CS Energy has released a photo showing the damage to Unit C4 at Callide Power Station after a fire that sparked a major electricity outage last week.

The company has confirmed it will replace the damaged equipment and does not expect that generating unit to come back online for 12 months.

Revised return-to-service dates have been provided to the Australian Energy Market Operator (AEMO) for three other generating units at the Biloela power plant following inspections this week.

A fire in the turbine hall at the plant about 1.45pm on May 25 set off a chain reaction that disrupted power to more than 470,000 customers in Queensland and New South Wales.

Chief executive officer Andrew Bills said it was too early to speculate on the cause. “…We need to undertake a thorough and comprehensive investigation working with all authorities and regulators to determine the cause of this incident,” he said.

Mr Bills said CS Energy’s first priority was safety as crews worked to bring the three other generating units back online.

“There are currently 60 to 70 people working on site. Following risk assessments we will look to increase this as the week progresses,” Mr Bills said.

“However, we will not rush this process – we are following our methodical safety procedures at every step.” 

On Tuesday afternoon CS Energy informed AEMO that Unit B1 would be returned to service on June 11 and B2 on June 21. CS Energy owns 100 per cent of Callide B.

CS Energy owns Callide C in a 50/50 joint venture (JV) with InterGen. Callide Power Trading, which trades the output of Callide C on behalf of the JV, has informed AEMO that Unit C3 will return to service on June 22. 

Through the JV arrangement with InterGen, CS Energy operates Callide C and provides maintenance services.