According to an EU resolution, new vehicles are to be emission-free from 2035, with the exception of e-fuels - at the insistence of the German government. The current political debate means that e-fuels are currently on everyone's lips. While some people want to use e-fuels to save the combustion engine in cars for a climate-neutral world, others think this idea is absurd. What are the advantages and disadvantages of e-fuels? Who can use synthetic fuels and are e-fuels the solution for all vehicles? We put the alternative from the petrol pump to the test.
What are e-fuels and what happens during production?
The term e-Fuel (also known as synfuels or electricity-based synthetic fuels) refers to synthetic fuels that are produced from water and carbon dioxide (CO2) using electrical energy. This process is known as power-to-fuel. The production of e-fuels is very complex, because although hydrogen - an essential component of fuels - is present in large quantities in water, its extraction as a pure gas, e.g. by electrolysis, is very energy-intensive. Extracting CO2 from the air is even more difficult. Although this process requires many times more electrical energy, if this is obtained 100% from renewable, free energy sources, the amount consumed is actually of secondary importance, according to
Uniti, the association of medium-sized mineral oil companies. In other words, it shouldn't matter how much energy is consumed if it is generated in countries where solar and wind power are available in virtually unlimited quantities.
Are there enough e-fuels for everyone?
Falko Ueckerdt from the Potsdam Institute for Climate Impact Research (PIK) is focussing on the production of e-fuels. According to his calculations, climate-neutral e-fuels will hardly be available for years to come. By 2035, around 60 projects have been announced worldwide that will increasingly produce e-fuels on an industrial scale. However, a final investment decision has so far only been made for one per cent of the planned production volume.
If we assume that global e-fuel production grows as fast as solar power generation, coverage could rise to 50 per cent - mind you: only of the German aviation, shipping and chemical industry requirements. Therefore, e-fuels are an alternative for existing fleets of combustion engines to make them more climate-friendly. However, the rare stocks should not be planned for newly registered cars and smaller lorries. There are already enough alternative options with electric motors for this.
"e-fuels do not belong in the tanks of cars and lorries," says Prof. Dr Martin Wietschel, Head of the Competence Center Energy Technologies and Energy Systems at Fraunhofer ISI, in an interview with VDE. "Not only because they are far too expensive, but also because they are needed elsewhere." A clear prioritisation of possible applications would be desirable.
What is the price of e-fuels?
e-Fuels from the first demonstration plants are not intended for commercial use. The investments made by Porsche and international partners in the pilot plant in Punta Arenas, Chile (Haru Oni, ~$74 million) would result in costs of around €50.00 per litre of e-fuel. As soon as the production of e-fuels is established on an industrial scale with direct air capture, production costs of around €2.00 per litre may initially be incurred. This corresponds to two and a half times the typical wholesale price of fossil petrol of around €0.76 per litre. In the long term, production costs of less than one euro per litre of e-fuel are likely to be achieved. However, this depends heavily on the speed of the global market ramp-up of e-fuel production. Active policy is therefore needed to boost the ramp-up of e-fuels.
Together with international partners, the BMDV is promoting the ramp-up of electricity-based fuels
To this end, the Federal Minister for Digital and Transport Affairs, Dr Volker Wissing, the Lithuanian Minister for Transport and Communications, Marius Skuodis, and the Japanese Parliamentary Vice-Minister for Economy, Trade and Industry, Taku Ishii, signed the „Berliner Declaration“ for the ramp-up of e-fuels at the beginning of June 2024. The agreement was reached as part of the International e-Fuels Dialogue 2024, which the Federal Ministry of Digital and Transport hosted in Berlin together with the Lithuanian Ministry of Transport and Communications and the Japanese Ministry of Economy, Trade and Industry.
"Alongside battery-electric drive systems and hydrogen, e-fuels are an important option for climate-friendly transport. In the Berlin Declaration, we commit to technological openness and the importance of e-fuels." said Wissing.
Advantages and disadvantages of e-fuels
e-Fuels are user-friendly and convenient to use. Thanks to e-fuels, there is no need for an expensive change in transport technology. Existing vehicles can continue to be used. e-Fuels can be mixed with conventional fuels and can completely replace them. For consumers, this means: a short refuelling process and the range for further kilometres is restored.
Is every car able to run on e-fuels?
Any car with a classic combustion engine that is fuelled with petrol or diesel can also be refuelled with the corresponding e-fuel. It cannot be used for hydrogen cars and, of course, not for electric vehicles either. In the case of hybrids, however, synthetic e-fuels can be used.
But how far can a combustion engine go on a full tank?
"The efficiency of combustion engines is much worse, so an electric vehicle can travel five times further on the same amount of energy than a vehicle fuelled with e-fuels," says sustainability expert Michael Koch from the SRH Fernhochschule in Riedlingen. This means that a lot of electricity is wasted if it is used to produce e-fuels instead of charging electric vehicles.
While 13 to 15% of the electricity used for e-fuels ends up at the drive wheel of the vehicle, the figure for electric vehicles is 70 to 75%, write researchers from the Fraunhofer Institute for Systems and Innovation Research (ISI) in Karlsruhe in a discussion essay.
If e-fuels are used in aviation, a climate-warming effect occurs even if the electricity used is produced completely CO2-neutrally, as around two thirds of the climate effect of air traffic is not caused by the release of carbon dioxide, but by secondary climate effects. Therefore, switching to e-kerosene, which is produced using 100% green electricity, only reduces the climate impact of air travel by around one third.
As e-fuels are indistinguishable from conventional fuels in terms of their properties, it can be assumed that they cannot contribute to an improvement in air quality either, as air pollutants are also released during combustion, according to the German government in a statement in 2019, which refers to a study that states that the demand for liquid fuels will decrease drastically by 2050. By 2050, an almost complete technological shift from classic combustion engines to battery and hydrogen-electric drive concepts will already be complete.
What role will e-fuels play in the future?
A research project is attempting to increase efficiency in the production of e-fuels. According to a press release from the Karlsruhe Institute of Technology (KIT), up to 60 per cent is possible. In recent years, further progress has been made in the development and technology for the production of synthetic fuels. A haulage company in southern Germany drove over a million test kilometres with a fleet of different types of trucks using the reFuels fuel. For the first time, all relevant factors, from the production process to costs and product properties through to environmental influences, were assessed in their entirety.
Porsche was the first car manufacturer to drive forward the development of synthetic fuel with the pilot phase of the plant in Chile. Production capacity there is to be increased to around 55 million litres and to around 550 million litres of PtX per year by 2026. Porsche will be one of the main customers for the green fuel.
From this year, 2,500 tonnes of synthetic fuel are to be produced annually at a factory in Frankfurt-Höchst. This will also be used primarily in aviation and shipping. The investing company Ineratec has been subsidised for this purpose.
According to ADAC the EU is also working on introducing a mandatory quota of 2.6 to 5.7% green hydrogen and e-fuels in the European transport sector by 2030.
If you ask supporters or opponents of e-fuels about the future, you will certainly get different answers. Some see e-fuels as the panacea and solution to all problems, while others see synthetic fuels as a niche product to bridge the gap until battery-electric vehicles are more mature and meet all requirements in terms of range or charging infrastructure.
In the end, every user has to decide for themselves which technology they trust and want to use. The main thing is that it is a decision in favour of a sustainable and climate-friendly drive source.
Tip:
If you want to deal with the topic with a touch of scientific humor, we recommend the knowledge transmission with MAITHINKX Dr. Mai Thi Nguyen-Kim. There, interesting topics from different areas of science are treated with a wink, as well as the efficiency of e-fuels. Find out why, in her opinion, e-fuels in the car sector are "inefficient bullshit with sauce".
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