Based on the Energy Efficiency Improvement Act of 2015 (EEIA) enacted by Congress earlier this year, the Department of Energy has now updated its regulations to define a new product class for "grid-enabled water heaters." That's good news.
These are electric resistance household water heaters with communication and control capability that allow utilities to use them as low-cost thermal batteries, heating the water when power is cheaper and cleaner, and deferring heating when power is expensive. Advanced controls even offer the prospect of providing the grid with 'ancillary services' like frequency regulation and load following, reducing the need for power plants to ramp up and down as total energy consumption changes during the day. This can make the electricity system more flexible and ready to use renewable generation that has variable output, like wind and solar.
Smart water heaters present one promising possibility for a more efficient, more economic, and ultimately lower-emissions electricity system, even if they are less efficient in terms of energy use individually. There's much more to be learned about the possible role of smart water heaters and the trade-offs between system (the grid) and component (like these water heaters) efficiency, and we've long supported regulatory and legislative steps that would foster much better understanding.
Looking ahead, we expect that the law and the updated Department of Energy regulations will encourage more manufacturers, utilities and others to explore and build on the opportunity. We're working with some of them already, and look forward to more.
Since water heating represents over 15 percent of household energy use, and with rapidly emerging technologies such as grid-enabled water heaters and very high efficiency heat pump and condensing water heaters to reduce the energy needed to heat the water we use, there's a lot of opportunity.
And, of course, we'll continue our longstanding work on great energy standards that deliver environmental and consumer benefits on a wide range of appliances.