E-fuels: (Not) a solution for combustion engines?

E-fuels are often seen as the last lifeline for traditional diesel and petrol engines before the coming end of the combustion engine. While electric and hydrogen-based drive technologies remain the protagonists of the present and future of a green transport turnaround, there is increasingly talk of e-fuels in climate and transport policy. But what role will they play in making transport and the car industry climate-friendly? And to what extent do they really make a positive contribution to environmental and climate protection?  

As synthetic fuels produced from water and carbon dioxide by means of electricity, e-fuels can be used where other green fuels and drive systems cannot - or at least not without making some significant changes to the vehicle concerned. Indeed, without any adaptation, they can be fuelled directly from the conventional combustion engine and run the current vehicle fleet. This is precisely the strength of e-fuels, which is prompting more and more experts and politicians to advocate their greater promotion, development and use. 

In Germany, for example, legislative changes to promote the production and use of more climate-friendly fuels are already on the way. While the European Commission is still examining "the potential contribution of CO2-neutral fuels to achieving climate-neutral mobility", the German government, seems to have already taken a more decisive stance on the issue of synthetic fuels. It called for an EU proposal on the use of electric fuels, and to include them in the combustion phase-out strategy. Among other things, because of the impact that electric fuels could have on the automotive industry and road infrastructure, for example, in that they would not need too many changes to continue to be suitable for mobility in the near future. 

Finance Minister Lindner (FDP) has already announced a reform of the motor vehicle tax, which is to form the taxation of motor vehicles in view of a possible market growth for cars with sustainable fuels. Accordingly, cars that are fuelled with e-fuels "should be taxed less in the future than vehicles that currently run on petrol or diesel" - explains Lindner. This is because they do not release any additional climate-damaging gases during operation, unlike conventional fossil fuels such as petrol or diesel. According to current government plans, an "e-fuels-only" vehicle category is to be created by autumn 2024 and then integrated into the fleet limit regulation. 

However, doubts about the solution are justified. Firstly, because of the high electricity consumption during production and the high manufacturing costs, it is still unclear whether the production of cars powered by e-fuels is really worthwhile - for the car companies as well as for consumers. The final price for synthetic fuels is just under 10 euros per litre, and the costs could still fluctuate considerably to enable larger production volumes, for example. In addition, current production capacities are considered far insufficient to supply the current, as well as future, stock of cars running on e-fuels. Above all, however, because e-fuels are not as sustainable as one might think. Although no climate-damaging CO2 emissions are emitted during operation, every emission should be taken into account.  

According to a study by European environmental umbrella organisation Transport and Environment (T&E), e-fuels cars "provide only minimal savings in CO2 emissions over their lifetime compared to conventional petrol or diesel vehicles" - an emissions reduction of only around five percent. Even in the case of pure e-fuels produced with renewable electricity, "more is emitted than in the case of e-cars". Electric cars are responsible for about 53 percent less CO2 emissions than a combustion engine with synthetic fuels. This is mainly due to losses in the design-related inefficiency of combustion engines and in the manufacturing processes of electric fuel. In many plants, such as the Porsche factory in Chile, the process for collecting the required carbon dioxide is still far from the desired climate neutrality.

Although cleaner than diesel and petrol, e-fuels would have a negative impact on pollution levels and air quality under current conditions - especially if such vehicles were to operate in emission-controlled areas. What would happen if e-fuels became one of the permitted forms of propulsion in zero-emission zones and diesel-driving ban zones? 

For one thing, they would certainly pose a risk to the environment and to the achievement of climate targets to reduce greenhouse gases, as they are still responsible for high pollutant emissions. At the same time, the decision to allow them to operate in environmental zones would most likely be received negatively by environmentalists - as well as by all those who have taken measures in their private or professional lives precisely to reduce pollution in such zones. On the other hand, what is the point of allowing the use of synthetic fuels if the vehicles that run on them cannot circulate freely because they are deemed "not clean enough"? Will a differentiated system be introduced whereby some areas will remain accessible to their traffic and others not? Will any distinctions be made at all, for example in the regulations, between traditional internal combustion vehicles and internal combustion vehicles that only fill up with e-fuels? And if so, should cars powered by e-fuels really find the same space in emission control areas? Will there then be special environmental badges or licence plates to distinguish them from the normal combustion car - as is the case with electric vehicles? 

The questions must first be defined at a political level, nationally as well as internationally. Germany and the European Union have to decide on an approach first, with which they want to pursue the more sustainable design of the transport sector. And focus on developing and supporting these without scattering limited resources on approaches with limited potential. The electric mobility sector, for example, could benefit from intensive investment in road and energy infrastructure - for example, by standardising the expansion of the charging network through exclusive power supply using sustainable sources. 

In any case, it is time for policymakers to take a definitive stance in order to initiate the necessary change for the transport turnaround under the climate protection goals. What role e-fuels will ultimately play in this, including in future environmental zone regulations, remains to be seen.