Transgrid chooses lower cost option to connect NSW load centres with regional renewables

Plans for a “ring” of new transmission lines to link New South Wales’ coastal load centres with the state’s various renewable energy zones and with other major network upgrades are on public display via Transgrid.

Transgrid has published the preparatory report for the Reinforcing Sydney, Newcastle and Wollongong Supply (RSNWS), aka the Southern Ring, as it races to prepare the state’s grid for the exit of coal and build-out of renewables.

The Southern Ring aims to link the flows from Project EnergyConnect, HumeLink and VNI West via new 500 kV transmission lines from Bannaby into the Sydney western suburbs connecting to the ‘inner’ 500 kV system.

Transgrid has chosen its preferred route for Sydney Southern Ring, at a cost of roughly $1.5 billion, in preference to an alternative that was likely to cost nearly twice that much.

The project must still proceed through the Australian Energy Market Operator’s Integrated System Plan and RIT-T framework and Transgrid says it is important to secure easements around the new airport in western Sydney.

“The geographic dispersion of renewable generators …and the required growth of renewables to reliably and securely transition the NSW transmission network to net zero emission by 2050, necessitates new transmission infrastructure to efficiently transfer many GW of power across hundreds of kilometres,” the report says.

“To reach these new renewable generators, we need new transmission connections from REZs to the 500 kV Energy Superhighway transmission backbone supplying SNW via a 500 kV ring, providing efficient security of supply from both the north and the south.”

Transgrid says that for an area that accounts for around three-quarters of the state’s electricity demand – and with “no plans for new baseload generation” – supply will need to come from generation from outside the area.

And it says that if NSW coal generation retires earlier than expected, the state may need to “bring forward the planned in-service dates” of the Sydney Ring transmission projects to “reduce the risk of load shedding in Sydney, Newcastle and Wollongong.

New South Wales has a huge task ahead of it to build enough firmed renewable energy generation in time to wean the state from fossil fuels – and AEMO has warned that this can’t happen without the transmission task being completed first.

Transgrid earlier this month revealed it had finalised a deal to secure critical transmission equipment as it prepares to do its part in delivering national priority grid projects.

The $100 million contract with ZTT Australia has secured supply of 17,500km of high voltage conductors – enough to stretch from Sydney to Dublin, Transgrid said. A separate contract with another Australian company would secure supply of other locally-produced conductor elements.

Transgrid says the “bundling procurement” plan will save it up to $500 million on the hefty costs of its for major projects HumeLink, VNI West and EnergyConnect.

The stockpiling program – supported by $385 million federal funding from the Rewiring the Nation program – is also allowing the network company to purchase materials like substation equipment, earlier and at a lower cost, Transgrid says.

“We continue to build our global supply chain to secure the specialised kit needed to build the future clean energy grid and ensure competitive and efficient delivery of the Federal Government’s energy plans,” said CEO Brett Redman.

“It’s also reducing risk as we compete with other energy companies and nations to secure critical, large-scale equipment, materials and skilled labour to deliver the projects Australia needs,” added Transgrid executive general manager of delivery, Craig Stallan.