Last updated: 02 Jun 2026
Search
Last updated: 03 May 2023
Demand side participation
Last updated: 13 Sep 2022
Frequency keeper selection
Last updated: 11 Jun 2026
Black start
Black start is the first step in the process of system restoration in the unlikely event of an island-wide black-out.
Last updated: 12 Dec 2023
Voltage support
Last updated: 11 Jun 2026
Over frequency reserve
Over-frequency reserve is provided by generating units that can be armed when required and automatically disconnected from the power system due to a sudden rise in system frequency.
Last updated: 11 Jun 2026
Instantaneous reserve
Instantaneous reserve is generating capacity, or interruptible load, available to operate automatically in the event of a sudden failure of a large generating plant or the HVDC link.
Last updated: 11 Jun 2026
Frequency keeping
Frequency keeping services are required to manage short term supply and demand imbalances to ensure that the system frequency is maintained at or near 50 Hz.
Last updated: 23 Dec 2025
Current contracted providers
Last updated: 26 Mar 2026
About ancillary services
We procure ancillary services to support the reliable operation of the power system & assist us to meet our Principal Performance Obligations specified in the Electricity Industry Participation Code.