Grid Frequency Support from Distributed Inverter-Based Resources in Hawaii

Hawaii leads the nation in the portion of its electricity that is produced from distributed solar photovoltaics (PV). This high level of PV penetration, in combination with Hawaii’s small size and geographical isolation, is forcing Hawaiian electric utilities to confront emerging grid reliability and safety issues much sooner than their continental counterparts. For example, the sudden loss of a major generator or a downed transmission line could cause some distributed PV systems to also shut down as a safety response, potentially exacerbating the change in the grid’s electric frequency and causing a loss of grid stability. In addition, PV systems have displaced some of the conventional generators whose inertia and governor controls help to stabilize the grid.