We had a neighbor that put loops of wire under a 600kV line and got enough power to run a water pump for cows. The square law makes that kind of thing pretty low-return.
Yah, he was just running a 12V bilge pump on a battery, and used a charge controller to keep the battery up so just needed a voltage slightly above the battery voltage. I doubt it used a kWh per day as it cycled. He might still be using it, haven't talked to him in a few years.
