On 17 July 2025, the AEMC published a draft determination and draft rule that would introduce two new projected assessment of system adequacy (PASA) forecasts. These would cover supply, demand, and infrastructure capacity of the East Coast Gas System (ECGS) over seven-day and 12-month outlooks.

We are seeking stakeholders’ feedback on the draft rule, with stakeholder submissions due by 28 August 2025.

The draft rule would introduce a PASA that consists of two forecasts that bridge the gap between the present and the GSOO, which AEMO would publish on its website:

• short-term (ST) PASA with a daily publication frequency and seven-day horizon
• medium-term (MT) PASA with a weekly publication frequency and 12-month horizon.

Each PASA would include a forecast of demand, supply, and infrastructure availability. The ST PASA would also include any identified threats to reliability and supply adequacy (RSA) over the next week.

The projected assessment would be based on information collected from participants and/or modelled by AEMO on market, non-market, storage, LNG export and gas powered generator demand, and supply and infrastructure availability. Most of this information is already collected under the current rules.

The PASA would be generally based on information that is already collected, both through the bulletin board (BB), and through the information uplift provided by the stage one RSA reforms. In addition, we have identified several changes to the ECGS information disclosure regime that are necessary to ensure the PASA is produced from a complete, high-quality dataset.

AEMO would begin producing the PASA from 3 May 2027, and would recover its implementation costs from participant fees.

The AEMC requests submissions to the draft determination by 28 August 2025. We expect to publish a final determination for the rule change in October 2025.

Background

On 21 January 2025, we 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 proponents).

The proponents considered the ECGS currently lacks a complete set of high-quality information on the adequacy of gas supply and transportation capability to meet demand over the intra-year period. They were of the view that this is reducing stakeholders' ability to make timely, informed and efficient decisions about how to plan for and manage any emerging RSA threats.

To address this issue, they proposed to introduce two Australian Energy Market Operator (AEMO) produced forecasts in the ECGS over the intra-year horizon:

• ST PASA – over a rolling seven-day horizon
• MT PASA – over a rolling 12-month horizon

This is one of four rule changes proposed as part of Stage 2 of the RSA reforms for the ECGS. We included comprehensive information on stage 1 RSA reforms and an overview of the stage 2 rule change requests in our  background paper,  published alongside the ECGS reliability standard and associated settings consultation paper. The background paper also includes information on relevant features of the ECGS and the gas markets.

On 10 April 2025, the Commission published a consultation paper and initiated the rule change process. Submissions were due by 8 May 2025, with 15 submissions received.