TransGrid has recently published a Project Consultation Specification Report for reinforcing the New South Wales Southern Shared Network to increase transfer capacity to the state’s demand centres.
The Southern Shared Network includes existing transmission capacity and planned interconnectors, connections to the existing Snowy Hydro Scheme and other regional generation assets. It provides transfer capacity to demand centres and allows for interstate and regional transfers. The shared transmission network between the Snowy Mountains and Bannaby carries power from all generation across southern NSW to the major load centres of Sydney, Newcastle and Wollongong. It also carries all electricity that is imported from Victoria to the major load centres in NSW. The main transmission lines in this area are heavily congested at times of high demand, and will become more congested as new generation connects in southern NSW.
Snowy Hydro’s existing generation capacity connects to the Southern Shared Network at Upper Tumut, Lower Tumut, and Murray. Existing congestion at times of high demand limits access to the existing generation capacity of the Snowy Mountains Scheme at times of peak demand. Access to the additional 2000 MW capacity of Snowy 2.0 and other new generation in southern NSW would, therefore, be severely limited, without reinforcement to the Southern Shared Network.
TransGrid has put forward four credible options for consideration in this Project Consultation Specification Report:
Option 1: Lines running directly from Maragle to Bannaby
Option 2: Lines running from Maragle to Bannaby via Wagga Wagga
Option 3: A triangle linking Maragle, Wagga Wagga and Bannaby - which would unlock new renewable energy resources in the region
Option 4: A variant on Option 3, which further extends the new lines back to Sydney.
All four options include the construction of new single-circuit lines on diverse paths, designed to mitigate bushfire and extreme weather risks and ensure the reliable supply of electricity to major demand centres. TransGrid intends to consider variants for all four options of 330 kV, 500 kV and a flexible option with transmission built to enable 500 kV operation, though initially operated at 330 kV.
An increase in transmission capacity between the Snowy Mountains and Sydney of 2,000 MW could be provided under a range of options with indicative construction costs between $790 million and $1.9 billion.
This RIT-T will also consider non-network options which address the limitations on transfer capacity between southern NSW and Sydney and which may therefore contribute to meeting the identified need, either individually or in combination with other non-network and/or network options. Submissions are sought in particular on the four options cited above, and from potential proponents of non-network options.
In accordance with the requirements of the Rules, a summary of the Project Specification Consultation Report is made available on the AEMO website. A copy of the Project Specification Consultation Report can be obtained from TransGrid Website on the RIT-T Consultations page or by emailing RIT-TConsultations@TransGrid.com.au.
Submissions in response to this Project Specification Consultation Report are required by the closing date of 19 September 2019.