New approach to keep the lights on as old generators retire

Under changes proposed by the Australian Energy Market Commission (AEMC), transmission businesses will be required to maintain minimum levels of ‘inertia’ on the electricity system determined by the Australian Energy Market Operator.

Energy Networks Australia CEO John Bradley said the proposal recognises the value that transmission networks can provide as the mix of generation sources changes.

“As traditional synchronous generation is replaced by other sources, we will need to carefully manage frequency and system strength in Australia’s power system,” Bradley said.

“The loss of synchronous energy can affect the ability of generators to operate in a way that meets their technical performance standards, increasing the risk of cascading outages leading to major supply disruptions.

“Transmission businesses are ready to extend their current role supporting system security, by using their own resources and also buying services from the market.”

Bradley warned that system security issues facing the high-voltage transmission networks would increasingly need to be managed in distribution networks also.

“The current reform proposals focused on the National Energy Market are welcome but it’s important to recognise the potential for rapid changes in system security in some parts of the distribution grid too.

“Some distribution networks are losing system strength given significant levels of embedded generation connections and they are also impacted by changes in the generation on the transmission network.”

Bradley said it was also clear system security would require better notice and regulation of generation exit from the market.

“It’s increasingly likely that generator retirements will have implications for system strength and system stability, so the system can no longer cope as it previously has, with notice of just five months, or even one month,” he said.

“Energy networks will work constructively with the Australian Energy Market Commission to ensure efficient solutions which maintain system security.”

The Australian Energy Market Commission has proposed the changes in its System Security Markets Frameworks Review Directions Paper. It will provide a report to the COAG Energy Council.

Energy Networks Australia’s response to the Directions Paper is available here.