Sustainable Aviation Fuels: Paving the way for greener skies

SAF — the fuel of the future?

According to the International Air Transport Association (IATA), SAF could save up to 65 percent of emissions in the aviation sector. The development of SAF is therefore a decisive step toward climate-friendly aviation.
 

Two types of SAF are currently in focus: Bio-based SAF, which is made from biogenic raw materials such as vegetable fats, residuals or algae, and E-SAF, which is made from CO₂ and green H2. Both products have the potential to replace fossil kerosene — but there are technological and economic hurdles.
 

Bio-based SAF is currently produced from waste materials, such as old frying fat, using already established production processes. Some global airlines are already using this fuel to improve their carbon footprint. Therefore, production capacity has risen rapidly in recent years, but there could be a shortage of raw materials in the long term. E-SAF, on the other hand, could theoretically be produced indefinitely as soon as there is enough renewable energy and green CO₂. Production requires enormous amounts of green electricity. For instance, to achieve the EU's planned E-SAF quota of 2% by 2032 in Germany alone, approximately 75 terawatt hours of renewable energy would be needed, along with 1 million tons of CO₂. In addition, there is a great need for further investments in infrastructure and technology.
 

Regulatory support for SAF

Political decisions and regulations have given the industry a major boost. With the “ReFuelEU Aviation” initiative, the EU has set clear quotas for the supply of SAF: The ambitious targets envisage increasing the SAF share from a modest 2% in 2025 to an impressive 70% by 2050. SAF is thus to be transformed from a niche solution into the new standard. The targets are creating considerable pressure to scale up more sustainable fuels more quickly.
 

In addition, the strict European Emissions Trading System (ETS) is making CO₂ emissions more expensive for airlines. With rapidly rising EU ETS prices for aviation and a limited supply of allowances, the long-term use of kerosene is becoming increasingly unattractive — giving SAF a growing competitive edge. The introduction of environmental labels for flights from 2025 by the European Aviation Safety Agency (EASA) should also influence passengers' choices. Those who are aware of the ecological footprint of their flights may choose airlines that rely on SAF more often — a further incentive for the industry to fly sustainably. Some major air freight customers are already demanding greener services from airlines.

The overlooked climate threats

SAF alone will not solve all aviation problems. In addition to CO₂ emissions, flying generates other climate factors such as contrails, soot particles and nitrogen oxides. These so-called non-CO₂ effects are estimated to have a greater impact on global warming than the CO₂ emitted. Although SAF releases fewer soot particles and thus reduces the formation of contrails, they do not completely eliminate these effects. Without additional measures such as the optimization of flight routes and possible flight altitudes, more efficient engines and, above all, less air traffic, the carbon footprint of flying will remain burdened.

Outlook for sustainable aviation

The aviation industry is working intensively on the use of SAF to reduce its carbon footprint. Politicians have recently increased the pressure on the industry through quotas and the emissions trading system. SAF could reduce up to 65% of emissions, but high costs and technological hurdles are slowing down their large-scale use. Estimates predict investments of up to 1.5 trillion US dollars in the coming years — a large sum given the lack of bankability of the projects to date. In addition, non-CO₂ effects continue to have a negative impact on the climate. The decisive factors will be how quickly technological advances reduce the costs of SAF, whether investors, companies and customers are prepared to shoulder the enormous sums involved and how the EU can support the market with funding instruments.