Last week, at Hanover Fair in Germany Siemens and BMW debuted a non-contact charging station for Electric Vehicles. In the same way as an inductive charging mat can wirelessly refresh the battery in your cellphone, the EV charging station is connected to the public grid by a primary coil that is completely underground. A secondary coil is attached to the car, and the distance between the two coils is typically between eight and 15 cm. When the driver starts the charging process, an electric current begins to flow through the primary coil. The resulting magnetic field induces an electric current in the secondary coil, which recharges the battery. Electricity is transmitted from the grid through all of the components to the battery at an efficiency said to be more than 90 percent.
According to Siemens, this type of charging station is virtually invisibly because it's underground and could be implemented into pretty much any setting. One situation would be automatically charging taxis waiting at the cab stand, but there many other possibilities.
Starting in May, a prototype with a charging power of 3.6 kilowatts will be tested in an electric vehicle. Beginning in June, the test will be followed by trials in Berlin to determine improvements needed to integrate the system into production vehicles under real-life conditions and to obtain customer feedback.
