Wholesale power prices are expected to rise because of a delay in bringing two central Queensland coal-fired generators back online, the state's deputy premier said.
A fire at Callide Power Station, near Biloela, in May 2021 triggered one of the state's worst power outages in decades.
The two units were expected to progressively come back online from September.
But the owner, CS Energy, on Tuesday said this timeline has been set back.
One of the units, C3, is now predicted to be back at half its capacity from January next year.
C4 is expected to return from May next year.
Deputy Premier Steven Miles said the government was "frustrated" by the delay, but said an increase in wholesale prices would not necessarily flow on to retail customers.
"There is not a direct link between those wholesale prices and retail prices that households will pay," he said.
"But of course those are users who do pay wholesale power prices, they will inevitably pay these higher costs and some of that will flow through to consumers as well."
Callide C units 3 and 4 each produce a maximum 466 megawatts.
Australia Institute research director Rod Campbell said the delay, and any change it made to wholesale prices, was unlikely to be seen by consumers.
"Callide represents a little bit less than 10 per cent of the coal-fired generation capacity in Queensland, so 90 per cent of that capacity should be unaffected [by the delay]," he said.
"By the time that minor change to generation cost gets passed through transmission and distribution costs and retail costs, I really don't think this will be something that most households will discern at all."
Union expects more blowouts to cost, timeline
In a statement, CS Energy acting CEO Andrew Varvari said it was a "highly complex" project.
"CS Energy is acutely aware of the importance of reliable generation from coal-fired generators such as the Callide C Power Station, particularly at a time of high gas and coal prices and with reducing coal generation across the energy sector," Mr Varvari said.
"We have been working with the administrators of IG Power to progress the safe and timely return to service of the Callide C units and are doing everything we can to have the units safely back up and running as soon as possible."
The Queensland Mining and Energy Union said it expected further time and cost blowouts for repairs.
"Anything with a rebuild of such a scale will always have overruns," vice-president Shane Brunker said.
"I wouldn't be that game in setting a cast iron date until it was actually only two or three weeks away from running, but that's their call."
Mr Miles said an external independent investigation into the fire and explosion at the power station was not yet completed.
"It's critical that we understand exactly what happened there, not only because of the impact it's had on our electricity supply and on power prices, but also because of the safety issues associated," he said.
"It was quite frankly a miracle that no-one lost their lives in that incident and so we absolutely need to make sure it never happens again."
