The Australian Energy Market Commission (AEMC) has published a final rule to improve the quality and transparency of information that is collected and published about the future availability of generators as part of the medium-term projected assessment of system adequacy (MT PASA) process. 

The final rule is identical in substance to the draft rule that was published for feedback in May 2022.

Improving the quality and transparency of information about future generator availability, and making it publicly available, can give stakeholders a more detailed view about what the supply outlook may look like under different future scenarios. 

This includes scenarios where less flexible generators make changes to their operating schedules as they near the end of their technical life.

This will contribute to better operational, planning, policy and investment decisions as the power system transitions and ultimately support a more coordinated approach to delivering a lower emissions electricity system that is reliable and affordable.

Final rule

The final rule builds on existing MT PASA requirements, which require generators to indicate how many megawatts (MW) they could make available each day over the medium term horizon (this is between seven days and 36 months into the future). In addition to providing the MW availability, the final rule requires scheduled generators to also
provide a:

• unit state — that is, a scheduled generating unit’s availability or unavailability and the reason for its availability or unavailability (referred to as unit state, reason or reason code)
• unit recall time — to indicate the period in which the plant could be made available under normal conditions after a period of unavailability. AEMO would determine which unit states will require a unit recall time to be submitted.

This final rule actions one of the Energy Security Board’s (ESB) post-2025 recommendations to improve resource adequacy outcomes in the National Electricity Market (NEM).

The final rule is consistent with the main purpose of the PASA, which is to ensure that “...participants are properly informed to enable them to make decisions about supply, demand and outages of transmission networks...” and supports other PASA outcomes such as the publication of “sufficient information to allow the market to operate effectively with a minimal amount of intervention by AEMO.”

AEMO will develop the form and approach for collecting and publishing both reason codes and recall times and this will be reflected in updates to the Reliability standard implementation guidelines (RSIG)  and the MT PASA process description. This work will include determining which unit states will require a unit recall time to be submitted. AEMO is required to consult with stakeholders through the Rules consultation procedures when updating the RSIG.

Implementation timeframes

The key implementation dates for the rule are as follows:

• 30 April 2023 – AEMO guideline updates to be completed in consultation with stakeholders
• 9 October 2023 – information collection and publication requirements commence
• 3 June 2024 – requirements for bi-directional units commence

Rule change request and background

On 15 December 2021, the AEMC received a rule change request from AEMO to amend the National Electricity Rules (NER) to collect and publish more detailed information about scheduled generator availability in the MT PASA. This would help manage challenges as the NEM power system transitions.

On 3 February 2022, the AEMC published a consultation paper seeking stakeholder views on the proposal; ahead of a draft determination on 26 May 2022.

The draft determination was extended from statutory timeframes to allow for further consultation with participants and market bodies to respond to complex issues raised in stakeholder submissions to the consultation paper.

Submissions to both these documents can be found below, with feedback considered and responded to in the final determination.