E-vehicles or e-fuels - how will we drive from 2035?
Vehicles with combustion engines are on the brink of extinction – or are they? Although there was a broad consensus to ban new registrations of vehicles with petrol and diesel engines in Europe from 2035 and to rely completely on e-mobility, this ban has now been overturned. Newly registered vehicles may no longer emit CO2 from 2035, but if this requirement can also be met with crankshafts, pistons and cylinders, there is nothing to be said against the combustion engine. Catchwords such as technology openness and the breakthrough for e-fuels were cited as arguments in favour. But what is actually behind this fuel that is reputedly going to give the combustion engine a new lease of life, and is it really a sustainable replacement? What follows is an attempt to establish a perspective.
It should be noted at the outset that this law would in no way have led to a ban on diesel or petrol vehicles from 2035. Only the new registration of these vehicles would have been prevented by the regulation. Existing vehicles, however, may still be driven after 2035.
What are e-fuels?
E-fuels are fuels that are produced completely synthetically. No crude oil is needed, as is the case with classic petrol or diesel fuel. E-fuels consist of carbon dioxide (CO2) and hydrogen. The necessary CO2 comes from industry or, under certain circumstances, it can even be taken directly from the air. The hydrogen is obtained by electrolysis, i.e. the splitting of water into oxygen and hydrogen.[1] This process is very energy-intensive and should therefore be carried out using electricity from renewable sources. In this case, we speak of “green hydrogen”. This is the only way e-fuels can be produced in a climate-neutral way. After electrolysis, the hydrogen is combined with carbon dioxide and synthesised into a liquid fuel. This process can be used to produce synthetic diesel, petrol or paraffin alternatives.[2]
What are the advantages of e-fuels?
The components of e-fuels, i.e. hydrogen and CO2, are available in almost inexhaustible quantities. This means that a shortage of resources, as is the case with crude oil, is impossible. For the production of e-fuels, just as much carbon dioxide is removed from the atmosphere as is emitted during their use. This means that this fuel does not place an additional burden on the environment.
In addition, different fuel alternatives such as petrol and diesel, but also paraffin, can be produced this way. On account of this diversity, e-fuels could in future make an important contribution to more environmentally friendly passenger car and heavy goods traffic, but also to more sustainable shipping and aviation.
Another advantage is that existing vehicles with combustion engines can continue to be operated with the appropriate synthetic fuel – there is no need to modify the engine for this. The existing filling station network can also continue to be used for e-fuels. It is not necessary for a new infrastructure to be built up.
Surplus electricity from renewable sources (such as solar or wind power plants), which is currently difficult to store, could also be used to produce e-fuels in the future.
What are the disadvantages of e-fuels?
The biggest disadvantage of e-fuels is the large amount of electricity needed for their production. If a car is to be powered by e-fuels rather than electricity, about five to six times more electricity is needed than to run an electric car.[3]
E-fuels only contribute to environmental protection if they are produced using green hydrogen.
One fundamental problem of vehicles with combustion engines cannot be solved with e-fuels either: efficiency. In order to convert the energy stored in the fuel into motion, many steps are run through in the combustion engine. In the end, not much energy is left for the actual movement. Only 20 to a maximum of 30 % of the released energy reaches the wheels at the end.[4] The rest is usually lost as heat during the combustion process. In purely electric vehicles, on the other hand, more than 80 % of the energy from the battery is actually used for motion.
Price will also play a major role in the introduction of e-fuels. Since there are currently no large-scale industrial production facilities available for e-fuels, it is difficult to say what a litre of “e-fuel” will cost in the future. Optimistic forecasts range between € 0.9 - € 1.40 for the production of one litre of fuel. The actual selling price is likely to be significantly higher. One thing can therefore be said with great certainty: e-fuels will probably not become a cheaper alternative to petrol or diesel.
Conclusion
Technology openness and the related discussions on the topic of e-fuels are important and necessary. Excluding a technology from the outset is problematic because no-one can foresee how it will develop. However, it is doubtful that e-fuels will bring us closer to the goal of a transition to sustainable mobility over the next few years. Even if the life cycles of existing vehicles can be extended and they can be operated in a climate-neutral way, the capacities to cover the emerging demand are currently lacking. One possible solution would be for the industry to concentrate on heavy transport, shipping and aviation. But here, too, there is still a very long way to go before the first drops find their way into the tank.
For car manufacturers, the issue no longer seems to be an issue anyway. Most of them have already announced that they will no longer offer vehicles with combustion engines in Europe by the middle of the next decade.