This is interesting. The only things that'd be particularly easy to control would be laundry (could do all the drying after 7pm), running the dishwasher, and water heating (with a timer, assuming you had an electric water heater). If you had an electric car, this could be some nice, free charging. Otherwise, I'm not sure how much there would be to be saved. In summer, A/C units would still run for much of the day, unless you had some extreme programming. Lights and modern TVs and such are super cheap to run, assuming use of LEDs. And charging other electronics likely doesn't add up to too much money, anyway. It's a good premise but the window is pretty short and the penalty rate is a bit high, IMHO.