Literally decades ago we had a simple version of this. I think it was only for our pool pump...maybe the water heater. My understanding is my parents got some s

Literally decades ago we had a simple version of this. I think it was only for our pool pump...maybe the water heater. My understanding is my parents got some sort of fixed discount if the power company had the ability to periodically cut power. I'm not sure how the signal was sent, but I remember an electrician pointing out the wires. It was probably a small box next to the breaker.