Queensland’s CS Energy will undergo urgent assessments and repairs of generating units at its coal-fired Callide Power Station, following concurrent damage to three of the facility’s four generators.
Callide Power Station consists of two power plants, Callide B and C, each with two generating units (B1 and B2, C3 and C4).
Three of the power station’s four power plants are currently offline due to recent and past faults, resulting in ongoing refurbishment works.
Unit B1 came offline on 4 November due to a feed pump vibration and was returned to service at low load as CS Energy monitors its performance.
Unit B2 came offline on 1 November during scheduled testing of the unit, which is required every four years. 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. The return to service date for B2 has changed to 4 November to 9 November as additional cables need to be replaced before the unit can be safely returned to service.
CS Energy CEO, Andrew Bills, said safety is the highest priority as it manages urgent repairs to multiple units at Callide Power Station.
“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,” Mr Bills said.
“Our immediate focus is to work methodically and safely to restore these units to service as quickly as possible.
“The unavailability of our generating units is the result of a number of concurrent yet distinct issues.”
Ongoing repairs to Callide Power Station’s C3 have also been delayed, following structural failure of part of its cooling plant. As a result, unit C3’s return to service date has changed from 21 November 2022 to 3 January 2023.
CS Energy owns 100 per cent of Callide B and owns Callide C in a 50/50 joint venture (JV) with InterGen Australia. CS Energy operates Callide C on behalf of the JV owners.
Mr Bills said CS Energy had appointed Breezewater Pty Ltd structural engineer Graeme Spencer, who has worked on other cooling tower failure investigations, and engineering firm Hartz EPM on 4 November.
“These external engineers are leaders in their field and will help us understand what went wrong on the Unit C3 cooling tower and what needs to be done so that this does not happen again,” Mr Bills said.
“Safety is our highest priority at CS Energy and we will do everything we can to support these external, independent experts in carrying out their work.”
This investigation is separate to the Queensland Workplace Health and Safety investigation that is also currently underway.
The decision by the JV owners to change the return for Unit C3 is based on advice from external experts and on-site assessments, which have provided an improved understanding of the condition of the cooling plant, the scope of repairs required and the time required to procure replacement materials.
Recovery works on Unit C4 are continuing following an explosion in May 2021, which resulted in power outages for 470,000 homes and businesses, the unit is expected to return to service in April 2023.
These return to service dates are based on the information available at this point in time and may be subject to further change.