Island mode

Island mode is the operating state in which a battery storage system supplies selected circuits while that part of the home installation is separated from the electricity grid. In standards and battery handover documents, it usually appears around backup power, EPS outputs, maintained circuits and maintained loads during a grid outage. The installation must isolate the islanded circuits from the grid and provide suitable earthing, protection and changeover arrangements, so the term is not a promise of whole-property backup or uninterrupted supply. The usable supply still depends on inverter output, battery state of charge, solar availability on supported hybrid systems and the loads connected to the backup path.