The Australian Energy Market Commission (AEMC) has developed a new rule to help prepare for the risk of power system events caused by abnormal conditions.
Under the AEMC’s final rule, the Australian Energy Market Operator (AEMO) can manage the risk of indistinct events in similar ways to its current management of events deemed ‘reasonably possible’.
This approach means that AEMO can take extra action to keep the system stable, such as procuring additional ancillary services, using constraints, and issuing directions.
The rules allow the 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, AEMC chair Anna Collyer said.
“This is an 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,” Collyer said.
This was the third and final rule change following the AEMC’s 2019 review of the black system event in South Australia – an indistinct event that threatened many different elements of the power system.
“In the energy sector, unpredictable and uncertain events are referred to as ‘indistinct events,’ and they can threaten multiple elements on the power system,” she said.
“It is not only difficult to predict the occurrence of such events, but also to predict their consequences on the power system.”
This discretion is stabilised with transparency and governance measures to safeguard the long-term interest of consumers, including a principle that AEMO must act, predictably and consistently, with the requirements to report on its actions.
As technology mix changes and storms and bushfires become more intense and frequent, indistinct events are a growing threat to maintaining secure electricity supplies to customers.
This new rule will help keep the system secure while minimising costs to consumers by using existing contingency event frameworks.