This concept is called Demand Response and is quite prevalent. Consumers receive a discount for reducing their load at peak times.

This frequently targets very high demand customers rather than residential for the simple fact that it's easier to ask a company to delay starting a single piece of machinery than to reduce the load on an equivalent but large number consumer appliances like refirgerators.

Doing this at a residential level will require significant costs to support at a residential scale. Technology is the key in solving this problem.