Queensland's larger businesses are being encouraged to scale back electricity use again as the fallout from a major power plant fire continues.
The Australian Energy Market Operator has forecast a second "lack of reserve" notice in 24 hours, following the fire at the Callide C power station in central Queensland on Tuesday afternoon.
The fire knocked out about 3100 megawatts, or 10 per cent, of the state's power capacity affecting about 477,000 customers.
Power was restored to most customers within two hours, but the impacts lingered on Wednesday.
AEMO is expecting loss of reserve 1 (LOR1) conditions for 5.30pm until 7pm on Wednesday.
"LOR1 market notice signals a reduction in pre-determined electricity reserve levels, encouraging generators to offer more supply, or large industrial or commercial consumers to reduce their demand," AEMO said in a statement.
Energy Minister Mick de Brenni said the fire was unprecedented and luckily none of the plant's 226 workers were injured.
Earlier on Thursday, he said he was confident Queenslanders wouldn't experience more outages linked to the accident.
"Actions taken last night will ensure electricity supply continues to exceed demand and the Australian Energy Market Operator has forecast sufficient supply going forward," Mr de Brenni told parliament.
"We will have continue to monitor the situation closely and update Queenslanders of any changes.
"This incident shows that unforeseen events can happen anywhere, and can have a cascading effect across the electricity system."
AEMO already issued a "lack of reserve" notice to the national market to import power to Queensland on Tuesday night.
Later, it was telling households to avoid using heavy appliances to "minimise stress on the system" until at least 9.30pm to mitigate the risk of further blackouts or brownouts.
However, Queensland was still buying electricity from NSW on Wednesday morning for dispatch prices as high as $14,000 per megawatt hour.
Mr de Brenni said prices would fall and the state would return to exporting electricity to southern states as renewable solar and wind generation came online during the day.
"In fact, it was the very diversity of our fleet, and especially our important pumped hydro, that kept the system in balance last night, and will ensure supply remains stable," he said.
The minister said the cause of the blaze and subsequent explosion of one of four turbines was under investigation.
Built in 2001, the Callide C plant is one of the newest electricity generators in the state.
Mr de Brenni said AEMO would assess how the accident occurred.
Opposition energy spokesman Pat Weir was thankful no one was injured in the fire.
He said there should be workplace health and safety probe and another open and independent probe into the cause of the fire.
"That event yesterday impacted upon hundreds of 1000s of people and businesses across the state, so we need some transparency around that investigation and some answers," Mr Weir said.
CS Energy executives met workers on Wednesday morning to discuss the situation, including the time frame for restoring the damaged turbine.
The Construction, Forestry, Maritime, Mining and Energy Union warned it could take months or even years to repair.
Australian Associated Press
