Expected repair times have blown out as CS Energy works to restore multiple units at Callide power station near Biloela.

Chief executive officer Andrew Bills said the unavailability of generating units at the site was the result of a number of concurrent yet distinct issues.

“I acknowledge that our plant reliability at present is not good enough,” Mr Bills said.

“I have been at Callide Power Station this week talking with our people and unions to address their concerns.

“Our immediate focus is to work methodically and safely to restore these units to service as quickly as possible.”

Callide Power Station is comprised of two power plants, Callide B and C, each with two generating units (B1 and B2, C3 and C4).

Unit C3 – offline after a structural failure of part of its cooling plant earlier this week – is now expected to remain down until January.

CS Energy said the change, from November 21, was based on advice from external experts and on-site assessments, which had provided an improved understanding of the condition of the cooling plant, the scope of repairs required and the time required to procure replacement materials.

Unit B1 came offline early this morning due to a feed pump vibration and was returned to service mid-morning at low load. CS Energy is monitoring its performance.

Unit B2 came offline on November 1 during scheduled testing.

The government-owned generating company said cabling in the unit’s bottom ash conveying system was damaged and this was detected by the unit’s automated control system and the team on site, who acted quickly to make the unit safe.

“No one was injured when B2 came offline and an investigation into the incident will be completed,” Mr Bills said.

The return-to-service date for B2 has changed from November 4 to November 9 as additional cables need to be replaced before the unit can be safely returned to service.

Recovery works on Unit C4 are continuing following the incident in May 2021 and it is expected to return to service in April 2023.