Install a Timer and Use Off-Peak Power for Electric Water Heaters
If you have an electric water heater, you can save an additional 5%–12% of energy by installing a timer that turns it off at night when you don't use hot water and/or during your utility's peak demand times.
You can install a timer yourself. They can cost $60 or more, but they can pay for themselves in about 1 year. Timers are most cost effective if you don't want to install a heat trap and insulate your water heater tank and pipes. Timers aren't as cost effective or useful on gas water heaters because of their pilot lights.
Contact your utility to see if it offers a demand management program. Some utilities offer "time of use" electricity rates that vary according to the demand on their system. They charge higher rates during "on-peak" times and lower rates during "off-peak" times. Some even offer incentives to customers who allow them to install control devices that shut off electric water heaters during peak demand periods. These control devices may use radio signals that allow a utility to shut off a water heater remotely anytime demand is high. Shut-off periods are generally brief so customers experience no reduction in service.