Cause of major Top End blackout revealed
A "ONE-OFF" blunder that occurred while trying to reinstall a piece of equipment likely caused the gas supply to be cut off at the Northern Territory's largest power station, triggering a widespread outage that impacted up to 40,000 homes and businesses in the Top End.
An official investigation will determine the cause of the Top End's worst blackout since the system blackout of 2014, but the private company that operates the gas pipeline has confirmed it was most likely them who triggered the event.
It's understood that just before 4pm on Wednesday, during routine maintenance at Channel Island Power Station, technicians from gas pipeline owner APA Group committed a fault while reinstalling a "piece of technical equipment".
A spokesman for APA Group, Australia's largest gas infrastructure company, said the "unprecedented" and "one-off" event caused the gas supply to be cut off.
"The issue can be narrowed down to a specific task, and we will take steps to ensure it is not repeated" he said.
The blunder meant Channel Island Power Station, which was producing 120MW of electricity during the Top End's most in-demand hour for power, was cut from its single-pipe source of gas.
Territory Generation, which runs the station, has since confirmed it did not move to diesel power generation as gas was determined as the "fastest and most efficient method of restoration".
Gas supply wasn't cut off to Weddell and Katherine power stations, the other main electricity generators in the Darwin-Katherine grid.
Initially operating at 80 per cent and 54 per cent of full capacity, a spokeswoman for Territory Generation said the two power stations were increased to full capacity to minimise impact to the system, which meant "some areas in the Darwin region" didn't lose electricity.
Power was gradually restored about two hours after the blackout.
The Darwin-Katherine grid is now operating as normal.
Essential Services Minister Eva Lawler said Power and Water Corporation would work with APA Group and prepare a report for the Utilities Commission, with the results set to be made public once the investigation is complete in about two weeks.
"The reality also is that we're dealing with machinery, and at times there are faults with machinery and that was the issue (on Wednesday)," she said.
Ms Lawler also jumped to the defence of renewable energy, saying it was not to blame, as debate heats up about the ability of the Darwin-Katherine grid to handle the load as more projects come online.
The Utilities Commission, in its recent annual report, urged the Territory government to immediately begin the process of finding solutions for new power generation or risk the Darwin-Katherine grid becoming significantly less reliable in six years as ageing generators on Channel Island are retired.
"There is a need for additional new generation, demand response, and or storage to be in place in the Darwin-Katherine power system by 2026-27, to maintain acceptable levels of reliability … the commission recommends the time to commence this process is now," the report noted.
"This process should include, among other things, consideration of learnings from the recent major changes in the Alice Springs and Tennant Creek power systems and rigorous due diligence, noting the costs are likely to be borne by electricity consumers and or Territory taxpayers, and any solution may be relied upon for at least the next couple of decades."
Channel Island Power Station, which is natural gas-fired, has a built capacity of 310MW, although it has current operational capacity is 279MW due to the ongoing decommissioning of an ageing turbine.
Originally published as Cause of major Top End blackout revealed