Molecules
e-Fuels & Synthetic Fuels CₙHₘ
The most expensive and least efficient way to move energy — and the only option for aviation and some heavy transport. Both of those statements are true at once.
For where nothing else fits
What it is
e-fuels, also called power-to-liquid or synthetic fuels, are hydrocarbon fuels made from hydrogen and CO2 rather than from crude oil. They are chemically equivalent to the fuels they replace, so they work in existing engines, turbines, pipelines and distribution networks with no modification — which is precisely why they matter for applications that cannot be electrified or converted.
How it is produced
Fischer-Tropsch synthesis
Hydrogen and CO2 converted to syngas and then to liquid hydrocarbons, which are refined into kerosene, diesel and naphtha fractions. Long-established chemistry applied to a new feedstock.
Methanol-to-jet and methanol-to-gasoline
Producing methanol first, then converting it to jet or gasoline-range fuels. Frequently attractive because it builds on commercially available methanol synthesis.
Other routes
Including ethanol-to-jet and various hybrid pathways, at differing stages of certification and commercial readiness.
Conversion
e-fuels are the end of the conversion chain. Each preceding step — electrolysis, carbon capture, synthesis, refining — takes its share of the input energy, which is why the delivered efficiency from electricity to usable fuel is low compared with direct electrification. That penalty is the price of a drop-in molecule.
Storage
Conventional fuel storage in its entirety. e-fuels are chemically equivalent to existing fuels, so tanks, terminals and safety systems need no modification, and the fuels are stable over long periods.
Transport
Existing fuel logistics without modification — pipelines, tankers, rail, road, and airport fuelling systems. This is a material advantage for aviation in particular, where alternatives would require a wholesale redesign of aircraft and ground infrastructure.
Infrastructure
Hydrogen supply, a CO2 source, synthesis and upgrading, and conventional fuel distribution. The upstream requirement is large: e-fuel plants are electricity-intensive at a scale that usually implies dedicated renewable generation.
Economics
Currently the most expensive molecular-energy product per unit of delivered energy, because it accumulates the cost and losses of every upstream step. The commercial case rests on applications with no alternative and on policy — aviation mandates in particular create demand that price alone would not. Any credible project has an unusually strong dependence on very low-cost electricity at high load factor.
Applications
- Sustainable aviation fuel, where drop-in compatibility is effectively a requirement
- Marine fuel where a liquid hydrocarbon is preferred
- Heavy transport that is hard to electrify
- Existing vehicle fleets, without modification
- Chemical feedstock as a naphtha substitute
Commercial challenges
- High cost relative to the fossil fuels they replace
- Low overall efficiency from electricity to delivered fuel
- Large CO2 requirement, with the same sourcing and accounting problems as methanol
- Fuel certification for aviation is demanding and route-specific
- Policy-dependent demand, which is a real commercial risk
Questions
If e-fuels are so inefficient, why pursue them?
Because for some applications there is no alternative. Long-haul aviation cannot be battery-electric with foreseeable technology, and the existing fleet and fuelling infrastructure will be in service for decades. A drop-in fuel is the only option that works within those constraints, and inefficiency is the cost of that.
Is e-SAF the same as sustainable aviation fuel?
e-SAF is one type. SAF also includes fuels made from waste oils, fats and biomass, which are cheaper today but limited by feedstock availability. e-SAF is synthesised from hydrogen and CO2 and is more scalable in principle, more expensive in practice.
What decides whether an e-fuel project is viable?
Electricity price and load factor above everything else, then CO2 cost and accounting status, then whether a policy mandate or a premium offtake exists in the target market. Projects without very cheap, high-availability power do not close, regardless of how good the rest of the design is.
Where e-fuels & synthetic fuels matters
How we can help
Techno-Economic Analysis
Levelised cost modelling with the assumptions exposed and the sensitivities tested.
Read more →Policy & Regulation
What the rules require, what the incentives are worth, and how both change your commercial case.
Read more →Offtake & Buyer Discovery
Finding and qualifying the buyers a production project needs to be financeable.
Read more →Working with e-fuels & synthetic fuels?
Whether you produce it, buy it, build for it or are deciding whether it fits your region, the starting point is the same conversation.