I suppose that's going to vary by utility. As far as I know, our utility doesn't care. You just tell them you want to switch to time-of-use billing and that's that. It's up to you to make sure your usage and equipment takes advantage of it, but it's not something I've put a lot of research into. (broken link removed to http://www.centralhudson.com/timeofusebilling/index.aspx) Looks like you can really get bitten by it though. You save 11% off normal rates for off peak, but pay +18% of normal for on-peak, so you've got to have your electrical ducks in a row to not blow it.That's something else I'm waiting for here. It's sort of here, but to get it you need to buy & install (have installed) a real, 'approved', ETS heating unit. As far as I know. Which are kind of spendy I think. I have everything here already to do that with (electric boiler & water tanks), would just need to add a couple of controls & change a bit of piping - but that doesn't qualify. Unless they've changed things - been a little while since I asked. I will be asking again at some point.
With all the hype about the Tesla home battery thing recently, I've wondered if that's going to get marketed toward this. Just charge your batteries off the grid at night, and deplete them during the peak hours. Not sure if there's a real payoff for that given how expensive the battery setup is likely to be.