When a new hybrid-electric bus in a Stockholm suburb pulls up to the last stop on its route, it stays a few extra minutes after the last passenger gets off: under the pavement, a wireless charger is recharging the bus.
A full charge—enough for the bus to run its entire route on electric power—takes six or seven minutes.
"Bus stop fast-charging capability is important in order to keep to the timetable of the bus service," says Markus Fischer from Vattenhall, the company that owns and operates the charging station, supplying it with renewable electricity.
The route is part of a new pilot run with the city of Södertälje, the bus manufacturer, Scania, and the Stockholm-based Royal Institute of Technology. While there are other ways to charge an electric bus—like overhead wires or plug-in charging stations—the partners wanted to test hidden chargers partly for aesthetic reasons.
"The design of the inductive technology has been adapted so as not to disturb existing urban environments and is essentially invisible," says Fischer.
In the pilot, the bus charges overnight via a standard wired charger. Then, each time it comes to the final stop throughout the day, it quickly recharges. A sensor shows the bus driver exactly where to park, and a charging box on the bus lowers until it almost touches the ground.
Sweden plans to make all vehicles in the county fossil-free by 2030, and a simple system to charge buses is part of that; unlike most cars, buses drive all day long and can't rely on an overnight charge alone.
On a longer bus route, multiple stops might have even faster chargers, each charging for 20 to 30 seconds. Eventually, entire roads might also be electrified. Vattenhall believes that wireless charging would also be useful for private cars and trucks.
"In the future, we believe wireless charging will be essential to make it easy and hassle-free to own and use electric vehicles," Fischer says.