The Australian Energy Market Operator (AEMO) manages and maintains the national electricity grid, balancing supply (electricity generation) with customer demand (load).
One of AEMO’s key jobs is to ensure the integrity and stability of the electricity grid. At times, rapid shedding of customer load (load shedding) is required to avoid even wider loss of supply or even a grid shutdown.
What happens when load shedding takes place?
There are two main types of load shedding:
Equipment in the electricity grid automatically switches off to stabilise and protect the network. This is normally in response to a sudden and unexpected disruption of the stability of supply in the national electricity grid, such as occurred after the collapse of transmission towers (which led to the State-wide blackout on 28 September 2016).
When AEMO identifies (in advance) that demand is going to exceed all the available generation, it directs utilities like us to reduce load by turning power off to some areas to maintain balance in the national electricity grid.
It’s called rotational load shedding because the outages for customers are kept to about 30-40 minutes, with load shedding rotated between suburbs and regions.
Lines supplying critical infrastructure and the CBD are exempt from rotational load shedding. These exemptions are determined by the State Government Office of the Technical Regulator. You can see the load shedding list of groups and details of the most recent load shedding events here.
What can trigger load shedding?
A number of factors can cause an imbalance between generation and demand. For example:
- a sudden or unexpected loss of a generator, or a fault on a transmission line, reducing the amount of energy that can be supplied
- spikes in demand for power, often during extended heatwaves, causing demand to exceed available supply.
What should I do during an outage?
If your power goes off we recommend you turn off all appliances and leave a single light switch in the ON position so that you know when power has been restored. You can then turn appliances on gradually once the power returns. If appliances at your home, and your neighbours’ homes, all turn on as the power is restored it could put pressure on the network and make your outage last longer).
Read our tips on what to do and how to stay safe during an outage.