A system that is not connected to a network.
A PV installation not connected to a utility power line. A 'direct system' uses the PV-produced electricity as it is produced, e.g. a solar-powered water-pumping station. A 'battery storage system' stores the PV-produced electricity for use a later time, e.g. at night or on cloudy days.
A solar PV installation that is not connected to a utility power line (the grid).
An system that operates independent of any utility company grid or electric transmission and distribution network.
An autonomous or hybrid energy system not connected to a grid. May or may not have storage, but most stand-alone systems require batteries or some other form of storage.
(SA) A system which operates independently of the utility lines. It may draw supplementary power from the utility but is not capable of providing power to the utility.