Does the “green car” really exist? While there is consensus in favor of electric cars, with their environmental impact much less than that of thermal vehicles, today's automobile industry must face considerable environmental challenges. From the construction phase to the afterlife of our vehicles, what is the real ecological balance sheet of car manufacturers ?

Manufacturing a car: different stages

A dynamic recovery, savings and above all, zero CO2 emissions: this is the promise of 100% electric E-Tech technology. Renault. Ten years of research have enabled the manufacturer to offer a quiet vehicle, which does not use fossil fuel and which, ultimately, is more economical because it generates fewer maintenance costs.

On paper, the promise is good and in reality, the interest in electric vehicles is obvious. However, is this enough to respond to the ecological emergency?

The carbon footprint of a car, all manufacturers combined, cannot be reduced to the conditions of use it offers. To make a more realistic and complete ecological assessment, it is also necessary to go back and in particular to the crucial stage of its manufacturing.

Supply of metals and raw materials

Cobalt, phosphorus or even nickel: the manufacture of a thermal or electric car necessarily involves a phase of extraction of raw materials. During the latter, the intensive use of water, the combustion of fossil fuels by machines and the use of chemicals are highly problematic.

According to figures provided by Ademe, the ecological transition agency, a diesel car would weigh around 1145 kilos compared to 1 kilos for an electric car, without battery. If the weight of ferrous and steel materials are similar for the two types of vehicle (031 kilos for the first, 711 for the second), just like the weight of polymer materials (658 and 218 kilos), the weight of fuel, in the thermal vehicle, and the battery, in the electric vehicle make the difference. An electric vehicle battery can in fact vary between 208 and 250 kilos depending on the model. The extraction of cobalt, lithium and graphite from which it is generally composed can contribute to environmental pollution.

From extraction sites to production sites

The raw materials are obviously not transformed and used on their extraction site. They are first transported to processing plants which will use energy to produce the final materials. These will be transported again to assembly plants which will also use energy to assemble the parts, paint them and test them. In addition to the CO2 emissions from processing and assembly plants, each transport of materials considerably increases the carbon footprint linked to the manufacture of the vehicle and must obviously be taken into account.

End of life and recycling : what is the state of affairs?

Considerable progress is expected in the development of new generations of electric batteries. The batteries of tomorrow will in fact be much less polluting, in particular thanks to the introduction of batteries based on lithium-iron-phosphate (LiFePO4). They are in fact made using much less toxic materials.

Perhaps it’s because of their relative newness to the automotive market? It would seem that the question of recycling lithium-ion batteries from electric vehicles is of more interest than that of thermal cars. The latter, when they are scrapped, nevertheless benefit from a second life. The recovery of reusable parts, the depollution of vehicles (oils and various fluids) and the sorting of materials are important steps but still too often followed by the burial of the final residues, i.e. those that are currently impossible to reuse. or recycle.

However, burying automobile waste is not without consequences since it increases the risk of the release of methane, a powerful greenhouse gas, not to mention the degradation of local biodiversity.

The zero carbon car does not exist

An electric car, however interesting it may be ecologically speaking, is never zero carbon.

A debt impossible to ignore

The production of a car, however ecological it may be, is synonymous with greenhouse gas emissions responsible for global warming. Depending on the model, an electric car would have a carbon debt of 5 to 15 tonnes of CO2 equivalent. And against all expectations, this ecological footprint would even be up to three times greater than that attributed to the manufacture of a thermal car.

A more or less clear compensation for use

It is in use that the electric car demonstrates its interest. Logically, the latter emits less CO2 than a thermal car, particularly when the electricity production comes from either renewable sources or nuclear power. In a few words: the more an electric car drives, the more advantageous it is, ecologically speaking. In fact, over a lifespan of 200 kilometers on average, we consider that an electric car will have a carbon impact 000 to 2 times lower.

Less particle emissions

In addition to reducing greenhouse gas emissions, manufacturing an electric car can significantly reduce air pollution. In fact, electric motors do not emit nitrogen oxides and a much lower quantity of particles.

Despite significant technological advances, the ecological footprint linked to the automobile industry remains significant. According to Ademe, to minimize the environmental impact of our vehicles, it would be necessary to consider the car of tomorrow with greater sobriety and therefore to review its size and weight. Opting for more circular production, with the integration of recycled materials into the various production processes, is also a particularly promising avenue. The increasingly significant number of written off vehicles represents a good source of materials to separate, transform and revalue.

To considerably reduce the environmental impacts linked to the automobile, reviewing daily habits would remain the key to everything because the most virtuous car possible will never be sustainable. Public transport, walking or the choice of carpooling can make it possible to envisage this transition with more optimism.