On 4 September 2025, the Reliability Panel published a draft determination for the Review of the System restart standard (Standard). The Draft determination includes a revised draft Standard along with draft recommendations for actions to enhance system restart preparedness.

The Panel’s draft determination is informed by technical advice provided by the Australian Energy Market Operator (AEMO) that describes the challenges and opportunities related to system restart in the context of the transitioning power system.

In response to AEMO’s technical advice, the draft Standard provides greater flexibility for AEMO to support its procurement of System restart ancillary services (SRAS) to meet the needs of the changing power system.

The Panel invites interested stakeholders to attend a public forum on the draft determination on 22 September 2025. Register here.

Submissions to the draft determination are due by 16 October 2025.

Nb. An updated version of the draft determination was published on 17 September 2025 to correct an error in the earlier published version. The correction related to figure B.7 which incorrectly showed the estimated total cost of SRAS (2024 – 25) for South Australia as $8.8m and the total benefit of the 1:18 year outage for the 36hr outage delay as $101m. The correct values are $4.5m and $109m respectively.

The transition introduces challenges in ensuring system restart capability

AEMO has identified several challenges for the provision of System Restart Ancillary Services (SRAS) and system restart planning due to ongoing changes in the power system:

• there is a reducing availability and participation of existing restart units which is impacting the ability to meet the Standard.
• high concentrations of distributed photovoltaic (PV) generation at consumer locations can impact the ability to stabilise restart islands.
• resiliency and flexibility is required in restart pathways as the power grid becomes inherently more complex.

Summary of the draft standard

In response to AEMO’s technical advice, the draft Standard provides greater flexibility to support procurement of SRAS to meet the needs of the changing power system. The key elements of the revised draft standard are:

• Revised targets for system restoration to support enhanced restart preparedness & procurement of restoration support services.
• Increased aggregate required reliability for SRAS in the mainland NEM regions reflecting the Panels analysis of the value provided by a reliable system restart capability.
• A requirement for AEMO to consider advice provided by a regional Jurisdictional system security coordinator with respect to the strategic location of SRAS and the potential impact to sensitive loads such as aluminium smelters.

The Panel propose for the revised standard to take effect from 1 July 2027.

Summary of draft findings on the NEM System restart frameworks

The Panel considers the current system restart regulatory framework, alongside the revised draft Standard, provides AEMO sufficient flexibility and guidance to deliver adequate system restart capability through the energy transition.

At the same time, the Panel has developed a series of recommended actions for AEMO to undertake to improve system restart preparedness and adapt to the changing needs of the power system.

The draft recommendations relate to:

• proactive procurement of SRAS to meet power system needs
• identification of system restart needs in advance, supported by future focussed restoration modelling
• Enhancement of information provided to AEMO through local black system plans.

Initiation of the review

On 12 December 2024, the Reliability Panel (Panel) published the terms of reference and Issues paper to commence its periodic review of the Standard.

Background

In the event of a major supply disruption, SRAS or restart services may be used to supply sufficient energy to restart power stations in order to begin the process of restoring the power system. Such an event, also known as a black system event, typically involves a substantial loss of generation and supply to customer load.

Under clauses 8.8.1(a)(1A) and 8.8.3(aa) or the National Electricity Rules (NER), the Panel is responsible for determining the Standard. The Standard sets out several key parameters for system restoration, including the speed of restoration, how much supply is to be restored and the level of reliability of SRAS and guides AEMO’s procurement of SRAS.

The Standard is part of the system restart regulatory framework that relates to the requirements and responsibilities for the restoration of the power system following a major supply disruption that leads to the unplanned de-energisation of part of the transmission system.