AEMO recently consulted on two significant reports that it proposes to use in its 2025-26 forecasting and planning activities for the 2026 ISP.
Draft 2025 Inputs, Assumptions and Scenarios Report
Published every two years, the Draft 2025 Inputs, Assumptions and Scenarios Report was issued for consultation in two stages.
AEMO received 36 submissions on Stage 1. The report focused on future energy scenarios which represent plausible future worlds within which the energy transition occurs. Each scenario evaluating the power system needs to achieve government policy and reflect broader uncertainties affecting the energy transition. AEMO also considered additional inputs and assumptions, including the need to better integrate gas into the ISP, enhanced demand forecasting and opportunities for consumer energy resources.
The stage 2 consultation received 27 submissions. The report focused on the inter-related components that decarbonise the NEM such as carbon budgets, electrification (including electric vehicles), energy efficiency and fuel switching (including hydrogen and biomethane).
Stakeholder feedback is now being considered and the final report will be issued in July 2025.
ISP Methodology
The ISP Methodology comprises modelling and cost benefit analysis approaches that help AEMO to prepare the ISP.
AEMO is required to review the Methodology every four years and, this year, it is also being updated to incorporate the Energy Ministers’ response to the ISP review.
AEMO published a draft report and a Draft ISP Methodology on 13 March 2025 and stakeholder feedback was specifically sought on changes proposed in the issues paper, namely:
- Integrating gas in the ISP
- Improving demand side modelling
- Assessing actionability of transmission projects.
- Enhancing selected ISP modelling approaches.
The Draft ISP Methodology consultation closed on 14 April 2025 and 21 submissions were received. The overall sentiment was supportive of the proposed changes, and recommendations were given for further enhancements. Most recommendations were about CER and distributed resources, with some for gas, perfect foresight and hydrogen. The final report and ISP Methodology will be published on 25 June 2025.
AEMO thanks all stakeholders who have made a submission to these consultations. Their contributions help ensure that the 2026 Integrated System Plan will be fit for purpose in the context of Australia’s energy transition.