Australia's Tomago aluminium smelter has been forced to cut its power to conserve electricity as a heat wave grips much of the country.

The state’s power grid has been pushed to the max and beyond, as temperatures have risen above the century mark over the past few days.

Tomago Aluminium’s CEO Matt Howell confirmed that the plant was able to restart one potline on Friday and had high hopes for restarting a second line. Nevertheless, it could take up to a week to return the plant to normal operating conditions he said.

“That’s our concern. Every minute counts,” said Howell. “There is no guarantee we can bring them back immediately.”

“We have seen what happened at Portland. If it doesn’t come back on it’s a catastrophe,” he concluded, referencing the five-hour power blackout at the Portland Aluminium smelter in Victoria in early December last year.

The smelter located 150 km (90 miles) north of Sydney and capable of producing more than a half-million tonnes of aluminium annually, is jointly owned by Anglo-Australian group Rio Tinto and Oslo-based Norsk Hydro.