What is loadshedding?
This can cause a trip out country-wide (a blackout) and that could take days to restore.
Have you ever wondered why you are being loadshed?
Eskom’s national spokesperson Khulu Phasiwe explained how loadshedding works and why we have to endure loadshedding.
Phasiwe said loadshedding is a measure of last resort to prevent the collapse of the power system country-wide.
“When there is insufficient power station capacity to supply the demand (load) from all the customers, the electricity system becomes unbalanced. This can cause a trip out country-wide (a blackout) and that could take days to restore.”
When power is insufficient, Eskom either increase supply or reduce demand to bring the system back into balance.
As the difference between supply and demand becomes small, they refer to it as: “the system being tight”.
This implies that action has to be taken to prevent the system from becoming unstable.
“Eskom normally takes a sequence of steps to keep the system stable and to avoid loadshedding,” said Phasiwe.
“The steps include first asking large customers to reduce load voluntarily. However, if several power station units trip suddenly and unexpectedly, they have to skip those steps and go straight to loadshedding.”
This is done to prevent the system from becoming unstable.
“Scheduled loadshedding is controlled by way of sharing the available electricity among all its customers. By switching off parts of the network in a planned and controlled manner, the system remains stable throughout the day, and the impact is spread over a wider base of customers.”
He said loadshedding schedules are drawn up in advance to describe the plan for switching off parts of the network in sequence during the days that loadshedding is necessary.
On days when loadshedding is required, the networks are switched off according to the predetermined plan.
“This is to ensure that customers experience loadshedding in accordance with the published loadshedding schedules as far as possible.”
In South Africa, the national control centre in Germiston controls the power transmission network throughout the country.
“Each power station on the Eskom grid will keep national control informed of their capabilities ensuring that power is available when the customers want it.”
