A country’s safety, productivity, comfort and convenience depend on a reliable supply of electric power. The electric power system is a complex cyber-physical system composed of a network of millions of components spread out across the country. These components are owned, operated and regulated by South Africans through their elected leaders and therefore the government.

Power system operators work hard to assure a safe and reliable service, but large outages occasionally happen. Given the nature of the system, there is simply no way that outages can be completely avoided, no matter how much time and money is devoted to such an effort. The system’s reliability and resilience can be improved, but never made perfect. Thus, the national power utility must prioritise its investments based on potential benefits. 

Enhancing the resilience of Eskom focuses on identifying, developing and implementing strategies to increase the power system’s sustainability in the short term while building long-term resilience in the face of events that can cause large-area and long-duration outages — blackouts that extend over multiple service areas and last several days or longer. 

Resilience is not just about lessening the likelihood that these outages will occur. It is also about limiting the scope and impact of outages when they do occur, restoring power rapidly afterwards and learning from these experiences to better deal with similar events in the future. 

National grid failure

A national grid failure is the total loss of power on the national network, caused by a fault that affects the distribution of electricity. It is often precipitated by massive unanticipated breakdowns of generation units or wide-scale transmission faults that cause the electricity frequency on the grid to drop below minimum required levels, thereby overwhelming the system (equipment becomes overloaded — equipment trips — supply decreases — cascading trip-outs) and causing it to shut down in its entirety. 

There are three broad categories of causes for power grid failure: acts of nature, human error and issues inherent in the technology. Inside the broad categories are factors such as poor governance, weather, including ice and high winds, earthquakes and other natural disasters, increased demand, planned and preventative maintenance, human error, ageing infrastructure, physical attack, cyber attacks, solar flare hit (coronal mass ejection) and nuclear explosion (electromagnetic pulse). 

In February, Eskom came very close to a national grid failure, with electricity demand almost outstripping supply, and technically implemented Stage 8 load shedding. Rolling power cuts, implementing rotational power cuts and reducing supply to industrial customers are the best practical ways to prevent a grid collapse and total blackout. 

Total grid failure could also lead to fuel shortages, which in turn would affect transport and industry and a host of facilities that use backup generators, such as hospitals, laboratories and morgues. In a matter of days, the cellular towers fail, individuals’ cellphones, computers and laptops run out of battery life, water reservoirs are unable to be filled up, water cannot be pumped to households and businesses, water treatment plants fail, sewage treatment grinds to a halt, ATMs stop working and fridges in supermarkets, dairies and mortuaries stop working. 

An unprecedented national catastrophe

The ensuing outage could last anything from days to weeks and would be a monumental and unprecedented national catastrophe that would threaten many lives, with a heightened risk of social unrest, looting and vandalism. Failing power grids are a leading reason for disastrous power outages that can affect residential and commercial activities. 

Countries that fail to invest in modern technologies for their power grids run the risk of suffering great financial loss. Power loss can range from a few hours to several days. While modern power grids have better technology than those in the past, they are still prone to risks. 

Power outage causes can range from solar flares to cyber-attacks. However, since much of the world does not have access to the latest technologies they are destined to suffer the largest relative losses due to power outages. Some countries that have experienced a total grid failure are Afghanistan, Uganda, Madagascar, South Sudan, Tanzania, Nigeria, Ghana, Nepal, Yemen and Pakistan.

The experience of Venezuela, whose society and the economy were crippled by an extended blackout in 2019, is the closest example of what South Africa could expect. Nationwide recurring electrical blackouts in Venezuela were experienced in 2013, 2016 and in March 2019. Experts and state-run Corpoelec (Corporación Eléctrica Nacional) sources attributed the electricity shortages to a lack of maintenance, lack of technical expertise in the country resulting from a brain drain, and sabotage. 

The largest power outage in the country’s history was in 2019. It caused serious problems in hospitals and clinics, industry, transport and the water service, resulting in at least 43 deaths. The country was without power for at least 10 days and the outage cost it $200-million a day. 

Although Eskom has “black start facilities” (generating units that can operate independently of the grid and are used to fire up power stations and gradually restore them to service), restoring the entire system could take as long as two weeks. 

As business, (especially those companies that provide communications, banking and food, over and above having installed backup power and accelerated planning for even deeper power cuts) in conjunction with Eskom, we have begun engaging in contingency plans to keep operating, staff safe and services running throughout a grid collapse and total blackout. 

Notable wide-scale power outages

There is a long list of notable wide-scale power outages. Below are some from this year alone:

On 23 January, Pakistan’s 220 million people were without power from 7.34am to 5.15 the next morning because of chronic power frequency fluctuations in the south of the country.

On 1 March in Argentina, parts of Buenos Aires and the provinces of Buenos Aires, Santa Fe, Neugu’en, Córdoba and Mendoza experienced blackouts for at least two hours during a heatwave, with traffic lights failing to function and Buenos Aires metro stations plunged into darkness. The outage was believed to have been caused by a fire in a field near high-tension lines connected to the Atucha Nuclear Power Plant.

On 14 March nearly 300,000 people in the San Francisco Bay Area, California, were without power after strong windstorms. On 5 April more than 1.1 million people in Montreal, Canada, were left without power after a major ice storm. 

On 9 April, more than 2.5 million people in Pretoria were left without power after vandalised high voltage 132kv power lines caused seven pylons to collapse on to the N4 highway. 

Zimbabwe and Nigeria were plunged into several days of darkness after the collapse of their power grids in 2021 and 2022, respectively.  

Historically, infrastructure to mitigate load shedding, flooding and heat has been designed to be fail-safe, meaning it is designed not to fail. But the concept of fail-safe can be a dangerous illusion.

Load shedding and extreme events present a great challenge to national and global sustainability, and urban areas are particularly vulnerable to these events, which can cripple the infrastructure that enables transit, electricity, water and other crucial urban services. This leaves citizens cut off and in danger. The poor and vulnerable are often disproportionately affected. Sewage-contaminated stormwater that floods, pollutes drinking water and ultimately makes its way into our oceans sounds like a problem of developing countries, but we have been subjected to far worse.

As it is apparent that the only logical outcome of our ailing grid is ultimately total grid failure, we will be irresponsible if, at the very least, we do not simulate this scenario.

From fail-safe to safe-fail

South Africa needs to migrate from its current fail-safe methodology to one of safe-fail. We can solve our grid problem in two ways. Fail-safe is a method to prevent errors from occurring. This could be done by employing sophisticated, expensive and hefty shielding to protect our sensitive equipment.

It is built on a risk management principle. It’s all about how often does it happen, how potentially bad is it, and who does it affect? Those are the parameters and you work with acceptable levels of those parameters. It leads you to build things that are bigger and heavier.  

Safe-fail has to be built on less certainty, but it also has to be built on restructuring the dynamics of the system. We need a better understanding of these dynamics. Safe-fail requires us to design our solution in such a way that any potential errors will not result in ill effects. If we know that during the calculation of a trajectory an error can be introduced, the easiest way to continue on the correct course is the use of statistics.

If we perform the same manoeuvre multiple times, we can surmise that the most common result is the desired one. By bringing this all together we may be able to really talk to the people who build the future. From the first day of designing something like highways and power grids, we are going to talk about how the Earth’s systems work and how human institutions react — and we will have to build for that. We must build infrastructure to be more resilient and equitable and not just more efficient. DM