Transgrid has published the Project Assessment Conclusions Report (PACR) for Maintaining system strength requirements in NSW. The PACR has been prepared as the final step in the Regulatory Investment Test for Transmission (RIT-T) process and follows the Project Assessment Draft Report (PADR) published in June 2024 and the PADR Supplementary Report published in October 2024.
The forecast retirement of NSW coal generators in the coming decade (80% retiring by capacity) and the growth of inverter-based resources (IBRs) is driving an urgent need to add new sources of system strength. As the System Strength Service Provider (SSSP) for NSW, Transgrid has system strength obligations under the National Electricity Rule (NER), Section 5.1.14, to provide the minimum and efficient levels of system strength forecast by AEMO at each of the NSW system strength nodes, from December 2025 into the future.
Outcomes of the PACR have been shaped by consultation throughout the RIT-T process, including eight submissions and significant Joint Planning with industry bodies. Non-network solutions were identified through an extensive Expression of Interest process which led to more than 60 individual non-network solutions being considered.
To meet system strength requirements, the PACR assessment identified a preferred credible portfolio option from more than 100 individual system strength solutions. The preferred option contains:
- ten Transgrid synchronous condensers;
- modifications to and redispatch of synchronous generators;
- 5 GW of grid-forming batteries; and
- 4 smaller synchronous condensers or 200MW of grid-forming batteries for the Hunter-Central Coast REZ (to be determined through a non-network procurement process).
The portfolio is expected to deliver over $8.8 billion in present value net benefits over the assessment period.
Due to the long-lead time of new build system strength solutions, the preferred portfolio option does incur a risk of gaps in system strength in NSW in 2027/28 to 2028/29. The PACR identifies if the procurement of synchronous condensers can be ‘accelerated’ and delivered earlier, there are significant additional net economic benefits and risks of gaps are closed in 2028/29.
In accordance with the requirements of the National Electricity Rules, a summary of the PACR is made available on the AEMO website. The PACR can also be found on Transgrid’s website.