
This year, the EU mandated 2% Sustainable Aviation Fuel (SAF) blending in all airports feeding into aeroplanes. The definitions of SAF for EU is clear, mostly based on a whitelist of feedstocks that are proven to be ‘sustainable’ and achieves a high level of carbon emissions reduction on a lifecycle basis (70% or more compared to A1 Jet Fuels). Unlike CORSIA, which puts the onus on airlines to reduce their emissions from jet fuels, RefuelEU regulations put the responsibility on fuel suppliers that supply to the airports. These suppliers will need to quote their prices to airlines accounting for these regulations, and while airlines don’t have to deal with the hassle of making sure the blend is correct to meet compliance requirements, they will need to bear the increased costs.
Now, there are also similar SAF regulations in the US under Renewable Fuel Standards, but their requirements for feedstocks and lifecycle carbon emissions reductions are different. Just to caveat first that I’m way less familiar with the US standards and requirement but based off some work from my colleagues, I understand they are less stringent, defining SAF to require 50% reduction in lifecycle carbon emissions compared to conventional jet fuels. This allows feedstocks such as corn ethanol, or other dedicated energy crop-based feedstocks (including canola, other oilseed crops) to be used for their SAF.
And if you refer back to the ICAO standards set under CORSIA, they only require that there’s 10% reduction in carbon emissions. It is still unclear to me what would constitute ‘SAF’ to the countries in Asia Pacific that are all introducing some SAF volumetric blending mandate.
One of the key challenges with just defining a standard threshold for carbon reduction and then setting a volumetric SAF target is that you don’t incentivise SAF producers to reduce their lifecycle carbon emissions. It becomes a race to the bottom for the airlines or fuel suppliers to buy the cheapest SAF that meets the threshold for compliance. If instead, we set a carbon emission reduction target and require the blend to achieve that target, then we can benefit from a greater diversity of SAF feedstocks and pathways that meets the economics on the basis of a unit carbon abatement cost. After all, the carbon emission reduction is the piece of value we care about for SAF at the moment, won’t it be better to price that?