In accordance with clauses 2.13.6D and 2.13.6E of the Wholesale Electricity Market (WEM) Rules, AEMO may determine a Tolerance Range to apply to Facilities and Facility Tolerance Ranges to apply to individual Facilities for the purpose of AEMO’s Dispatch Instruction compliance monitoring obligations under clauses 2.13.9 and 7.10 of the WEM Rules. In making this determination AEMO must consult with all Participants.

WEM Rule 2.13.6G requires AEMO to review the Tolerance Range and any Facility Tolerance Ranges at least annually and, if required vary the Tolerance Range and any Facility Tolerance Ranges following this review.

Tolerance Range reviews

• 2019 Review of Tolerance Ranges (480 KB, pdf)
• 2018 Review and Determination of Tolerance Ranges

Tolerance Range applied from 20 July 2018

Based on the consultation process, AEMO has decided to set the Tolerance Range as proposed, and has therefore determined that the following Tolerance Range will apply from 20 July 2018:

(a) For Scheduled Generators, the Tolerance Range is:

TR (MW) = (+/-) MAX (6, MIN [5% NPC, 4*RR])

Where:

• NPC is the nameplate capacity of the Scheduled Generator, expressed in MW, using the value set in Standing Data [Appendix 1(b)(ii)]; and


• RR is the ramp rate of the Scheduled Generator, expressed in MW/min, using the value set in Standing Data [Appendix 1(b)(v)].

(b) For Non-Scheduled Generators, the Tolerance Range is:

TR (MW) = (+) 6

(c) For Demand Side Programmes, the Tolerance Range is:

TR (MW) = (+) MAX (6, 5% MCL)

Where:

• MCL is the maximum amount of load that can be curtailed by the Demand Side Programme, expressed in MW, using the value set in Standing Data
  [Appendix 1(h)(iii)].

(d) For all other Facilities:

TR (MW) = 0