Net-zero-energy buildings, which create roughly as much as power as they use in a year, have been around for a while. But the newest sustainable homes go far beyond net zero to become mini power plants, able to charge electric cars and feed electricity back into the local grid.
A new house completed today in Norway is intended to demonstrate exactly how well the latest technology and techniques work. Made for ZEB, the Research Centre on Zero Emission Buildings, the experimental house can produce more than twice as much energy as it uses.
“I guess you can say it’s a pretty extreme target, to have a house that produces that much energy within its envelope and reduces its impact simultaneously on the environment,” says Kristian Edwards, project manager for Snohetta, the architecture firm that designed the house.
The slanted roof is set at the optimal angle to absorb sun throughout the year and also helps naturally ventilate the house. “We didn’t want to allow the technology to be the driver of the design in the house,” says Edwards. “We didn’t want the experience of the dwelling to just be electric equipment and sensors, so we focused on natural ventilation. The windows fully open, and it’s shaped for a natural updraft, to let air out of the building.”
The house was also designed to maximize natural light without overheating in Norway’s long summer days. “One of our goals was not to need sun shading, so you don’t have to pull down blinds when you most want to see out your window,” Edwards explains. “For example, the atrium gives an enormous amount of light but doesn’t require you shades that close out the view.”
Different technologies will be tested as the house operates, like multiple systems for heating and hot water, so the team can measure and analyze which is most efficient.
Outside, a swimming pool stays warm from the home’s extra heat. An electric car plugged into the house will serve as a battery to store some of the excess power the building creates. Though the demo house is located in a fairly remote area, it may also feed power back into the grid.
As similar “plus houses” are becoming more common throughout Norway, the country is debating the best way to handle all of the extra power they create–and how to properly compensate homeowners, who are currently paid less for extra solar power than they’re charged for energy they use through the grid. In Bergen, a new development will include 700 to 800 similar homes, all pumping out extra power.
ZEB is working on more demonstration projects, all of which aim to completely eliminate greenhouse gas emissions.
“I’d like to think that all homes could be designed to this standard, and the quicker the better,” says Edwards. “ZEB is a generator of the building code in Norway, so certainly some aspects of the project will actually manifest themselves in the building code, probably in the next 10 to 15 years.”