The AEMC’s Reliability Panel today published a draft determination for stage one of the review the frequency operating standard (FOS) that applies in the national electricity market.

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 stage one draft FOS 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.

The stage one draft determination includes a preliminary discussion of issues identified for consideration during stage two of the review.

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 take into account considerations by the AEMC made through the Frequency control frameworks review  which is looking into 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.

The Panel invites submissions on the draft determination by 10 October 2017.

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.