A new rule will help prepare for the risk of power system events that are caused by abnormal conditions and have unpredictable consequences, such as widespread bushfires, major storms and cyberattacks.

AEMC Chair, Anna Collyer, said today's rule allows the Australian Energy Market Operator (AEMO) to better prepare for the risk of power system events  caused by abnormal conditions, where the event’s impact is hard to predict or identify. 

Ms Collyer said this authority will help to keep the system secure while minimising costs to consumers by making use of existing 'contingency event frameworks’. 

‘This is a particularly important new rule as the National Electricity Market (NEM) continues to transition to renewable energy sources and as extreme, abnormal conditions become more frequent with climate change,’ Ms Collyer said.

‘In the energy sector, unpredictable and uncertain events are referred to as ‘indistinct events’ and they can threaten multiple elements on the power system.

‘Examples include major storms, flooding, widespread and catastrophic fires, as well as non-climate related events such as cyberattacks.’

‘It is not only difficult to predict the occurrence of such events, but also to predict their consequences on the power system.’

Ms Collyer said that as the technology mix changes, and as storms and bushfires become more intense and frequent, indistinct events are a growing threat to maintaining a secure supply of electricity to customers.    

Under the AEMC’s final rule, AEMO can manage the risk of indistinct events in similar ways to its current advance management of events deemed ‘reasonably possible’. This approach means AEMO can take extra actions, such as procuring additional ancillary services, using constraints and issuing directions, to keep the system stable. 
This discretion is balanced with appropriate transparency and governance measures to safeguard the long-term interest of consumers, including a principle that AEMO must act, predictably and consistently, as well as requirements to report on its actions. 

Ms Collyer said this was the third and final rule change flowing from the AEMC’s 2019 review of the black system event in South Australia, an indistinct event that threatened many different elements on the power system.