Utilities explore the potential of zero-energy homes.
Like much of California’s Central Valley, Sacramento has a Mediterranean climate, with cool, wet winters and summers that are hot, dry and clear. It makes an ideal place for solar-integrated homes; to wit, the sun reliably shines hardest on the peak load days, when extra power generation is most needed.
A moderately-sized new home built to code in the California capitol draws about 4.5 kW at a summer peak. But at Premier Gardens, a 95-house subdivision, that number has been shaved to just 1.5 kW.
Built to energy-efficiency standards that far exceed the state’s stringent building code and outfitted with photovoltaic roofs, Premier Gardens is on the green-building vanguard. And yet the houses actually could be better. Built in 2003, the homes don’t have smart meters. That means no net metering or smart-home efficiency savings.
“We went from 4.5 kW to 1.5 kW without smart meters,” says the U.S. Department of Energy’s Lew Pratch. “A smart house would take the home’s demand down from 1.5 kW to being maybe a net producer.”
Pratch is project manager for the Zero Energy Home program, a DOE effort to build affordable, energy-neutral houses in all the nation’s major climates by 2020. The Premier Gardens development shows just how close that goal is to reality.