Frequently asked questions concerning Sustainable Aviation Fuel (SAF)

SAF is the generic term for all aviation fuels that are produced without the use of fossil raw materials such as crude oil or natural gas. SAF is an important technological key for more sustainable flying and essential for the energy turnaround in aviation. Various manufacturing processes exist and different feedstocks are available as energy sources. The current generation of SAF used by SWISS and the Lufthansa Group is produced mainly from biogenic residues, for example from used cooking oils and waste fats.

Although the combustion of SAF and fossil kerosene produces identical amounts of CO₂, the use of SAF creates a CO₂ cycle: Biogenic residues (e.g. used cooking oil) are used for production, which have previously extracted CO₂ from the atmosphere. Consequently, when SAF is burned, only as much CO₂ is emitted as was previously removed from the atmosphere by the starting materials. Since CO₂ is currently still generated in the manufacturing and supply process of SAF, SAF reduces CO₂ emissions by approximately 80% rather than 100% when compared to fossil kerosene over the entire lifecycle. In order to completely neutralize the CO₂ emissions of an individual flight, a correspondingly higher proportion of SAF is therefore fed into the flight operation by Lufthansa Group, so that the remaining CO₂ emissions are also offset.

The SAF currently used by SWISS and the Lufthansa Group is produced in the HEFA process (Hydroprocessed Esters & Fatty Acids) from biogenic residues such as used cooking oils. This SAF is produced from raw materials in accordance with the Renewable Energy Directive (2018/2001/EU Article 30) "RED II". All SAF used are certified according to the ISCC or RSB system with a greenhouse gas reduction of at least 80 percent. The SAF used by the Lufthansa Group complies with applicable European law, in particular the Renewable Energy Directive.

SAF plays a central role in achieving the goal of CO₂-neutral aviation by 2050. SWISS and the Lufthansa Group has been involved in SAF research for many years and is driving forward the introduction of sustainable next-generation aviation fuels. Special focus is placed on the future-oriented Power-to-Liquid (PtL) and Sun-to-Liquid (StL) technologies, which use regeneratively generated electricity or solar heat as energy sources.

The Lufthansa Group procures SAF via established suppliers from Europe, such as from NESTE or OMV at the Schwechat site. SAF is purchased by the Lufthansa Group's fuel department, blended with fossil kerosene by the supplier, and then transported to the Lufthansa Group hubs, especially in Frankfurt.

The maximum blending rate of SAF permitted under the fuel specification is currently 50 percent. A passenger flight fueled 100 percent with SAF is currently not yet possible for regulatory reasons.

Yes, Lufthansa Group passengers can already reduce the CO₂ emissions of their individual air travel with SAF by calculation. This option can be selected and purchased directly when booking. In addition, the Green fares offer a new fare option with a fixed SAF share on European flights.

When a passenger books an SAF option, the Lufthansa Group purchases the amount of SAF required for the individual CO₂ reduction and feeds it into flight operations at one of its locations within six months.

No, it cannot be guaranteed that the passenger's specific aircraft will be fueled with SAF. The SAF is purchased centrally by the fuel department of the Lufthansa Group, mixed with fossil kerosene by the supplier and then transported to various airports (including Frankfurt and Vienna Airport for example) for use.

As aircraft are then fueled with SAF, the CO₂ reduction is realized. Lufthansa Group guarantees that the SAF will be put into Lufthansa Group flight operations within six months of acquisition.

Lufthansa Group calculates the surcharge incurred for replacing fossil kerosene with SAF for an individual flight.

Example:

For a flight from Brussels to Copenhagen, approximately 94 kg of CO₂  per person are emitted, depending on booking class and aircraft type. This amount can either be offset by supporting climate projects or reduced by using SAF. When using SAF, passengers only pay the difference between the regular kerosene price and the SAF price. Lufthansa Group guarantees that the SAF will be put into Lufthansa Group flight operations within six months of acquisition.

The amount of SAF available globally is still extremely small; currently, only around 0.1 percent (=240,000 tons) of the fuel required worldwide is of non-fossil origin. This is currently not yet sufficient to use large quantities in flight operations. The Lufthansa Group used around 13,000 tons of SAF in 2022. This was approximately 0.2 percent of the Lufthansa Group's fuel requirements and about 5 percent of the SAF available worldwide. In the coming years, the Lufthansa Group intends to successively increase this amount. The Lufthansa Group is already ensuring that customer demand for SAF can be met.

The price of SAF depends on the technology and the oil price development. Currently, the market price for existing SAF from biogenic residues is three to five times higher than the price for fossil kerosene. Next-generation SAF is currently still up to ten times more expensive than fossil kerosene. The Lufthansa Group is involved in numerous projects to ensure that Sustainable Aviation Fuels become available in larger quantities as quickly as possible. The more the production becomes industrialized, the more the price is likely to decrease.

Electricity-based fuels, so-called Power-to-Liquid Fuels (PtL) or "eFuels", also belong to the category of Sustainable Aviation Fuels. In this next generation SAF, regeneratively generated electricity, water and CO₂ (from the atmosphere) are used to create a synthetic crude oil that can be processed into kerosene. PtL aviation fuels are currently still in the development stage towards industrial production but are considered an important step towards CO₂ -neutral flying in the long term.

Sun-to-liquid (StL) technology uses high-temperature solar heat, water and CO₂  (from the atmosphere) to produce a synthesis gas from which liquid fuel such as kerosene can be manufactured in standard industrial processes. Such StL fuel closes the CO₂ cycle, since when it is combusted it releases only as much CO₂ as was previously used to produce it. Together with the Lufthansa Group SWISS is driving forward the development of this technology and is cooperating here with the Swiss solar fuel pioneer Synhelion.