Corentin Boillet is an analyst at Enerdata. He has 5 years of experience in the energy sector and benefits from a broad scientific background in this field. Within Enerdata, he has participated in different assignments on grid flexibility, storage systems, PV, and synthetic fuel.
What do we mean by the term e-fuels, what are their main ingredients and how are they obtained?
Carbon is mainly obtained through various carbon capture processes such as direct air capture or post combustion capture. Once green hydrogen and carbon are obtained, there are several processes for producing e-fuels. The main ones are as follows:
- Power-to-Methanol
- CO₂ catalytic synthesis
- Electro-catalytic synthesis of CO₂
- Direct electro-catalytic synthesis of CO₂
- Power-to-Liquid :
- Fischer-Tropsch with Reverse Water Gas Shift
- Fischer-Tropsch with co-electrolysis
- Methanol-to-Gasoline/Kerosene
- Power-to-Ammonia
- Electric Haber-Bosch synthesis
How are these components combined to obtain a synthetic fuel capable of replacing conventional fossil fuels? And how efficient is the whole process?
Corentin Boillet: For Power-to-Methanol, the main process is based on the catalytic synthesis of CO₂ using hydrogen. This approach uses catalysts similar to those employed in conventional methanol synthesis from syngas.
For Power-To-Liquid, two pathways stand out for the production of synthetic fuels. The first pathway relies on the Fischer-Tropsch process using syngas composed of carbon monoxide and hydrogen. The second pathway is based on the conversion of alcohols into synthetic fuels (Alcohol-to-Jet).
For Power-to-Ammonia, water (H2O) is split into hydrogen (H2) and oxygen (O2) via electrolysis. Nitrogen (N2) is purified from air. Then, the hydrogen and nitrogen are converted to ammonia in an electric Haber-Bosch synthesis loop.
The efficiency varies depending on the production process, but the conversion rate from renewable electricity to e-fuel typically ranges between 30% and 50%. When you factor in the efficiency of the engine converting the fuel into useful mechanical energy, the overall system efficiency drops further, to around 20%.
Where are e-fuels used today and what future applications do you foresee? Could you share some examples?
Corentin Boillet: Given the efficiency figures mentioned above, it is clear that e-fuels will be limited to applications where no more efficient decarbonisation alternatives exist. The two main uses for e-fuels are therefore aviation and maritime transport.
One notable example is the largest operational e-fuel project in Europe, led by European Energy, which aims to produce nearly 42,000 tons of e-methanol annually to fuel a vessel operated by the Danish shipping company Maersk.
One of the most promising projects is the Norwegian Norsk e-Fuel project, supported by Norwegian Airlines and with technology providers like Sunfire or Carbon Centric. They have announced, a production capacity of 200 000 tons in 2030 by establishing three industrial-scale e-fuel production plants in Norway.
Considering the entire life cycle of e-fuels – from hydrogen generation and carbon capture to combustion – how much do they actually contribute to reducing carbon dioxide emissions?
Corentin Boillet: E-fuels can reduce carbon emissions by 70% to 90%, but this depends primarily on the electricity mix and, above all, on assumptions about the source of the carbon. These figures only hold true if the carbon is captured directly from the air (direct air capture). If the carbon comes from industrial smokestack emissions, the claimed emission reductions become much more debatable.
What about their market price, are they competitive enough compared to other options?
Corentin Boillet: Cost remains the critical barrier to the development of e-fuel projects. According to the ICCT’s 2050 cost projections for e-kerosene (International Council on Clean Transportation Working Paper, 2022), even under optimistic scenarios – assuming significant reductions in CO₂ costs, electrolyzer expenses, and renewable energy prices – e-kerosene would still be 1.5 times more expensive in the US and 2.5 times more expensive in Europe than conventional kerosene.
Similarly, IRENA’s optimistic projections for e-methanol (International Renewable Energy Agency, Renewable Methanol Outlook, 2021) suggest that, by 2050, its price could fall to around $250 per tonne – provided green hydrogen costs drop to approximately $1/kg and CO₂ costs to about $100/tonne. Even at these reduced prices, e-methanol would still be more expensive than today’s grey methanol.
Achieving cost competitiveness for major e-fuels compared to fossil fuels thus remains highly challenging, even in the long term (2050).
What role do you envision e-fuels playing in the transition to climate neutrality?
Corentin Boillet: For aviation, due to the expected sharp increase in global air traffic, the development of e-fuels – as mandated by European legislation such as ReFuelEU – will not be sufficient to reduce the aviation sector’s CO₂ emissions. According to the NGO Transport & Environment, by 2049, European aviation will still be consuming the same amount of fossil fuel as it did in 2023.
In the maritime sector, the European Union has set the most ambitious CO₂ reduction targets and they include the deployment of e-fuel projects. However, they remain largely insufficient: the goal is to reduce the sector’s emissions by just 6% by 2035 and to incorporate a minimum of 2% e-fuels into fuel consumption in 2034.
As a result, e-fuels are expected to have a negligible impact on greenhouse gas emissions in the short term, with their effects becoming more significant only in the long term, around 2050.