Australia’s states and territories play different roles in the national energy picture.
The Productivity Commission summarises the national picture as follows:
Electricity production is concentrated in four states: Queensland; New South Wales; Victoria; and Western Australia.
The electricity supply industry in Australia consists of five geographically distinct networks.
Four of these networks supply electricity entirely within the state in which they are located — two in Western Australia, one in the Northern Territory and one in Queensland.
Only the NEM straddles state borders. It uses high voltage interconnectors to link the transmission networks in Queensland, New South Wales, Victoria, South Australia and Tasmania.
Electricity in Australia
Electricity in Australia is supplied through five geographically distinct networks, or grids. These are:
• National Electricity Market (NEM)
• South West Interconnected System (WEM)
• North West Interconnected System
• Darwin to Katherine network
• Mount Isa-Cloncurry supply network
National Electricity Market (NEM): Runs down the east and southeast coast of Australia. Covers coastal Queensland, NSW, the ACT, Victoria, South Australia and Tasmania. The NSW transmission grid services the ACT. The NEM is Australia’s largest network, handling more than 80% of production and consumption.
South West Interconnected System (SWIS): Covers the south-west of Western Australia (Albany - Kalgoorlie – Kalbarri).
North West Interconnected System (NWIS): Covers part of the north west of Western Australia (Dampier, Tom Price, Port Hedland, Karratha and Roebourne). Major electricity customers in the NWIS include the port operations of BHP, FMG, Roy Hill and other miners, Rio Tinto’s port operations and inland mines, and industrial, commercial and residential loads. (Source: Hansard WA).
Darwin to Katherine Interconnected System (DKIS): Runs from Katherine to Darwin in the Northern Territory.
Mount Isa-Cloncurry supply network (Mt Isa Network): Runs from Cloncurry to Mount Isa in Queensland.
Electricity in ACT
The New South Wales transmission grid also services the Australian Capital Territory.
Electricity in Northern Territory
The following is from PowerWater Corporation:
There are three regulated networks in the Northern Territory:
• The northern network grid services about 150,000 people and stretches from Darwin to the south of Katherine including Batchelor, Adelaide River, Pine Creek, Mataranka and Larrimah.
• The Tennant Creek network grid services about 7,000 people in and around Tennant Creek.
• The southern electrical grid services the Alice Springs area which is home to about 28,000 people.
Unregulated networks: PowerWater also manages and maintains smaller electricity networks, servicing small towns and communities including Daly Waters, Ti Tree, Timber Creek, Newcastle Waters and Elliott. These areas are not connected to the regulated networks and not monitored by the Australian Energy Regulator.
Indigenous Essential Services networks: PowerWater subsidiary, Indigenous Essential Services, provides electricity services to Aboriginal communities. Within each of these communities is a small isolated and unregulated network.