Ive often wondered if you was to place a coil in the vacinty of a large transformer station if you could generate some usable electricity? If it was possible and you owned the land adjacent to said station could you bury a larger appliance to really get a jolt? Legal?
Being near the substation isn't particularly useful. The fields in the transformer are really IN the transformer.
Being under or next to a high-tension line, on the other hand, makes it easy to pick off a significant amount of power. The energy flows in the fields AROUND the wires, not THROUGH the wires. And those fields don't fall off all THAT fast, so a significant amount ends up flowing through the space outside their right-of-way.
You ARE lifting the power company's power. But at least one judge has ruled that if they can't keep it inside their wires that's their tough luck. B-) Your mileage may vary depending on your state and your judge, of course.
There was a discussion on this a few months back. Basic idea is to string a line parallel to the power line and just outside their right-of-way easement (so there's no issue of violating their right-of-way). Think a half-turn transformer or a radio transmission line directional coupler. (Look it up in the Radio Amateur's Handbook.)
LOTS of caveats about how not to get electricuted while doing this and about putting serious surge protection on your system so the power company can't set your place on fire by doing a bit of swtiching that dumps some big spikes into your system. Story aobut how they were alleged to have done this deliberately, a half-century back, to a farmer who built such a system (after they ran a line over his farm but still wanted big bucks to string him a feed).
Note that even if they don't deliberately try to fry you a little switching can produce amazing crud on transmission lines and things coupled to them.
