Imagine going from Lille to Nice in an electric car, without ever stopping at a charging station and even arriving at your destination with a battery far from being flat… Current models are very far from offering such autonomy and will probably never get there. On the other hand, with the help of Electric Road System (ERS)we may be there one day.
The idea is to design electric roads and highways on which you can drive while maintaining the level of your battery, or even recharging it. As part of a call for projects launched by BPI, the public investment bank, and with several partners, Vinci Autoroute will launch a project in September to dig this track.
Tests in real conditions on the A10 towards the end of 2024
This will be spread over three years and will begin with closed circuit tests, near Rouen (Seine-Maritime), before experimentation in real conditions, rather towards the end of 2024, on two sections of two kilometers each of the A10 motorway. Upstream of the toll Saint-Arnoult (Yvelines) in the Paris-Province direction, announces Vinci in a press release.
Two sections like so many dynamic charging solutions that this project wants to test. To tell the truth, Nicolas Hautière, head of ERS activities at Gustave-Eiffel University (Seine-et-Marne) including several laboratories participating in the project., cites a third large family of ERS again. “It’s charging by pantograph, already used for example on trams or trolleybuses and which allows vehicles to capture the current by friction on a catenary just above, he recalls. This solution has already been extensively tested for heavy goods vehicles, particularly in Germany. We wouldn’t add much more. »
Like the car circuits of our childhood
The choice therefore fell on the two other families of solutions: induction and by conductive rail. Both have already been tested in other countries, but never on the highway, assures Vinci. For induction, “the operation is the same as for a saucepan that you place on an inductive hob, describes Nicolas Hautière. A receiver is placed in the road and a transmitter under the vehicle. When the two inductive coils face each other, the transmission of electrical energy is triggered. For the conductive rail, the researcher takes us back to the electrical automobile circuits of our childhood. “It will be necessary to equip the underside of the cars with a pad which will rub along a rail on the road and this friction allows recharging”, he continues.
Both of these solutions have their advantages and disadvantages. “The one by inductive rail on the ground offers in particular a power and a significant efficiency”, indicates Nicolas Hautière. But the disadvantage is this friction, “which requires finding the right balance between seeking power in the load and the need to avoid too rapid wear of the equipment”, he continues. Louis de Pasquier, in charge of this ERS project at Vinci Autoroute, also adds the need to ensure that this flat rail on the road does not present any risk of loss of grip for road users. “This is one of the challenges of this project and in particular of the closed-circuit tests”, he points out. The absence of contact and modification on the road are the great strengths then of the other method, by induction. “On the other hand, the power and the outputs are a priori less, until requiring, perhaps, to have to install several transmitters under the vehicles”, continues Nicolas Hautière. To dig there again.
A boon for heavyweights?
The progress of the project will be closely scrutinized by road transport stakeholders. It is for this sector, which also needs to decarbonize as quickly as possible, that the promise of electric roads is greatest. For a long time, “battery electric” technology seemed out of reach for heavy goods vehicles, as it involved carrying large batteries under the hood in order to have sufficient autonomy. And therefore, less space to transport goods. But in parallelgreen hydrogenthe other way of doing electric mobility and which was more precisely dedicated to trucks, also has its limits, recalls Clément Molizon, general delegate of theNational Association for the Development of Electric Mobility (Avere). Not only do we have doubts about our ability to produce it in large quantities, but other sectors, from aviation to chemicals, are also betting on it to reduce their greenhouse gas emissions. »
In short, competition is tough on hydrogen. For two years, Clément Molizon has seen manufacturers take the turn to battery electrics, “including for long-haul trucks”. “And this possibility of one day having electric roads should further accentuate this trend”, he continues. By allowing heavy trucks to charge continuously, the promise is that they can make do with much smaller batteries. “We could potentially divide their planned size by three,” says Louis de Pasquier, referring to the calculations ofa study coordinated by Patrick Pelataformer CEO of Renault, on behalf of the Ministry of Transport and published in July 2021.
9,000 km of road equipped in 2035?
The challenge is not only to decarbonize the transport of goods. “It is also to reduce the need for cobalt, lithium, copper and other strategic metals necessary for the manufacture of these batteries”, adds Louis de Pasquier. We are talking in millions of tons. It is very interesting from an environmental and economic point of view, but also from a national sovereignty point of view. »
It remains to confirm the promises on the ground, to choose the right technology – “it is unlikely that the three can coexist”, slips Nicolas Hautière -, then to deploy these electric highways on the right scale. Patrick Pelata’s study imagines nearly 5,000 km of road network – mainly motorways – equipped in 2030 and nearly 9,000 in 2035. The cost would be far from negligible. “Whatever the technology, we would be between 40 and 50 billion euros if we go so far as to equip 9,000 km of roads, announces Louis de Pasquier. But this figure should be compared to the savings made on raw materials and on charging stations, the number of which could then be reduced. »
This is precisely one of the fears raised by Clément Molizon. “Road transport must reduce its greenhouse gas emissions without delay and European regulations provide, as such, the obligation to equip motorway areas with truck charging stations by 2025,” he recalls. We therefore need to quickly see clearly the potential of ERS, if only to avoid installing terminals which for some would turn out to be useless. »