# Resonant inductive coupling and Schumann resonances

I was reading about WiTricity (http://en.wikipedia.org/wiki/WiTricity) a technology developed by MIT to wirelessly transmit electricity through resonance, and I have this question:

Given the phenomenon of resonant inductive coupling which wikipedia defines as:

the near field wireless transmission of electrical energy between two coils that are tuned to resonate at the same frequency. http://en.wikipedia.org/wiki/Resonant_inductive_coupling

And the Schumann resonances of the earth ( ~7.83Hz, see wikipedia), would it be theoretically possible to create a coil that resonates at the same frequency or one of it's harmonics (7.83, 14.3, 20.8, 27.3 and 33.8 Hz) to generate electricity?

I have a feeling that these wavelengths may be too big to capture via resonance (they are as large as the circumference of the earth if I understand it correctly), so alternatively would it be possible to create a coil that resonates with one of the EM waves that the sun sends our way?

1. $Q$. Every resonance has a quality factor which represents how quickly the energy in the mode drains away by assorted dissipative processes. I don't know what it is for the Schumann resonances, but I'll give you long odds that it is not good: much of the energy you put into the field will just dribble away into space.
3. Antenna dimensions. The naive way to design an antennas to use at frequency $f$ requires conductors of length on order of $c f$. Bit of a problem for frequencies of a few or few tens of Hertz.