East Coast Gas Reforms
In August 2022, Energy Ministers agreed to take a range of actions to support a more secure, resilient and flexible east coast gas market. These actions include urgent regulatory amendments that empower the Australian Energy Market Operator (AEMO) to better manage gas supply adequacy and reliability risks ahead of winter 2023 (Stage 1); and in the longer term, progress development of further supply adequacy and reliability measures which will help to guide how AEMO delivers its new functions (Stage 2).
Stage 1 ECGS RSA reforms
AEMO operationalised Stage 1 of the east coast gas system reliability and supply adequacy (RSA) reforms ahead of winter 2023. The Stage 1 RSA reforms expanded AEMO’s powers under the National Gas Law, National Gas Rules and the National Gas Regulations to better manage gas supply adequacy and reliability risks with tools to monitor, signal and manage gas supply shortfalls.
The following document summarises AEMO’s responses to Frequently Asked Questions (FAQs) on the implementation of the Stage 1 RSA reforms.
Stage 2 ECGS RSA reforms
On 8 December 2023, Energy Ministers agreed to progress Stage 2 measures of the east coast gas system (ECGS) RSA framework, expected to build on Stage 1 of the reforms. Energy Senior Officials submitted four rule changes to the AEMC as part of Stage 2 of the RSA reforms for the ECGS:
ECGS Projected Assessment of System Adequacy
Background
On 21 January 2025, the AEMC received a rule change request from Energy Senior Officials on behalf of the Energy Ministers’ Sub Group and the Honourable Lily D’Ambrosio MP. The rule change request proposed to introduce two AEMO-produced forecasts in the ECGS over the intra-year horizon:
- ST PASA reported daily over a 7-day outlook
- MT PASA reported weekly at daily granularity over a 12-month outlook.
The proposed rule change seeks to address the lack of a regular, systematic, intra-year assessment of reliability and supply adequacy in the ECGS. The rule change request highlights that the tightening supply-demand balance, together with the energy transition and increasing interrelationship with the NEM, is expected to result in the ECGS becoming more exposed to intra-year reliability and adequacy threats. There is a greater risk therefore that supply interruptions may occur unexpectedly, limiting the ability of market participants to respond in a timely, informed and efficient manner. In addition to hindering market-led responses, the lack of a regular and systematic intra-year assessment could also hinder AEMO’s ability to respond efficiently when the market fails to respond. It may also limit the ability of policy makers and jurisdictional Ministers to make timely, informed and efficient decisions.
The AEMC has progressed this rule change request and on 17 July 2025 published a draft determination and draft rule.
High-Level Implementation Assessment (HLIA)
AEMO has produced a High-Level Implementation Assessment as the first stage of AEMO’s east coast gas system (ECGS) Projected Assessment of System Adequacy (PASA) implementation process under stage 2 of the ECGS reliability and supply adequacy reforms. It outlines high-level views of AEMO’s system, process and operational changes and the indicative timeline that would likely be required. It also provides a general indication of what these changes may mean for market participants.
AEMO welcomes any stakeholder feedback on this HLIA by COB Thursday, 11 September 2025 via email to [email protected].