On the whole subject of utility bills, I believe the key is simply keeping them paid and the power company happy, there are any number of home businesses that could easily suck up $1000+ in power per month, especially if they're using older, less efficient equipment. Some things that come to mind are pottery, wood working, welding, etc. An older HVAC system can be a huge money drain, washers/dryers, those commercials telling you to throw out your old beer fridge in the garage aren't just propaganda, those things suck down the juice, add in a couple big freezers from 10+ years ago and you'll be surprised by how high your bills get.
I think you're right, for the most part. A grower's power bill is the DEA's for the asking, however. When they get a line on a suspected grower then a huge power bill is just another piece of evidence in building a case. Smart meters also reveal the cycle times of power use, another giveaway. It's hard to imagine anybody but a grower pulling 12KW from 7PM to 7AM every day of the week for months on end.
Problems usually manifest themselves from another direction. Nosy neighbors. Poor odor control. Too much traffic, particularly w/ out of state plates. Visible loading of vehicles. Visible trash from growing. Visible non-code alterations to the electrical service. Child welfare issues. Domestic violence calls. Rollovers.
Unlicensed commercial growers are sitting ducks. Success depends on having the skill of an Apache warrior- hiding in plain sight.