The AEMC has released a consultation paper on a proposed rule change from AEMO to change notification requirements related to routine testing of system restart ancillary services (SRAS).

Restart services are provided by generators with specialised equipment which allows them to restart after a system-wide blackout without needing electricity from the grid. AEMO recently enhanced the testing regime for these restart services to include a ‘short notice’ test, where  AEMO gives the generator five business days’ notice of the test date.

However, under the National Electricity Rules, generators contracted to provide SRAS must give the relevant network service provider at least 15 business days’ notice of any test of connected equipment that would require changes to its normal operation at the connection point.

AEMO therefore proposes an amendment to the rules to exempt generators from notifying network services providers about a short notice test of SRAS capability. Instead, AEMO will work directly with network service providers to plan the test date.

As the AEMC considers this to be a non-controversial rule change proposal, we are proceeding under an expedited process, with a final rule due in March 2018.

Subject to any objections to the expedited process, there will only be one round of consultation. Objections to the use of the expedited process must be lodged by 20 February 2018.

Submissions on the rule change request are due by 6 March 2018.

Media: Prudence Anderson 0404 821 935 or (02) 8296 7817


What happens in a system black event?

A large-scale blackout of the power system is called a system black event. These events are extremely rare.

System black events can occur when a sudden, unexpected loss of a major source of supply causes very rapid changes in system frequency which undermines the security of the electrical system. Generators and networks automatically disconnect or ‘trip’ when there is a very rapid change in frequency in order to protect equipment and personnel from harm.

If supply from the system is lost, most generators are not capable of independently restarting if they have tripped off. They need power from the grid to start running again.

What are system restart ancillary services?

Restart services put energy back into the grid after a power outage so generators can start producing electricity again. Some generators have specialised equipment that allows them to restart without an external ‘kick start‘. These generators provide what are called system restart ancillary services (SRAS). AEMO contracts system restart ancillary services from generators throughout the power system.

Following a system black event AEMO coordinates the restart and restoration process:

  • Transmission network companies work with AEMO to establish network paths to generators.
  • Transmission network companies work with the distribution network providers to prepare blocks of load to be reconnected progressively
  • Distribution network providers prepare local networks to have power restored and coordinate reconnection with the transmission business.
  • AEMO and the transmission and distribution network companies must coordinate the restoration process with each state’s system security coordinator. These are known as jurisdictional system security coordinators.