Transgrid has recently published a Project Assessment Draft Report (PADR) for Maintaining system strength requirements in NSW. Publication of this PADR represents the second step in the RIT-T process.
As the System Strength Service Provider for NSW, Transgrid are required to make sufficient system strength available as specified by AEMO, under NER:
Clause 11.143.15 to address the system strength Shortfall declared by AEMO from 1 July 2025 to 1 December 2025 at Newcastle and Sydney West1, and
Schedule 5.1.14 to provide the minimum and efficient levels of system strength forecast by AEMO at each of the NSW system strength nodes from2 December 2025 into the future.
Transgrid have commenced this RIT-T to assess options to ensure the above NER requirements are met. Transgrid considers that this will enable it to identify the optimal solution to meet both the short-term and long-term needs.
To achieve this, Transgrid and Baringa Partners have developed a power system and market modelling methodology to account for the complex, non-linear nature of system strength and to enable us to identify optimal portfolios of solutions. This involved the consideration of over 60 non-network solutions and 40 network solutions to determine the optimal portfolio that would produce the highest net energy market benefits.
The PSCR and accompanying non-network Expression of Interest were released in December 2023. Transgrid received five submissions to the PSCR and 25 submissions to the EOI, representing over 60 non-network solutions. PSCR submissions intended for the public are available via Transgrid’s website.
The results of the PADR assessment find that the preferred credible portfolio option involves fourteen synchronous condensers required by 2032/2033, modifications to or redispatch of synchronous generators and 4.8 GW of grid-forming batteries. This option has a forecast total capital cost of $2,580 million over the 20-year assessment period.
However, Transgrid has also found the potential for increased market benefits with other portfolio options, if the credibility of certain elements can be confirmed. Hence, through the RIT-T process, Transgrid will work to clarify and resolve the uncertainties associated with these portfolio options, focussing on the possible acceleration of synchronous condenser delivery and the technical feasibility of a confidential proposal.
Transgrid welcomes written submissions on materials contained in this PADR. Submissions are due on 2 August 2024 to regulatory.consultation@transgrid.com.au.
In accordance with the requirements of the National Electricity Rules, a summary of the PADR is made available on the AEMO website. A copy of the PADR can be obtained from Transgrid’s website.