This is a non-radiative method: in the absence of a receiving device with a correctly tuned inductance, in the field surrounding the emitter there will be no, or hardly any E x B field. In other words, there would be no, or hardly any energy leaving the emitter.

Most interestingly, the method they describe can be used in a unidirectional manner, and the power supplied would fall off much less quickly than 1/r^2. One could even put a switch on the receiving circuit. When the circuit is broken, the total energy expended by the emitter would zip down to zero passively, without any control required. In fact, it's a fairly straightforward game to construct one of these on one's own. Too bad I didn't think of it ;-)