Callide Power Station unit ‘C4’ had been part of $60m overhaul just six months before explosion

The generator unit that exploded at Queensland’s second-largest power station this week causing mammoth outages had undergone a multimillion-dollar overhaul just six months ago.

The generator unit that exploded at Queensland’s second-largest power station had undergone a multimillion-dollar overhaul just six months ago, as operator CS Energy says nothing is being “ruled out or in” on what caused the major incident.

Nearly half a million homes and business across the state and down into NSW lost power on Tuesday after a generator unit at Callide Power Station near Biloela caught fire and exploded.

Supplied Editorial Callide Power Station today after a fire. Photo - Steve Vit

It can be revealed the unit at Callide C, officially known as “C4”, was part of a $60m overhaul at the power station last year, with works finishing in November — just six months before Tuesday’s incident.

According to a CS Energy spokeswoman, prior to the most recent works a “major overhaul” of C4 was undertaken in 2017.

“For the Callide C generating units major overhauls are carried out every five years, with minor overhauls carried out in between,” she said.

Explosion at Callide ‘won’t hit Qld bills’

“During these overhauls the plant is inspected and repaired to ensure statutory compliance requirements are met and the plant operates safely and reliably.”

CS Energy, a Queensland Government-owned entity, did not say if there was any indication the overhaul works could have contributed to Tuesday’s issue or if workers had warned of issues with C4 in the days prior to the “major incident”.

“Nothing is being ruled out or in regarding the cause of incident until a full investigation is complete,” the spokeswoman said.

“A full investigation with appropriate experts and authorities will be undertaken to understand what has occurred and led to what appears to be a major incident.”

It comes after it was revealed in state parliament that CS Energy had returned almost $500m in dividends to the state since 2017.

Energy Minister Mick de Brenni refuted suggestions from the Opposition that maintenance at Callide Power Station had perhaps not been prioritised above safe operation.

“We can guarantee all of the maintenance work that is required to be done on all of our power stations has been done,” he said. “There is a statutory obligation to do that.”

The severely damaged C4 is expected to be offline for the next 12 months