Water heating is typically the second largest use of energy in residential buildings, following space heating and cooling, said ACEEE. The study, Emerging Hot Water Technologies and Practices for Energy Efficiency as of 2011, surveys and examines a suite of 16 products and services ranging from heat pumps (50-55 percent savings) and high efficiency gas water heaters (30-39 percent savings) to best maintenance practices for multifamily buildings (25 percent savings).
“The technologies we evaluated represent a sea change in the way we think about heating water,” said Harvey Sachs, lead author and ACEEE Senior Fellow. “Consumers can now choose among many sophisticated tank, tankless, and solar water heating systems to meet their needs.”
One of the prominent features of this study is the variety of water heating technologies available today: the storage, tankless, and hybrid units surveyed suggest that consumers can now select a water heater that not only saves energy, but also offers hot water service tailored to their needs. For example, in some applications, point-of-use water heaters can deliver hot water to isolated fixtures (such as new home additions and remote lavatories) faster and with less waste than whole-home storage units.
Other findings in the report include:
• The 11 electric technologies included offer a cumulative 1.6 quadrillion Btu savings through 2025, at an average cost of saved energy of $0.03/kWh. These energy savings are enough to serve a typical city of about 17 million people for a year, and the cost of energy savings is less than one-third of what the average residential customer pays for electricity.
• Commercial point-of-use water heaters can deliver hot water to lavatories and sinks in new buildings at a negative incremental cost to developers.
• Drain water heat recovery devices and on-demand recirculation pumps can greatly improve system performance at very low cost compared with standard plumbing.
The water heating technologies evaluated in this study could prove particularly useful for utility program administrators as they explore options to meet rising energy demands and satisfy new environmental regulations. ACEEE noted that utilities act as key players in efforts to bring emerging technologies into the mainstream through their incentive programs and customer education.
“We were pleased to help sponsor ACEEE’s research to help raise awareness about new water heating technologies that will help better serve our customers,” said Ahmed Abdullah, emerging technologies program manager, SoCalGas, one of several sponsors of the project. Other sponsors include BC Hydro, Energy Trust of Oregon, National Grid, New York State Energy Research and Development Authority, Southern Company, and the U.S. Department of Energy.
ACEEE projects that the majority of measures evaluated in this report (11 of 16) will prove cost-effective by 2025, the end of the analysis period. Others will be chosen by consumers for amenity value, such as “endless hot water.”
“An exciting finding from this study,” said Jacob Talbot, report coauthor and research analyst, “is that there are a great number of technologies with both large savings potential and an economic benefit to consumers.”
For the complete report, go to http://aceee.org/research-report/a112.
Publication date: 10/10/2011