200,000 South Australian premises lost power in the early hours of 1 December 2016 when the state’s electricity grid disconnected from the National Electricity Market (NEM).
The fault that caused the disconnection of the Heywood interconnector occurred on the Victorian side at around 1:03am.
To protect the system, load shedding occurred to bring supply and demand into balance, which resulted in some loss of power in South Australia.
It is understood 220MW of load was shed during this under frequency load shedding, affecting around 200,000 South Australian customers.
At about 1:15am the Australian Energy Market Operator (AEMO) instructed the network businesses to incrementally restore load. At 2:15am AEMO instructed the network businesses that the remainder of load could be restored.
The SA power system operated stably in its islanded state (whilst disconnected from the rest of the NEM).
At 5:11am SA was reconnected with the rest of the NEM.
South Australian Mineral Resources and Energy Minister, Tom Koutsantonis, said, “South Australia’s grid operated effectively as an island and load began to be restored within half an hour, with SA reconnected to the national grid at around 5.11am.”
Mr Koutsantonis said the grid had protected itself from damage as it was supposed to, and decisions to scuttle a proposed interconnector to NSW were proving devastating.
“If we had a second interconnector to the eastern states load could have been drawn that jurisdiction to prevent power outages.
“The event also emphasises just how important it is to supply our local generators with affordable gas. The Liberal gas moratorium will make gas expensive in this state, and will make it harder, and more expensive, for generators to manage local demand in the future.
“We are working with other states through the COAG process to modernise the NEM and implement reforms that will make it more stable and fairer to all states.”