You have probably heard terms planned outage, unplanned outage, blackouts, and load shedding, regularly used during summer. But, did you know there are key differences to how they occur and are managed? To learn more about why you might be experiencing a power outage at certain periods, check out our easy-to-understand explainers below.
These outages are prearranged to undertake routine maintenance, make repairs and to safely inspect electricity infrastructure, including generation plant, right through to the transmission and distribution powerlines to homes and business.
Often, planned outages of generators or high voltage transmission wires can occur without consumers losing power as a large part of the network is built with contingency (that means one line can be under maintenance, while another keeps your power flowing).
Planned outages at the local level will be managed by your local power distributor, who will usually notify you in advance if work has been scheduled.
Unplanned outage or fault
On the other hand, an unplanned outage or fault is an unscheduled interruption to electricity assets (generation units, electricity transmission or distribution assets).
At a distribution network level, unplanned outages may result in a loss of supply to individual homes or businesses, or to certain areas, and it is what most of us experience when the ‘lights go out’.
This can occur as a result of various things, including damaged powerlines or poles due to lighting strikes, falling trees, motor accidents, bushfires, or general equipment failure.
Restoration of power to your home in these events will also be managed by your local distributor.
Another commonly misused term is load shedding This action is the controlled shutdown of electricity supply to parts of the power system, to help protect critical infrastructure from long-term damage, and help prevent the failure of the wider power system.
Load shedding is used as an absolute last resort, and once the system is secure again, electricity is restored as quickly and safely as possible to the impacted areas.