Looks like one of the major problems of wireless energy transfer is efficiency. For example, Magne Charge high power charging system seems to have about 86% efficiency which means that quite a lot of energy is lost when passing several kilowatts of power.
Yet seems like Bombardier PRIMOVE technology is efficient enough for powering and in-road charging a moving bus or even a moving tramcar in a wireless manner - a ton of wires is installed under the road or the driveway and those wires are controlled by some clever service electronics to be energized when a vehicle is passing over them and act like a primary coil of a wireless energy transfer system. The vehicle is equipped with the secondary coil.
Each time I inquire about wireless energy transfer seems like the distance between the coils is one of the critical factor. In the above scenario there will be some clearance under the vehicle and also the wires will be installed into the road and so will be covered with asphalt or concrete, so the distance can't be less that say 0,2 meters. Also the vehicle is moving which means that its secondary coil won't be perfectly aligned with the wiring in the road.
How is efficient energy transfer possible is such setup?