Primary frequency response


On 26 March 2020, the Australian Energy Market Commission (AEMC) made a final rule to require all scheduled and semi-scheduled generators in the NEM to support the secure operation of the power system by responding automatically to changes in power system frequency.

Stable frequency is an important part of maintaining a secure power system. Frequency varies whenever electricity supply does not exactly match consumer demand and uncontrolled changes in frequency can cause blackouts.

This rule change is part of the ongoing Frequency control work plan which has been developed by the Energy Security Board (ESB) and market bodies which sets out a series of actions that Australian Energy Market Operator (AEMO), the AEMC and the Australian Energy Regulator (AER) are undertaking to review and reform the frequency control frameworks in the NEM.

Key aspects of the final rule include:

  • all scheduled and semi-scheduled generators, who have received a dispatch instruction to generate to a volume greater than 0 MW, must operate their plant in accordance with the performance parameters set out in the Primary frequency response requirements (PFRR) as applicable to that plant
  • AEMO must consult on and publish the PFRR, which will specify the required performance criteria for generator frequency response, which may vary by plant type.
  • Generators may request and AEMO may approve variations or exemptions to the PFRR for individual generating plant.

Primary frequency response requirements document consultation

Consultation on the Interim Primary Frequency Response Requirements Document is now complete. This consultation was conducted under clauses 11.112.2(b) of the National Electricity Rules (NER).

To view submissions, forum notes and AEMO's determination to the consultation please visit:

Primary frequency response requirements documents

Implementation of the Mandatory Primary Frequency Response Rule – status update

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