I am almost certain that this is a ridiculous question, but cannot figure out why it wouldn't work.
From what I understand, current from the electrical station is distributed to houses through power lines, then, to complete the circuit, returns to the station through the earth. Is there anything stopping someone from burying two electrodes of a simple, low-impedance element deep enough into the ground that the current will travel through it in its path back to the power station?
Low impedance bulb
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Best Answer
No, power is generally not delivered by using the earth as one of the conductors. This has been done in the past, but most of those have been replaced, and I don't think anything new is getting installed like that.
You are however right in that two stakes in the ground in line with the current flow at the right location where the ground is being used as a conductor would exhibit a potential. And, you could extract power from that. The funny thing is you'd actually be doing the electric utility a favor by making the overall ground resistance a tiny bit lower. In other words, the power you would extract would be less than the wasted power it would displace.
There have been cases in the past where these ground currents have causes problems. For example, a pipe coming in one side a house can be at a different potential than the ground at the other side of the house. Under the right conditions people have gotten zapped.
However, things aren't done this way anymore in part because of the problems but also because the loss was high. Where the current went in the ground was unpredictable, and sometimes it got concentrated in inconvenient places where the resulting potential offset would cause trouble.