The U.S. Department of Energy has officially designed zero energy buildings, which also are referred to as net zero or zero net energy buildings.
The definition – which took a year-and-a-half to formulate – defines an a zero-energy building as “an energy-efficient building where, on a source energy basis, the actual annual delivered energy is less than or equal to the on-site renewable exported energy.” The definition extends to campuses, portfolios and communities. The DoE publication includes guidelines for measurement and implementation.
The DoE collaborated with the National Institute of Building Sciences (NIBS) on the project.
It is an important step, especially considering that the number of zero energy buildings doubled from 2012 to 2014 across 36 states. In Fontana, California, The Electric Power Research Institute is overseeing a pilot in which nine net zero homes are being built. Other participants in the project are SunEdison, which is supplying battery systems for the project, and builder Meritage Homes. The California Public Utilities Commission and Southern California Edison also are participating, according to pv magazine.