Sustainable Aviation Fuels: A Game-Changer to Reduce CO2.
Reducing global carbon dioxide (CO2) emissions is the critical global challenge of our time. Consequently, many countries have set themselves legally binding targets on achieving net-zero carbon emission by 2050 such as the UK, France, Denmark, Hungary, New Zealand, Japan and South Korea; Sweden by 2045.
Aviation accounts for approximately 2.5% of overall global CO2 emissions according to data cited by Our World in Data. Over the recent decades significant technological developments have taken place in most areas of the aviation sector, except for the use of fossil-based fuel which has remained relatively unchanged. Although alternative clean propulsion technologies are under development, such as Airbus’ projects for electric-powered and zero-emission aircraft fuelled by hydrogen, unfortunately these solutions are unlikely to be commercially viable before 2035.
The last decade in particular has seen considerable progress in developing Sustainable Aviation Fuels (SAFs), which are capable of reducing aviation CO2 emissions by up to 80% in comparison to fossil-based fuels.
SAFs are a clean substitute for fossil-based fuels. Rather than being refined from petroleum, SAFs are produced from sustainable resources such as waste oils from a biological origin, agricultural residues or non-fossil CO2 (SkyNRG).
To have a better understanding of SAF, please let IATA explain to you.
Another great benefit of SAFs is that they can be mixed with regular jet fuel with no need to modify the engine. For example, SAFs are certified for blends of up to 50% with conventional jet fuel and can be used on all current Rolls Royce engines. On 1st February 2021 Rolls Royce announced its first test of 100% SAFs on its latest business jet aviation engine in development, the Pearl 700, in Dahlewitz, Germany, which came just weeks after unblended SAFs were successfully used for the first time in engine ground tests on a Trent 1000 engine in Derby, UK. The tests demonstrated that its current engines, for both large civil and business jet applications, can operate with 100% SAFs as a full “drop-in” option, laying the groundwork for moving this type of fuel towards certification. The SAF that was used in the tests was produced by low-carbon fuel specialist World Energy in Paramount, California, sourced by Shell Aviation and delivered by SkyNRG. This is another important step in enabling Rolls Royce’s customers to achieve net-zero carbon emissions.

SAFs tested on the Pearl 700 (Source: Rolls-Royce)
However, the uptake of SAFs remains very low, currently less than 1% of total aviation fuel consumption, and is due to various factors including the limited supply and costs of the fuel. In Europe, the price of bio-based aviation fuel produced from used cooking oil can be in the range of €950-€1,015 per tonne, meanwhile a typical price for fossil-based aviation fuel would be €600 per tonne (58%-69% lower). Hence in order to incentivise airlines to use more SAFs, their price must be near or at cost parity to fossil fuels.
In conclusion, SAFs could be a game-changer for the aviation industry to reduce carbon emissions. However, they require significant investment in advance to scale up their production and bring the costs down significantly. Governments need to have a long-term policy to both provide certainty and reduce the investment risks for the production companies, and to give investors the confidence to make the big investments required to grow supply.