Call for Expressions of Interest for Essential System Services

AEMO is required by clause 3.15B.1 of the Electricity System and Market (ESM) Rules to conduct a Frequency Co-optimised Essential System Service (FCESS) expression of interest (EOI) process at least once every two years from the New Wholesale Electricity Market (WEM) Commencement Day, 1 October 2023.

The purpose of this EOI information request is to inform the Economic Regulation Authority (ERA) of the services which may be provided. The ERA can use this information in carrying out its monitoring and review functions under the ESM Rules, including its monitoring pursuant to clause 2.16.9, and in deciding whether to trigger the Supplementary Essential System Service Mechanism (SESSM) in accordance with clause 3.15A.2. This includes:

1. the criteria and processes used by AEMO for the procurement of Essential System Services through the Real-Time Market, the SESSM, and under any contracts entered into by AEMO; and
2. inappropriate and anomalous market behaviour, including behaviour related to market power and the exploitation of shortcomings in the ESM Rules or WEM Procedures by Rule Participants.

AEMO published the Call for Submissions on VendorPanel seeking submissions from new or existing providers of FCESS to accredit additional FCESS quantities. The EOI requests details including lead time required to develop and commission the facility or capability, location, quantity of FCESS which could be made available and costs.

All submissions:

1. Must be provided in good faith but are not binding on the respondent (clause 3.15B.6)
2. Are Confidential Information under the ESM Rules (clause 3.15B.7), subject to the requirement to provide the EOI forms and supporting information to the ERA
3. Will be provided to the ERA as soon as practicable following the closing date for the EOI (clause 3.15B.8)
4. May be used by the ERA as indicated above (clause 3.15B.9).

Submissions must be provided via VendorPanel in accordance with the Call for Submissions Form by 5.00pm AWST on Tuesday 30 September 2025.

Interested stakeholders should register with VendorPanel in advance to be notified when any supporting documentation, such as clarifications to questions, is published.

Queries should be submitted by email to [email protected].

FCESS Markets

The New WEM commenced on 1 October 2023, including markets for five Frequency Co-optimised Essential System Services:

1. There are two Regulation services, measured in megawatts (MW) of response capability, which frequently adjust the Injection or Withdrawal of a Facility in accordance with an AEMO centralised control scheme in order to assist in maintaining the SWIS Frequency according to the Frequency Operating Standards. The markets for Regulation are:
   • Regulation Raise, that operates to raise the SWIS Frequency; and
   • Regulation Lower, that operates to lower the SWIS Frequency.
2. There are two Contingency Reserve services, measured in MW, of holding response capability associated with a Facility in reserve so that the relevant Facility can rapidly adjust Injection or Withdrawal in order to assist in maintaining the SWIS Frequency according to the Frequency Operating Standards after a Contingency Event. The markets for Contingency Reserve are:
   • Contingency Reserve Raise, that enables a Facility to adjust Injection or Withdrawal to raise the SWIS Frequency; and
   • Contingency Reserve Lower, that enables a Facility to adjust Injection or Withdrawal to lower the SWIS Frequency.
3. Rate of Change of Frequency Control Service (“RoCoF Control Service”), measured in MW.s, provides Inertia which provides instantaneous response to slow down the rate of change of the SWIS Frequency.

The ESM Rules also include Essential System Services (ESS) which are not related to managing frequency and not included in this EOI.

All providers of FCESS must be accredited by AEMO. Details of accreditation requirements, including relevant WEM Procedures, are available on the AEMO website.

A description of FCESS requirements and the location of historical data is provided in the attached document.