Would a person with low income prefer A) having an option to lower the electricity bill or B) pay more because there is no such option, and more expensive power needs to be sourced from peaking power plants?

There are already day-ahead electricity markets with prices that vary throughout the day. You _already_ pay a premium over those variable prices, for the convenience of a fixed rate. All I'm saying is that it would be good if consumers had the _option_ of eliminating some of that premium, in exchange for demand shifting.