U.S. Department of Energy - Energy Efficiency and Renewable Energy
Building Technologies Program
Water Heating R&D
Current Building Technologies Program Water Heating R&D projects include the "drop-in" residential heat pump water heater research and development project and the Utility Solar Water Heating Initiative.
"Drop-in" residential heat pump water heater
Heat pump water heaters (HPWH) can attain much higher efficiencies than conventional electric water heaters. Yet the residential market for HPWHs has remained small because of long payback times, low perceived reliability, and the need for specialized installation and service. DOE, in a cooperative effort with private industry and the Oak Ridge National Laboratory, developed and tested a HPWH that overcomes these drawbacks, opening the way to greater market acceptance.
A "drop-in" replacement for 50- or 80-gallon electric water heaters, the new HPWH has the same footprint as the original water heater and an identical electrical hookup, and Laboratory testing verified the durability and lifetime expectancy of components. The HPWH not only saves annual energy but also contributes to peak load shaving, and, as a side benefit, provides cool, dehumidified air to help condition the surrounding space in summer, spring, and fall. Advanced HPWHs under development promise significantly lower first costs.
Utility Solar Water Heating Initiative
The Utility Solar Water Heating Initiative (USH2O) is a coalition of utilities and the solar thermal industry that works to increase the use of solar thermal technologies on a large scale. USH2O partners include solar thermal program managers from investor-owned utilities, municipal and other publicly owned utilities, as well as manufacturers, distributors, and installers of solar water heating systems.