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

Procedure Change Proposal

Wholesale Electricity Market Rules – Clause 2.10

Date of Notice: 2 April 2020

This notice informs all Rule Participants and interested parties (Consulted Persons) that AEMO has published a Procedure Change Proposal concerning the revisions to the Balancing Merit Order tie-break methodology. The revisions require amendments to the Market Procedure: Balancing Facility Requirements and the Market Procedure: Balancing Market Forecast. AEMO is conducting a consultation process in respect of this proposal. 

This consultation is being carried out in accordance with the Procedure Change Process detailed in clause 2.10 of the Wholesale Electricity Market (WEM) Rules. 

Matter under Consultation

The matters under consultation are proposed amendments to the Market Procedure: Balancing Facility Requirements and the Market Procedure: Balancing Market Forecast. In summary, the proposed amendments will assist AEMO manage Power System Security during periods of low demand by enabling Facilities’ to offer minimum generation quantities as a separate tranche at the Minimum STEM Price. In low demand scenarios, these minimum generation tranches will be curtailed after the curtailment of other energy tranches at the Minimum STEM Price, reducing risks associated with the de-synchronisation of these Facilities.

Further details are provided in the Procedure Change Proposal and the proposed Market Procedures published with this notice. 

The Consultation Process

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

Process Stage  Date
 Closing date for submissions in response to the Procedure Change Proposal 5 May 2020
 AEMO Procedure Change Proposals Rejected 30 April 2021

Documents related to this Procedure Change Proposal

Invitation to Make Submissions

AEMO invites written submissions on this Procedure Change Proposal, including any alternative or additional proposals you consider may improve the procedure/s or better meet the Wholesale Market Objectives 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. 


In your submission, you may request a meeting with AEMO to discuss the Procedure Change Proposal, stating why you consider a meeting is necessary or desirable. 

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

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 5 May 2020. 

All submissions must be forwarded in electronic format (both pdf and Word). Further, all emails relating to this Procedure Change Proposal must be entitled “AEPC_2020_02 Revisions to the Balancing Merit Order tie-break methodology - [Name of the submitting company or individual]”. Submissions should use the Procedure Change Submission form available at:

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.

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