Draft 2026 Forecasting Assumptions Update

Timeline

Key contact

Email: [email protected]

Matter under consultation

AEMO delivers a range of forecasting and planning publications for the National Electricity Market (NEM) and Wholesale Electricity Market (WEM).

This consultation relates to proposed updates to assumptions to apply in the Reliability Forecast for the NEM and WEM Electricity Statements of Opportunities. This consultation provides transparency and stakeholder engagement opportunities on these assumptions in accordance with the Australian Energy Regulator's Forecasting Best Practice Guidelines (FBPG).

AEMO prepares the Draft 2026 Forecasting Assumptions Update, and an accompanying Draft Forecasting Assumptions Update Workbook which contains the updated data. This report complements the 2025 Inputs, Assumptions and Scenarios Report (IASR) that was finalised in July 2025.

This Draft 2026 Forecasting Assumptions Update uses the latest information available to update assumptions specifically relevant to the reliability assessment for the 2026 Electricity Statement of Opportunities (ESOO).

The updates include (but are not limited to):

• Updated consumer energy resources, including home batteries and electric vehicles
• Draft 2025-26 GenCost report (developed by CSIRO).

Alongside AEMO’s Draft 2026 Forecasting Assumptions Update, CSIRO has published its draft GenCost 2025-26 report for consultation. GenCost, which is supported by AEMO, provides the cost of new build electricity generation in terms of capital costs and comparative costs of delivered electricity from individual technologies.

The draft GenCost 2025-26 report highlights that renewables (led by solar PV and onshore wind) form the basis for the least-cost generation mix, and the role of electricity is expected to increase materially over the next 30 years with electricity technologies presenting some of the lowest cost abatement opportunities.

For more information on the draft GenCost 2025-26 report, visit www.csiro.au/gencost. 

The Draft Forecast Assumptions Update included questions for stakeholder feedback on PV, battery and EV uptake forecasts. To support consumer advocate engagement, AEMO held a consumer advocates verbal submission session on 2 February 2026.

Submissions on the Draft 2026 Forecasting Assumptions Update and Draft 2025-26 GenCost report closed on Monday, 2 February 2026. Submissions received are published below, subject to AEMO’s Consultation submission guidelines.