The Life Cycle of a Sustainable Airline Fuel (SAF)


We´ve been writing extensively in this blog about how a new breed of aircraft fuels known as SAFs, which are revolutionising aviation in terms of environmental impact, are sustainable in terms of life cycle. But what exactly does this mean?

When the sustainability of a product is assessed in terms of life cycle, as may be the case with the SAF, we have to refer to the LCSA (Life Cycle Sustainability Assessment) approach defined by the United Nations Environment Programme in collaboration with SETAC (the Society for Environmental Toxicology and Chemistry). This commonly accepted approach proposes identifying sustainability by analysing three factors:

  • Environmental impact (Life Cycle Analysis, LCA)
  • Cost (Life Cycle Cost, LCC)
  • Social impact (Social Life Cycle Assessment, SLCA)

The Environmental Impacts of SAFs

LCA (life cycle analysis) evaluates how a certain product impacts the environment from the beginning of its production to its disposal phase. In a case like that of the SAF, the impact on the soil, the use of water, emissions into the atmosphere, preservation of biodiversity, waste and chemicals, etc. is evaluated.

We´ve already seen one of the figures that the SAF shows: it saves 80 precent of emissions to the planet. But not only in direct emissions – that is, those of the airplane flying – but from when it is produced until it is consumed.

SAF comes from various sources: liquid or solid biomass, which generates biofuels, and capturing carbon dioxide. Both processes are clearly cleaner than traditional fuel manufacturing. Biofuels are generated from waste (used oils, remains from agriculture or forestry, etc.); Power-to-liquid or e-fuels are made from renewable energy sources.

But there´s another important factor that affects the environmental impact: that SAF can be used in current aircraft without having to make any modifications. If, for example, aircraft engines had had to be changed, this process (manufacturing and disposal of the previous ones) would have left a more than considerable carbon footprint. However, this new fuel avoids this process.

Economic Costs

Sustainability also involves putting figures on the economic costs involved in generating this product (cost analysis or life cycle cost, LCC). Here not only are the costs derived from the creation of this product or asset taken into account for future decisions, but also those generated later (maintenance, availability, etc.).

Currently, producing SAF is still expensive because it´s is still little used and the infrastructure for its large-scale manufacturing and distribution are still being created; at the moment there are few refineries that produce it, and its cost is between three and five times higher than that of traditional fossil fuel.

The challenge is to ensure that its production increases progressively in the coming years. At the end of 2023 the Spanish energy company Repsol launched its refinery is the city of Cartagena, capable of supplying 250,000 annual tons of biofuel generated from waste. This plant alone can provide the estimated orders for 2025 in Spain (about 200,000 tons, 2 percent of the total fuel).

This low-emissions project will generate biofuel from lipid waste, and in addition it has a positive impact on the economy, generating around a thousand jobs. It´s also a booming sector that could grow the GDP in Spain and make it a world leader in SAF production.

By 2030, the IAG group to which Iberia belongs will be using 10 percent of SAF, double what the European Union recommends, and reach zero net emissions in 2050. This implies that the economic costs of generating SAF will decrease as its use increases.

Social Impacts

Another point that is taken into account in the life cycle of the SAF is the analysis in social terms (Social Life Cycle Assessment). For example, issues such as human rights; working conditions; health and safety; the preservation of cultural heritage; and socioeconomic repercussions are analysed.

This is a very important leg of the analysis, especially in areas of the planet where the rights of people involved in certain production processes may be at risk. In the particular case of the SAF, and especially its possible mass manufacturing in Spain, we´re talking about a territory in which human, labour and health and safety rights are amply protected throughout the entire process of creation and use of this biofuel.

Some of the socioeconomic repercussions of a possible new SAF industry in Spain were revealed in the report prepared by the  PricewaterhouseCoopers International consulting conglomerate for Iberia and its subsidiary Vueling, which estimated the creation of more than 270,000 direct and indirect jobs between now and 2050, and an increase in GDP of around 56 billion euros.