E-fuels: few chances for designer fuel

Production facilities for e-fuels are still under construction except for pilot plants.
©Porsche

In particular, the FDP repeatedly drives the debate on e-fuel for cars. But the idea will probably not save the internal combustion engine.

The internal combustion engine is dying out in Europe. From 2035, new cars with petrol or diesel engines may no longer be registered. Hopes for survival using e-fuels have recently fallen again. Environmentalists welcome this, but parts of industry and politics see it as a mistake.

The main ingredient in e-fuels is electrical energy, which is used to chemically replicate classic mineral oil fuels from carbon and water. In contrast to biofuels, the carbon does not come from biomass, but usually from CO2, which is taken from the atmosphere. This is available everywhere. The situation is different with the necessary water and green electricity. Above all, you won’t find both together everywhere – just think of large solar parks in the desert.

Existing vehicles could run cleaner

Because e-fuels are synthetically reproduced fuels, they can be used in all internal combustion engines that currently use comparable mineral oil fuels. A conversion of the engines is usually not necessary. Transport and gas station infrastructure could simply continue to be used.

However, e-fuels do not burn without emissions. Therefore, according to the current status, they are subject to the EU ban on internal combustion engines as much as diesel and petrol. In addition to the usual pollutants such as NOx, particulate matter and CO, combustion also produces CO2. Of the latter, however, only as much as was used in production. In terms of balance, e-fuel is therefore climate neutral. A weighty argument is that existing vehicles will continue to be able to be driven relatively cleanly in the coming decades. In addition, the synthetic fuel is in principle suitable for storing excess wind or solar energy in a form that can be stored and transported.

However, the synthetic fuels are not available in large quantities either in Germany or elsewhere. Production currently hardly goes beyond the scope of demonstration and pilot plants. Even optimistic forecasts do not foresee a significant production volume until 2030. 2050 seems more likely to many experts.

Expensive to manufacture, poor efficiency

In addition, the production of e-fuels is currently very expensive. The fuel would be similarly expensive at the gas station. With increasing demand and favorable developments in the price of electricity, the price of synthetic fuels before energy taxes may fall in 2030. Optimists assume between 1.20 and 1.40 euros before tax, but more cautious experts also expect values ​​below two euros.

But the real crux is something else: e-fuel mobility has a poor level of efficiency, which is primarily due to the energy-intensive production. From 1 kilowatt hour invested energy after hydrogen electrolysis, CO2– Extraction, synthesis gas, crude oil and finally gasoline production only 0.5 to 0.6 kWh liquid energy left. If the power had been loaded directly into the electric car, at least 0.8 kWh would have ended up in the battery despite charge loss. Because the electric motor also uses energy more efficiently, the overall comparison is even clearer in the end. The e-mobile generates a range of around 6 kilometers from 1 kWh of electricity. An e-fuel internal combustion engine would only travel about 1.5 kilometers with the same amount of energy.

It is undisputed that e-fuels will play an important role in the decarbonisation of society. However, based on the current status, it is quite unlikely that they will do this in private cars. However, the designer fuels are certainly interesting for ships, planes and possibly trucks as well. In view of the required range in these areas, battery e-mobility is often not possible or only difficult. (SP-X)

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