Europe's e-SAF Mandate: Why Counting e-HEFA Could Undermine the Policy

Europe’s ReFuelEU rules set a dedicated sub-mandate for synthetic aviation fuel, or e-SAF, requiring jet fuel suppliers to blend a rising share of fuel made from green hydrogen and captured CO2 beginning in 2030. The obligation has been public for years, yet most suppliers have yet to build out their own e-SAF production capacity.

That gap has opened the door to a proposed workaround: letting so-called “e-HEFA” fuel count toward the mandate. The approach would treat certain hydroprocessed esters and fatty acids as if they satisfied the synthetic fuel requirement, a change critics argue would blur the line between genuinely novel e-SAF and established pathways.

Advocates of the strict reading say watering down the definition would send the wrong investment signal. If conventional HEFA output can be counted, suppliers face less pressure to fund the costly electrolysis and CO2 capture projects the mandate was designed to spur. The result could be a mandate that looks fulfilled on paper while delivering far less new synthetic capacity.

The debate lands as European policymakers weigh how flexibly to interpret the e-SAF target. For the rule to drive real industrial scale-up, supporters of a narrow definition argue, the synthetic portion must remain reserved for fuels that actually come from green hydrogen and captured carbon.