Callide Power Station

Callide Unit C4 recovery

The safety and wellbeing of our people is our priority following the incident in Unit C4 at Callide Power Station.


Callide Power Station is comprised of two power plants, Callide B and C, each with two generating units (B1 and B2, C3 and C4).  CS Energy owns 100 per cent of Callide B and owns Callide C in a 50/50 joint venture (JV) with InterGen Australia.

On 25 May 2021 an incident occurred on Unit C4, which resulted in an explosion and substantial damage to the unit, forcing it offline. Shortly afterwards Callide’s other operating units tripped and went offline. Multiple power stations and high voltage transmission lines in Central Queensland also tripped, leading to a significant reduction of load and temporary separation between Queensland and the rest of the NEM.

Our first priority was to make sure workers and the Callide site were safe. The power station was fully evacuated and nobody was injured.

In the days and weeks that followed, our focus was on helping our Callide team deal with this traumatic incident and safely bring the power station’s other units back online, which collectively account for 1,120 megawatts of capacity.

Safety was front of mind as we worked to progressively return Callide’s other three generating units to service. After a tremendous effort involving more than 300 employees and contractors, both B station units were returned to service in June 2021 and Unit C3 went back online in July 2021.


CS Energy is committed to understanding the facts that led to the C4 event so we can learn from it and improve the safety of our people and plant.

Forensic engineer Dr Sean Brady has been engaged to lead an external, independent investigation and review. Dr Brady is based in Queensland and recently completed the Brady Review, an investigation into the causes of fatalities in the state’s mining and quarrying industry.

We have shared our initial learnings from the C4 event with other power stations operators and we will also share the findings from the independent investigation with them.

There are other stakeholders investigating what has occurred at Callide, including Workplace Health & Safety Queensland and the Australian Energy Market Operator.


CS Energy is working with our Callide C JV partner InterGen on returning Unit C4 to service. Work is underway on site and the unit's forecast return to service date is 7 April 2023. 

This return to service date is based on an improved understanding of the condition of the unit, the components that will need to be replaced and the resulting schedule and repair work required.

Returning Unit C4 to service is a unique and complex project. The return to service date is based on the information that the JV has available at this point in time and may be subject to further change.

It not unusual for generators to adjust their return to service dates for units that are undergoing major maintenance or repairs, depending on issues identified during the process.

latest updates



What was the cause of the explosion in Unit C4 at Callide Power Station?



How long will the investigation by Dr Sean Brady and others take?


Repairs to C4

How long will it take for C4 to become fully operational?

What will be the cost of the repairs?