WEM Procedures
Current versions of the Wholesale Electricity Market (WEM) Procedures can be found on this page.
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Administrative WEM Procedures
Procedure Description Head of power clauses Commencement date Monitoring and Reporting Protocol This Procedure sets out how AEMO will carry out its obligations to monitor Rule Participants' behaviour for compliance under clause 2.13.7, as well as how AEMO will carry out its obligations to notify and support the Economic Regulation Authority in relation to compliance matters.
2.15.4
1 October 2023
Notices and Communications
This Procedure documents the method by which notices and communications under the WEM Rules are to be given to, or by, AEMO. It also sets out the conditions under which AEMO may declare an Emergency Operating State and provides a description of events that AEMO would consider significant for the purposes of clause 7.11.5(j).
1.6.2, 3.5.1A, 7.11.8(a)
1 October 2023
Data and IT Interface Requirements This Procedure documents the data and IT interface requirements, including security standards in respect of systems required for Market Participants to operate in the Wholesale Electricity Market. 2.36.5 29 July 2021 -
DER WEM Procedures
Procedure Description Head of power clauses Commencement date DER Register Information This Procedure specifies the obligations of AEMO and Network Operators in relation to the submission, storage and reporting of data for the DER Register. 3.24.8 2 October 2023 -
Market Operations WEM Procedures
Procedure Description Head of power clauses Commencement date Dispatch Settlement and Monitoring Data
This Procedure documents the procedures to be followed by Rule Participants in providing settlement and monitoring data to AEMO. It also specifies the methods that AEMO will use to determine estimates under clause 7.13.6 and the process for revising an estimate under clause 7.13.7.
7.13.3, 7.13.8
1 October 2023 Capacity Credit Allocation
This Procedure documents the Capacity Credit Allocation process. This includes the processes that Market Participants must follow when making or withdrawing a Capacity Credit Allocation Submission; the processes AEMO must follow in deciding whether to approve or reject a submission; and the processes AEMO must follow when an application is withdrawn, or where Capacity Credit Allocations are amended.
4.30.12
1 October 2023
Determination of Market Schedules
This Procedure documents the processes for determining Market Schedules.
7.8.9, 7.2.5(b)(vi)
1 April 2024
Identification of Affected Dispatch Intervals
This Procedure provides for the automatic identification of Affected Dispatch Intervals and outlines the circumstances where AEMO will identify a Dispatch Interval as an Affected Dispatch Interval.
7.11C.1
1 October 2023
Meter Data Submissions
This Procedure outlines the format and processes for submitting Meter Data by Meter Data Agents.
8.6.2
1 October 2023 Real Time Market Timetable
This Procedure documents the Real-Time Market Timetable.
7.1.2(a), 7.1.3
1 October 2023
Rule Participant Registration Processes
This Procedure documents the processes that AEMO and other Rule Participants must follow regarding Rule Participant registration and deregistration, as well as the criteria and processes for Rule Participant registration exemptions.
2.31.25(a), 2.28.21
1 October 2023
WEM Submissions
This Procedures specifies the Real-Time Market Acceptance Horizon, and documents processes relating to Real-Time Market Submissions and DSP Withdrawal Profiles Submissions. 7.4.21, 7.4.38, 7.4.57A, 7.4.62, 7.4A.12, 7.4A.20, 7.4A.24
1 October 2023
Settlements
This Procedure describes the settlement processes for publishing the Settlement Timeline; calculating the Metered Schedule and settlement amounts; performing the Adjustment Process; providing Settlement Statements and Invoices; payment of Invoices; settlement in Payment Default situations; settlement in Repaid Amount situations; the application of taxes and interest to settlement transactions; the collection and distribution of Financial Penalties; and the processes to be followed in relation to Notices of Disagreement and Notices of Dispute.
9.2.1, 9.2.2
1 October 2023
Individual Reserve Capacity Requirements
This Procedure describes the processes to be followed in calculating Indicative Individual Reserve Capacity Requirements and Individual Reserve Capacity Requirements.
4.28.12
1 October 2023
Consumption Deviation Applications
This Procedure covers the process and information required for a Market Participant to submit a Consumption Deviation Application, and the process AEMO must follow when assessing an application, including the criteria for assessment.
4.26.2CE, 4.28.9E
1 October 2023
Adjustment of Real-Time Inputs
This Procedure documents the information and processes AEMO will use in making a determination under clause 7.4.52, and the circumstances in which AEMO will adjust the inputs specified in clause 7.4.52.
7.4.53
1 October 2023
Prudential Requirements
This Procedure describes the determination of Credit Limits; assessment against the Acceptable Credit Criteria; processes for Credit Support arrangements; the calculation of Trading Margins; the list of factors to be considered in assessing the expected value of transactions; the issuing of Margin Calls; and other matters relating to clauses 2.37 to 2.42.
2.43.1
1 October 2023
Facility Registration, De-Registration and Transfer
This Procedure covers the process for a Rule Participant to register, de-register or transfer its Facilities, and the process to be applied by AEMO in processing applications.
2.29.4N, 2.29.5N, 2.29.9, 2.31.25.
19 March 2021
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Dispatch and Planning WEM Procedures
Procedure Description Head of
power
clausesCommencement date Dispatch Compliance
This Procedure documents the process for setting and reviewing a Tolerance Range or Facility Tolerance Range(s), and for AEMO to undertake various dispatch compliance monitoring functions.
2.13.19,
2.15.4(b),
7.10.21(a),
7.10.5
15 October 2024
Outages
This Procedure outlines the processes for the submission, evaluation and approval of Outage Plans; the circumstances where a Facility has failed to comply with a Dispatch Instruction for the purpose of clause 3.18.3(f); requirements for Rule Participants to notify or seek consent to commence or complete an Outage; Outage coordination, information requirements for processes relating to Outages; forecast assumptions and the methodology to be used for Outage Evaluations; the methodology for assessing whether there would be a shortfall of available accredited capacity to provide Essential System Services if an Outage Plan is approved; publication of Outage-related information; other matters relating to clauses 3.18 and 3.18A to 3.21; and reporting Forced Outages, including the determination of Forced Outage quantities pursuant to clause 4.26.1J.
3.18.4,
3.18C.12,
3.18E.10,
3.21.10
1 October 2023
Commissioning Tests
This Procedure provides a description of the activities that AEMO consider would constitute a Commissioning Test, and therefore require submission of a Commissioning Test Plan; additional information required to be contained in a Commissioning Test Plan; the timelines for submitting and revising different categories of Commissioning Test Plans to AEMO; the criteria AEMO will use to assess whether to approve or reject a Commissioning Test Plan including notification processes; the process for rescheduling a Commissioning Test within the Commissioning Test Period; the process and timeframes for adjustments to an approved Commissioning Test Plan; the summary details of a Commissioning Test Plan that AEMO will publish on the WEM Website; and the requirements for undertaking a Commissioning Test.
3.21A.27
1 April 2024
Constraint Formulation This Procedure documents (with respect to Constraint Equations that are not Preliminary RCM Constraint Equations or RCM Constraint Equations): the processes to be followed by AEMO and the matters it must consider in formulating and updating Constraint Equations; the processes to be followed and the methodology to be used by AEMO in determining Constraint Equation terms and coefficients for Network Constraints; the processes to be followed and the methodology to be used by AEMO in selecting one or more Constraint Equations to represent a Network Constraint; the processes and timeframes to be followed by AEMO for creating new Constraint Equations and Constraint Sets in response to a Non-Credible Contingency Event; and other processes relating to Constraints or Network congestion. 2.27A.10(b),
2.27A.10(cA), 2.27A.10(cB), 2.27A.10(cC), 2.27A.10(d)
1 October 2023 Direction of Registered Facilities in Scarcity Conditions
This Procedure sets out the process AEMO will follow to determine which Registered Facility to direct following a Low Reserve Condition Declaration:
• to make a Real-Time Market Submission to remedy a shortfall in energy or Essential System Services; or
• to synchronise to provide Essential System Services.
7.7.14 15 October 2024
Limit Advice Requirements
This Procedure documents the information and data to be provided by each Network Operator to AEMO under clause 2.27A.2; and the processes to be followed for the provision and updating of such information and any other information referred to in clause 2.27A.4. It excludes Limit Advice that is not RCM Limit Advice. 2.27A.10(a), 2.27A.10(d)
1 October 2023 Facility Dispatch Process
This Procedure describes the processes AEMO and Market Participants must follow in issuing, recording, receiving, confirming, and responding to Dispatch Instructions; the methodology and data requirements for converting sent-out Dispatch Instructions to as-generated Dispatch Instructions; the process and basis for issuing Dispatch Instructions where AEMO is unable to successfully run the Dispatch Algorithm for a Dispatch Interval; the process to be used by AEMO for selecting, applying, invoking and revoking Constraint Equations or Constraint Sets in response to Network Constraints for use in the Dispatch Algorithm; the circumstances in which AEMO will use Fully Co-optimised Network Constraint Equations and Alternative Network Constraint Equations in the Dispatch Algorithm; the processes to be followed and information to be provided by a Market Participant making an application under clause 7.10.12, or notifying AEMO under clause 7.10.16; the processes to be followed by AEMO in determining whether or not to grant permission under clause 7.10.14 or to revoke permission under clause 7.10.17; and the timeline for assessing an application under clause 7.10.12 and notifying a Market Participant of its decision.
7.5.4, 7.6.3, 7.6.18,
7.10.21(b) – 7.10.21(e)
1 April 2024 Essential System Service Quantities
This Procedure documents the methodologies and processes in determining the quantity and calculation method of Regulation to schedule and dispatch, for each Pre-Dispatch Interval and Dispatch Interval; the combination of Contingency Reserve and RoCoF Control Service required to maintain the frequency of the SWIS within the Credible Contingency Event Frequency Band; the expected quantities of any other Frequency Co-optimised Essential System Services required in each Dispatch Interval or Pre-Dispatch Interval to meet the Essential System Service Standards; the Dispatch Algorithm used by AEMO for the purpose of the Central Dispatch Process and setting Market Clearing Prices and the mathematical formulation of the Dispatch Algorithm as it relates to clause 7.2.5(a)(i)-(ii); and the methodology AEMO uses to determine Contingency Raise Offsets, Contingency Lower Offsets, Facility Performance Factors, the Minimum RoCoF Control Requirement, the Additional RoCoF Control Requirement, and the RoCoF Upper Limit.
3.11.7,
7.2.5(a)(i)-(ii), 7.2.5(b)(i)–(v) and (vii)
1 October 2023 Verification of Dispatch Inflexibility
This Procedure documents the forms of independent verification to be used to support a reason given under clause 7.6.31(b).
7.6.33
1 October 2023 Congestion Information Resource
This Procedure specifies the information to be published in, and the processes for maintaining, the Congestion Information Resource; the processes to be followed by AEMO in preparing the annual congestion report; and the information that AEMO requires of Rule Participants to assist in carrying out its obligations under clause 2.27B.
2.27B.8
1 October 2023
Dispatch Algorithm Formulation
This Procedure documents the Dispatch Algorithm used by AEMO for the purpose of the Central Dispatch Process and setting Market Clearing Prices and the mathematical formulation of the Dispatch Algorithm as it relates to 7.2.5(a)(iii)-(vii); the processes for AEMO and Market Participants in accounting for Inflexible Facilities; the processes to be followed in the relaxation of Constraints; the processes when issuing Dispatch Instructions that override the output of the Dispatch Algorithm; situations that are deemed significant for the purposes of 7.6.24(b); and the methodology for determining Market Clearing Prices under clauses 7.11C.7, 7.11C.8 and 7.11C.10.
7.2.5(a)(iii)-(vii), 7.2.5(c), 7.2.8, 7.6.27, 7.11C.11
1 April 2024 RCM Constraint Formulation
This Procedure documents the processes for AEMO to determine and update RCM Constraint Equations. The Procedure also describes the terminology, conventions, and process by which mathematical expressions of physical limits of the Network are converted into RCM Constraint Equations, which are required as an input to the Network Access Quantity Model.
2.27A.10(b), 2.27A.10(c), 2.27A.10(cA), 2.27A.10(cB), 2.27A.10(d)
13 June 2024
Power System Security
This Procedure documents the process to be followed by Rule Participants in providing Equipment Limit information to AEMO. It also includes the process to be followed by AEMO in establishing and modifying the Technical Envelope; ensuring the SWIS operates according to the Technical Envelope applicable to each SWIS Operating State; determining Inertia Requirements; and assessing and maintaining Power System Stability.
3.2.7
1 October 2023
Communications and Control Systems This Procedure describes the communication and control system requirements necessary to support the dispatch process and enable AEMO to remotely monitor the performance of the SWIS. It also documents the high-resolution time synchronised data requirements necessary to enable AEMO to investigate incidents on the SIWS; accredit and monitor a Facility’s Frequency Co-optimised Essential System Services capability; and to monitor compliance with Registered Generator Performance Standards. Finally, the Procedure specifies the minimum standards and specifications of communication and measuring information; the manner in which communications data and measuring information is to be provided to AEMO; and other relevant matters required for AEMO to perform its obligations in respect of section 2.36A. 2.35.4,
2.36A.51 October 2021 Credible Contingency Events This Procedure sets out the process for determining and classifying Credible Contingency Events; Contingency Reclassification Conditions; factors in reclassifying a Contingency Event; the process for reclassifying a Non-credible Contingency Event as a Credible Contingency Event; the procedures for notifying affected Rule Participants under clause 3.8A.7; and a description of the Contingency Events that are generally considered as Credible Contingency Events. 3.8A.4 29 July 2021 The purpose of this Procedure is to document the requirements for GPS Compliance, including monitoring and testing arrangements.
1.41.6,
3A.6.2,
3A.9.1
29 October 2024
Frequency Co-optimised Essential System Services Accreditation
This Procedure documents the processes for accreditation for a Frequency Co-optimised Essential System Service (FCESS); the FCESS performance requirements and accreditation parameters; RoCoF Ride-Through Capability accreditation; setting the RoCoF Ride-Through Cost Recovery Limit; and transitional processes for the accreditation of FCESS. 2.34A.13. 1 April 2024 IMS Interface This Procedure sets out the arrangements by which Network Operators and AEMO must provide each other with information under the WEM Rules. 2.36.7 1 July 2019 Network Modelling Data This Procedure specifies the information that a Network Operator must provide to AEMO for each of its Networks; the processes to be followed by Network Operators and AEMO; and the technical and communication criteria that must be met. 2.28.20 13 October 2017 System Restart This Procedure documents the methodology and processes AEMO uses to determine the System Restart Standard and System Restart Plan; the factors AEMO may consider when determining whether changes from the standard form contract are reasonably required; the processes for procuring System Restart Services; and the processes to be followed in conducting a review under clauses 3.7.10 and 3.7.11. 3.7.40 1 June 2022 -
Reserve Capacity WEM Procedures
Procedure Description Head of power clauses Commencement date Certification of Reserve Capacity
This Procedure documents the procedures that Market Participants must follow when applying for Certified Reserve Capacity; the methodology AEMO uses for determining Planned Outage rates and Forced Outage rates; the procedures AEMO must follow when processing applications for Certified Reserve Capacity; the processes for the application of early certification of Reserve Capacity; the matters AEMO will have regard to in forming its opinion under clause 4.28C.1(d); and the information required to be provided by a Market Participant under clause 4.10A.6 in support of its nomination that a Facility be classified as a Network Augmentation Funding Facility.
4.9.10,
4.28C.15,
4.10A.11
15 April 2024
Indicative Facility Class This Procedure documents the processes followed by AEMO in determining and assigning an indicative Facility Class and an indicative Facility Technology Type to a new Facility or Facility upgrade under clause 4.8A; the information required to be provided in support of an application under clause 4.8A.3; and the processes to be followed by an applicant when making an application under clause 4.8A.3. 4.8A.7 21 March 2024 Reserve Capacity Security
This Procedure outlines the process for determining Reserve Capacity Security and DSP Reserve Capacity Security, the applicable arrangements for Reserve Capacity Security and DSP Reserve Capacity Security, and the assessment of persons against Acceptable Credit Criteria. 4.13.8,
4.13A.23
2 October 2023
Reserve Capacity Testing This Procedure describes the processes to be followed in performing Reserve Capacity Tests and Verification Tests. 4.25.14
1 October 2024 Reserve Capacity Performance Monitoring
This Procedure documents the processes in performing Reserve Capacity monitoring, including requirements for supporting documentation.
4.27.12
1 October 2023 Supplementary Capacity
This Procedure documents the process AEMO follows in acquiring Eligible Services; entering into Supplementary Capacity Contracts; determining how a payment in relation to a Supplementary Capacity Contract is to be made to a party that is not a Market Participant; determining that a provider of an Eligible Service has access to the network; and requirements (including timelines) for information and assistance required from Western Power.
4.24.18
10 September 2024
Mid Peak Electric Storage Resource Obligation Intervals
This Procedure documents the processes for determining changes to the Trading Intervals that will be classified as Mid Peak Electric Storage Resource Obligation Intervals; the processes for publishing the Trading Intervals classified as Mid Peak Electric Storage Resource Obligation Intervals; and the circumstances that allow AEMO to determine that the Trading Intervals classified as Mid Peak Electric Storage Resource Obligation Interval for a specific Trading Day is not the Mid Peak Electric Storage Resource Obligation Interval published by AEMO.
4.11.3A(c)
1 July 2024
Network Access Quantity Model
This Procedure documents the processes, methodologies, inputs, parameters and assumptions to be applied in the Network Access Quantity Model for modelling the prioritisation and determination of Network Access Quantities to Facilities under Appendix 3; the processes for determining the facility dispatch scenarios under clause 4.15.5; the processes for determining Network Access Quantities for a Reserve Capacity Cycle; the processes for publishing the information under clause 4.15.16; information that must be provided to AEMO for the purposes of operating the Network Access Quantity Model and determining Network Access Quantities to Facilities under Appendix 3; and the process for the application of section 4.28C and the matters AEMO will have regard to in forming its opinion under clause 4.28C.1(d).
4.15.17,
4.28C.15
30 September 2024
Declaration of Bilateral Trades This Procedure outlines the process Market Participants must follow to submit a Bilateral Trade Declaration and the process AEMO must follow to assess and approve or reject a Bilateral Trade Declaration.
4.14.11 1 September 2022 RCM Limit Advice Requirements This Procedure relates to information to be provided by a Network Operator to AEMO under clause 2.27A.2 (to the extent that the information relates to RCM Limit Advice) and the processes AEMO must follow in providing information to Network Operators under clause 4.4B.2.
It includes the information and data to be provided by each Network Operator to AEMO and the processes to be followed (including timeframes) for the provision and updating of information.2.27A.6(a)(iii), 2.27A.10(a),
2.27A.10(bA)
2.27A.10(d)15 March 2022 Facility Sub-Metering This Procedure outlines the characteristics and requirements of Facility Sub-Metering, including accuracy requirements; the procedures for auditing of Facility Sub-Metering; the communication requirements and protocols between a Market Participant and AEMO; and the processes for providing Facility Sub-Metering information. 2.29.15 1 December 2021 Undertaking the Long Term PASA This Procedure describes the procedure AEMO follows in conducting the Long Term PASA. 4.5.14 13 June 2024
Outstanding WEM Procedures from pre 1 October 2023
| WEM Procedure | Head of Power clause(s) |
|---|---|
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Reliability Standard Implementation |
3.3.2 |
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ST PASA |
3.16.10 |
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Low Reserve Conditions |
3.17.11 |
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MT PASA |
3.16.10 |
|
Real-Time Market Suspension |
7.11D.4 |
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Forecast Unscheduled Operational Demand |
7.3.4 |
|
SESSM Procurement |
3.11.4; 3.15A.46 |
|
Network Modelling Data |
2.28.20 |
|
IMS Interface for Network Operators |
2.36.7 |
|
Facility registration, de-registration and transfer |
2.29.4N; 2.29.5N; 2.29.9; 2.31.25(b); 2.31.25(c); 2.31.25(d) |
At the 14 September 2023 WEM Reform Implementation Group (WRIG) meeting, AEMO advised that the above WEM Procedures will not be published prior to the New WEM Commencement Day. The presentation explains the delay and expected timeframes for publishing, along with advice for Market Participants in the interim period. Any questions regarding the status of these WEM Procedures or how they may impact you should be emailed to wa.marketdevelopment@aemo.com.au