off the grid

Off the grid is a designation for facilities that produce all their own energy and are not connected to any external source, such as the electrical power grid. To be considered fully off the grid, buildings have to be completely self-sufficient, independent of public utilities including water, sewage and natural gas systems as well as the electrical grid. Geothermal, solar and wind-based technologies are among those used for off-grid electrification. 

Because fully off-the-grid buildings are completely autonomous, they can be functional in many situations -- such as widespread power outages -- that affect other facilities. 

See also: off-grid data center