"Richard Crowley" wrote in message
...

Sure you can. The "earth's crust" is a conductor just as a
piece of copper wire is. It is not quite as good as copper
wire, but megawatts of power are transmitted all over the
planet using the earth's crust as the return path of the circuit.

The power that runs the computer you are reading this on
is likely transmitted through the ground (on the return path
of the high-voltage side). When you see a single wire on
the power poles with taps going into the transformers, note
that the other side of the transformer is connected to a ground wire. The
electricity comes from the generator,
through the single wire along the poles, into the transformer
(the "destination"), and then returns through the earth's
crust back to the generator.

Are you sure about that? I've heard of some telephone systems that used the
earth as a conductor, but surely it would be hazardous to transmit
substantial amounts of AC power through the earth, and I've never heard of
it being done. People walking barefoot on the ground would be electrocuted.
There would be a constant risk of setting things on fire on the ground. And
the conductivity of the earth is very variable -- your power would fail when
the ground got dry.

As far as I know, all high-voltage power transmission systems are 3-phase
systems, with a fourth wire connected to the earth for safety purposes, but
no substantial current flowing through the earth.