The partial return to service for a key Queensland coal-fired power plant has been delayed for the second time in as many months.
The Callide C plant near Biloela in central Queensland can generate up to 1540MW of electricity - about 30 per cent of the state's overnight demand.
A partial return to service for two of the plant's four units was pushed back by 17 days in December.
However, the plant's operators - state-owned electricity generator CS Energy - announced on Monday the C3 and C4 units would experience further delays.
All four units at the power plant were briefly inoperable in November 2022 following a series of accidents and equipment failures.
It was the second incident in over a year at the plant after an explosion in its turbine hall in May 2021 that resulted in 470,000 homes and businesses being left with no power.
Callide B's two units, which are run by CS Energy, were quickly back in operation following the incident.
But Callide C's two units C3 and C4, run through a joint venture with Intergen, has been delayed through 2023 and now into 2024.
The forecast return to partial service for C3 had been moved from January 7 to January 24.
It is now expected for a partial return to service on February 29.
The C4 unit has also had its partial return to service revised from May 19 to June 30.
Unit C3 is expected for a full return to service on March 31 and unit C4 on July 31.
There are no forecast changes to energy prices given the pushback, CS Energy CEO Darren Busine said.
"We don't expect that this short delay is going to cause a material change to the wholesale contract prices or the prices for consumers," he said on Monday.
Mr Busine said reconstructing the cooling towers and reinstating the unit at the plant was one of the most complex endeavours of its kind in Australia in the past 20 years.
About 400 employees and thousands of tonnes of international materials have been involved in the project.
An external investigation and review into the 2021 incident at the plant is in its final stages Mr Busine said, with forensic engineer Dr Sean Brady set to deliver his findings.
