What is sustainable aviation fuel (SAF)?

‘Sustainable Aviation Fuel’, or ‘SAF’, refers to jet fuel that, rather than being refined from petroleum, is produced from renewable feedstocks such as waste oils (e.g. used cooking oil). SAF is a so called ‘drop-in’ fuel, which means it can be blended with fossil jet fuel and that the blended fuel requires no special infrastructure or equipment changes. Once it’s blended, our fuel is fully certified (ASTM D1655/ DEFSTAN 91-91) and has the same characteristics, and meets the same specifications as fossil jet fuel. Currently SkyNRG supplies SAF that’s produced with the HEFA-technology but as long as the SAF meets both the technical specifications and our sustainability criteria, we are willing to consider any feedstock-technology combination.

Why is sustainable aviation fuel important?

Currently, aviation accounts for approximately 2% of all manmade global carbon dioxide emissions. That figure could rise to as much as 5% by 2050 due to the sector’s anticipated rapid growth and forecasted carbon reduction from other industries. In order to maintain this growth and at the same time address environmental impact, the aviation industry (IATA) has committed to reducing net aviation carbon emissions to 50% below 2005 levels by 2050.c
More than 99% of airline emissions and approximately 50% of airport emissions result from the combustion of kerosene. Increased energy efficiency and energy demand reduction are effective ways and first priority to reduce fuel consumption and related greenhouse gas emissions. But efficiency improvements do not offer a sole solution to aviation related emissions and dependency on oil. Because airplanes are not able to switch to alternative energy sources like hydrogen or electricity in the foreseeable future, sustainable aviation fuel made from renewable biomass is the only way to significantly reduce the industry’s carbon footprint and at the same time also reduce the dependency on fossil kerosene. But besides reducing CO2 emissions & increasing energy security, sustainable aviation fuel can offer many benefits to airlines, companies, airports, governments and travelers worldwide. More information can be found on the page where we explain the rationale for sustainable aviation fuel.

Can you fly on 100% sustainable aviation fuel?

For commercial flights on sustainable aviation fuel (SAF), the product is always blended with fossil jet fuel. The maximum blend percentage is prescribed as part of the ASTM certification process, but in general ranges from 10 to 50% depending on the production process. Once the neat SAF (this refers to the 100% SAF before it’s blended with fossil jet fuel) has been blended with fossil jet fuel, the resulting blended fuel is indistinguishable from fossil jet fuel. It meets the same specification as conventional jet fuel (ASTM D1655 and DEFSTAN 91-91). For more information on the production process visit the page that describes our supply-chain.

Do you need new engines for an airline to use sustainable aviation fuel?

No. The sustainable aviation fuel (SAF) supplied by SkyNRG is a so-called “drop-in” fuel. Once the neat SAF (this refers to the 100% SAF before it’s blended with fossil jet fuel) has been blended with fossil jet fuel, the resulting blended fuel is indistinguishable from fossil jet fuel. It meets the same specification as conventional jet fuel (ASTM D1655 and DEFSTAN 91-91) and therefore we refer to it as a “drop-in fuel”: it means no change is required in the aircraft systems, engines and in the fuel distribution system.

Is it safe to fly on sustainable aviation fuel?

Yes. The sustainable aviation fuel (SAF) supplied by SkyNRG is certified according to the same standards as fossil-based kerosene (ASTM D1655 and DEFSTAN 91-91) and therefore meets the same quality and safety requirements. As a matter of fact, many commercial SAF flights have already been supplied by SkyNRG and operated by airlines link KLM, Qantas, Finnair, Air Canada, Thai Airways and South African Airways.

How is sustainable aviation fuel different from CO2 compensation?

When compensating for CO2 emissions, a company or airline first emits CO2 and compensates for these emissions afterwards. When a company flies on sustainable aviation fuel (SAF), 80% less CO2 emissions are emitted, compared to flying on fossil jet fuel. This means that by flying on SAF you reduce your carbon footprint so you don’t have to compensate for these emissions afterwards.

Where is SkyNRG’s sustainable aviation fuel produced and by who?

Currenly, most of SkyNRG’s sustainable aviation fuel (SAF) is produced by AltAir Fuels. AltAir is the first and only bio-refinery in the world with dedicated production capacity for SAF. This makes AltAir a key partner for SkyNRG in supplying customers and scaling-up the use of sustainable jet fuel. So far, SkyNRG and AltAir have supplied South African Airways and KLM together.

How does SkyNRG guarantee that its fuel is sustainable?

SkyNRG has its operations RSB certified and is structurally advised by an independent an Independent Sustainability Board consisting of leading NGO’s and scientists, advising on all feedstock decisions, communication strategy, policy implications and growth strategies. Members of SkyNRG’s sustainability board are the WWF-International, Solidaridad, and the Energy Academy Europe. For more information visit our sustainability page.

How does SkyNRG calculate the reduced CO2 emissions?

SkyNRG calculates the reduced CO2 emissions with a Life Cycle Assessment (LCA). This is a method to map the activities and the corresponding CO2 emissions in the entire life cycle of a specific product. In the case of fossil jet fuel and sustainable aviation fuel (SAF), the key difference is the source of the carbon: fossil fuels release additional carbon that was previously stored in reservoirs. SAF recycles CO2 emissions that were emitted previously and subsequently absorbed from the atmosphere during feedstock production (see ATAG graph). Since SAF can be produced from a variety of feedstocks, with different carbon footprints, the carbon emission reduction also varies. For example, SAF produced from used cooking oil has a more significant carbon reduction than SAF that is made from energy crops like Camelina. Therefore, for every delivery is calculated how much CO2 is reduced depending on the production, supply location and the used feedstock of that particular delivery.


graph ATAG: Life cycle for fossil jet fuel and sustainable aviation fuel (SAF)

What technology does SkyNRG use to produce sustainable aviation fuel?

Currently, SkyNRG’s sustainable aviation fuel is produced with the HEFA technology. For more info, visit the page where we explain the HEFA supply-chain.

How much does sustainable aviation fuel cost?

At present, sustainable aviation fuel is approximately two to three times more expensive than regular fossil jet fuel, depending on the feedstock, technology and the set-up of the supply chain.

How does SkyNRG cover the price premium between sustainable aviation fuel and fossil fuel?

There are different ways to bridge the price gap between sustainable and fossil aviation fuel. A few programmes that we have in place are the KLM Corporate BioFuel Programme, the Fly Green Fund and Tribuu. But besides our propositions for airlines, companies and travellers, we also work actively together with airports and governments to cover the premium for sustainable aviation fuel.