Coppabella Wind Farm - Line 99M Rebuild

Rebuild of Transmission Line 99M from the Coppabella Wind Farm to Yass Substation.

  • The project

    Transmission Line 99M forms an approximate 73 km 132 kV single circuit connection between the Yass 330 kV substation and the Murrumburrah 132 kV substation, located in the Southern Tablelands region. To facilitate the grid connection of the Coppabella Wind Farm development, TransGrid is proposing to rebuild an approximate 39 km section of Line 99M between the Coppabella Wind Farm (at Structure 143) and Yass substation as a double circuit line (the project). The rebuilt section of Line 99M would comprise new 40 metre high steel or concrete pole transmission structures, which would be up to 20 meters higher than the existing wooden pole structures. The project would also involve the construction of a new switch bay and associated electrical and communications connection works at Yass substation.

  • Why is TransGrid undertaking the work?
    Goldwind Pty Ltd. has received approval to construct and operate the Coppabella Wind Farm. The Coppabella Wind Farm would connect to the National Electricity Market via TransGrid’s Transmission Line 99M. The current line rating of Line 99M was not sufficient to accommodate the proposed generation of the Coppabella Wind Farm. While the former approved project (July 2018) involved uprating the line by replacing the existing conductors, further network constraint studies determined that the line would still be constrained under certain operating conditions, particularly due to the introduction of new renewable generation sources in the region. Additionally, the rebuild of Line 99M would address the marginal loss factor which would have been applied to the former approved transmission line uprating project by the Australian Energy Market Operator (AEMO). 
  • Planning Approval and Environmental Assessment
    Main REF

    TransGrid prepared a Review of Environmental Factors (REF) under Part 5 of the Environmental Planning and Assessment Act 1979, which was made available for community and stakeholder comment between 13 June 2019 and 9 August 2019.

    TransGrid has now determined the project. The REF, Submissions Report and Decision Statement can be viewed via the links below.

    View the Review of Environmental Factors: 

    Vol_1_Line_99M_REF_Main Report.pdf

    Vol_2_Line_99M_REF_Appendix A to D Ecology.pdf

    Vol_3_Line_99M_REF_Appendix E Heritage.pdf

    Vol_4_Line_99M_REF_Appendix F Visual_Part A.pdf

    Vol_4_Line_99M_REF_Appendix F Visual_Part B.pdf

    View the Submissions Report and Decision Statement:

    Submissions Report 
    Decision Statement

    Addendum REF
    As a result of the connection of other renewable generation assets in the Yass region, there is now limited transfer capacity in the 132 kV network. As such, there is a requirement to connect the Coppabella Wind Farm to TransGrid’s 330 kV network, which would require the installation of an additional 132/330 kilovolt transformer at Yass substation. 

    To support the new transformer, a new transformer compound and switchbay would need to be constructed in the former switchyard at Yass substation. Due to the positioning of the proposed new switchbay and transformer compound, the overhead crossing of the Coppabella Wind Farm transmission connection into the new switchbay would require approximately three additional transmission structures. The reason for the positioning of the transformer on the former switchyard bench is due to insufficient space within the current switchyard area.

    Approval for the modified project is being sought under Part 5 of the Environmental Planning and Assessment Act 1979. TransGrid has completed an Addendum Review of Environmental Factors (Addendum REF), which can be viewed via the link below. The Addendum REF will be available for public and stakeholder comment for a period of 20 business days between 3 August 2020 and 7 September 2020. During this exhibition period, TransGrid welcomes your feedback.

    View the Addendum Review of Environmental Factors

    Make a submission to the Addendum REF - email 

    Following the exhibition of the Addendum REF, a Submissions Report will be prepared to address any submissions received. TransGrid will consider all submissions as part of the modified project approval process. Subject to determination of the modified project, TransGrid anticipates that it will commence construction works in quarter 4 2020. Construction works are anticipated to take approximately 18 months.

  • How can I get more information?

    You can contact our Community Engagement team on 1800 222 537 or via

  • Figures

    Locality map

    Proposed modified activity area