✈️ eSAF Complete Guide · May 2026 · e-saf.ai

What Is eSAF? The Complete Guide to
Electro-Sustainable Aviation Fuel in 2026

Definition · How it’s made · ReFuelEU mandates · Production gap · Costs · Key players · 2030–2050 outlook

eSAF — electro-Sustainable Aviation Fuel — is the most strategically important fuel in European aviation policy. It is the only pathway that can meet ReFuelEU’s long-term mandates, decarbonise long-haul aviation without electrification, and be produced entirely from renewable energy without biomass constraints. Yet in 2024, it represented a fraction of a percent of global jet fuel. This guide explains everything: what eSAF is, how it is produced, what the mandates require, how far supply falls short, what it costs today and what the road to 2050 looks like.

What Is eSAF? — The Simple Definition

eSAF (electro-Sustainable Aviation Fuel) is jet fuel produced from renewable electricity, green hydrogen and captured CO₂ — with no fossil fuels involved at any stage of production. It is chemically identical to conventional jet fuel and works in all existing aircraft without any modification.

The “e” stands for electro — referring to the renewable electricity that powers the entire production chain. This distinguishes eSAF from bio-based SAF (produced from waste oils, agricultural residues or municipal solid waste), which relies on limited biological feedstocks.

How eSAF Is Produced — The Power-to-Liquid Process

eSAF is produced via Power-to-Liquid (PtL) technology — a multi-step electrochemical and thermochemical process that converts renewable electricity into liquid hydrocarbon fuel.

Renewable electricity — the starting point of the eSAF production chain · Solar + wind → electrolysis → green H₂ → CO₂ capture → Fischer-Tropsch → eSAF · Photo: Unsplash (free license)

ReFuelEU Aviation — The eSAF Mandate in Detail

ReFuelEU Aviation (EU Regulation 2023/2405) entered into force on 1 January 2024 and applies to all flights departing from EU airports. It sets binding minimum SAF blending requirements for aviation fuel suppliers — with a specific sub-mandate for eSAF (synthetic fuels only).

As of 1 January 2026, Switzerland has also adopted the ReFuelEU Aviation Regulation, meaning aviation fuel suppliers at Zurich and Geneva airports must also ensure a minimum 2% SAF blend, ramping up to 70% by 2050.

The Production Gap — The Central Challenge of the Decade

Industrial scale-up is the central challenge — only 4 European large-scale eSAF projects at advanced stage in 2025 · Photo: Unsplash

INERATEC ERA ONE (Frankfurt, June 2025): Europe’s first commercial-scale eSAF plant · Photo: Unsplash

The most critical challenge facing the eSAF industry is the gap between what mandates require and what plants can actually produce. The numbers are stark.

SAF prices exceed fossil-based jet fuel by a factor of two, and by up to a factor of five in mandated markets. The growth rate for SAF production is slowing down — while SAF output is expected to hit 1.9 Mt in 2025, growth is projected to crawl to 2.4 Mt in 2026, reaching only 0.8% of jet fuel consumption.

eSAF Costs — Where Are We Today?

eSAF is expected to be commercialised after 2030 and more widely available post 2040. Renewable energy costs have dropped 90% in the last decade, and with these costs expected to continue decreasing alongside innovations in carbon sourcing — securing carbon monoxide from existing industrial sources instead of processing CO₂ from the atmosphere helps cut energy costs by around 30% — it is feasible that eSAF could reach cost parity with other jet fuels.

Key Players in eSAF Production 2025–2026

The pathway to 2050: eSAF scaling from today’s fraction of a percent to 35% of all EU aviation fuel by 2050 · Photo: Unsplash (free license)

eSAF Outlook 2026–2050 — What Needs to Happen

It is estimated that 104 to 106 additional SAF plants need to be built in the EU by 2050 to cater for the necessary alternative aviation fuel production capacity — of which around 40 large-scale e-fuel projects are already planned in Europe, with a potential production capacity close to 3 million tonnes.

Three things need to happen simultaneously for eSAF to meet its mandates:

1. Green hydrogen costs must fall below €2/kg. At current costs of €4–8/kg, eSAF is uncompetitive. The IEA targets sub-€2/kg green hydrogen by 2030 through electrolyser scale-up — this is the single most important cost lever.

2. FIDs must be secured for large-scale plants by end of 2026. Given 3–4 year construction timelines, any FID beyond early 2027 means the 2030 eSAF sub-mandate cannot physically be met from European plants alone.

3. Regulatory clarity must be maintained. The Industrial Accelerator Act unveiled 4 March 2026 will contribute to scaling green hydrogen through a “Made in Europe” proposal extending to electrolysers, with easier permitting for e-fuel projects and the creation of green lead markets. This is the right direction — but implementation speed matters.