Matteo Mirolo is aviation policy officer at clean transport campaign group Transport & Environment
In today's world, aircraft rely almost exclusively on fossil jet fuel to operate, and as global passenger traffic continued to grow – at least until the onset of the pandemic – so did the harmful emissions generated by the aviation sector.
If Europe is to achieve its net zero climate objective, it is essential that aircraft emissions are reduced and eventually eliminated.
New zero-emissions aircraft will be essential in the future, but the only solution we have right now is to mandate the use of sustainable advanced fuels (SAFs). The ReFuelEU Regulation proposal aims to do precisely this.
The two types of SAFs
SAFs are aviation fuels that can be dropped into existing aircraft engines. They can be divided into two broad categories: firstly, advanced biofuels, which are made from wastes and residues and, with the right safeguards, they can be sustainable.
And secondly, e-kerosene, which is produced from water, renewable electricity (thus forming green hydrogen) and captured CO2. When the renewable electricity is additional and the CO2 is captured from the atmosphere (Direct Air Capture, or DAC), the fuel has close to full CO2 circularity.
In addition to decarbonising aviation, SAFs are also likely to reduce aviation’s non-CO2 effects, most notably contrail clouds, due to their generally low aromatic content.
It is important, however, to note that not all SAFs are made equal when it comes to their true potential to reduce aviation’s climate impact.
Crop-based biofuels, for example, are a cure worse than the disease given their negative impacts on climate and biodiversity and should therefore be avoided at all costs.
Even for advanced biofuels, a lot depends on the type and whether essential safeguards are in place to ensure their environmental integrity. For example, current EU rules still support unsustainable options as advanced biofuels, like biofuels produced from energy crops. In general, true waste and residues with no competing uses are limited in availability so supply targets for these fuels should be kept low.
When it comes to e-kerosene, the devil is in the way the CO2 is sourced. As mentioned above, while CO2 captured from ambient air makes for a close to carbon circular fuel, the same cannot be said for CO2 extracted from smokestacks.
Not only does this process, known as “point-source CO2”, rely on a dirty and unsustainable feedstock, it creates a business case for the continued use of fossil fuels.
While it is important to be pragmatic and enable SAFs to be scaled up rapidly to meet the urgent decarbonisation needs of the aviation industry, it is equally crucial to be forward thinking and gradually restrict SAFs to only the most future-proof and clean types.
Fuelling demand for SAFs
What will it take to accelerate the use of clean fuels for aviation? Given their much higher price than traditional Jet A1 kerosene, it is essential for policymakers to give unambiguous signals to both producers and investors that there is a market for these new fuels.
Mandating the use of SAFs is therefore the most effective way to build a growing market, and this is what the ReFuelEU regulation aims to achieve. At the same time, it is also crucial to continue investing in economic measures, such as fossil kerosene taxation and carbon pricing, as well as better demand management, in order to reduce the demand for alternative fuels needed in the future.
The ReFuelEU proposal introduces an obligation on jet fuel suppliers to blend a growing share of SAFs into fuel provided to airports in Europe. That obligation covering both types of fuels – advanced biofuels and e-kerosene – starts in 2025 at 2 per cent, and grows to 5 per cent in 2030 and further beyond that, up to 63 per cent in 2050.
This will apply to all fuel sold in the EU, meaning this proposal, unlike the jet fuel tax and ETS proposals, will cover long-haul flights. Finally, Europe accepts that it should regulate all aviation emissions, not just a minority.
While ReFuelEU has good foundations given that it excludes crop-based biofuels, it can still be improved by correcting the balance between advanced biofuels and e-kerosene. That means increasing the 2030 e-kerosene subtarget of 0.7 per cent and decreasing the advanced biofuel target so as not to create too much pressure on the supply of limited feedstocks.
Even if it will play a major role in driving the uptake of SAFs, this mandate is not everything and should therefore be accompanied by an ambitious industrial policy to encourage innovation and efficiency gains, so as to help bring down the price of SAFs.
At the same time, airlines, which are the final customers, should not be forgotten. Mechanisms to mitigate the price gap with fossil kerosene, such as contracts for difference (CfD), could help them afford SAFs, and attention must be paid to avoiding competitive distortion to the disadvantage of European airlines
If done right, SAFs can immediately and sustainably start reducing aviation's climate impact without any changes to the way aircraft operate. SAFs and especially e-kerosene production would also give a boost to multiple innovative chains in the decarbonisation of the EU economy.
With the right safeguards in place and a forward-looking perspective, it is high time the EU started to tap SAFs’ potential for clean aviation.