The Western Australian Government owns Western Power and Horizon Power, which operate the three major electricity networks.
Western Power operates the transmission and distribution systems within the South West Interconnected System (SWIS), the biggest electricity network in Western Australia. The boundary of the SWIS extends to Kalbarri to the north, Albany to the south and Kalgoorlie to the east.
Horizon Power operates the North West Interconnected System (NWIS) in the Pilbara region, the smaller Esperance network, as well as over 30 discrete networks in regional towns and remote communities.
Privately owned electricity transmission and distribution networks mainly service mining operations in the Pilbara.
The Economic Regulation Authority regulates third party (retailers and large-scale users) access to Western Australia's electricity networks covered by the Electricity Networks Access Code. Currently, the only regulated electricity network is Western Power’s South West Interconnected System.