State of the System update

10 min

Welcome to AEMO’s third State of the System update, a regular round-up of developments in the east coast energy system. Its aim is to provide updates, build awareness of emerging issues and highlight engagement opportunities on important initiatives and consultations.

We welcome feedback via email to

NEM connections update

New Generators

 Since 1 March 2021, AEMO registered four new generators in the NEM with a total capacity of 226 MW and five generators contributing a total of 383 MW completed their commissioning and in commercial operation.

New generators registered:

  • Gangarri Solar Farm (120 MW) - QLD 
  • Winton Solar Farm (85 MW) - VIC 
  • Ferguson South Wind Farm (7 MW) - VIC 
  • Adelaide Desalination Plant Solar and Battery (14 MW) - SA 

New generators commissioned and in commercial operation: 

  • Maryrorough Solar Farm (27 MW) - QLD 
  • Bomen Solar Farm (100 MW) - NSW 
  • Molong Solar Farm (30 MW) - NSW 
  • Elaine Wind Farm (82 MW) - VIC 
  • Cattle Hill Wind Farm (144 MW) - TAS 

The NEM generation maps will be updated to reflect the latest connections status by early May.

Generation Developer Survey

In the coming weeks, AEMO Account Managers will commence surveying Generation Developers regarding their end-to-end experience during connection application, registration and commissioning of their generating system. They will be seeking feedback on recent interactions for projects that may have reached one or more of these milestones in the last 12 months. Once the results are collated, AEMO will review and assess any improvement suggestions and identify activities to address these with updates to be communicated in the next newsletter. 

West Murray Zone update

Following on from the good progress reported in February, two additional committed solar farm projects have completed integration assessment with one of the projects, Winton Solar Farm, going on to achieve registration in March. The remaining committed wind farm project in Victoria from the original committed projects list, will complete integration assessment in early May.

AEMO has commenced work with the NSPs and project proponents to commence the scheduling for the uncommitted projects, with the first projects beginning integration assessment late April. AEMO has recently written to all Project Proponents with uncommitted projects giving them a status update. For more information, please refer to the AEMO West Murray Zone webpage

VNI West RIT-T update 

On 24 March, AEMO published a progress update on the Victoria to New South Wales Interconnector West (VNI West) Regulatory Investment Test for Transmission. This update highlighted that the AER has recently granted AEMO and TransGrid an extension to publish the Project Assessment Draft Report publication from March 2021 until 10 December 2021.

The goal of this change in timing is to allow:
a) further refinement of key inputs related to the ISP decision rules for the project; and
b) the RIT-T modelling to adopt the latest ISP assumptions from the 2021 Inputs, Assumptions and Scenarios Report (IASR), which will be released this July.

Aligning the VNI West RIT-T with the latest ISP parameters will facilitate a more robust cost-benefit assessment and is critical to determining the best outcome for energy consumers.

You can read the report here

QNI Upgrade

Upgrading the Queensland-NSW Interconnector (QNI) will boost interstate transmission capacity and increase power flow on existing lines. This will make it easier and more efficient to share power generation across the National Energy Market, helping improve reliability and put downward pressure on market prices. The project has been identified as a priority by both AEMO in the 2020 Integrated System Plan and by the State Government in the NSW Transmission Infrastructure Strategy. Work is underway to upgrade existing transmission lines and to install additional dynamic voltage control equipment referred to as Static Var Compensators (SVCs). 

To support the safe and timely release of new inter-network capacity, AEMO is working with TransGrid and Powerlink to develop a test program in accordance with clause 5.7.7 of the National Electricity Rules. Consultation undertaken as part of the 5.7.7 process will provide stakeholders an opportunity to provide feedback on the tests proposed. Commissioning is planned to commence in January 2022 and conclude in June 2022 when transfer capacity can be realised, associated with line thermal limits and lower ambient temperature conditions in the winter period.

AEMO will commence industry engagement regarding the test plan in the coming months, including consultation regarding proposed test and monitoring arrangements. Please visit our consultation page. Transparency regarding the test program including timing of capacity release will also help inform industry of potential impacts on power system constraints and market outcomes. 

For more info, see the TransGrid website

Engineering Framework

Last month, AEMO released the Engineering Framework March 2021 report, the next step in a multi-year plan to deliver an integrated roadmap for the NEM. It builds on the Renewables Integration Study (RIS) Stage 1.

The Engineering Framework seeks to go beyond renewable integration alone, by taking a broader perspective, and acknowledging the various activities that are already happening across industry. Ten focus areas have been identified, which are spread across three broad themes: attributes, operability and integration. 

The focus areas are used to frame the current work and avenues for engagement in the March 2021 report. They will also be used to collaborate on identifying where increased industry focus is needed to bridge the gap between current work and future operational conditions. 

AEMO is looking to work closely with stakeholders on the Engineering Framework to inform its future priorities and identify areas for collaboration. If you want to get involved head to the website for how.

Transmission outages in South Western Victoria

On 31 January 2020, several transmission towers collapsed on the double circuit Moorabool – Mortlake and Moorabool – Haunted Gully 500 kV lines due to a severe convective downburst during thunderstorm activity. This resulted in the separation of the Mortlake Power Station, the APD Portland aluminium smelter and South Australia from the rest of the NEM for 17 days. Both circuits were restored using temporary structures.

We are pleased to report that the rebuild of the permanent structures was successfully completed by AusNet Services during March 2021 by taking two planned outages. There is a plan to organise two additional daily outages during April to transfer the Optical Power Ground Wire (OPGW) cable (Moorabool – Haunted Gully line on 16 April) and undertake maintenance activities (Moorabool – Mortlake line on 29 April), with AusNet Services planning to separately remove the temporary tower structures. 

From when the incident occurred on 31 January 2020 to now in April 2021, there has been a significant amount of collaboration and planning across industry and government. This has included regular industry briefings and technical meetings with impacted participants, to communicate progress of works, answer questions, understand impacts on businesses, and work through required preparatory arrangements. During the two outages, daily meetings were held with impacted participants to provide an update on the progress of works. Collectively this framework supported the success of the program of works. 

AEMO would like to thank those that worked closely with us during this significant outage exercise, and look forward to ensuring this collaborative effort continues. 

For more information or to see the latest update of these outages in the Network Outage Schedule, visit AEMO’s website

SA Synchronous Condensers Update

To fill the declared system strength gap in South Australia, ElectraNet (Transmission Network Service Provider for South Australia) is installing four large synchronous condensers, two at Davenport and two at Robertstown.

According to an April update from ElectraNet, contractors are currently installing two synchronous condensers at Davenport substation. The first synchronous condenser is expected to be in service in June 2021 and the second unit in July 2021.Works for installing the synchronous condensers at the Robertstown substation are well progressed, on track to be ready for operation before the end of June 2021.

These synchronous condensers will reduce the number of large synchronous generators that are required to be online to provide necessary system strength. AEMO and ElectraNet have conducted analysis to identify the impacts of the Davenport synchronous condenser on the system strength limit. It has been identified that higher asynchronous generation can be supported with the installation of the Davenport synchronous condenser, and also that it will reduce the number of synchronous generators that are required to be online for system strength purposes.

Further details regarding the amount of supportable asynchronous generation and required synchronous generators is available here.

Primary Frequency Response (PFR) implementation update

AEMO has been reporting approximately monthly on the progress of implementation of Mandatory Primary Frequency Response, which is being carried out in three tranches. The reports detail generator self-assessment of the ability of their generating systems to provide primary frequency response (PFR) in accordance with the primary frequency response parameters. 

The latest progress update from mid April shows that:

Tranche 1 (generating units larger than 200 MW capacity): Self assessments and settings changes have now been completed for around 30,500 MW, or around 85% of tranche 1 capacity. 

Tranche 2 (generating units between 80 MW and 200 MW capacity): Initial assessments for a majority of these are now completed. Implementation of setting changes has commenced or completed for around 4,400 MW, or 28% of tranche 2 capacity.

Tranche 3 (generating units less than 80 MW capacity): The results for generation in Tranche 3 were due 17 February 2021, with 81 received to date. Some affected generators provided self-assessments earlier and around 1,300 MW, or 28% of Tranche 3 capacity has commenced or completed setting changes. 

ISP draft Methodology

The Integrated System Plan’s draft Methodology is due for release on 30 April. In response to stakeholder feedback, the Draft Methodology includes additional information that AEMO had not intended to publish until later in 2021, such as a proposed approach to scenario weighting as part of the process to identify the ISP optimal development path.

The National Electricity Rules require AEMO to develop, consult and publish the ISP Methodology in accordance with the Australian Energy Regulator’s (AER’s) Forecasting Best Practice Guidelines.

In developing the ISP Methodology, AEMO aims to seek stakeholder input and feedback through workshops as well as written submissions. Submissions to the draft Methodology should be sent via email to by 28 May.

Please also note that AEMO has amended the ISP timetable to delay the publication of the final ISP methodology. The final ISP methodology will now be published on 30 July 2021, the same day as the final Inputs, Assumptions and Scenarios Report that will be used in modelling the 2022 ISP.

Connections website and document updates

The following documents were updated in the last 2 months: 

Dynamic Model Acceptance Test Guidelines – Updated – Modelling Requirements webpage 

This guideline provides information on how AEMO assesses the accuracy, consistency and robustness of computer models used for power system analysis, and explains the process for carrying out dynamic model acceptance tests (DMATs) for root mean square (RMS) and electromagnetic transient (EMT) type models. 

Generator Performance Standards template – Updated - Stage 3 Application webpage 

General update to S5.2.6.1 and updated S5.2.5.3 frequency ranges for continuous uninterrupted operation to be consistent with the frequency operating standard and considering the "Supply Scarcity" system condition. 

The following documents will be updated by end of April 2021: 

Generator Connection Application Checklist – Updated - Stage 3 Application webpage 

Generator Connection R1 Submission Checklist – Updated - Stage 6 Completion webpage 

Update the documents links in the checklist and updated the model acceptance and communication systems failure requirements to align with the Dynamic Model Acceptance Test guidelines and Communication Systems Failure guidelines.

Generator Modelling Information

Generators are reminded of their obligations to provide updated information to AEMO and Network Service Providers under clause S5.2.4 of the National Electricity Rules. This includes information pertaining to protection systems, control systems and computer models. This encompasses all control systems that respond to voltage or frequency disturbances on the power system, and which are either integral to the generating units or otherwise part of the generating system, including those applying to reactive power equipment that forms part of the generating system.

As the power system transitions to operation with higher levels of inverter-based resources, distributed resources as well as operation of fewer synchronous machines it is increasingly crucial for NSPs and AEMO to have accurate information for power system planning, design and operational purposes. Equally, proactive management of obsolescence for software tools, models and compilers is also a critical enabler for power system modelling and analysis undertaken by NSPs, AEMO and proponents seeking to connect (or modify their connection) to the National Electricity Market.

If you have any questions or wish to provide updated information, please contact including provision of details of the changes and any impacts to performance.

Enrolments open: Connecting & Registering Generators in the NEM

An overview (3-part series) w/c 17 May 2021

AEMO has developed a new course for individuals and organisations directly involved in connecting and registering generators in the NEM. Held over three sessions, AEMO subject matter and technical experts will explore the key connections and registrations processes in the context of the energy transition and the current regulatory environment.

Sessions 1 and 2 document success tips and resources to help participants navigate the connections and registrations processes. Our expert presenters will also walk participants through an overview of the State of the System, including key risks and considerations, and ongoing compliance requirements.

Session 3 provides practical insights into the common challenges and risks encountered by proponents in establishing or modifying a connection to the Victorian transmission network. It will use case studies leveraging experiences from a variety of connection projects across different technologies, and an interactive Q+A format. 

Connecting & Registering Generators in the NEM: An Overview (3-part series) is an expert instructor-led course delivered live online over Microsoft Teams. The three sessions are scheduled for the week commencing 17 May 2021. Pricing: $1,250 (plus GST) to attend Sessions 1 & 2 only, $1,750 (plus GST) to attend the complete 3-part series. For more information or to enrol, contact

Enrolments are also open for AEMO’s highly regarded Network and Frequency Control Ancillary Service Constraints in the NEM course. This expanded technical course explores the network characteristics that determine constraints, how constraints are derived and formulated, and their effects on dispatch outcomes. 

For information on this and other upcoming courses, visit the AEMO Energy Education courses webpage or contact for enquiries. 

Useful resources

To follow the latest news and updates from AEMO you can subscribe to a number of our newsletters on our subscribe page, or check out our newsroom.

Look for the Network and FCAS constraints in the NEM in the AEMO learning academy catalogue here 

Did you find this update on the State of the System interesting or useful? 

AEMO is preparing this update for the benefit of our stakeholders. Let us know what you think about our State of the System updates in this survey.

To learn more or to work with AEMO on these updates, contact the Stakeholder Relations team.

AEMO is preparing this update for the benefit of our stakeholders. Let us know what you think about our State of the System updates in this survey.

To learn more or to work with AEMO on these updates, contact the Stakeholder Relations team.

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