I don't know. It seems there can be quite an effect by shifting usage even slightly as power generation has to be real-time and handling the peaks costs up all

I don't know. It seems there can be quite an effect by shifting usage even slightly as power generation has to be real-time and handling the peaks costs up all more. Free-market pricing seems wrong, as would per-minute pricing, but something like a 3-window (on-peak, off-peak, standard) time-of-day rate seems more acceptable.