The home hot water heater is hardly the cool kid in the appliance schoolyard. It doesn’t receive daily human interaction. It mostly dwells in the basement. There is no former Apple designer bringing us a new, sexy water heater.
But that doesn’t mean the appliance is completely forgotten. There is a tussle brewing in Washington over the second-largest energy hog in the house. The lowly hot water heater has long been part of load control programs run by electric utilities. Some hot water heaters also receive significant rebates as part of utility energy-efficiency programs. Now the two programs are potentially pitted against each other because of proposed energy conservation standards for residential hot water heaters put forth by the U.S. Department of Energy.
Demand response and energy efficiency are often seen as two peas in a pod. While efficiency can drive down overall energy use, even more kilowatts can be shed when the grid needs it most.
The point of contention is that large water heaters, over 55 gallons, will be required to have an energy factor of at least 2.057, a figure that’s double the efficiency of a high-efficiency electric storage heater. The new standard could only be met with heat-pump water heaters, instead of the classic electric resistance water heaters.
The problem is that heat-pump water heaters, while far more efficient, are essentially no good for demand response. The heat-pump water heaters are far more efficient because they move heat from one place to another (i.e., from the room to the water), instead of generating it directly.
For some of the larger appliances, including hot water heaters, there is also a natural gas option, which is inherently more efficient than electric, because the energy source does not have to be turned into electricity and then transported with losses to the home. About 60 percent of water heaters are already powered by natural gas, and there is a move afoot to introduce more gas clothes dryers to the U.S. market.