Essential System Services Procurement
The Pilbara ISOCo is required to procure frequency control and spinning reserve services (Essential System Services or ESS) to enable its control desk to maintain the power system within the prescribed technical envelope and, should this cease being the case, return it to a secure state as soon as practicable.
Each year, ISO publishes an Annual Report into the Cost and Effectiveness of ESS:
- 2025-26 Annual Report into the Cost and Effectiveness of ESS
- 2024-25 Annual Report into the Cost and Effectiveness of ESS
- 2023-24 Annual Report into the Cost and Effectiveness of ESS
Energy Balancing and Settlement
The Rules place an obligation on covered networks to balance electricity generation and consumption. Practically, this is not always possible, and therefore the ISO has implemented an energy balancing and settlement regime in accordance with Chapter 8 of the Rules and the Energy Balancing and Settlement Procedure to allocate the cost of Essential System Services and address energy imbalances.
The Energy Balancing and Settlement Engine Stakeholder Guide provides participants with further information on energy balancing and settlement.
The Energy Balancing and Settlement Variables, including the Administered Price, Administered Penalty Price and Tolerance Margin, are set according to the Rules and methodology outlined in the Procedure.
The following templates are to be used when submitting information outlined in the Procedure:
- ISO Template – Balancing Nomination Notice
- ISO Template – Appointment of Nominator – Single Balancing Point, Multiple Users
- ISO Template – Appointment of Nominator – Single User, Multiple Balancing Points
The ISO engaged ACIL Allen to conduct an independent review of the EBAS Engine and Frequency Control ESS load swing calculations tool to provide independent assurance that energy and ESS are being settled in accordance with the Rules. Further information can be found here: