Ancillary services are those services that are necessary to maintain the system security and reliability, and ensure appropriate quality of electricity supply. These services include:
- Load Rejection
- System Restart
- Spinning Reserve
- Dispatch Support
- Load Following
Apart from Load Following Ancillary Service (LFAS), all other services are contracted by the System Manager. LFAS is bought and sold in the market specifically designed for it.
The ERA is required to determine regulated prices for load rejection, system restart and spinning reserve services. In addition, System Management must obtain the approval of the ERA before entering into a contract for dispatch support. The ERA must determine whether the contract would achieve the lowest cost to market. System Management is also required to submit its ancillary services requirements and plan to the ERA for audit and approval each year.