New Zealand has this for grid attached water heaters. They can be placed on a lower tariff, but will be turned off during times of peak load. It is implemented

New Zealand has this for grid attached water heaters. They can be placed on a lower tariff, but will be turned off during times of peak load. It is implemented by putting the stored heat device (water heater, air heater) onto a separate meter with something called "ripple control" [2]. This gives the power company the ability to avoid spinning up peaking plants - which are very expensive compared to base load. Nest also offers this as a service to power companies - they allow the power company to shift cooling load the same way. The power company then passes this cost savings on to the customer. It ends up being about 1c/kwh [1]. Personally, I had to turn it off, our ripple control kept going bad. Nothing worse than a cold shower in the morning. Instead, I went with a timer and switched to a night rate. The heater would come on after hours and warm up the next day's water. [1] https://www.genesisenergy.co.nz/plans-and-pricing https://www.genesisenergy.co.nz/plans-and-pricing Anytime vs Controlled. [2] https://en.wikipedia.org/wiki/Load_management#Ripple_control https://en.wikipedia.org/wiki/Load_management#Ripple_control