The EU states have decided to largely phase out the internal combustion engine from 2035: No new passenger cars or light commercial vehicles powered by gasoline or diesel will be allowed to be registered. But a loophole remains open: Even after 2035, cars with internal combustion engines will be allowed to be newly registered if they are fueled with e-fuels.
E-fuels have come into focus in the discussion about sustainable mobility. But are e-fuels really a climate-friendly alternative? And can this technology keep up with electromobility? In this blog post, we look at the "e-fuels vs. e-cars" debate.
What are e-fuels?
E-fuels are synthetic fuels that, like gasoline, diesel or kerosene, are made from hydrocarbons, but differ from one another in terms of how they are produced: Fuels such as gasoline or diesel are derived from fossil fuels, while synthetic fuels are produced with the help of electricity. The starting materials for production are water and carbon dioxide. The water and carbon produced can be combined using electrolysis and synthesis processes so that the resulting hydrocarbons can be further processed in a subsequent step into fuels such as e-gasoline, e-diesel or e-kerosene.
How climate-friendly are e-fuels?
Since e-fuels absorb CO₂ during their production and release it again when they are burned, they are often described as "climate-neutral" because the cycle would close. But it is not that simple.
In terms of CO₂ accounting, the entire life cycle counts – from raw materials, production, and distribution to use and disposal. A vehicle can never be climate-neutral over its entire life cycle, regardless of whether it is powered by fossil fuels, e-fuels or battery-electric. This is because the production of the materials and the manufacture and combustion of the fuels also always produce emissions.
E-fuels are not climate neutral, but can they be climate friendly?
How climate-friendly e-fuels can be depends largely on how the energy needed to produce them is generated. If e-fuels are produced from renewable energy sources and the carbon released when they are burned has previously been filtered out of the atmosphere, they can help reduce CO₂ emissions from transportation.
However, the production of e-fuels is complex and expensive. A lot of energy is needed to produce them, and the facilities and infrastructure required are currently very limited. If the energy needed to produce e-fuels comes from fossil fuels, more CO₂ is emitted than if fossil fuels were used directly. GermanZero calculates: "If electricity from the German electricity mix is used to produce e-fuels in 2018, approx. 1,050 g of CO₂ are emitted per kWh of synthetic diesel – more than three times as much as the 306 g of CO₂ emitted over the entire life cycle of diesel". So if e-fuels are produced with a poor electricity mix, they are more CO₂-intensive than conventional diesel.
Electric cars are more environmentally friendly than cars powered by e-fuels
A lifecycle analysis by think tank Transport & Environment (T&E) confirms that synthetic fuels are a far less environmentally friendly solution for cars than battery-powered electric cars. The total lifecycle emissions of cars purchased in 2030 have been analyzed. The result: a car powered by a blend of e-fuels and gasoline would reduce its lifecycle emissions by only 5 percent compared to conventional fuels. An electric vehicle manufactured and charged with the average EU electricity mix expected in 2030 would produce 78 percent fewer emissions over its life cycle than an internal combustion vehicle.
Even a pure e-fuel vehicle manufactured with renewable electricity would emit more over its life cycle than an electric car. This would be 53 percent cleaner by comparison than a car powered by synthetic fuels, according to the analysis.
What are the disadvantages of e-fuels compared to e-vehicles?
- Efficiency: The production of e-fuels is very energy-intensive and inefficient compared to the direct use of renewable energies such as solar or wind energy to power electric vehicles. According to an article in the journal Nature Climate Change: With 100 percent renewable energy, only 10 percent ends up in an e-fuel powered car. An electric car, on the other hand, gets about 50 percent of the original energy. So an e-fuel car needs about five times as much electricity as an electric car.
- Cost: E-fuels are currently still very expensive to produce because they are a new technology and the production processes are not yet fully developed. In comparison, electric cars are already established on the market and will become increasingly affordable in perspective.
- Emissions: Although the combustion of e-fuels releases fewer emissions than fossil fuels, there are still emissions that result from the combustion process. In contrast, electric cars emit no CO₂ emissions when driven.
- Limited potential: E-fuels can only make a limited contribution to decarbonizing the transport sector, as their production is currently still very complex and cost-intensive. Electric cars, on the other hand, are already an available and cost-effective alternative, and their technology is constantly being improved.
What are the advantages of e-fuels?
The advantages of e-fuels are evident in areas where electrification is difficult, such as aviation and shipping. Due to the limited energy density of batteries and the considerable amount of energy required for transport in the case of cargo ships, for example, electromobility is a major technical challenge here. The use of e-fuels is a promising alternative in this respect to replace conventional fuels and reduce CO₂ emissions.
According to an analysis by the Potsdam Institute for Climate Impact Research, all currently planned e-fuel projects worldwide would only meet about 10 percent of Germany's e-fuel needs. Of course, there are uncertainties and experiences regarding the market ramp-up of energy technologies, for example, solar PV has been the most successful energy technology with a global growth of 40 to 65 percent per year. If e-fuels were to grow as fast as solar PV, the total global supply in 2035 would still only meet about 50 percent of the e-fuel needs for Germany.
Overall, e-fuels are indispensable for climate protection and are proving useful in some sectors that are difficult to convert to electric drives due to their specific requirements. These include aviation, shipping, and the use of e-fuels in chemical production. However, e-fuels are not suitable as a substitute for the electrification of road transport.