The Energy+ Household – Bay Area, California
Over the past several years the Ghosh family has retrofitted their 2,170 ft2 house with a host of technological solutions. This project exemplifies the integration of efficiency, electrification, on-site electricity generation, and the use of electric vehicles as a way to substantially reduce a household’s carbon footprint. The family of four has zero energy bills! That is, in day-to-day living, the Ghosh family pays zero electricity bills, zero natural gas bills, and zero gasoline bills. They use no propane or firewood. The family meets the energy needs of its all-electric home through a 11 kW PV array. The solar system generates a net surplus which has been used to operate two cars for commuting, chores, and occasional weekend trips. This single-family home was built in 1997; in 2010 it consumed 600 therms of natural gas and 5,500 kWh of electricity (23,000 kWh site energy). Current household energy use, without the contribution of the PV generations is estimated to be <10,000 kWh. The average site energy use of a single-family California home is 20,000 kWh.