In the past few months, millions of South Africans have been haunted by the same concern when the lights go out for the umpteenth round of load-shedding: Is this the beginning of the end for the power grid?
The fear of a complete collapse of the power grid is possibly fueled by the ripple effect it will cause: No water, no telecommunications, no economy – and possibly anarchy.
Experts in the field, some associated with Eskom, this week mapped out the A to Z of a possible collapse of the power grid. They say that although the terrifying scenario of an entire network collapse is highly unlikely, it is nevertheless never impossible.
“The fears that a total collapse of the power grid is imminent are unfounded,” says Isabel Fick, general manager at Eskom’s system operator.
“As with any operator it is wise to plan for all the possibilities; therefore we have been planning and preparing for a long time for the possibility of a collapse of the power grid.”
What does a collapse look like?
Prof. Jan de Kock, associated with the North-West University and the South African Institute of Electrical Engineers (SAIEE), explains that a collapse of the power grid is a confluence of events.
Sometimes the generation assets are compromised – either by power grid disturbances, plant and human errors or even design errors – which then leads to a disconnection from the power grid, says De Kock.
Fick says examples around the world show that a collapse of a power grid is not due to a lack of capacity, but rather an event that originates in the transmission space.
Weather phenomena are indeed one of the main reasons why a collapse can occur suddenly and unplanned.
According to Fick, the Western Cape and KwaZulu-Natal are examples of regions that have been plunged into darkness due to severe weather conditions.
Should the entire country be without power, all spheres of the economy and society would be affected, says Fick.
Water supply will be interrupted, there will probably be a fuel shortage, telecommunications will fail leading to the collapse of the security, financial and retail spheres.
This could eventually result in full-scale rioting.
Eskom estimates that after such an event it will take between six days and two weeks to restore the power supply across the country. This is because parts of the network must first be set up and connected to stabilize the network.
Why is a collapse ‘unlikely’?
According to Fick, load shedding is one of the ways Eskom uses to prevent a total collapse of the power grid.
“We apply load shedding when the demand for power is more than the power that can be generated and carried,” she says.
“Higher load shedding phases are also not an indication that the power network is on the verge of collapse, but reflects the operator’s ability to protect the network.”
She says that recently maintenance is done more often on infrastructure when load shedding is introduced and this helps to keep the infrastructure in better condition.
However, gravity is not the only way to prevent a collapse.
Fick explains that there are several “barriers” built into the network that help protect Eskom against a total collapse.
Another measure that Eskom uses is research and technology carried out by the CSIR.
Monique le Roux, a researcher and electrical engineer at the council, says she and Dr. Sipho Mdhluli is now working with Eskom on a map of the country’s power grid.
“The map is an important tool that is used to see how the power grid reacts if something changes to it, such as a substation that breaks down or a plant that is taken out of service,” she says.
“It offers a glimpse of what is happening without it having to be implemented in practice. It’s like a road map that we use to see what needs to be brought online to keep the power grid stable.”
Fick says that Eskom has, for example, already carried out tests on the effects on the power grid if units 1 and 2 of Koeberg were to be omitted. Due to the back-up network in the area, the power network as a whole is still stable – even without Koeberg.
Prospects
Fick says it is impossible to predict what load shedding will look like over the next few months, as the status of the power grid is constantly changing.
More planned maintenance work is usually carried out in the summer months, which puts the power grid under more pressure and “results in more load shedding”.
However, Eskom is constantly trying to look at renewable energy sources to improve the generation capacity.
Although renewable energy can lead to a more unstable power grid, Eskom is currently learning from countries such as Denmark and Germany to ensure that the power grid with more renewable energy is still stable. These countries’ power grids have around 60% renewable energy and yet they still successfully maintain the power.
