Source: Toolbase Services - www.toolbase.org
Imagine a home that is not only energy efficient, but also produces its own power. Just like a typical home, a Zero Energy Home (ZEH) is connected to, and uses energy from, the local electric utility. But unlike typical homes, at times the ZEH makes enough power to send some back to the utility. Annually, a ZEH produces enough energy to offset the amount purchased from the utility-resulting in a net-zero annual energy bill.
A ZEH combines state-of-the-art, energy-efficient construction techniques and equipment with renewable energy systems to return as much energy as it takes on an annual basis. Specifically, when renewable resources cannot provide all the home's power, e.g., at night or on a cloudy day, the homeowner purchases energy from the utility. When renewable resources produce more than the house is using, e.g., during sunny days when no one is home, power is sent back into the utility grid. Some utilities operate the home's electric meter in reverse, essentially providing the homeowners full retail value for their energy.
The NAHB Research Center has worked in conjunction with builders on several ZEH projects. The most recent project, the Bob Ward Companies Ultra-Efficient Home, was built in Bel Air, MD. Another current project is the John Wesley Miller ZEH house in Tucson, AZ. In addition, the Research Center worked with Asdal Builders to remodel a farm house into a ZEH house in Califon, NJ. While each project has unique facets, many similarities reinforce the successful approach to energy efficient construction.