On 15 December 2023, we released our final decision on Transgrid's revenue determination for the 2024-29 regulatory control period for the Waratah Super Battery project. 

Our final decision is set out in the determination document below and accompanying attachments. As a number of issues were settled at the draft decision stage or required only minor updates, we have not prepared all attachments. In these circumstances our draft decision reasons form part of this final decision. The draft decision attachments that haven’t changed and may be referenced as part of this decision are Appendix A – Assessment approaches, Appendix C – Adjustment Mechanisms. Confidential Appendix D – Rate of return averaging periods will not be published.

On 19 June 2024, the AER released its reviewed and remade decision on the costs of the non-contestable components of the Waratah Super Battery project for the 2024–29 regulatory period. This is because a material error was identified in our December 2023 decision, which was the omission of an adjustment mechanism to carry out the AER’s intention to update the return on equity if required. The remade decision includes an additional adjustment mechanism to update the return on equity.