The AEMC has made a final rule that clarifies how AEMO may share information about system restart plans with generators, networks and other key parties involved in restoring the electricity system after a widespread blackout. 

AEMO is responsible for maintaining power system security. Following a large-scale blackout AEMO coordinates the restart and restoration process, using emergency procedures set out in a system restart plan.

The final rule gives AEMO express authority to share and discuss system restart plans with relevant parties including generators contracted to provide system restart services, network businesses and jurisdictional system security coordinators. It also clarifies the confidentiality obligations that apply to these parties.

The new rule starts on 27 February 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.

How is the system restarted?

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. 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, 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.