Transgrid’s global search to future-proof our power system as coal retires

The transmission giant recently turned to the world’s innovators to find efficient and cost-effective technology to develop a new approach to network system strength, as coal generators change operating patterns or retire in favour of renewable energy.

Executive General Manager of Network Marie Jordan said: “We are acting now so we have the time to ensure emerging technology is tried and tested before the need for additional system strength grows beyond 2025 as more coal generators retire.

“We have reached out to the global market to find robust and low-cost solutions to ensure a strong and resilient system in the event of a disturbance or fault in the future and we are very pleased numerous industry participants and innovators around the world want to join us on this important journey, to ensure we can safely and securely operate the power system into the future,” said Ms Jordan.

Transgrid is taking proactive action now to keep the network strong during the energy transition, with periods with up to 100 per cent instantaneous renewable energy possible in the next few years.

“Large spinning machines such as coal, gas and hydro generators have the ability to keep the grid stable and ride through disturbances, including lightning strikes or equipment trips. However, existing ‘grid-following’ renewable energy sources such as wind and solar don’t have the same capabilities and need to follow a strong signal from the network - or will disconnect,” Ms Jordan said.

Transgrid’s recent Expression of Interest process resulted in more than 60 potential technology solutions, including over 10GW of existing or conversions of existing synchronous generators, a pipeline of more than 10GW of innovative grid-forming batteries, and over 5GW of other new generation and energy storage projects, including pumped hydro and gas.

“We are also looking at tested and cost-effective solutions such as synchronous condensers and will be drawing on learnings from the South Australian experience in installing four synchronous condensers to provide system strength and inertia.

“Due to the growing penetration of inverter-based renewables in Australia, our system strength requirements exceed the complexity and scale of other international power systems.

“Boosting our system strength is a key component of our broader efforts to ensure system security, including accelerating the delivery of nation-critical transmission infrastructure to connect renewables and storage capacity to maintain energy reliability for consumers as we transition away from thermal generation.”

Transgrid is undertaking a Regulatory Investment Test for Transmission (RIT-T) process to identify existing and new sources of system strength as thermal generators retire.

Submissions for the Project Specification Consultation Report (PSCR) and the Expression of Interest (EOI) for market-based (or non-network) services closed at the end of March, as part of Transgrid’s efforts to meet system strength requirements from 2025 and beyond.

Transgrid is now carrying out a comprehensive Expression of Interest assessment process and portfolio optimisation and market model steps to identify the optimal combination of network and non-network solutions that meet NSW’s system strength requirements with the greatest benefits to consumers.

A Project Assessment Draft Report (PADR), including a full quantitative analysis of all credible options, is expected to be published in late 2023 for consultation.

For more information visit our System Strength page.

*System strength is the ability of the power system to maintain and control the voltage waveform at any given location during steady state operation and following a disturbance.

Transgrid media contact:

Mark Nolan 0429 047 136