A zero energy home uses state-of-the-art, energy-efficient building techniques and renewable energy systems to produce its own energy. A zero energy home produces enough energy to offset the amount purchased from a local electric utility. This offsetting results in a net-zero energy consumption status from the local electric utility and a net-zero annual energy bill.

To learn more (and to see some examples of zero energy homes), go to:
http://www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10360
http://www.toolbase.org/Home-Building-Topics/zero-energy-homes/zero-energy-home-project
http://www.fsec.ucf.edu/En/research/buildings/zero_energy/index.htm