System Management 2017 Review of Proposed Tolerance Range and Facility Tolerance Range, and Request for Facility Tolerance Range

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

Date First Published on the AEMO Website: 2 June 2017

Closing Date: 5:00PM (AWST) on Friday 14 July 2017

Current Status

The submission period closed on 14 July 2017.


Clause 2.136G of the Wholesale Electricity Market Rules requires System Management to review the Tolerance Range and Facility Tolerance Ranges at least annually. The Tolerance Range or a Facility Tolerance Range is relevant for breach reporting purposes under clause 2.13.6B – System Management is not required to report an alleged breach of clause 3.21 or clause 7.10.1 if it is within the Tolerance Range or the Facility Tolerance Range. When conducting the annual review of the Tolerance Range and Facility Tolerance Ranges, System Management must consult with Rule Participants.

Clause 2.13.6E of the WEM Rules provides that System Management may determine a Facility Tolerance Range to apply to a specific generation Facility in place of a Tolerance Range. Clause 4.3.2 of the Monitoring and Reporting Power System Operation Procedure (PSOP) provides that a Market Participant may request a Facility Tolerance Range where the Tolerance Range is not suited for its particular Facility. When determining the Tolerance Range to apply for a specific generation Facility, System Management must consult with Market Participants.


Submissions should be made by email to:

Documents relating to this Consultation

Submissions received

The consultation period closed on 14 July 2017. One submission was received from Alinta Energy.

Tolerance Range to apply from 1 September 2017

The result of the 2017 Review of the Tolerance Range is set out above in the document '2017 Outcome of Tolerance and Individual Facility Tolerance Review'.

The Tolerance Range to apply to Scheduled Generators from 1 September 2017 will continue to be calculated with the following formula:

Tolerance Range = (+/-) MAX (6, MIN [5% NPC, 4*ROC])


NPC: Name plate capacity of the generator, expressed in MW (Market Rules Appendix 1(b)(ii))

ROC: Rate of Change or Ramp Rate of a Unit per minute (Market Rules Appendix 1(b)(v))

See Tolerance Range page for further information.

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