Load shedding explained - after SA woes

WHAT IS LOAD SHEDDING?

* Groups of electricity customers have their power turned off at a given time.

WHY IS IT DONE?

* To balance supply and demand in the national electricity system and keep it stable when there's not enough electricity to meet demand.

* A range of factors could lead to a supply and demand imbalance, including an electricity generation plant going offline unexpectedly or because power lines or other assets have been damaged.

WHO CONTROLS IT?

* The Australian Energy Market Operator decides how much energy consumption needs to be shed.

* Electricity distribution companies, such as SA Power Networks, work out how to do it locally.

SA EXAMPLES

* About 40,000 customers lost power for 30 minutes on February 9 while the temperature was above 40 degrees because of too much demand.

* About 110,000 homes and businesses lost power for more than two hours in November 2015 after an interconnector between SA and Victoria went down.

Source: Australian Energy Market Operator