Outages and commissioning

Wholesale Electricity Market Rules (WEM Rules) commenced on Sunday, 1 October 2023. The new Rules can be accessed here.   

Equipment List

In accordance with clause 3.18A of the Wholesale Electricity Market Rules (WEM Rules), AEMO must maintain and publish a list of all equipment (Equipment List) in the South West Interconnected system (SWIS) that it determines is be subject to outage scheduling.


Planned Outages

Under Chapter 3.18 of the WEM Rules, AEMO must assess outage requests for Facilities or items of equipment that are on the Equipment List and following this assessment, approve or reject those outages accordingly.

To lodge these outage requests, Participants must use Outage Management System (OMS), which can be accessed via WEMS MPI Portal. The user guide for the OMS can be accessed here. For queries regarding the OMS, please contact WA Operational Planning on 1300 989 797, option 2.

To coordinate switching of the Western Power Network, information on access to the Western Power Network is available from Western Power’s website.

AEMO is required to publish details of real-time and historical generator outages. These details can be accessed here

For further information, refer to the WEM Procedure: Outages (under Dispatch and Planning Procedures)

Forced Outages

Under section 3.21 of the WEM Rules, Participants must lodge Forced Outage information with AEMO as soon as practicable but no later than the end of the next Business Day following the Business Day on which the Forced Outage commenced. When advising AEMO of any Forced Outage of a Registered Facility on the Equipment List:

  1. Contact AEMO’s Control Room via the direct number indicated in the Operating Protocol; and
  2. Provide full details via OMS.

For further information, refer to the WEM Procedure: Outages (under Dispatch and Planning Procedures)

Data Communication Facilities (DCFs)

Planned activities

Market Participants and Network Operators are required to notify AEMO of planned activities on communications and SCADA equipment in accordance with paragraph 6.4.2 of the WEM Procedure: Communications And Control Systems (under Dispatch and Planning Procedures).

If the communications and SCADA equipment is listed on the Equipment List or is a Self-scheduling Outage Facility, the Network Operator or Market Participant must advise AEMO via an Outage Plan or where otherwise agreed by AEMO in an Operating Protocol. 


As per Appendix B, paragraph B.3.3.1 of the WEM Procedure: Communications And Control Systems, in response to a failure of a High-Resolution Time Synchronised Data Recorder, a Network Operator or Market Participant must respond to the failure and rectify as soon as practicable which must be no more than 10 Business Days after the Network Operator or Market Participant becomes aware of the failure, unless another timeframe is agreed between the Rule Participant and AEMO.

If the Network Operator or Market Participant is unable to rectify within 10 Business Days of the failure, they must notify AEMO and provide AEMO with a rectification plan within 5 Business Days.

Notification for communications and SCADA equipment not on the Equipment List

If the relevant communications and SCADA equipment is not on the Equipment List, notifications relating to planned maintenance and failures should be sent to wa.sm.planning@aemo.com.au. The notification should include:

  • A description of the activities being undertaken/failure
  • Time/date of commencement of the activities/failure
  • Duration of the activities/failure (if known)
  • The identification of any Facilities impacted by the activities
  • Contact details for further information

Projected Assessment of System Adequacy (ST PASA and MT PASA)

The projected assessment of system adequacy (PASA) is a forecasting study undertaken by AEMO. It contains statistical load forecast information against projected available capacity figures (allowing for quantities of non-scheduled generation capacity based on historical figures).

AEMO publishes two versions of the PASA.

  • Short term PASA (ST PASA) is published by AEMO daily across a seven-day horizon in advance forecast.
  • Medium term PASA (MT PASA) is published by AEMO weekly across a three-year forecast.

Reports for both versions can be found in the here.

Commissioning Tests 

A Participant can conduct a Commissioning Test when commissioning a new Facility or following significant maintenance of a Facility or item of equipment. When submitting a request to AEMO to conduct a Commissioning Test, Participants must include a Commissioning Test Plan. The template for this plan can be accessed in the WEMS MPI Portal.

A Market Participant must submit all Commissioning Test Plans that are under the category of High Impact or Commissioning of a new Facility via the CTP Portal and also via email to system.analysis@westernpower.com.au. For further information, on identifying if the Commissioning Test is considered High Impact refer to the WEM Generator Performance Standards. 

Commissioning Test Plans

For Commissioning Test plans submitted after January 2014, refer to our Market Data site.

Please note that Commissioning Test plans occurred before January 2014 can be accessed in the following Archive.

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