Described herein are embodiments of transmitting power wirelessly that include driving a high-Q non-radiative resonator at a value near its resonant frequency to produce a magnetic field output, said non-radiative-resonator formed of a combination of resonant parts, including at least an inductive part formed by a wire loop, and a capacitor part that is separate from a material forming the inductive part, and maintaining at least one characteristic of said resonator such that its usable range has a usable distance over which power can be received, which-distance is set by a detuning effect when a-second resonator gets too close to said resonator.