2025-26 Inputs, Assumptions and Scenarios

AEMO delivers a range of planning and forecasting publications to inform decision making including the Electricity Statement of Opportunities (ESOO), the Gas Statement of Opportunities (GSOO) and the Integrated System Plan (ISP).

AEMO strives to ensure its planning and forecasting publications are of highest quality, with data that is fit for purpose and industry-reviewed and processes that are transparent. To build confidence in the forecasts, and help decision makers understand the outcomes, AEMO consults on and publishes its scenarios, inputs, assumptions and methodologies. Confidential information is withheld from public release, but is incorporated in the modelling conducted, if necessary, to deliver assessments that are as accurate as possible.

2025 Inputs, Assumptions and Scenarios 

AEMO has consulted on the Draft 2025 Inputs, Assumptions and Scenarios Report (IASR). Stage 1 of the Draft 2025 IASR was published on 11 December, and consultation submissions closed on 11 February 2025. Stage 2 was published on 28 February 2025 and consultation submissions closed on 31 March 2025. The final 2025 IASR will be published in July 2025.

2025 Electricity Network Options Report and 2025 Gas Infrastructure Options Report 

AEMO is consulting on the Draft 2025 Electricity Network Options Report, published on 22 May 2025, and submissions close on 23 June 2025. This report identifies potential augmentation options in electricity networks within the National Electricity Market, and now considers both transmission and distribution opportunities.

AEMO is consulting on the Draft 2025 Gas Infrastructure Options Report, published on 22 May 2025, and submissions close on 23 June 2025. This new report outlines gas infrastructure options and gas infrastructure cost components to ensure that electricity investments – particularly in gas powered generation – consider and are resilient to the capacity, availability and limitations of gas as a fuel for electricity generation.