Issue date
AER reference
NR 25/23

CS Energy Limited (CS Energy) has paid a $67,800 infringement notice issued by the Australian Energy Regulator for an alleged breach of the National Electricity Law (the Electricity Law) for operating a generating system without the required regulatory approval.

The alleged breach was discovered as part of the AER’s ongoing investigation into the power system event involving the trip of multiple generators and high voltage transmission lines in Queensland following an initial plant issue at the Callide C Power Station on 25 May 2021.

This alleged breach is distinct from the AER’s ongoing investigation into the events that led to the 25 May 2021 power system event.

Any entity that owns, controls or operates an electricity generator must apply to the Australian Energy Market Operator (AEMO) to be a Registered Participant for the activity or for an exemption from registration.

It’s alleged that CS Energy breached section 11(1) of the Electricity Law by operating the Callide C Power Station without being a Registered Participant or having an exemption from registration. CS Energy has been operating Callide C Power Station for a number of years, including on 24 May 2021, but only submitted an application for exemption following the AER’s investigation.

CS Energy subsequently obtained this exemption in September 2023.

AER Board Member Mr Justin Oliver said it’s important for market participants to seek registration or exemption so AEMO can maintain the National Electricity Market.

“Failure to obtain the appropriate registration and exemptions can impede AEMO’s ability to track changes in the control or operation of a generating system.

“This reduced visibility could cause operational issues for AEMO including its ability to contact the appropriate staff that are responsible for the operation of generating systems to raise important matters including compliance issues and activities,” said Mr Oliver.

The AER is continuing its investigations into the 25 May 2021 power system event.

Note to Editors

Power generators

There can be more than one owner, operator and controller for any generator in the National Electricity Market.


The payment of the infringement notice does not constitute an admission of liability by CS Energy Limited.

The AER can issue infringement notices when it believes on reasonable grounds that a person or business has contravened certain provisions of the National Electricity Law.