Human error on internal IT network blamed for latest Callide coal outage

The state owned utility CS Energy has blamed human error on an internal IT network for the sudden outage that caused the trip of the two units at the Callide C coal generator last Thursday.

The company had originally blamed a control system error for the outage and the sudden loss of 800 megawatt capacity heading into the evening peak on a hot summer’s day, but on Monday changed this to cite “human error” as the cause.

“Our preliminary investigations have identified that an internal IT network overload caused by human error was the cause of the unplanned outage of the units on 15 January,” CS Energy said in a statement on Monday afternoon.

“The control system operated as designed on the day and automatically tripped the units.”

The troubled Callide C operations, hit by an explosion at the C4 unit in 2021, followed by structural failures in its smoke stakes and then a boiler issue last year, also underwent an $80 million maintenance program late last year.

The two units were scheduled to return to service after the latest outage on Sunday, but C3 only began to ramp up again on Monday afternoon and the C4 unit is now expected to return to service on Tuesday.

CS Energy says it has put in place “immediate corrective actions” to prevent a repeat of the error on the internal IT network, and will implement further improvements once an investigation is completed.

The latest outage on what is emerging as one of the country’s most notoriously unreliable coal generators has again put focus on the state LNP government’s decision to jettison the state’s renewable energy targets, cancel some projects and threaten to do so to others, and seek to extend coal power until the 2050s.

See also: Queensland’s fossil-first energy plan under attack with new outages and evacuation at troubled coal plant