TransGrid has recently published a Project Assessment Conclusions Report for managing safety and environmental risks on Line 81 (Newcastle – Liddell).
Constructed in 1964, Line 81 is a 330 kV transmission line which spans approximately 100km between Newcastle substation and Liddell 330 kV switching station. The transmission line is comprised of 288 steel tower structures and forms part of the network that provides a key link between approximately 4,400 MW of existing generation in the Hunter Valley and Newcastle.
A significant proportion of the steel transmission structures of Line 81 are impacted by various levels of deterioration and corrosion. The affected components include tower steelwork, foundations and earthing, insulators, conductor fittings, earthwire and associated fittings. This greatly increases the likelihood of transmission structure failures, conductor drop, and subsequent bushfire and safety risks.
TransGrid considered two 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.
No submissions were received in response to the Project Specification Consultation Report (PSCR) during the consultation period which closed on 21 January 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 PSCR are maintained in this PACR. TransGrid has updated the estimate for capital expenditure that was published in the PSCR to reflect a reduction in the construction component which has been reduced by $15,000.
The works for the preferred option are to be completed by 2021/22. The estimated capital cost of the proposed preferred option is $7.8 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 RIT-TConsultations@TransGrid.com.au