Queenslanders face ongoing electricity bill uncertainty after a major coal power generator delayed its return to full capacity until next year.
CS Energy says its 1540MW Callide power station near Biloela, which meets roughly 30 per cent of the state's electricity demand, will not run at full capacity until January 2024.
The plant hasn't been running at full capacity since May 2021 when one generation unit was destroyed in an explosion, while a second unit was also knocked out of service by a cooling tower failure in October last year.
The state-owned company says the cooling towers on both units will need to be rebuilt, which will delay the return of the generators to limited service until October and full capacity until January next year.
"The change in return to service dates reflects CS Energy's support for rebuilding both cooling towers," the company said in a statement on Wednesday afternoon.
CS said it would need to scope the projects and tender contractors for both towers, which will be done with its JV partner Genuity, formerly known as InterGen.
The company insist the delay is "not unusual" and depends on issues identified during major repair and maintenance.
The announcement reportedly triggered a leap in wholesale electricity prices bringing fresh uncertainty about whether those prices would be passed onto household consumers and businesses.
Queensland Energy Minister Mick de Brenni has previously stressed the state has enough generation capacity to meet demand with Callide running at reduced capacity.