Improving stability in south-western NSW


South-western NSW has seen significant growth in renewable generation connections to the transmission network. 

This trend, which is forecast to continue, is having an impact on how this part of the power system operates as more power from new renewable generation flows into the transmission network.

These changes in power flows are expected to lead to an increasing risk of power system instability going forward.

TransGrid has identified the opportunity to strengthen the transmission network and provide wider market benefits to the National Electricity Market (NEM).

To test the economic viability of different solutions TransGrid is applying the Regulatory Investment Test for Transmission (RIT-T) to options for improving stability in the south-western New South Wales power system. Publication of this Project Assessment Draft Report (PADR) represents the second step in the RIT-T process and follows the Project Specification Consultation Report (PSCR) published in July 2020. 

We welcome written submissions on the material contained in this PADR. 

Submissions close on 5 November 2021.

Submissions should be emailed to our regulation team via regulatory.consultation@transgrid.com.au.  In the subject field, please reference ‘PADR Improving stability in south-western NSW.’

Project funding approval process

To be given final investment approval, TransGrid must show that the preferred option for improving stability in south-western NSW will deliver the greatest net benefits to energy consumers. The net benefits delivered by the project are assessed using the Regulatory Investment Test for Transmission (RIT-T) administered by the Australian Energy Regulator (AER). 

The RIT-T assesses network and non-network solution options from a technical and economic perspective by:

  • Informing stakeholders of the investment need and proposed options to address this need
  • Testing the market for alternative and more efficient solutions
  • Explaining to stakeholders the basis on which the preferred option has been selected. 

The draft conclusion of this process is that a new Darlington Point to Dinawan 330 kV transmission line is expected to provide the greatest net benefit of all options considered. 

RIT-T process and submissions

Project Specification Consultation Report

In July 2020, TransGrid published the Project Specification Consultation Report (PSCR) .The PSCR detailed the need to improve stability on the south-western NSW power system and describes credible options to meet the need, including technical characteristics that would be required of a non-network option. 

TransGrid received submissions from seven parties in response to the PSCR. Submissions approved for publication are below:

Neoen Australia

Reach Solar Energy Co Pty Ltd

Letter from Narrandera Shire Council (submitted by Reach Solar Energy Co Pty Ltd)

RWE Renewables Australia Pty Ltd

Sunraysia Solar Farm Pty Ltd

Project Assessment Draft Report

Comments from the submissions received in response to the PSCR were considered when preparing the Project Assessment Draft Report (PADR), published in September 2021.  The PADR includes a full quantitative analysis of the proposed options and expected net market benefit across a range of scenarios and sensitivities. We have published the following supporting documents:

Net Present Value Model Output (PADR)

Market Modelling Report (PADR)

Market Modelling Report Outputs Summary – Central Scenario (PADR)

Market Modelling Report Outputs Summary – Fast Change Scenario (PADR)

Market Modelling Report Outputs Summary – Slow Change Scenario (PADR)

Market Modelling Report Outputs Summary – Step Change Scenario (PADR)

TransGrid welcomes written submissions on the material contained in this PADR. Submissions are due on 5 November 2021.

Submissions should be emailed to TransGrid’s Regulation team via regulatory.consultation@transgrid.com.au.  In the subject field, please reference ‘PADR Improving stability in south-western NSW.’

If you have any questions about the project, please contact community@transgrid.com.au or phone 1800 222 537.