Bus fleets across Switzerland and Europe are going electric, but keeping them running isn’t cheap. Today’s e-buses carry massive batteries and rely on heavy-duty chargers at the depot, and operators pay a lot for both upfront and over time. According to ETH Zurich, its spin-off Winduction has a smarter idea: let buses charge through their tyres at bus stops.
How does a tyre charge a bus?
Wireless charging isn’t new, as you can already charge phones and even some electric cars without cables. However, most systems beam power from a coil in the road to one under the vehicle, and the bigger that gap, the more energy gets lost.
Winduction’s founders, Sonam Bhuka, Sylvain Fricker, and Laurin Schwitter, found a clever workaround. Fricker realized that no matter the vehicle, its wheels never leave the road. That idea gave the company its name, which is short for “wheel-based induction.”
The setup is surprisingly simple. A charging plate is built into the road at a bus stop, and when a bus parks its back wheel on top, coils hidden inside a custom tyre collect the energy and feed it to the battery. It’s over 90% efficient, with no cable in sight.
There was one catch, though. Regular bus tyres are reinforced with steel, which would waste much of the energy as heat. To get around this, the team is working with partners to design a new tyre with no steel at all.
Why should bus operators care?
It all comes down to cost. Since buses top up throughout the day, they can use smaller batteries, which makes them cheaper and leaves more room for passengers. It will also result in fewer reserve buses required, less strain on the power grid, and more use of cheaper daytime solar energy.
Winduction is building a test lab and test bus stop in Winterthur, with its first passenger pilot planned near Zurich Airport in 2028. If it works, you could ride one of these buses without ever realizing it’s charging under your feet.