WEM Electricity Statement of Opportunities

The Wholesale Electricity Market (WEM) Electricity Statement of Opportunities (ESOO) is an annual publication that provides reliability forecasts for the WEM over the 10-year outlook period.

The WEM ESOO assesses whether there is sufficient electricity generation, storage and demand side programme capacity to meet forecast annual electricity consumption and peak demand over the outlook period for Western Australia’s South West Interconnected System (SWIS).

The report is a key source of electricity supply, consumption and demand analysis that supports long-term investment and policy decisions in the SWIS.

The ESOO also plays an important role in the WEM’s Reserve Capacity Mechanism (RCM) process by forecasting the Peak and Flexible Reserve Capacity Targets (RCTs) for each Capacity Year in the outlook period, and by setting other parameters such as the duration requirement for batteries (ESR Requirement Duration).

2026 WEM ESOO

AEMO published the 2026 WEM ESOO report on 23 June 2026.

The 2026 WEM ESOO informs the planning and decision-making by WEM participants, investors and policymakers, by providing information on and projections of:

• annual electricity consumption and peak demand across a range of weather conditions and growth scenarios;
• expected available electricity supply from generation, storage, and Demand Side Programmes (DSP);
• forecasts of power system reliability and the balance between electricity supply and demand including expected unserved energy (USE) under various scenarios;
• Reserve Capacity Targets (RCTs), including the Peak RCT, which identifies the total capacity needed to meet the Planning Criterion, and the Flexible RCT, which identifies the flexible capacity needed to manage the largest expected Four-Hour Demand Increase (FHDI);
• Electric Storage Resources (ESRs) and DSP requirements, including the ESR Duration Requirement and DSP Dispatch Requirement, and
• potential investment needed to maintain power system reliability and security.

2026 Reserve Capacity Information Pack

The 2026 Reserve Capacity Information Pack for the 2026 Reserve Capacity Cycle is available in the links at the bottom of this page, along with historical information packs.

The 2026 Reserve Capacity Information Pack contains the following information:

• Reserve Capacity Requirement for the 2028-29 Capacity Years.
• Instruction on how to obtain the 2026 Request for Expressions of Interest (EOI) and the 2026 EOI summary from the WEM Website.

Feedback

AEMO welcomes feedback on the 2026 WEM ESOO.

Please direct any questions relating to the 2026 WEM ESOO to the WA Future System Planning & Forecasting team.

Email: [email protected]

For any questions relating to the Certified Reserve Capacity process for the 2026 Reserve Capacity Cycle, please email the WA Capacity Investment & Assessment team. 

Email: [email protected]

2026 WEM ESOO documents and supporting materials

Please note, an earlier version of the data register published on 23/06/2026 contained a minor error in Ch 2_F.15 H122, Ch 2_F.15 H170 and Ch 2_F.16 H42 and has been updated.

Previous WEM ESOO Documents