The startup Winduction has developed a wireless charging system for electric buses that operates more efficiently than existing alternatives. This technology allows for a reduction in the size of the traction battery—the heaviest and most expensive component of any electric vehicle.
Charging Electric Vehicles Through Tires: An Innovative Concept from Switzerland
The Winduction team has unveiled a unique wireless charging system designed for electric buses.
The charging station is embedded into the road surface at bus stops—precisely where buses pause to pick up passengers. Induction coils, which generate a magnetic field, are positioned beneath the vehicle’s wheels. Corresponding induction coils are integrated into the tires themselves; these capture the transmitted energy and convert it into an electric current, recharging the bus’s battery.
While wireless charging technology is not new, the Swiss system distinguishes itself by placing the receiving unit within the tires rather than the vehicle’s chassis. This positions the receiver much closer to the ground, significantly enhancing energy transfer efficiency. According to the developers, the electric bus receives at least 90% of the energy transmitted.
The concept necessitated the development of specialized tires.
Standard automotive tires contain a structural framework made of steel wire, which shields the magnetic field and interferes with energy transfer. Consequently, Winduction had to engineer unique tires featuring a non-metallic framework.
Although these specialized tires are more expensive than conventional ones, the overall benefits are substantial. Currently, electric buses are typically charged overnight at their depots, which precludes the use of affordable solar energy. By implementing wireless charging at bus stops, the batteries can be replenished throughout the day while the vehicles are in service. Furthermore, the system will allow for a reduction in the size of the traction battery, which will significantly lower the cost of the electric bus as a whole.
The startup team hopes to implement the wireless charging system on a bus route to Zurich Airport by 2028.
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