes, the strain on renewable electricity generation could intensify at precisely the moment demand is accelerating across transportation, manufacturing, and data infrastructure.
The Chalmers study also highlights another emerging concern: industrial lock-in. Once large-scale SAF production facilities are financed and deployed, those systems are likely to remain operational for decades. Regulations established today may therefore shape not only near-term emissions outcomes, but the long-term architecture of Europe’s clean fuel economy.
Johanna Beiron, lead author of the study and researcher in Physical Resource Theory at Chalmers, noted that current incentives appear misaligned with the EU’s broader sustainability objectives.
“It is surprising that EU rules do not provide clearer incentives for the most efficient alternatives,” she said. “The current regulatory framework risks causing lock-in to combustion-based energy systems, even though technically mature processes already exist that would provide both lower energy use and lower cost.”
The timing of the research is particularly significant as geopolitical instability continues to refocus attention on energy security and domestic fuel production. Volatility in global oil markets, exacerbated by conflict in the Middle East, has reinforced the urgency behind Europe’s efforts to establish resilient, fossil-free fuel supply chains.
Yet the study argues that climate policy cannot rely solely on emissions accounting. Resource efficiency, industrial scalability, and energy intensity will ultimately determine whether decarbonization strategies remain economically viable at continental scale.
For aviation — one of the world’s hardest sectors to decarbonize — that distinction could prove decisive.
