State of the System update

10 min

Welcome to AEMO’s latest State of the System update, a regular round-up of developments, initiatives and consultations relating to the National Electricity Market (NEM).

As always, we welcome feedback via or through our survey and encourage anyone who is interested in receiving future updates to subscribe.

NEM Connections update

Since late May 2022, four generators with a total capacity of 330 MW achieved registration and four generators with a total capacity of 505 MW completed commissioning and are now in full operation. These projects are: 

Achieved registration

  • Christies Beach WWTP, SA, 5 MW 

  • Columboola Solar Farm, QLD, 162 MW 

  • Mortlake South Wind Farm, VIC, 153 MW 

  • Queanbeyan BESS, ACT, 10 MW 

Completed commissioning

  • Snapper Point Power Station, SA, 150 MW 

  • Winton Solar Farm, VIC, 85 MW 

  • Wellington Solar Farm, NSW, 170 MW 

  • Wandoan BESS, QLD, 100 MW 

Financial Year 2022
During the past financial year: 

  • 37 projects totalling 4.20 GW had performance standards agreed

  • 28 projects totalling 3.81 GW achieved registration

  • 15 projects totalling 2.11 GW completed commissioning. 

Consultation opens on changes to AEMO's system strength instruments

System strength can broadly be described as the ability of the power system to maintain and control the voltage waveform at any given location in the power system, both during steady state operation and following a disturbance.

In October 2021, the AEMC released its final determination on the efficient management of system strength on the power system. This has introduced new rule requirements for the System Strength Requirements Methodology (SSRM) and System Strength Impact Assessment Guidelines (SSIAG), as well as consequential changes to the Power System Stability Guidelines (PSSG). AEMO has begun consultation on the proposed changes to these documents.

The Draft SSRM and PSSG, and an accompanying Determination, will be released for consultation today. The broad categories of issues covered by the SSRM consultation include determining minimum fault level requirements, criteria for stable voltage waveforms (‘efficient’ level of system strength), forecasting inverter-based resource (IBR) connections and behaviour of synchronous machines, selection of system strength nodes, and planning for critical outages. AEMO will hold a webinar on the Draft reports on 11 August 2022 at 1.00pm (AEST).

More information on the consultation can be found here

Due to the number and complexity of issues to be addressed, and following discussions with several participants and market bodies, the original consultation timeframe will be extended for the SSIAG.

New frequency service sought in South Australia:  Emergency Under Frequency Response (EUFR)

AEMO is collaborating with SA Power Networks to define a new service in South Australia: Emergency Under Frequency Response. This service aims to assist in the management of rare, extreme under-frequency events that are traditionally managed with Under Frequency Load Shedding (UFLS).   

In periods of low operational demand, the availability of traditional UFLS is significantly reduced, so SA Power Networks is seeking complementary services from any proponents that can cost-effectively deliver additional generation increase or load reduction to improve management of these rare events. This includes rapid services (delivered in 200-500ms following a rapid drop in frequency below 49Hz), as well as slower services to assist frequency recovery in the subsequent minutes.  

SA Power Networks will soon be seeking Expressions of Interest (and recently released a draft specification for comment). Interested parties should get in touch with SA Power Networks at to be put on the mailing list to receive updates, and get a copy of the Expression of Interest documents.

Expressions of Interest are now open for the Connections Simulation Tool

A world first, the Connections Simulation Tool is expected to be available in the coming months and aims to help proponents better prepare their connection applications.

The Connections Simulation Tool will allow proponents (and their consultants/OEMs) to run studies against a four-state PSCAD model while protecting network model confidentiality. Higher quality applications will result in fewer approval iterations to gain approval and thereby reducing time and cost to connect.  

Expressions of Interest are now open. By filling in the form you will assist AEMO in gauging demand and will be added to a list of prospective users. You may also have the opportunity to become an early adopter of the tool.  

For more information or to access the Expression of Interest Form please refer to the project page on the AEMO website or email us at  

Consultation on NER S5.2.5.10 Guideline - Protection to trip for unstable operation

AEMO is seeking stakeholder views on the preparation of a guideline on National Electricity Rules (NER) clause S5.2.5.10 for asynchronous generating systems and reactive plant.  

Through working with Network Service Providers (NSPs) and market participants, AEMO has found that there is uncertainty on the requirements of clause S5.2.5.10 “Protection to trip for unstable operation” of the NER and relating the requirements to the Power System Stability Guidelines (PSSG).

As such, AEMO has identified an opportunity to establish a consistent understanding and approach for the technical requirements under, and compliance with, S5.2.5.10 for asynchronous generating systems and reactive plant such as Static Var Compensators (SVCs) and Static Synchronous Compensators (STATCOMs).  

AEMO has prepared an initial summary guide to give a broad range of stakeholders a summary perspective on some of the challenges to date, an overview of a proposed S5.2.5.10 guideline, and an opportunity to provide input to the development of the said guideline.  

AEMO invites written submissions in response to the initial summary guide. Submissions should be sent by email to by 5.00pm (AEST) on 24 August 2022.  

For more information please refer to the consultation webpage or email

Integrating Energy Storage Systems (IESS) implementation underway

In July, AEMO’s IESS project moved from mobilisation to early execution of changes to procedures and systems required under the IESS rule. One of the changes required for the initial release on 31 March 2023 involves the introduction of “Aggregate Dispatch Conformance”. It is intended to reduce barriers to the integration of energy storage and combined renewables and energy user loads by increasing operational flexibility and reducing curtailed energy for technologies behind a large scale connection point. AEMO has released an information paper outlining the proposed changes and is welcoming stakeholder feedback.  

In early July, AEMO also released a draft Implementation Strawperson for consultation which is intended to enable energy market participants to plan for IT, system and process changes required by the rule.

Stakeholders are welcome to provide feedback on both consultations, by COB 12 August 2022 to

New Fast Frequency Market

On 22 July AEMO published its Market Ancillary Service Specification (MASS) Draft Determination and Draft MASS as part of its review of the MASS. The review of the MASS was initiated following the AEMC's Final Determination and Final Rule published in July 2021 to introduce two new market ancillary services – very fast raise, and very fast lower FCAS – collectively known as very fast FCAS.  

This MASS Draft Determination builds on AEMO’s MASS Issues paper published on 2 May 2022 and initiates the second stage of consultation on the MASS. This determination incorporates stakeholder submissions, independent analysis from the University of Melbourne and advice from metering subject matter expert Michael Guy.  

The review and consultation of the MASS will focus on proposed amendments to the MASS to include the new very fast FCAS services. AEMO is required to publish the MASS amendments by 19 December 2022.  

AEMO will hold a public forum on Tuesday 2 August 2022 to provide stakeholders with an opportunity to engage with the content included in the MASS Draft Determination. Please register your interest in attending this public forum here.  

Submissions on the MASS Draft Determination should be forwarded to by 5.00pm (AEST) on Friday 19 August 2022.

NEM registration documentation updates

AEMO has updated its Guide to Generator Exemptions and Classification of Generating Units in response to two recent rule changes and to provide clarity on the application of the guide. 

Rule changes: 

  • Generator Registration and Connections Rule Change
  • Global Settlement and Market Reconciliation Rule Change 

High level changes to the guide: 

  • Additional information has been provided on the exemption application process.
  • AEMO has articulated the circumstances under which AEMO will impose terms and conditions on classification or exemption (where it is permitted to do so) and the nature of those terms and conditions. 
  • Non-Scheduled generating unit classification references have been updated to reflect the changes made as part of the Generator Registration and Connections Rule Change.
  • Clarification of the application of the guide to exemptions for generators connected to a distribution system or transmission system through an embedded network. 
  • Clarification of how nameplate rating is determined for DC coupled systems in relation to the application of the exemption framework.  
  • Expansion of the Notifiable Exemption to accommodate generating systems where a single generating unit is over 5 MW.  

For more information about these document amendments please contact AEMO's Registration team via

Engagement commences on scenarios for the 2024 ISP

AEMO held a public webinar on 13 July to discuss potential changes to the scenarios set used in planning and forecasting activities, including the Integrated System Plan (ISP), and the Electricity and Gas Statements of Opportunities (ESOO/GSOO). AEMO received feedback from a broad range of stakeholders via structured polling and written comments. AEMO is now considering this feedback and will update stakeholders on next steps once these are decided. AEMO will also continue to engage on specific inputs and assumptions through the monthly Forecasting Reference Group, which is an open forum. AEMO will publish a Draft 2023 Inputs, Assumptions and Scenarios Report for stakeholder feedback in late 2022.

Engineering Framework – Priority Actions are published

On Wednesday 8 June 2022 AEMO published the NEM Engineering Framework – Priority Actions Report.  

This publication provides an update on the status of the NEM Engineering Framework and outlines an initial list of high priority near-term actions that will help prepare the power system for six identified future operational conditions, including preparation for 100% instantaneous penetration of renewables.  

The publication outlines a number of key actions being led across industry and AEMO’s action commitments by end of June 2023, and identifies some proposed priority actions where appropriate implementation pathways and stakeholder accountabilities are still to be confirmed.  

This publication is the first step towards action prioritisation, with significant work remaining to undertake actions and monitor progress.  

Please contact to sign up to our mailing list or register interest to attend further discussions, or for any other Engineering Framework matters.  

Intermittent Power System Oscillations Update

AEMO continues to observe intermittent power system oscillations in the West Murray area (VIC/NSW), with oscillations observed as recently as 25 July 2022. The frequency of oscillations observed were around 18-19 Hz (RMS) with maximum peak-peak magnitude of 0.35% observed at Red Cliffs Terminal Station (RCTS) 220 kV. 

As mentioned previously, AEMO, in collaboration with AusNet and Powercor, is currently developing a report that will provide further information on the observed intermittent power system oscillations. The report is on track to be published before end of Q3 2022. 

West Murray Zone Update

AEMO continues to work closely with Network Service Providers (NSPs) on the integration assessment for projects in the West Murray Zone (WMZ). Only one project is currently undergoing WMZ integration, and a further six projects in the WMZ have commenced Stage 1 Due Diligence review and are expected to commence WMZ integration in the coming months.

Connecting projects within the WMZ remains very challenging in terms of capacity. AEMO's National Connections team remains committed to working with all NSPs and developers to progress projects, but it is critical for developers at every stage to keep in regular contact with the relevant NSP and inform themselves of all potential impacts of WMZ congestion on their project.

If you are planning to move forward with your project, please work closely with your NSP and complete all the requirements outlined in AEMO’s Connecting generators in the West Murray Zone – sequencing uncommitted projects.

If you are unsure if your project is in the WMZ, please see the WMZ map on the AEMO website or alternatively, please contact your connecting NSP.

You can find more West Murray updates here on our website.

Education notes

Enrolments are now open for the remainder of AEMO’s energy education courses in 2022! You can find all dates on the AEMO website.  

Set out for the next five months, this calendar highlights the comprehensive list of AEMO-run gas and electricity courses. As a result of increased demand and interest from industry, government, and regulatory bodies, AEMO is this year delivering more courses to provide a better understanding of the complexities of Australia’s existing and emerging energy systems and markets.  

In the second half of 2022, selected NEM Overview courses will be offered face-to-face in NEM capital cities. Virtual course delivery will continue to be available to complement our face-to-face courses.  

All courses are open to existing and intending market participants, government, energy industry members and other interested parties. These courses are a fantastic opportunity to develop your Australian energy industry understanding and expertise.  

To explore, enrol and pay for AEMO energy education courses, visit the AEMO Learning Academy.  

Keeping across AEMO’s events and meetings

Engaging our stakeholders is a key priority in our corporate plan. We aim to be a trusted partner through collaborative engagement and enhanced transparency. One way we strive to do this is through our wide range of engagement events and forums. To keep up to date on all the activities we are holding check out our Industry Meetings Calendar to see which meetings might be relevant for you. If you are interested in attending a meeting, click the meeting to find email contact details.

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