The aviation industry faces a significant challenge in reducing its climate impact, as it accounts for approximately 2-3% of global CO₂ emissions. However, electrification—successful in other sectors—is not viable for aviation. This is because electric storage, such as batteries, has critical limitations: the energy density of current batteries is insufficient to meet flight demands without increasing the aircraft’s weight to impractical levels.

Sustainable Aviation Fuels, or SAFs (from their English acronym), derived from renewable and alternative feedstocks, have emerged as a key option in the transition to a low-emission air transport system. Interest in SAFs has grown considerably, as they enable CO₂ reductions without the need to modify the infrastructure of current aviation engines.

SAFs are defined as aviation fuels produced from biomass or waste sources. There are multiple production pathways, which allow us to distinguish three main types:

SAF technology allows integration into aviation engines through blending with Jet A-1 fuel, enabling immediate use in the existing aircraft fleet. This facilitates a gradual implementation of SAFs in the commercial aviation market, where test blends ranging from 10% to 50% SAF are being used, although some countries and companies are moving towards flights fully operated with SAF.

The use of SAF can reduce CO₂ emissions by up to 80% compared to conventional fossil fuels. This reduction is possible because the carbon in the feedstocks is part of a natural cycle, meaning it does not increase atmospheric CO₂ concentrations, resulting in a lower carbon footprint over the fuel’s lifecycle. Additionally, SAFs contribute to improving the sector’s energy efficiency by reducing particulate matter and other pollutants.

Despite their environmental benefits, SAFs face significant technical and economic challenges. Production is currently limited due to the high costs of feedstocks and production technologies. Large-scale economic viability will require advances in production processes, government regulatory support, and the development of distribution infrastructure to expand the availability of these fuels.

In conclusion, SAFs represent a promising solution to decarbonise aviation, but their widespread implementation will depend on technological development and institutional support to overcome current barriers and make sustainable aviation a reality.