Currently the WPT transfer distance is in range of several centimeters. Among the technical challenges to overcome we can mention:
- acceptable power transfer efficiency at high transfer range
- increasing power level
- misalignment tolerance
- safety considerations
Coil-to-coil distance & 30 m working wavelength transfer efficiencies
2-turn copper ribbon coil (3cm wide, 0.14 mm thick) with d=60cm and 5 to 70 pF adjustable high voltage capacitor. The quality factor of the resonator is 1338 in the absence of the metallic plane and 1329 in the presence of a metallic plane.
Source: Safe Wireless Power Transfer to Moving Vehicles: Design of Radiationless Antenna