Implementation of the ECGS PASA, ERSAA and SoLR rule changes

Timeline

Overview

AEMO is consulting on proposed procedure changes to implement the East Coast Gas System (ECGS) Projected Assessment of System Adequacy (PASA), Enhancing Reliability and Supply Adequacy Arrangements (ERSAA) and Supplier of Last Resort (SoLR) rule changes, finalised by the Australian Energy Market Commission on 25 June 2026.

The consultation covers amendments to the ECGS Procedures, Gas Bulletin Board Procedures, STTM Procedures and DWGM Wholesale Market Operation Procedures, together with the introduction of new SoLR Procedures.

AEMO invites stakeholders to review the Proposed Procedure Change (PPC) and accompanying draft Procedures and provide feedback on the proposed arrangements.

Proposed changes

The proposed changes include:

• PASA: determining PASA regions and specifying the inputs, methodologies, outputs and publication arrangements for short- and medium-term assessments.
• Risk or threat assessment: establishing probability and severity assessment methodologies and a three-tier risk or threat classification framework.
• SoLR: establishing arrangements for procuring and activating SoLR services, including cost recovery and proceeds distribution.
• Participant reporting and market processes: updating Bulletin Board, STTM and DWGM procedures to support the new arrangements.

Changes to the ECGS Guidelines will be subject to a separate consultation under rule 8 of the National Gas Rules.

Engagement

AEMO plans to hold a stakeholder workshop on 19 November 2026 to discuss the proposed procedure changes implementing the ECGS PASA, ERSAA and SoLR rule changes. The workshop will provide an opportunity for stakeholders to ask questions to support the preparation of their submissions.

Submissions

AEMO invites written submissions on the proposed procedure changes by 5:00 pm AEDT on 10 December 2026.

Please email submissions to [email protected].

All submissions will be published on AEMO’s website unless marked confidential. Please clearly identify any confidential information in your submission.