The Australian Energy Market Operator (AEMO) has released a suite of technical reports to kick off modelling for the 2026 Integrated System Plan (ISP).
The release marks the halfway point in the two-year development cycle for the national energy roadmap.
The 2025 Inputs, Assumptions and Scenarios Report (IASR), the Electricity Network Options Report, and the Gas Infrastructure Options Report will form the foundation for AEMO’s next round of long-term planning. The Draft 2026 ISP is due for consultation in December.
More than 1,100 stakeholders contributed to the consultation process, including 240 formal submissions.
“This high level of engagement is critical to preparing a well understood and robust ISP,” AEMO Executive General Manager of System Design, Merryn York, said.
The 2026 ISP will expand its modelling scope in line with Energy and Climate Change Ministerial Council recommendations, adding analysis of consumer energy resource integration and east coast gas market capability alongside traditional transmission planning.
The IASR retains three core planning scenarios – Slower Growth, Step Change and Accelerated Transition – covering variations in demand growth, electrification, consumer energy uptake, and emerging clean energy industries.
Each is modelled under mandated emissions targets set in the National Electricity Rules.
The Electricity Network Options Report lists more than 100 potential transmission projects, from conceptual upgrades to advanced actionable developments progressing through the RIT-T or jurisdictional approvals. For the first time, it incorporates distribution network considerations. Updated cost data shows transmission project costs have risen sharply, in some cases doubling since the 2024 ISP.
“These revised cost inputs are material, and we will consider them carefully as we model an optimal development path,” Ms York said.
The Gas Infrastructure Options Report adds detailed inputs on supply, storage, and pipeline capacity to guide modelling of gas-powered generation (GPG). For the first time, AEMO will align ISP gas modelling with its Gas Statement of Opportunities, considering both electricity sector needs and broader east coast gas demand.
AEMO will present the reports in a webinar on 12 August.