New eco circuit breakers a crucial step towards decarbonising the grid

Australia’s largest transmission business has installed its first non-sulphur hexafluoride (SF6) circuit breakers at a substation in NSW’s North West Slopes, paving the way for a network-wide rollout and eventual elimination of the greenhouse gas from this equipment.

SF6, which has been commonly used by electricity utilities around the world since the 1950s, is a powerful insulation medium that keeps electrical current safely confined within the equipment, enabling the safe operation of the network.

Transgrid Executive General Manager of Network Jason Krstanoski said the successful installation of two non-SF6 circuit breakers on 132kV transmission lines at Gunnedah is a significant milestone in decarbonising the high-voltage network in NSW and the ACT.

“We are proud to be among the best performing utilities globally for SF6 emissions, with rigorous systems in place to detect and manage leaks, ensuring the gas stays within the equipment,” he said.

“Transgrid is now taking this commitment further, trialling non-SF6 circuit breakers as an important first step in our efforts to deliver the clean energy system of the future.

“While it will take decades to transition the whole network as the technology improves over time, we are proud to be among the first in Australia to begin phasing out SF6 equipment, which is a huge challenge for the electricity industry worldwide.”

Transgrid General Manager of Asset Management Lance Wee said alternative SF6 technologies and management solutions were rapidly evolving.

“We will continue with trials and investigations to understand the viability and potential of these emerging alternatives for our network,” he said.

“Our SF6 Management Strategy balances the cost-effective implementation of new insulation technology with our responsibility to ensure network safety and reliability.”

Transgrid selected two end-of-life circuit breakers at Gunnedah substation for replacement with non-SF6 technology following a risk assessment that matched equipment capability to network requirements.

Siemens Energy was awarded the contract to supply two 132kV dry air-insulated circuit breakers with vacuum interrupters following a global tender process and rigorous technical evaluation.

Transgrid is now monitoring their performance and developing standards for installation, operation and maintenance that will enable replication across the network.

“We are delivering the critical transmission infrastructure required to transition the grid from coal to renewable energy,” Mr Krstanoski said.

“Reducing our own greenhouse gas emissions is an important part of our role in mitigating climate change and decarbonising the grid for future generations to come.”

Transgrid is targeting net zero by 2040 for its Scope 1 emissions, comprising SF6 gas leaks and on-site fossil fuel use, on its way to an overall goal of net zero by 2050.

Media enquiries: James Atkinson 0475 965 030 / james.atkinson@transgrid.com.au