Worked as trainee at an electrical company southern Sweden many years ago. The company noticed a unusual power loss between to nodes in their power grid, couldn’t figure it out for years. Eventually they got suspicious about a local farmer and could see that the loss of power correlated with him running his watering system. Turns out he’s buried a big coil of copper wire beneath the high voltage power line. By carefully crafting it he was able to induce just enough power to drive his watering system.