The AEMC’s Reliability Panel today set a new frequency operating standard (FOS) for the national electricity market that gives clearer guidance on how frequency should be controlled during extreme events.

Under the national electricity rules, the Australian Energy Market Operator (AEMO) must keep the power system stable and securely operating at a frequency close to 50 hertz. The specific frequency requirements that AEMO must meet under different power system conditions are set out in the frequency operating standard, which is determined by the Reliability Panel.

This review is investigating the appropriateness of the settings in the standard, in light of the ongoing energy market transformation as conventional synchronous generation leaves the market and non-synchronous generation such as wind and solar panels enters the market.  

The Panel is undertaking the review of the FOS in a staged manner.  This final determination and FOS represents the conclusion of stage one of the FOS review.

The new FOS made differs from the current FOS in a number of key ways, including:

  • the inclusion of a FOS for protected events
  • a revised requirement relating to multiple contingency events
  • a revised definition of ‘generation event’
  • the revision of the definitions in the FOS relating to island operation
  • a revised limit for accumulated time error in the mainland.

Stage two will consider the various components of the frequency operating standard, including the settings of the frequency bands and time requirements for maintenance and restoration of system frequency.

Stage two will commence at a later date when the Frequency control frameworks review is further progressed.   This will allow the Panel to take into account the AEMC’s considerations on whether:

  • mandatory governor response requirements should be introduced
  • existing frequency control arrangements remain fit for purpose
  • frequency control ancillary services (FCAS) markets are appropriately structured.

This review is an integrated part of the AEMC’s system security work program which is addressing the implications for power system security as the energy market transforms.

Media: Prudence Anderson 0404 821 935 or (02) 8296 7817


How is reliability and security managed in the national electricity market?

To keep the lights on, the power system needs to be:

  • secure – able to operate within defined technical limits, even if there is an incident such as the loss of a major transmission line or large generator
  • reliable - have enough capacity (generation and networks) to supply customers.

AEMO is responsible for maintaining power system security and reliability in accordance with standards and guidelines, including those set by the AEMC’s Reliability Panel.

Reliability Panel

The Reliability Panel's core functions relate to the safety, security and reliability of the national electricity system. The focus of the Panel's work is on determining standards and guidelines which are part of the framework for maintaining a secure and reliable power system. The Panel is chaired by AEMC Commissioner, Mr Neville Henderson. Its members are broadly representative of all stakeholders interested in the operation of the power system and the electricity market including consumer groups, generators, network service providers, retailers and the power system and market operator, AEMO.

What are Frequency Control Ancillary Services?

Frequency Control Ancillary Services (FCAS) are necessary for maintaining a secure power system. These services are procured from market participants to help keep power demand and supply continuously balanced. When the frequency is too low, it is increased by FCAS services, which either increase generation or decrease demand. When the frequency is too high, it is reduced by FCAS services which lower generation. Demand response can help re-balance supply and demand, as it can help to maintain the frequency of the power system.