3 June 2024 IESS Registration, classification, and bidding changes release

The Participant Toolbox is a central location for useful resources to help market participants understand and prepare for the changes associated with the Integrating Energy Storage Systems rule’s implementation. This page pertains to the 3 June 2024 IESS release that comprises of registration, classification, and bidding changes. 

Resources are added to this page progressively over the course of AEMO’s preparation and implementation of the changes. 

To access resources for other IESS releases, click here.


Technical documentation


  • Has AEMO reached a final position of new IRS that may enter the market using the same bidding platform systems as existing IRS/ market participants? Are they given until the Mar-25 timeline?

    For participants that start operations from or after the 3rd of June, the default expectation is that they would begin operation as a single DUID. However AEMO is conscious that there will be extenuating circumstances which we will try to accommodate. Where this is the case, the participant will still need to begin single DUID operations before 03 Mar 2025.

  • Where a participant has both BDU and other asset types, will they transfer to the IRP Participant category? If so, are there any impacts for the other asset types?

    Participants with BDUs will transfer to an Integrated Resource Provider (IRP) participant category. The IRP is intended to be a universal category and provides flexibility in how an organisation may want to organise their other asset types.

    The Infographic in AEMC’s final determination [AEMC, IESS Rule, Figure 1 p.6] is a useful resource to identify the interaction of different participant types and the types of units they can classify in relation to the IRP.

  • Do we have a view of how many BDUs we have in the NEM?

    Existing BESS are listed in the NEM registrations list

    Connections pipeline is published in Key connection information list

  • Can you please confirm that UFE changes will only be applied from 2 June 2024, and is not applied retrospectively?

    UFE changes will commence at the same time as other settlement changes and will not be applied retrospectively.

  • Outside the supported Market Trial will the AEMO pre-production environment be available for participants to continue testing (after the actual Market Trial has concluded)?

    Once released to pre-production, capability is available for participant testing, and will remain so after the production release. Defects raised after a production release are managed and deployed by AEMO's BAU Support teams.

  • Who can participate in the Market Trial?

    The IESS market trial has three test phases, each with different affected participants. For details please refer to section 3.1.1 of the IESS industry testing and market trials strategy.

  • Can you please confirm what MT PASA submissions will look like for batteries?

    MT PASA submissions are to be based on the generation (or discharge) side of a BDU. The load (or charge) side of a BDU will not need to be forecasted.

  • I want to understand what the bid validation messages will be for BDUs.

    Some BDU Bid Format Validation rules are available here. Note that AEMO has not finalised the validation messaging. Once confirmed and finalized, AEMO will update relevant documents accordingly.

  • Who can make use of the Participant Development Support Environment (PDSE)?

    AEMO's IESS Participant Development Support Environment Fact Sheet contains information about who can make use of the PDSE.

  • Where can we find information on how FCAS will work under the new BDU model?

    AEMO released information on this via its BDU readiness focus group, held on 12 October 2023. Please view presentation here. 

  • Will we initiate and process applications for IRPs in advance of the IESS effective date to enable registrations effective from 3rd June 2024?

    Yes. AEMO will notify affected participants once relevant application forms are available. AEMO will also publish an IRP Transition Plan to guide participants regarding this process.

  • How can I find more detail regarding the Participant Development Support Environment?

    AEMO's IESS Participant Development Support Environment Fact Sheet contains information about the PDSE.

  • With regards to identification of which DUID’s are BDU’s, will we see this reflected via a new value in the DUDETAIL and DUDETAILSUMMARY tables?

    Yes. DISPATCHTYPE field (DUDETAIL table) will support a new enumerated value of BIDIRECTIONAL. Additionally, UNITTYPE field (DISPATCHABLEUNIT table) will support a new enumerated value of BIDIRECTIONAL.

    For detail on new and modified columns associated to tables of the PARTICIPANT_REGISTRATION package, see EMMS - Technical Specification - Data Model v5.3 - March 2024

  • How will SGAs operate post-IESS?

    AEMO expects that SGAs with exempt battery systems will be able to operate in a similar manner post-IESS, under the new IRP participant category. Further information on how exempt batteries are accommodated under the existing framework is provided in the NEM Small Generation Aggregator Fact Sheet.

  • I have plans to register a BESS after 03 Jun 2024. How can I develop and test my settlement systems before my BESS becomes operational as 1-DUID?

    Settlements will work for BDUs in the same way as for other connection points configured to be delivered as individual meter reads. That is, in the same way as an existing market generator DUID.

    Settlement of consumption and generation will be on a single record in the new Energy Transactions table against the connection point ID of the BDU, with the only difference being the meter type flag.

    Given that there is no unique settlement treatment for batteries in future, participants can use the market trial settlement runs on other (non-battery) DUIDs to confirm the new settlements database structure.

    Separately, dispatch of the BDU can be validated in pre-production as part of the registration process.

  • How can I access detail about the data model, including for the new BDU model?

    All sources providing the definition (i.e. Postman and EMMS Tech Spec) are progressively updated for release to participants. The guides and resources are updated and published for the pre-production Release Date are:

    EMMS Technical Specification and Data Model 5.3

    Data Interchange Online Help

    NEM Dispatch Bidding Open API Specification Reference (Postman)

    Markets Portal Help

    If participants would like to be notified of updates to these information sources, they can subscribe to relevant notifications by asking their company to add them to the support hub mailing list maintained as part of the registration process.

    Further, you may consider attending the Market Systems User Group (MSUG), which is an industry group designed to facilitate the continuing improvement of NEM wholesale and retail IT systems, Data Model, and Data Interchange releases (including gas markets). All interested parties are welcome to attend and ask questions.

    More Information:

    IT change and release management

    Market systems user group (MSUG)

  • Will the Market Trial include settlement statements for the new 1-DUID BDU model? 

    Participants will not see single DUIDs settlement statements in the Market Trial. Testing of BDU bidding and dispatch will occur during Phase 3 of the Market Trial, in April 2024. These new BDU DUIDs will not have settlements as there is no retail meter data to support it.

For more information, please contact IESS@aemo.com.au.

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