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Blackouts vs system outages – what’s the difference?

2 min

You have probably heard words like ‘blackouts’, ‘power outages’, and ‘load shedding’ being thrown around as explainers for why we might be without power.

But what do these words actually mean?

Let’s start with planned outages. These interruptions are prearranged and necessary for routine maintenance, inspections and improvements on various electricity infrastructure like generators, powerlines, or other associated equipment on either a transmission or distribution network.

Often, planned outages of generators or transmission wires (the higher up wires above those on the street connecting to your home) can occur without consumers losing power as a large part of the network is built with contingency (one line can be offline, while the other one is in service). Planned outages at the street level will be managed by your local power distributor, who will usually notify you in advance if work has been scheduled.

An unplanned or forced outage, on the other hand, is an interruption to the generation, transmission, or distribution of electricity that is unscheduled. At a distribution network level, more often than not, unplanned outages result in a loss of supply to certain areas. It is what most of us experience when the lights go out.

These can occur as a result of damage to wires caused by storms, lighting strikes, falling trees (or branches), motor accidents, bushfires, equipment failure etc.

There is a common misconception that an unplanned power outage is the result of an imbalance between demand and supply. The fact is, the outage is more likely going to be due to one of the causes above.

Another commonly misused term is load shedding. This action is the deliberate shutdown of electricity supply to parts of the power system to protect the failure of the entire power system, and typically occurs as the result of a supply/demand imbalance. This measure is a last resort to protect the power system and avoid a system black. Once the system is secure again, electricity will be restored to areas affected.

Finally, the term blackout, is often used (incorrectly) interchangeably with a power outage. A blackout event is defined as the complete interruption of energy supply that cause outages across major parts of the system, even whole states, and is a rare occurrence in Australia.

Now that you know more about the different types of power interruptions, here are a few tips about what to do when your power goes out:

  • First, make sure the issue isn’t caused by a tripped circuit breaker or safety switch in your switchboard. It might be a case of resetting these for a return of power to your home.
  • If this is not the case and you are still without power, you might be experiencing a planned outage. Check to see if others in your street are without power, and then visit your local energy provider’s webpage for details about power interruptions in your area.
  • If no outages are visible, the outage might be due to a random unforeseen circumstance. Contact your local energy distributor for more information. Find your distributor here.
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