Net-Zero House Succeeds GoalCategory: Science & Technology
Posted: July 2, 2014 06:39AM
Anyone who has had to pay a power bill or seen rates increase can understand one reason why energy efficiency is important. Sometimes it feels like anything that could reduce usage would be worth it, but could it be possible for a home to zero net energy usage over a year? That is a question researchers at NIST decided to test and the year is up, with great success.
The Net-Zero Energy Residential Test Facility (NZERTF) is a four-occupant house and laboratory in Maryland with many technologies to reduce energy usage, or to even produce energy. There are solar panels on the roof, a geothermal system underground, a solar water-heating system, and the house was built with double the insulation level. Inside the home had all of the appliances you can find around your own house, with extra equipment to control and monitor them, in order to simulate the use of a four-person family. After a year, which included severe weather, the home not only met the net-zero energy goal but exceeded it with a 491 kilowatt hour surplus. In total it used 13,086 kWh, which was 3000 kWh more than expected with normal weather, but roughly 14,000 kWh less than a comparable Maryland home, built to state energy standards, would use.
With this experiment done, and the point of a net-zero home proven, the NZERTF will continue to be used to test technologies and measures to reduce energy use and improve efficiency, with an aim at reducing costs. The researchers estimate the technologies used and efficiency-enhancing construction would add about $162,700 onto the cost of a comparable home built to Maryland's building code, when totaled together.