Are synthetic fuels more ecological than electric cars?

Are synthetic fuels more ecological than electric cars?

It is now official, in Europe, new thermal cars will be banned from sale in 2035. The electric car will have already taken the lead by then, but other alternatives may have emerged by then. And, why not synthetic fuels?

As you surely know, if you follow the automotive news closely, in 2035, manufacturers will be banned from selling new thermal cars in Europe. The text has been adopted by the European Parliament, and this regulation will obviously benefit the electric car industry.

While virtually all manufacturers have now begun their energy transition, some are legitimately asking the question of alternatives, such as Toyota. Indeed, the future seems promised only to the electric car, and the few credible alternatives which seem to point the tip of their nose today are not mature enough to register in the short term as another choice to the electric.

The hydrogen car, for example, is of interest to many manufacturers, but, for the moment, the development of this technology remains very superficial, in particular, because of the development costs much higher than those of an electric car and the disadvantages that it results.

What if the real alternative could eventually come from heat engines? With over 100 years of research and development in this industry, the heat engine is about to disappear now. At least in Europe at first. But if technology were to “save” the thermal engine, would the European Parliament reverse its decision?

Or at least, will he adapt his decision to better accommodate what can be a credible alternative to the electric car? This technology is synthetic fuel (also called “e-fuel”), synthetic fuels produced from the water following a series of chemical processes.


E-fuels, also known as electro-fuels or, more simply, synthetic fuels, are fuels produced artificially through the use of “Power-to-X” technology from a base common: water. Through a chemical process of electrolysis triggered by the use of electricity generated from renewable sources (if this is not the case, there would be no environmental benefits), the water is divided into oxygen and green hydrogen.

Hydrogen, thanks to the Fischer-Tropsch process (which consists in involving the reduction by heterogeneous catalysis of carbon monoxide by hydrogen in order to convert them into hydrocarbons), is combined with CO2 taken from the environment or stored thanks to carbon capture technology, thus creating a gas which, depending on the process of chemical synthesis and subsequent refining, is transformed into e-fuel. E-fuels are produced without petroleum or biomass but from CO2 and low-carbon electricity. We will see this below, but the notion of low-carbon electricity is very important.


The answer is yes, and their chemical specificities may even be superior to those of today’s diesel and unleaded. These fuels being synthetic, you can put “whatever you want” in them, namely elements that burn perfectly in an engine and with good energy efficiency.

On the other hand, e-fuel does not in any way reduce pollutant emissions at the exhaust, such as those of nitrogen oxides (NOx) or particles. The interest is, therefore, to reduce polluting emissions during the manufacturing process. For example, synthetic fuel could make current thermal models more or less climate-neutral by capturing CO2 upstream, CO2 which will then be used to produce synthetic fuel again, and so on.

This technology still needs to be mass-available, which is not yet the case.


Many of them have been working on it for longer than it seems since their work began when the first alarm bells on the need to decarbonize the transport sector began to ring ten years ago. Even before the costly but necessary electric transition, manufacturers have been looking for new technologies that could offer a viable alternative to internal combustion engines.

Today, several projects for the development and production of these environmentally friendly artificial fuels have emerged. One of the first to take this path is Audi. The firm with the rings produces synthetic fuels in several European factories, notably in France, in a factory located near Reims. However, the volumes remain marginal enough to hope for mass production.

Audi is part of the Volkswagen group, and other brands have looked at the topic of synthetic fuels. Porsche is one of the most active and has launched a pilot project with Siemens Energy to build an artificial fuel production plant in Chile, which is expected to produce up to 550 million liters of fuel by 2026. Initially, this fuel will only be used to power the Porsche 911 GT3 Cup in the Supercup, one of the many one-make championships organized by the manufacturer.


In addition to our thermal engines, synthetic fuels can also be a sustainable solution for sectors that do not have other alternatives to reduce their CO2 emissions. Heavy and long-distance mobility (land, sea, air), for example, is encountering decarbonization problems, and electrification will require 10 to 20 years to adapt their engines and charging infrastructures. The same goes for hydrogen, which will require several decades before becoming more popular, or not, in these industries.

Here again, synthetic fuel, therefore, appears to be a transitional solution that will not aim to compete with electricity or hydrogen but to offer a sustainable low-carbon solution for sectors that will not be able to adopt other short and medium-term decarbonization strategies.

The most significant example is surely the aeronautics sector. This industry has very few alternatives to kerosene, especially on long-haul aircraft. Electric or hydrogen is not yet possible alternatives for this type of use. These energies would require major changes to the entire energy delivery infrastructure, tank design, and even aircraft in the broadest sense of the term.

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With electricity, the amount of energy on board the tank is less than kerosene due to lower energy density. Thus, to travel the same distance, the energy reservoirs, in this case, the batteries, occupy a volume at least 3 to 4 times greater than the kerosene reservoirs.

Synthetic fuels, in this case, synthetic kerosene, generally make things easier since the molecule is the same but produced differently. As a result, there is no need to change long-haul aircraft fleets.


Water and CO2 are the only sources of material for producing synthetic fuels, unlike petroleum and its fossil derivatives, which contain significant impurities in sulfur and nitrogen and must be eliminated during refining.

Indeed, there is indeed CO2 used for synthesis, and this can be of different origins (fossil, biological or atmospheric), but synthetic fuels are characterized by a reduced carbon footprint over their entire manufacturing cycle of at least less than 70% compared to petroleum fuels.

And since these can directly replace petroleum fuels, it is, therefore, a serious and effective alternative for reducing transport emissions. Synthetic fuel does not use fossil resources such as gas or oil and benefits from the same qualities in terms of energy.


On the other hand, it takes a lot of energy to produce this synthetic fuel. E-fuels, produced from CO2, will strongly require the production of low-carbon electricity for the production of hydrogen or the electrolysis of CO2. In a current context where energy savings are required, the development of synthetic fuel could be slowed down in order to favor more democratized and more advanced technologies such as the electric car.

These needs must therefore be planned and anticipated. The good news is France is one of the good students in this area, even to the point of becoming one of the leaders. Why? Because the carbon intensity of synthetic fuel is very dependent on that of electricity. And as you are surely aware, in France, our electricity is one of the most carbon-free.


The effect would be completely opposite in Germany, for example, where coal-fired power plants are still rampant in the country. Producing e-fuels from electricity from coal-fired power plants would not be of great ecological interest, especially since the amount of energy needed to produce a liter of e-fuel is substantial, in this case, 20 kWh.

20 kWh is the consumption of an electric car at 130 km/h over approximately 100 km. By doing a quick calculation, we notice that even if the production of synthetic fuel has a lower environmental impact compared to traditional fuels, for a thermal car that consumes, for example, 6.0 l/100 km, it will therefore have taken 120 kWh to produce these 6 liters of e-fuel, i.e., an electricity consumption five times greater than that of an electric car to cover the same distance.

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Earlier, we gave you the example of Porsche, which chose to set up its fuel manufacturing pilot plant in Chile. Why Chile? Because it is a particularly windy region and wind turbines provide 3.5 times more electricity there than if they were installed in Germany. This energy could also avoid being lost because the low population density located nearby does not allow it to be used directly.

However, there is still a drawback: the transport of fuel to Europe, which undermines the virtuous nature of the equation. We, therefore, come back to the chapter above, where, in the long term, synthetic fuel will certainly have more credibility for maritime or air transport, two sectors where electricity today seems unlikely in the short and medium term. But one thing seems certain, in the current state, if the electricity resources to manufacture e-fuel do not decrease, there is not really any interest in favoring synthetic fuels over electric cars.

Especially since the price of synthetic fuels will surely be very high because of their very complex and very expensive production, some estimates announce a double price compared to gasoline, without forgetting that they will still continue to pollute, in particular by releasing nitrogen oxides and other fine particles.

As can be seen in the chart above, in terms of CO2 emissions, a recent Transportation & Environment study concluded that electric cars emit less CO2 over their entire life cycle compared to electric cars. Heat effect. Even if it runs on synthetic fuel made from “clean” electricity (solar and wind).

Finally, what remains for synthetic fuels? Not much, except to allow manufacturers to continue to offer thermal engines.