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.
Construction is expected to start in mid 2024.
Why is the work taking place?
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).