AEPC_2026_07 Dispatch Algorithm Formulation

The consultation process

The consultation process is outlined below. Dates are indicative only and subject to change.

Procedure change proposal

Electricity System and Market Rules – Clause 2.10

Date of Notice (version 1): 13 July 2026 [Documents now superseded]
Date of Notice (version 2): 15 October 2026

Matter under consultation

AEMO has commenced the Procedure Change Process to propose amendments to the WEM Procedure: Dispatch Algorithm Formulation to reflect changes made to the Dispatch Algorithm in accordance with clause 7.2.3 and to undertake process improvements.

Amendments have been made to reflect urgent changes undertaken under clause 7.2.3 to improve the operation of the Dispatch Algorithm, regarding the treatment of Facilities to respect relevant Frequency Co-optimised Essential System Services (FCESS) trapezia and address potential violations of safe limit and defined contingency constraints. Further proposed amendments have been informed by AEMO’s operational experience and observed need for uplift to address emergent or potential issues in dispatch.

AEMO has proposed the following amendments to the Procedure:

• updating Constraint Violation Penalties following urgent changes implemented by AEMO in accordance with clause 7.2.3 on 30 October 2025, 5 November 2025, and 4 December 2025.
• reducing RoCoF Control Service Requirement fluctuation when both costs of RoCoF and Contingency Raise services are zero.
• improving estimates of a Facility’s potential Droop Response in the Essential System Service pre-processing calculation.
• aligning the Procedure with current system functionality, with respect to relaxation of Enablement Limits for RoCoF Control Service in Pre-Dispatch Intervals in the Pre-Dispatch Schedule and Week-Ahead Schedule.
• various updates to respond to an initial tranche of recommendations arising from the Coordinator of Energy’s WEM Procedure Content Review that are able to be implemented quickly.

Improvements of an editorial nature are also made to various paragraphs and explanatory Notes.

On 6 February 2025 the State Electricity Objective (SEO) replaced the Wholesale Market Objectives under section 3A of the Electricity Industry Act 2004.  Following an assessment, AEMO considers the Procedure is consistent with the SEO.

As per the notice below, AEMO has extended the consultation period for AEPC_2026_07 under section 2.10 of the ESM Rules and has published updated versions of the Procedure Change Proposal (version 2) and draft WEM Procedure (v5.2). These documents published on 15 October 2026 supersede the initial documentation published on 13 July 2026.

Invitation to make submissions

AEMO invites written submissions on this Procedure Change Proposal, including any alternative or additional proposals may improve the Procedure or better meet the State Electricity Objective under section 3A of the Electricity Industry Act 2004.

AEMO requests that respondents identify any parts of their submission that they wish to remain confidential, explaining why. AEMO advises that it may still publish that information if it does not consider it to be confidential, but will consult with the respondent before doing so.

When making a claim for confidentiality, AEMO encourages respondents to familiarise themselves with Chapter 10 of the Electricity System and Market Rules (ESM Rules), which imposes obligations in respect to the release of documents. 

Notice of Extension

Electricity System and Market Rules – Clause 2.10
Date of Notice: 15 October 2026

AEMO has extended the consultation period for Procedure Change Proposal until 12 November 2026 in accordance with clause 2.10.17 of the ESM Rules.

This Procedure Change Proposal initially opened for consultation on 13 July 2026 and the consultation process was scheduled to close on 10 August 2026. AEMO has extended consultation on the following bases:

• issues of sufficient complexity had been identified relating to the original Procedure Change Proposal, including matters raised during the AEMO Procedure Change Working Group (APCWG) meeting on 20 July 2026 relating to the new proposed content in paragraph 2.4.43 of the draft amended Procedure (version 5.1).
• additional proposed amendments have been identified by AEMO operational teams to simplify the implementation of provisions to better estimate a Facility’s potential Droop Response in the Essential System Service pre-processing calculation.
• AEMO has received feedback arising from the Coordinator of Energy’s WEM Procedure Content Review, with an initial tranche of minor matters incorporated into additional proposed changes under AEPC_2026_07. [Further proposed amendments are expected in the first half of 2027 to respond to Review outcomes of a more detailed and substantive nature.]

AEMO has now published a revised draft amended Procedure (version 5.2) and Procedure Change Proposal (version 2) with sufficient time for stakeholder consideration and feedback ahead of the commencement. Consultation timeframes under the extension are provided in the revised Consultation Process table above.

Meetings

Before the closing date for submissions, any person may request a meeting with AEMO to discuss the issues and proposed changes raised in the Procedure Change Proposal, stating why they consider a meeting is necessary or desirable.

If appropriate, meetings may be held jointly with other stakeholders.

Subject to confidentiality restrictions, AEMO generally makes details of matters discussed at meetings available to other stakeholders as part of the final published Procedure Change Report (or earlier, where applicable).

Closing date and time

Submissions in response to this Procedure Change Proposal should be sent by email to [email protected], to reach AEMO by 5.00 pm (AWST) on 13 November 2026.

All submissions must be in electronic format (pdf or Microsoft Word) and should use the Procedure Change Submission form.

AEMO is not obliged to consider submissions received after the closing date and time. Any late submissions should explain the reason for delay and the detriment expected if AEMO does not consider the late submission.

Publication

All submissions will be published on AEMO’s website. Confidential information will not be published, other than as specified above.