Zero Energy Houses in the US
Zero Energy Houses in the US
Study Explores Impact of Zero Energy Homes in Reducing Future U.S. Energy Consumption
A newly published study, The Potential Impact of ZEH, developed through a collaborative effort by the NAHB Research Center, the U.S. Department of Energy and the National Renewable Energy Laboratory (NREL), presents a far-reaching outlook into the possibilities for Zero Energy Home (ZEH) technologies in the new home market and their potential impact on U.S. energy consumption through 2050.
Zero Energy Homes, which are connected to the utility grid, combine highly energy-efficient design and technology with solar electric and thermal systems to produce as much energy as they use on an annual basis, resulting in net zero energy consumption. While ZEH are technically feasible and exist today, they have yet to widely penetrate the new home construction marketplace. However, market penetration of highly efficient homes with solar energy systems has already begun and will continue in certain geographic areas. EPA Energy Star® home sales have experienced enormous growth, going from zero in 1995 to 130,000 in 2004, with up to 40 percent penetration in select markets.
As energy costs continue to rise, a number of energy-efficiency improvements in appliances, building envelopes, windows and mechanical systems are moving into the market. Solar electric (photovoltaic) system costs have continued to decline and new, solar water heating designs are under development that will reduce costs and improve efficiency. These factors combined with state and federal tax incentives for renewable energy systems suggest that as energy-efficient technologies become more affordable, consumers will embrace the long-term energy and environmental benefits of ZEH; making them economically competitive with conventional construction when utility costs are included in the cost of homeownership.
The Potential Impact of ZEH concludes that with continued federal research and development programs to lower the cost of advanced energy-efficiency building technologies, the ZEH concept will begin to diffuse into the U.S. home market as early as 2012. This could ultimately result in annual energy savings in 2050 of approximately 17 percent of the U.S. energy consumption in single-family homes even as over a million new homes are added each year.
For more information on zero energy homes and the The Potential Impact of ZEH study, or to download a copy, visit www.toolbase.org/zeh.
(Green Building News, May 2006)