If you've got free electricity you'd rather grow pot.
Anyway I call bullshit.
There are plenty of people who have either free electricity from the university where they host their machine or where they work. Not to mention living quarters with flatrate electricity. (of course somebody else is paying for it, so technically it's not free).
Or if you invested in solar power, 25k kWh/year gives you plenty of room to run a few miners. Fact, not bullshit.
Well the one is stealing which will get noticed if you consume a significant amount and the other.
And solar power panels are still too expensive their roi is even worse than the mining rigs and I doubt that anyone who writes here and claims free electricity has a high end solar system.