As temperatures soared across Australia this summer, many of the country’s coal-fired power plants seemingly couldn’t keep up.
According to Reliability Watch, a collaboration between Queensland, New South Wales and Victoria’s peak environmental bodies, there were 108 outages across the National Electricity Market (NEM) between October 2025 and February 2026 – 90 of which were unplanned.
This equated to NSW and Victoria having an average of 25 per cent of its coal-fired capacity offline at any point across the five-month period – above the 11 per cent unavailability forecast determined by plants in October 2025.
Facilities such as Gladstone and Callide C in Queensland, Loy Yang A in Victoria and Eraring in NSW each experienced more than 10 outages, with Gladstone having the lowest availability over the period at 59 per cent.
Yallourn 2 (offline for 138 days) and Tarong 1 (offline for 114 days) experienced the longest scheduled outages – both being offline for at least 60 days more than predicted. This contributed to many of the 18 scheduled outages overrunning forecast downtime, with units on average offline for 14 days more than expected.
The Millmerran, Mt Piper and Loy Yang B achieved higher-than-forecast availability across the five months at a 90 per cent average.
In releasing its Transition Plan for System Security report in December, the Australian Energy Market Operator (AEMO) detailed how energy stability in Australia can be maintained throughout the energy transition.
Interestingly, outage management was a primary theme of the report, with AEMO suggesting power system operability is complicated “in real time” by the need for planned outages and the occurrence of unplanned outages.
AEMO indicated that major outages require “extensive planning, coordination and mobilisation of specialist resources” and can pose “significant security risks” depending on their location and timing.
“Although AEMO has powers to defer transmission outages and request rescheduling of generator outages where these threaten system security, these actions can have costs and significant flow-on effects on subsequent outage schedules, unplanned outage risks, or the installation and connection of new assets,” AEMO said.
AEMO indicated that improved visibility of planned generator and transmission outages across industry would “ensure outage needs can be met while maintaining power system security”.
The energy watchdog said it was seeking engagement with individual generators on planned outages at near-term transition points. This includes the closure of the Eraring power station in 2029.
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