It could take at least a week before power is fully restored to all parts of South Australia following the unprecedented state-wide power blackout on Wednesday which was brought on by a 'one in 50-year' weather event, electricity industry sources have warned.
Much of the network around Adelaide is on line and operating normally, with power companies starting up from mid-evening Wednesday, after being forced to shut down earlier in the day.
"In the north of the state, the network companies are seeking to determine what protection equipment worked, and what didn't," one senior electricity industry figure said. "They can't just bring the network back up, since this could trigger the same failure.
"There was a similar situation in the North East of the US about a decade ago which took weeks to bring the network back up. This could be similar."
Much of the north east of the US was blacked out in 2003 and it took as long as a week for all power to be restored.
But why all of South Australia was blacked out for a time on Wednesday out is yet to be clarified.
"Lightening strikes knocked out transmission towers in the north of the state. That shouldn't have taken out the rest of the state," the industry figure said.
"Clearly something's broken; there should have been some protection."
A limited population base and the closure of large cheap power stations as its reliance on renewable energy sources such as wind has risen has raised a series of technical issues which the electricity transmission companies in South Australia are now grappling with.
"The generation profile in South Australia doesn't help," another industry source said, referring to the loss of some so-called 'baseload power capacity which operates 24 hours a day as the use of renewables has risen.
"But AEMO 'going black' by shutting down the industry due to a weather event is highly unusual."
It is believed AEMO sought to shutdown parts of the system which "triggered a full shutdown of the system to protect itself", was the way one industry figure put it.
The Australian Energy Markets Operator, which runs both the national gas and electricity energy markets, forced a shutdown of all power generators late on Wednesday.
It has blamed the severe storm for damaging transmission and distribution assets within the state, leading to the state-wide power outage.
It is expected to conduct a full inquiry to clarify the reasons for the disruption.
AEMO said the electrical transmission network from Adelaide to the Victorian border was fully early Wednesday restored, with over 1,000MW of load being supported from local generation in South Australia, and Victoria via the Heywood interconnector with the smaller Murraylink connector also back up and running.
"Given the severe weather conditions and potential damage to electricity infrastructure, it is anticipated restoration times across the state will vary, particularly in the northern region, which appears to have received the most damage," AEMO said in a statement.
Earlier Thursday, South Australian Premier Jay Weatherill blamed the lengthy outage on Wednesday's unprecedented weather and not the state's reliance on renewable energy.
"What happened yesterday was a storm event," he told reporters in Adelaide. "What it did was destroy infrastructure. What the system did was to protect itself so that we could get it up and running quickly and that's exactly what happened."
Market estimates are that a much as 72 per cent of South Australia's electricity was being supplied by wind when the system collapsed, with some electricity also sourced from Victoria at that time.
Along with large areas of the state's north, both the Eyre Peninsula and north of Port Pirie were without power, the local power company said. "Initial indications are that supply may not be restored until tomorrow."
