Wireless EV charging tested in Switzerland shows 90% efficiency, major grid benefits

A real-world trial by scientists in Switzerland has demonstrated that wireless EV charging can achieve up to 90 percent efficiency compared with conventional cable-based systems, while offering far greater convenience. Supported by the Swiss Federal Office of Energy and the cantons of Zurich and Aargau, the project, called INLADE, was carried out by researchers from Empa in collaboration with the electric utility Eniwa AG.

Through this first-of-its-kind initiative, the team tested wireless inductive charging under real-life conditions in Switzerland. They are certain that what has long been routine for phones and electric toothbrushes could soon become a reality for EVs. The aim was to test the existing technology in everyday use, clarify technical and regulatory issues and demonstrate its potential for the energy transition, Mathias Huber, from Empa s Chemical Energy Carriers and Vehicle Systems lab, said.

Switzerland tests wireless charging The new initiative aims to make EV charging as effortless as parking. Instead of plugging in, drivers would simply stop over a ground-embedded charging plate, and the system would start automatically. According to the researchers, a transmitter coil in a base plate transfers energy through a magnetic field to a receiver coil in the car. At the same time, a display guides drivers into the optimal position.

Before charging begins, the system automatically checks for any obstacles or living beings between the coils to ensure safety. Once the car is parked correctly, charging begins automatically with no cables, no connectors and no extra steps. But the team claimed the project could go even further. With EVs automatically linked to the grid whenever they are parked, they could eventually act as mobile energy storage units and help stabilize the power system.

The big advantage of an inductive system is that vehicles are connected to the grid much more frequently without the need for any active intervention a plus for both convenience and the energy transition, Huber revealed. First real-world trial For the project, AMAG and several other partners helped retrofit existing EVs with receiver coils. They then integrated them into the car s charging and high-voltage systems. The aim was to ensure that the magnetic field generated during inductive charging did not interfere with other devices inside or outside the vehicle, or with people, Huber pointed out in a press release.

After extensive electromagnetic compatibility (EMC) tests and safety verification, the vehicles received approval for road use. This placed them among the first vehicles in Switzerland, and the world, to operate daily using inductive charging. A display inside the vehicle indicates the optimal parking position. The system automatically checks for objects or living beings between the coils.Credit: Empa The tests were carried out at the move mobility demonstrator in Dübendorf.

The researchers evaluated the system in real-world conditions including snow, rain, cold temperatures and slight parking misalignments. Their results confirmed consistent charging efficiency of around 90 percent, and matched that of plug-in systems. The technology works very reliably in practice and is similarly efficient to conventional charging systems, Huber concluded. In addition, according to the researchers, as electric cars are parked rough about 23 hours a day, automatically connecting them to the grid could transform them into mobile energy storage units.

They claimed that this hands-free connection opens the door to bidirectional charging.