Generators and Small Generators

This section assists generators, including small generators, in identifying the changes they need to make to implement 5MS and GS. It also provides links to the key information that triggers or supports the relevant changes.

The information provided by AEMO on 5MS and GS is general and may not be appropriate for any participant’s particular situation or market activities. Please also refer to AEMO’s privacy and legal notices.

  • At a high level, what are the 5MS/GS changes I need to make?

    To implement 5MS/GS, generators need to develop capability to:

  • How should we make these changes and when do we need make them?

    Generators are responsible for updating their systems and processes by 1 October 2021 for:

    • Submitting 5-minute bids
    • Managing 5-minute reallocations
    • Managing 5-minute metering data
    • Managing new NMI classification codes

    Generators should refer to the Bidding Transition Plan (BTP) for information on how and when to submit 5-minute bids. 

    The BTP was developed in consultation with industry through the 5MS and GS Readiness Working Group (RWG) and its subsidiary Dispatch Focus Group (DFG).

    Generators should refer to the Metering Transition Plan (MTP) for information on how and when to implement capability for managing 5-minute metering data and new NMI classification codes

    The MTP was developed in consultation with industry through the 5MS and GS Readiness Working Group (RWG) and its subsidiary Transition Focus Group (TFG). It provides co-ordinated guidance for AEMO and participants by setting out the expected responsibilities, detailed activities, dependencies and timeframes for completion for elements of the 5MS/GS metering transition. 

    Importantly, the Metering Transition Plan is the basis for participants, including retailers, to complete their own Metering Transition Plans. Participants will individually develop and manage their physical metering and metering data activity based on the timeframes agreed in the plan.

  • Which AEMO procedures that are relevant to me have changed?

    The 5MS Procedures Working Group was the forum for industry stakeholders to engage with AEMO on the 5MS and GS procedure development process. It was supported by:

    • Dispatch focus group
    • Settlement focus group
    • Metering focus group

    Generators should refer to the following procedure packages, available on AEMO’s website, to further understand the 5MS/GS changes:

  • Which AEMO systems that are relevant to me will change?


    Impact on local generators?


    Reallocations Yes Affects all generators who submit reallocations for periods beyond 1 October 2021 via online screens.
    MDM Yes Key changes affecting generators are CATS – NMI classification code updates.
    Dispatch Yes  Requires 5-minute bidding
    Allows for bidding via FTP, API or web
  • How and when do we test the changes?

    The approach to and timing for participant testing for 5MS and GS is set out in the Industry Test and Market Trials Strategy.  Details of the testing will be set out in the test plans to be developed in consultation with the Industry Testing Working Group

    Note that generators are responsible for:

    • Testing their systems and processes that interact directly or indirectly with AEMO’s market systems. 
    • Arranging bilateral testing with other participants.
  • What contingencies are in place?

    AEmO has Contingency Plans in place to respond to risks and issues, should they eventuate. These plans are documented in the Industry Contingency Plan section of the 5MS and GS market readiness strategies and plans table.

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