Market Wholesale Electricity Market (WA)
StageFinal Report
ConvenorAEMO WEM
Accepting submissions?No

Consultation process

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

  • Publication of Procedure Change Proposal
    26 October 2023
  • Closing date for submissions on Procedure Change Proposal
    23 November 2023
  • Publication of Procedure Change Report
    12 December 2023
  • Proposed commencement of amended WEM Procedure version 6.0
    12 December 2023

Procedure Change Proposal

Wholesale Electricity Market Rules – Clause 2.10

Date of Notice: 26 October 2023

Matter under Consultation

AEMO has initiated this Procedure Change Proposal to amend the WEM Dispatch Algorithm Formulation Updates Procedure to address changes arising from:

  • Allowances on ESS Trapezia where because of mandatory droop response, AEMO has observed multiple facilities were becoming unavailable for ESS when they dipped below their Enablement Minimum. AEMO proposes to modify the ESS Pre-Processing calculations in paragraph 2.5 of the Dispatch Algorithm Formulation.
  • Removal of lower bound on Contingency variables: certain Network Contingencies can become negative when large loads occur (e.g. the Contingency is non-existent). To avoid violations, we are removing the lower bound on the Contingency variable. These changes will commence immediately after publication of the Procedure Change Proposal.
  • Additionally, AEMO identified several implementation bugs to be resolved and has made some minor clarifications to other areas of the formulation.

These changes were implemented on 12 October 2023 to address system issues and improve market outcomes.

Further details are provided in the Procedure Change Proposal published with this notice. The proposed amended WEM Procedures are also published with this notice.

Invitation to Make Submissions

AEMO invites submissions on this Procedure Change Proposal, including any alternative options or drafting you consider may improve the proposed WEM Procedure or better meet the Wholesale Market Objectives specified in section 122(2) of the Electricity Industry Act 2004 (and clause 1.2.1 of the WEM Rules).

Please identify any parts of your submission that you wish to remain confidential, and explain why. AEMO may still publish that information if it does not consider it to be confidential, but will consult with you before doing so.


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

If appropriate, meetings may be held jointly with other stakeholders. Subject to confidentiality restrictions, AEMO will generally make details of matters discussed at a meeting available to other stakeholders, and may publish those details.

Closing Date and Time

Submissions in response to this Procedure Change Proposal should be sent by email to, to reach AEMO by 5.00 pm (AWST) on 23 November 2023.

All submissions must be in electronic format (pdf or Microsoft Word). Submissions 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 to you if AEMO does not consider your submission.


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


No submissions received. 

Cookies help us improve your website experience.
By using our website, you agree to our use of cookies.