The FESO is a detailed, scenarios‑based study that guides planning and infrastructure investment in the SWIS to 2050. Each scenario presents a distinct and plausible view of how electricity demand and supply in the SWIS may evolve over time.
FESO 2027 will explore how current and future trends and commitments - including, rising demand, supply chain challenges, emerging technologies, net zero by 2050, economic growth and population growth - could shape the evolution of the SWIS.
By providing a clear, whole-of-system outlook, the FESO will help inform Government and private sector investment decisions and ensure that the SWIS continues to provide secure, reliable, and affordable electricity.
The inaugural system plan, the Whole of System Plan (WOSP), was released by the Minister for Energy in October 2020. DEED has since undertaken multiple system planning activities, including the SWIS Demand Assessment, the SWIS Transmission Planning Update and the SWIS Transmission Plan.
The FESO will fulfil the system planning requirements of a Whole of System Plan under the Electricity System and Market (ESM) Rules, section 4.5A.
FESO 2027 is being delivered by a project team led by the Department of Energy and Economic Diversification (DEED) and supported by the Australian Energy Market Operator (AEMO), Western Power and modelling consultants.
To ensure the FESO is informed by a broad range of government, industry and consumer groups, we are consulting with industry participants, potential investors, policymakers, and consumers.
Stakeholder Engagement
Energy Policy WA ran a public consultation between 9 and 30 October 2026 on the draft Methodology, Scenarios and Assumptions (MISA), listed below. The MISA describes the modelling framework, the three scenarios being tested, the principal assumptions and data sources, and the methods used to turn those inputs into FESO results. The public consultation period is now closed.
Timeline
There will be opportunities for stakeholder engagement throughout the development of FESO 2027. Engagement timelines are outlined below, and will be updated as additional dates are confirmed.
| Event | Date | Information |
|---|---|---|
| Commencement of the FESO | 2 July 2026 | Announcement |
| Webinar 1: Introduction to the FESO | 15 July 2026 | |
| Public consultation period: Draft MISA | 9 October 2026 to 30 October 2026 |
|
| Webinar 2: Methodology, Inputs, Scenarios & Assumptions) | 19 October 2026 | Presentation Webinar recording |
| Event: Draft FESO 2027 | ||
| Public consultation period: Draft FESO 2027 | ||
| Event: Launch of FESO 2027 |
