What if all you had to do to recharge your electric vehicle was to… drive it? We do already have regenerative braking, which can re-add some charge to an EV’s battery, but a new project in France takes things to a different level.
On a 1.5 km stretch of the A10 motorway, about 40 km southwest of Paris, engineers have embedded 900 copper coils under the asphalt, which will charge certain electric vehicles driving over them by induction.
The so-called Charge as you Drive technology is the result of a collaboration between Electreon, Vinci Autoroutes, Gustave Eiffel University and Hutchinson. It is based on a principle already well-known in wireless chargers: energy is transferred from a coil installed, in this case under the roadway, to another located in the vehicle, via an electromagnetic field.
During initial tests, an average power of 200 kW was reached, with peaks of 300 kW - which would allow the vehicle's charge level to be maintained throughout the journey.
According to the project's promoters, the long-term goal would be to reduce the size of electric vehicle batteries, which would lighten their weight and manufacturing cost. Cars could thus carry less energy while remaining connected to an intelligent road network capable of ensuring their continuous charging.
Technical revolution
For now, the project is only in the experimental phase. Only a few specially adapted vehicles can take advantage of the system, notably test buses and trucks. The plan is to have the installation in place for several years, in order to evaluate its large-scale durability, reliability and efficiency.
Viable in Canada?
It remains to be seen if such an innovation could one day be found on North American roads. Canadian climate conditions pose serious technical challenges. De-icing salt, snow, water and the freeze-thaw cycles could damage the circuits and affect the energy transmission between the road and the vehicle.
Many Canadian roads also put up with significant loads from heavy truck traffic and extreme temperature variations, which complicates the integration of coils under the asphalt.
Despite the uncertainties, the French demonstration is promising. If the technology proves to be effective and robust, it could transform the way we conceive of electric mobility, allowing for smaller batteries, less waiting at charging stations and a road network that is truly energy-providing.