In line with the adjustment mechanisms in our remade final decision (June 2024), we have adjusted revenue for the Waratah Super Battery project by:

• Updating the return on equity for 2024–29. We calculated the applicable rate of return in accordance with the 2022 Rate of return instrument and using the risk free rate averaging period nominated by Transgrid and accepted by the AER. As a result of this update, the updated return on equity for 2024–29 is 7.90 per cent (nominal).
• Updating the return on debt for 2024–25. We calculated the applicable rate of return in accordance with the 2022 Rate of return instrument and using the return on debt averaging period nominated by Transgrid and accepted by the AER. As a result of this update, the updated return on debt for 2024-25 is 6.11 per cent (nominal).
• Updating inflation for the pre-period 2023–24 and the first year of the regulatory control period, 2024–25. We calculated inflation using the consumer price index as specified in the inflation adjustment mechanism. As a result of this update, the updated rate of return for the pre-period 2023–24 is 6.93 per cent (nominal vanilla), and the inflation rate for 2024–25 is 4.05 per cent.

We have amended the quarterly schedule of payments (appendix B to the Final decision) to reflect the impact of each of these adjustments, in line with the annual adjustment process.

Update - 2025–26 annual adjustment

In line with the adjustment mechanisms in our remade final decision (June 2024), we have adjusted revenue for the Waratah Super Battery project by:

• Updating the return on debt for 2025–26. We calculated the applicable rate of return in accordance with the 2022 Rate of return instrument using the return on debt averaging period nominated by Transgrid and accepted by the AER. As a result of this update, the updated return on debt for 2025–26 is 6.07% (nominal).
• Updating inflation for 2025–26. We calculated inflation using the consumer price index as specified in the inflation adjustment mechanism. As a result of this update, the inflation rate for 2025–26 is 2.42%. 

On 31 March 2026, we received an annual revenue adjustment proposal from Transgrid relating to the Waratah Super Battery – Network augmentation and SIPS control system (WSB Non-contestable Project). 

On 1 May 2026, Transgrid submitted a revised annual revenue adjustment proposal. This revised proposal excludes the revenue adjustment related to Paired Generation Costs, which was included in Transgrid’s 31 March proposal. We expect this revenue adjustment will instead be included in Transgrid’s annual adjustment proposal in 2027.

Transgrid’s proposal included routine adjustments to replace placeholder financial inputs determined in our final decision with actual financial inputs. It also included a non-routine expenditure adjustment. We will assess Transgrid’s proposal against the requirements in the revenue determination, EII Regulation and the Revenue determination guideline for non-contestable network infrastructure projects (non-contestable Guideline).

Following our assessment, we will determine an updated maximum allowed revenue, quarterly schedule of payments and revenue models for this project. Consistent with our non-contestable Guideline, we will endeavour to complete this process within 42 business days.