Our transparency review assesses whether AEMO was adequately transparent in explaining how it derived its inputs and assumptions that go towards developing the ISP. Our review is centred on AEMO’s explanations and is not intended to assess the merits of AEMO decisions.
The AER’s report considers that the majority of AEMO's inputs and assumptions have been adequately explained and AEMO has demonstrated that it has considered stakeholder feedback. However, the report identifies some inputs and assumptions that should be explained to further support and strengthen stakeholder understanding of key inputs and assumptions in the 2026 ISP. AEMO must provide further explanation on these issues as an addendum to the IASR and consult on these issues in the draft 2026 ISP.
As required by clause 5.22.9 of the National Electricity Rules, the AER is required to finalise this review one month after AEMO published its 2025 IASR on 31 July 2025. Transparency in understanding AEMO’s approach is important to promote stakeholder understanding of the inputs and assumptions used in the ISP, and how they have contributed to its outcomes.
The next transparency review is required following the release of the draft 2026 ISP in December 2025.
Please visit our system planning compliance page for more information on our compliance activities with regard to the ISP and previous transparency reports.