Network Support and Control Ancillary Services Description and Quantity Procedure Amendments

AEMO has concluded the consultation on the Network Support and Control Ancillary Services (NSCAS) Description and Quantity Procedure, consistent with the requirements in clause 5.20.2 and the Rules consultation process in rule 8.9 of the National Electricity Rules (NER).

The Consultation Process

The consultation process followed is outlined below. 

Background

NSCAS is procured by AEMO or transmission network service providers to maintain power system security and reliability, and to maintain or increase power transfer capability of the transmission network. Each year, AEMO assesses the NSCAS needs for the upcoming five-year period. 

AEMO is required to develop and publish an NSCAS description providing a detailed description of each type of NSCAS, and an NSCAS quantity procedure explaining the determination of the location and quantity of each type of NSCAS required, consistent with the requirements in clause 3.11.4 and the Rules consultation process in rule 8.9 of the National Electricity Rules (NER). 

AEMO regarded the previous procedures unfit to fulfill the changing needs of the National Electricity Market (NEM) and embarked on a consultation process to align the procedures such that they address the challenges introduced by the energy transition.

A key change to the NSCAS description was to change the types of NSCAS to reflect the NSCAS need. The new types are Reliability and Security Ancillary Services (RSAS) and Market Benefit Ancillary Services (MBAS). 

Key changes to the NSCAS quantity procedure include:

• the ability to restore the network to a secure operating state within 30 minutes in RSAS assessments
• the assessment of forward-looking constraints in MBAS studies, which can be proposed by participants along with viable, technology agnostic solutions
• improved collaboration with transmission network service providers at the start and finish of the quantity determination process, to discuss inputs and assumptions and later study results. 

The changes made through the consultation process, recorded in the Draft and Final reports below, resulted in a combined NSCAS description and quantity procedure, effective from 1 October 2020.

The Draft and Final reports summarise feedback received from stakeholders, and AEMO’s responses to the feedback. 

Second stage submissions

Submissions for the second stage of consultation opened on 4 August 2020 and closed on 18 August 2020. 

A second stage submission was received from:

Submissions for this stage of consultation opened on 1 June 2020 and closed on 7 July 2020.

First stage submissions were received from: