How can SAF help aviation reach Net Zero by 2050? Your Top 7 Questions Answered

(Blog last updated: 23 November 2023)


Sustainable Aviation Fuel (SAF) has become an increasingly popular topic in the industry and as this technology is gathering momentum, many people still have questions about it. So, here’s everything you need to know about SAF ahead of the Sustainable Skies World Summit, as we answer the most talked about questions.


7. What is SAF?

Sustainable Aviation Fuel is an alternative to fossil fuels, typically made from plant and animal materials. Compared to traditional jet fuel, SAF reduces carbon emissions by up to 80%, depending on the source of material, method of production and the overall supply chain.

Other fuels being researched and tested include Lower Carbon Aviation Fuels (LCAF) and Zero Emission Fuels (ZEF)

Lower Carbon Aviation Fuels (LCAF)

  • LCAFs are bio-jet fuels that could act as a complementary measure to SAF.
  • The overall CO2 emissions savings vary. Currently, these fuels must be blended with kerosene for certification reasons but also because there is not enough production to meet fuel demand.
  • Recommendations to accelerate this sector call on policy makers to support initiatives delivering at least a 50% reduction in CO2 emissions and have a significant supply of feedstock in order to create LCAF at a big enough scale.

Zero Emission Fuels (ZEF)

  • ZEFs are also known as carbon-neutral fuels, meaning they produce no net-greenhouse gas emissions or carbon footprint.
  • They are typically made using carbon dioxide (CO2) as a feedstock, which involves capturing and converting CO2 into a viable aviation fuel such as liquid methanol.


6. Is SAF the same as biofuel?

SAF is generally the preferred term in aviation as it encompasses the scope of materials used to produce it, including both biological and non-biological resources. Biofuels are not necessarily always produced sustainably, and therefore the term is avoided when discussing aviation-specific fuels. Biodiesel in particular is not suitable for use in aviation.


5. Who makes Sustainable Aviation Fuel?

Currently, some of the top producers of SAF include Neste, World Energy, Gevo, Alder Fuels and SkyNRG. In December 2022, the UK government announced funding for 5 UK-based projects to produce SAF, some of which focus on converting household waste into sustainable fuel.


4. How does Sustainable Aviation Fuel reduce emissions?

Compared to conventional fuels, burning SAF fuel reduces the amount of CO2 emissions across its lifecycle as well as other impurities such as sulphur dioxide.  

‘One of things that really confuses people is that when we consume SAF in the engines we still produce a form of CO2, but it’s obviously made from biogenic sources or from captured CO2’ … ‘So in terms of increasing net CO2 in the atmosphere, SAF doesn’t do that. It’s the timeline over which we are recycling that carbon which is important’

Leigh Hudson, Environmental Manager – Carbon Management, British Airways (SSWS22 Webinar)



3. Is Sustainable Aviation Fuel actually sustainable?

SAF provides a significant reduction of CO2 emissions, but it is a drop-in solution meaning most current aircraft can only use a 50% blend of SAF and normal jet fuel. 100% SAF flights have been tested but they require technological modifications to the aircraft first.


2. Who uses Sustainable Aviation Fuel?

Based on recent data, more than 50 airlines are using or have trialled the use of SAF, with a total of over 450,000 flights to have taken to the skies (IATA). As it stands, the biggest barriers preventing more widespread usage of SAF is the cost and availability.


1. Is Sustainable Aviation Fuel more expensive?

Generally, SAF is far more expensive that traditional fuels, often double the cost. This is the main reason why many airlines and carriers have been reluctant to adopt it. The cost of production partnered with the low demand is what is keeping the overall cost of SAF so high, with many citing the need for government incentives and investment as the solution.

‘SAFs are wonderful, they’re great, if you can get it. We wholeheartedly support any effort from government incentives and through the market to ramp up as fast as possible the production of these game changing sustainable aviation fuels.’

Sean Bradshaw, Technical Fellow – Sustainable Propulsion, Pratt & Whitney (SSWS22 Webinar)


SAF News in 2023 

  • Emirates became the world’s first airline to operate an A380 demonstration flight using 100% Sustainable Aviation Fuel. Read the full story here.
  • Gulfstream completed the World's First Trans-Atlantic Flight on 100% Sustainable Aviation Fuel. Read more. 
  • Rolls-Royce has successfully tested 100% SAF on a BR710 business jet engine, marking the completion of its compatibility testing programme. Read more.
  • Virgin Atlantic’s 100% SAF flight also took place at the end of November 2023. This marked the first Trans-Atlantic flight by a commercial airliner using 100% SAF. Read more.
  • Boeing and Zero Petroleum signed an agreement at Dubai Airshow to work together to advance Sustainable Aviation Fuels (SAF). The companies will jointly establish a testing program at the University of Sheffield’s Energy Innovation Centre (EIC) and its SAF research facility in the UK. Read more.
  • Farnborough Airport hit a milestone in the move to Sustainable Aviation Fuel (SAF), selling its millionth litre of the green fuel. Read more.


The Bigger Debate: SSWS24 Agenda

To accommodate for the increased predicted numbers of flights and passengers in 2050, a huge amount of SAF will need to be produced. So, how does the industry do this?

Is SAF the right strategy? Is hydrogen or electric a better investment?

The discussion around SAF and the road to Net Zero more generally will be a key topic of conversation in a number of panel sessions planned for SSWS24.

Explore the 2024 Agenda here.


Join the conversation at the Sustainable Skies World Summit, 15-16 May 2024

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