But I have seen farms here in the US that are gigantic. They must be turning a profit, and there's no way they're paying 3cents/kwh.
"Industrial" rates tend to be cheaper then anything else in the same area.
There are 2 counties in the US that have RESIDENTIAL rates under 3c/kwh (and a third that has mid-sized commercial and larger rates under 3c/kwh but residential and small commercial a bit over 4).