As the world's major economic superpowers prepare strategies to hit Net-Zero targets, attention has inevitably turned to the aviation industry's contribution to carbon emissions.
In the EU alone, direct emissions from aviation accounted for 3.8% of total CO2 emissions. To put this into perspective, someone flying from Lisbon to New York and back generates roughly the same level of emissions as the average person in the EU does by heating their home for a whole year - according to the European Commission.
The UK Government has recently announced its plans for 'Jet Zero', a scheme to reach UK Net Zero Aviation by 2050.
Further, in recent events Amsterdam's Schiphol airport attempted to curve carbon emissions locally by proposing to ban private jets arriving and departing at their airport from 2026. At present, the Dutch courts have put a halt to Schiphol's plans.
Evidently, and as climate change continues to pose significant global challenges, the aviation sector is now firmly within the crosshairs of environmental reform. But what's the solution?
In absence of fully electric or hydrogen powered aircraft, one of the more immediately available solutions has emerged in the form of Sustainable Aviation Fuel (SAF).
SAF, known as a 'drop-in' fuel can be directly fuelled into aircraft without adaptation to the airframe or fuelling systems. SAF is not just a step towards Jet Zero; it is a beacon of hope in the quest for a greener and sustainable future for aviation by the 2050 target.
The Evolution of Sustainable Aviation Fuel
Conventional aviation fuel, known as Jet A1 or Jet fuel, is derived from crude oil and is responsible for a substantial share of global carbon emissions. In contrast, SAF, a biofuel, is made from a variety of sustainable resources including plant waste, agricultural residues, wood chips, cooking oils and algae, which would otherwise be thrown away. The production process for SAF involves converting these raw materials into bio-based hydrocarbon molecules that can directly replace fossil-based jet fuel.
According to Shell, SAF has the potential to reduce lifecycle emissions by up to 80% when used neat, compared to conventional aviation fuels. In reality, the reduction in lifecycle emissions is likely to be somewhat less than 80% as SAF is not authorised for full neat use. Most who use SAF, apply it with conventional jet fuel at a blend of 6% SAF/JetA1 with a maximum blend of 50/50 ratio. The International Air Transport Association aims for a 65% blend by 2050.
What Are The Benefits of Sustainable Aviation Fuel?
1. Climate Change Mitigation: When used neat, SAF has the potential to reduce aviation-related carbon emissions by up to 80% compared to traditional jet fuel. Burning SAF releases significantly fewer greenhouse gases, including carbon dioxide (CO2), nitrogen oxides (NOx), and particulate matter (PM).
2. Technological Compatibility: SAF can be used in existing aircraft and infrastructure without requiring significant modifications or investments. This versatility allows the aviation industry to transition towards sustainability without interrupting flight operations.
3. Diversification of Feedstocks: Unlike conventional jet fuel, which relies on finite fossil resources, SAF can be produced from a wide variety of feedstocks. By diversifying the sources for SAF production, the aviation industry can reduce its dependency on traditional oil reserves and promote a more resilient and sustainable energy mix.
4. Rural Development and Job Creation: The sustainable aviation fuel industry has the potential to create numerous job opportunities in both urban and rural areas. The cultivation, harvesting, and processing of feedstocks for SAF production can generate employment in agriculture, biotechnology, and transportation sectors.
5. Availability: SAF is, for the most part, readily available for delivery into aircraft today. Air operators in the private and commercial sector are transitioning to a blend of SAF and A1 Jet Fuel. It is suggested that already over 125 million litres of SAF have been used in commercial and private flights. By 2025, it is projected that 2 million flights will be using SAF blends.
What Are The Barriers to Scale and Widespread Adoption for Sustainable Aviation Fuel?
While Sustainable Aviation Fuel presents a promising solution, there are several challenges that need to be addressed before widespread adoption can be achieved:
1. Infrastructure and Distribution: One of the most significant challenges for SAF is the development of an extensive infrastructure to produce, store, and distribute the fuel efficiently. Whilst SAF is currently available in some airports, it is not available across the board. A jet may have access to SAF in a larger European hubs like Amsterdam, Munich or Heathrow; but may have difficulty in refuelling with SAF in remote destinations in South America or Africa.
2. Cost Competitiveness: Currently, Sustainable Aviation Fuel is more expensive than traditional jet fuel due to relatively low production volumes. Addressing this cost discrepancy through economies of scale and technological advancements will be critical in making SAF economically viable for airlines.
3. Regulatory Framework and Certification: Establishing clear regulatory standards and certification processes for sustainable aviation fuel is essential to ensure reliable and standardised production across the industry. Certifying the sustainability and traceability of feedstocks is crucial in maintaining transparency and consumer confidence.
4. Alternative Solutions: Whilst SAF is readily available, it is not the desired solution to achieving Jet Zero as it is not yet ready or permitted to be supplied neat to aircraft. This in turn means that although SAF greatly reduces the carbon output of aircraft, it is unlikely going to allow aircraft to be fully carbon-neutral.
Hydrogen fuel cells however, are the front runner option for the aviation industry to achieve carbon-neutrality. Hydrogen fuel cells generate electrical power emitting only water vapour and warm air as the output - meaning that they truly offer a carbon net-zero solution. Hydrogen fuel cells are still in development and it is unlikely that we are going to see their implementation into aircraft for some time.
The aviation industry has a crucial role to play in global efforts to combat climate change. Sustainable Aviation Fuel offers a viable pathway to reduce greenhouse gas emissions and make air travel more sustainable as of today.
By investing in research and development, infrastructure, and supportive policies, the aviation sector can promote the widespread adoption of SAF, and accelerate the transition towards a greener future. It cannot be overlooked however, that until SAF is suitable for neat delivery into fuel systems, there may be other solutions on the horizon which will leave the internal combustion engines of today, in the past.