How close is South Africa to a national blackout?
National blackouts have been experienced in many countries and cities across the globe - including India, Italy, New York and Kenya.
JOHANNESBURG – State-owned power utility Eskom says a national blackout is always a risk when electricity demand exceeds supply - but that it has plans in place to avoid this at all costs and is learning from other countries that have been in a similar situation.
South Africans have experienced another bout of load shedding this week - with power cuts escalated to stage 4 for the first time.
President Cyril Ramaphosa has announced that a special Cabinet committee will handle all Eskom issues on a daily basis from now on - and there'll be a maintenance plan for the entity to prevent blackouts.
But since the start of load shedding in 2008, there's always been a fear of a national blackout - when the power grid trips and the whole country is plunged into darkness.
This is something that many countries and cities across the globe have experienced - including India, Italy, New York and Kenya.
In 2003 more than 50 million people in the US and Canada were left without power. It was less than two years after the September 11 attacks and New Yorkers initially feared terrorism . It transpired that the blackout was caused by a massive power outage, with some reports citing old power lines, summer heat and outdated equipment.
In the same year Italy experienced a blackout that affected almost all of the country's 57 million people for several hours.
In 2013 Kenya also experienced a national blackout for several hours when the power grid crashed. Kenya Power reportedly said two transmission lines had failed to carry 400 MW of electricity which caused the nationwide outage.
Other major blackouts affecting millions of people have occurred in India, Brazil and Thailand and South Africa is no exception when it comes to this risk.
Energy analyst Ted Blom says at any one time there's a 10% chance of an error which could result in a national blackout. He says this happens when demand exceeds supply and this can be by a minuscule amount, even just one megawatt. He says the grid will trip and freeze the entire system.
Blom says if Eskom anticipates this, they can do what he calls a ‘controlled blackout’ which hopefully won't damage any equipment. In this case, he says it could take South Africa about ten days to get back online.
However, Eskom's Andrew Etzinger says they follow a very conservative approach and they don't tolerate this risk by ensuring that supply and demand are in balance. If, however, demand does exceed supply, they implement load shedding. So Etzinger says as infuriating as load shedding is, this is the responsible action to take.
He says Eskom will even load shed half the country if that's what it takes to protect the integrity of the country. Then they would be able to restore supply in a few hours. Etzinger says a national blackout could take weeks before electricity is fully restored.
While there's been no load shedding for Friday at this stage, Eskom says it's unlikely to implement power cuts over the weekend - but has warned that the system still remains vulnerable.