The role of solar energy toward the goal of zero-energy homes in U.S.mixed-humid climates

Zero-energy homes (ZEHs) are residential buildings that generate on-site as much energy as they consume. The ZEH goal is being pursued at Oak Ridge National Laboratory, by combining energy-efficient technologies and methods, onsite photovoltaics (PV), and smart energy-management appliances. This work focuses on the performance of a 2.5 kWp PV system, a solar water heater, and smart energymanagement appliance during the summer, fall and winter of 2008. These technologies in combination with 10kWh of dispatchable battery energy, which is available to the energy management appliance, enable a near zero-energy home to generate on-site all the household energy needed and send an average of 2.65 kW back to the grid during the two hour electric utility system peak load time.