The National Institute of Standards and Technology’s (NIST) net-zero energy test house blew past the goals set by researchers for its first year of operation. It even managed to produce enough surplus energy to power an electric car for over 1400 miles.
To put it another way — and perhaps even more impressively — the net-zero system allowed for almost $4400 (average annual bill for a comparable modern home in the region) in saved/avoided energy costs, while also actually earning the virtual family of four residing there a cash credit via the exportation of surplus energy to the local utility.
This impressive performance by Net-Zero Energy Residential Test Facility (NZERTF) was despite five months of below-average temperatures and twice the normal amount of snowfall, so “average” years would have allowed for even more impressive performances.
“We made it — and by a convincing margin,” stated Hunter Fanney, the mechanical engineer who leads NZERTF-based research. “From here on in, our job will be to develop tests and measurements that will help to improve the energy efficiency of the nation’s housing stock and support the development and adoption of cost-effective, net-zero energy designs and technologies, construction methods and building codes.”
The press release from NIST provides more:
Both a laboratory and a house, the two-story, four-bedroom, three-bath NZERTF would blend in nicely in a new suburban subdivision. But it was designed and built to be about 60% more energy efficient than houses built to meet the requirements of the 2012 version of the International Energy Conservation Code, which Maryland has adopted.
The 2,700 square-foot (252-square-meter) test house’s features include energy-efficient construction and appliances, as well as energy-generating technologies, such as solar water heating and a solar photovoltaic system.
Despite 38 days when the test house’s solar panels were covered with snow or ice, the NZERTF’s sun-powered generation system produced 13,577 kilowatt hours of energy. That’s 491 kilowatt hours more than used by the house and its occupants, a computer-simulated family of two working parents and two children, ages 8 and 14.
As far as energy consumed per unit of living space, the NIST house is calculated to be about 70% more efficient than the average house in the region.
“The most important difference between this home and a Maryland code-compliant home is the improvement in the thermal envelope — the insulation and air barrier,” states NIST mechanical engineer Mark Davis. “By nearly eliminating the unintended air infiltration and doubling the insulation level in the walls and roof, the heating and cooling load was decreased dramatically.”
This high level of energy efficiency doesn’t come cheap though — by incorporating all of the NZERTF’s energy-related technologies and efficiency-enhancing construction improvements you would add around $162,700 to the price of a similar house built to Maryland’s state building code. So, with about $4,500 in annual energy savings, it would take about three decades to recoup the financial costs.
In related news, for all of the latest announcements about energy efficiency and solar energy, I recommend that you check out our latest “news carnival” on these subjects.
Everything from the increasing efficiency of Yingli solar cells, to solar skyscrapers in Germany, to DIY solar panels on Amazon, to “tiny” homes, to the increasing energy efficiency of malls, is discussed therein. Enjoy.
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