One of the two aluminium potlines at Alcoa’s Portland smelter has been shut down because of a power failure early on Thursday morning that also “browned out” hundreds of thousands of customers in South Australia.
Alcoa said it did not know when the potline would resume operation but none of the 750 jobs at the plant were affected at this stage.
Alcoa said both of its potlines lost power for about five-and-a-half hours after a fault occurred on the Victorian transmission network about 1.15am on Thursday.
It said the outage was followed by power instability and it had shut down one potline to ensure the safety of people inside the plant.
“It is too early to speculate on the full impact of the power outage, or on how long it may take to restore normal operations,” the company said.
A company spokesman said the cost of lost production was not yet known.
Member for South West Coast Roma Britnell said she understood the power outage had caused aluminium in production to solidify.
She also understood it was the first time in the plant’s 30-year history that power had failed.
“This interruption is completely unacceptable," Mrs Britnell said.
She said the problem was at the Heywood interconnector.
She said the issue had been caused by a transmission problem on the Victorian side of the border.
"Its cause must be fully investigated and the state government must help Alcoa get the plant back into full operation,” Mrs Britnell said.
"I'm worried about the impact this will have on jobs and the future viability of the plant.
“Any damage to the pots is the biggest concern.
“At a time when Alcoa is facing already thin profit margins, unexpected issues that are out of the company's control that cause damage to the plant are of major concern.
"The government and the energy market operator must do everything to ensure this doesn't happen again.”
Glenelg Shire mayor Anita Rank said the council understood Alcoa “was working around the clock to restore power”.
“The council is aware of the uncertainty that this event is causing both employees and the Portland community but we remain optimistic that this problem can be resolved promptly,” Cr Rank said.
“Portland Aluminium is Victoria’s single largest exporter.
“It is paramount that business can return to normal as soon as possible.”