Summary of impacts on Queensland power system on 25 May

Published: 26 May 2021 1:03pm

At approximately 1.45pm on Tuesday 25 May, a fire occurred in one of the turbine halls at CS Energy’s Callide power station. As a result, the three units that were generating at the time went offline.

The sudden trip and loss of 3,100 megawatts of generation immediately impacted other generators in Queensland and Powerlink’s transmission network in various parts of the state.

There were flow-on impacts to Ergon’s and Energex’s distribution network and Essential Energy in northern New South Wales.

This impact occurred within milliseconds of the incident at the power station.

At its peak, the outage impacted 470,000 customers – about 380,000 in South-East Queensland and another 90,000 in regional Queensland.

Powerlink, Energex and Ergon Network teams worked to progressively restore power supply as soon as it was safe to do so.

Power was progressively restored throughout the afternoon and the number of impacted customers continued to reduce.

All SEQ customers affected by the power station issue were resupplied within two hours. Most Ergon customers were restored within an hour, with the final regional customers back on by 4.30pm.

In response to the shortfall in available generation heading into the evening peak demand period, the Australian Energy Market Operator (AEMO) issued an actual Lack of Reserve 2 (LOR) notice at 4:45pm and a forecast LOR3 notice at 5:07pm identifying the potential for electricity demand to exceed supply in Queensland.

Queensland customers were also asked to voluntarily reduce their energy usage to assist in managing demand on the network.

This notice was later cancelled at 7:13pm due to sufficient power supply from generators returning to service around the state.

Investigations are now underway into the incident and our expert technical teams are looking in detail at the impacts to the Queensland power system.

We thank our customers for their patience during this unexpected event as AEMO, Powerlink, Ergon Network, Energex and CS Energy worked together to respond.

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