Australia: Transgrid is considering a major $3.5 B transmission upgrade to address growing bottlenecks between New South Wales’ renewable energy zones and major cities including Sydney, Wollongong and Newcastle.
In its Project Assessment Draft Report (PADR), the company has outlined six options for the Sydney Ring South project, identified by the Australian Energy Market Operator (AEMO) as essential for strengthening electricity supply across coastal demand centres.
The preferred option at this stage is Option 6: a new 500 kV transmission line running from Bannaby in the Southern Tablelands to South Western Sydney, combined with series reactors on the existing 330 kV network. The project is estimated to cost just over $3.5 B and could be delivered in stages between 2030 and 2034.
Transgrid says the upgrade would ease pressure on an increasingly constrained transmission corridor into Sydney as coal-fired generation retires and more renewable energy feeds into the system. The company estimates the option could deliver $3.2 B in net market benefits, including lower electricity costs for households and businesses.
The PADR also highlights that alternative solutions, including undergrounding sections of the line or relying more heavily on storage, would significantly increase costs. Partial undergrounding could add up to $2.7 B.
The project is still in early planning, with no final route or technology confirmed. Transgrid has stressed that consultation with communities, industry and stakeholders will shape future decisions.
Further reports, including cost-benefit modelling, are expected in mid-2026, followed by a final Project Assessment Conclusions Report.
Source: Renew Economy
