The consultation process is now closed. Relevant dates are outlined below.
| Process Stage | Date |
|---|---|
| Publication of Procedure Change Proposal | 29 August 2025 |
| Closing date for submissions on Procedure Change Proposal | 30 September 2025 |
| Publication of Procedure Change Report | 21 October 2025 |
| Commencement of amended Procedure | 30 October 2025 |
Procedure Change Proposal
Electricity System and Market Rules – Clause 2.10
Date of Notice: 29 August 2025
Matter under consultation
AEMO commenced the Procedure Change Process in relation to the WEM Procedure: Dispatch Algorithm Formulation (the Procedure).
Amendments were proposed primarily to implement new Constraint Equations to allow AEMO to co-optimise the size of the Largest Credible Load Contingency using the Dispatch Algorithm.
The amendments arose as a result of Schedule 4 of the Wholesale Electricity Market Amendment (Cost Allocation Reform) Rules 2024 (Amending Rules), which were published on 7 June 2024 and are available on Energy Policy WA’s website. The Amending Rules have now been scheduled to commence on 30 October 2025.
Improvements of an editorial nature were also made to various paragraphs to improve clarity, correct typographical errors, update in-text references, update definitions, and align with AEMO’s modern WEM Procedure templates.
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 considered the Procedure was consistent with the SEO, specifically:
- The Procedure is consistent with the SEO as it relates to Power System Security, Power System Reliability, and price outcomes, noting that the algorithms that inform the WEM dispatch engine are required to operate the electricity system efficiently and inform settlement outcomes.
- To the extent permitted under the ESM Rules, the Procedure is technology agnostic, allowing for low emissions technologies.
- The contents of the Procedure reflect the relevant clauses of the ESM Rules (including as amended) and AEMO’s requirements in relation to the development of the WEM Procedure: Dispatch Algorithm Formulation (e.g. heads of power).
Procedure Change Proposal documents
Invitation to make submissions
AEMO invited written submissions on this Procedure Change Proposal, including any alternative or additional proposals that may improve the Procedure or better meet the State Electricity Objective under section 3A of the Electricity Industry Act 2004.
AEMO requested that respondents identify any parts of their submission that they wished to remain confidential, explaining why. AEMO advised 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 encouraged 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.
Meetings
AEMO advised that, 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
AEMO advised that 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 30 September 2025.
AEMO advised that all submissions must be in electronic format (pdf or Microsoft Word). Submissions should use the Procedure Change Submission form.
AEMO noted that it is not obliged to consider submissions received after the closing date and time, and that any late submissions should explain the reason for delay and the detriment to you if AEMO does not consider your submission.
Publication
AEMO advised that all submissions will be published on AEMO’s website, and that confidential information will not be published, other than as specified above.