Currently, there are three main power transfer concepts for road electrification: overhead conductive lines, conductive rails in a road surface, or wireless solutions. All these concepts have their advantages and disadvantages and are being developed and marketed by different actors.
An overhead line solution uses conductive wire lines (also known as catenaries) above the vehicle to provide the energy. The energy is transferred to the vehicle by means of a power receiver device (sometimes called a pantograph) installed on top of the vehicle, and which follows and detaches automatically from the overhead lines.
A rail solution for conductive energy transfer from roadway to electric vehicles uses conductive rails installed in the road to provide the needed energy. The energy is transferred to the vehicle via a power receiver pick-up arm installed beneath the vehicle, and which follows and detaches automatically from the rail.
A wireless solution uses a magnetic field to provide the energy. Electric current in primary coils installed in the roadway create magnetic fields which induces current in a secondary coil installed beneath the vehicle.