A new report from the Peak Load Management Association estimates that 5.3 gigawatts of power would be saved if just 25% of the 53 million electric water heaters used in the United States were fitted with smart meters to turn off at peak demand times. The savings would be in excess of $420 million. Currently, electric hot water heaters account for up to 17 percent of national residential electricity use.
Currently, utilities communicate with residences through “direct load control” switches. But smart meters are being deployed which will enable interaction with the new generation of “smart” appliances being manufactured. General Electric rolled out its smart water heater in November 2009. These can be manually set by consumers to power down during peak hours or programmed to power down automatically to avoid peak energy prices.
Water heaters are also being recruited to serve as repositories for renewable energy because unlike other appliances, water heaters also store energy in the form of hot water. So power created by renewable means such as wind could be stored by water heaters modified to run hotter than the standard 120oF and fitted with controls to mix in cold water so residents weren’t burned by the ultra hot water being stored.
Duke Energy CTO David Mohler says the utility is considering using hot water heaters, among other solutions, to balance out power fluctuations produced from solar panels. “What I could do is come up with an algorithm to vary the power draw on the heating element on the hot water heater and use that to balance the fluctuation of the solar panel output,” he said. “We’re still grappling with how to orchestrate that.”