TransGrid PACR: Managing safety and environmental risks on Line 25 & Line 26 (Vineyard – Munmorah)

Market Network Service Provider, National Electricity Market
StageProject Assessment Conclusions Report
ConvenorAEMO NSP
Accepting submissions?No

TransGrid has recently published a Project Assessment Conclusions Report for managing safety and environmental risks on Line 25 & Line 26 (Vineyard – Munmorah). 

Lines 25 and Line 26 are two key 330 kV transmission lines from the Central Coast to Sydney. Spanning a route of 109 km, Line 25 connects Eraring substation on the Central Coast and Vineyard substation on the Greater Sydney network. Line 26 spans 123 km and runs between Munmorah substation on the Central Coast and Sydney West substation on the Greater Sydney network.

This RIT-T relates to single circuit section of Line 26, as well as the double circuit section of Line 25 and Line 26 between transmission Structure 11 and the Vineyard substation.

The transmission lines are part of the network that connects more than 4,000 MW of existing generators north of Sydney (Central Coast, Upper Hunter and northern NSW) and the major load centre of Sydney. They will continue to play a central role in supporting the flow of energy between regions to take advantage of naturally-diverse weather patterns, and in the safe and reliable operation of the power system throughout and after the transition to a low-carbon electricity future. 

Corrosion-related issues that will impact the safe and reliable operation of the network have been found on Line 25 and Line 26. The condition issues raise a number of risks associated with asset failure, including safety and environmental (bushfire) risks. As the asset condition deteriorates over time, the likelihood of failure and subsequent risks may increase should these issues not be addressed.

TransGrid considered four credible options that would meet the identified need from a technological and project delivery perspective. Refurbishment of the line remains the most economical and preferred option at this stage of the RIT-T process.

TransGrid published a Project Assessment Draft Report (PADR) for managing safety and environmental risks on Line 25 and Line 26 on 22 January 2020. No submissions were received in response to the PADR during the consultation period which closed on 10 March 2020. No additional credible options that could deliver a material economic benefit were identified throughout the process and the outcomes of the economic analysis contained in the PADR are maintained in this PACR.

The works for the preferred option are to be completed by 2021/22. The estimated capital cost of the proposed preferred option is $23 million +/- 25%. TransGrid is the proponent of the proposed network project.

In accordance with the requirements of the National Electricity Rules, a summary of the PACR is made available on the AEMO website. A copy of the PACR can be obtained from TransGrid’s website on the Regulatory Investment Tests page or by emailing

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