Source: The Conversation – Africa (2)
South Africa endured its worst year of loadshedding (scheduled power cuts by the country’s utility, Eskom) in 2023. The power went off on 335 of the year’s 365 days, often several times a day. The country hasn’t had these planned power cuts for more than a year and a half since.
Much has been written about how loadshedding affected businesses, healthcare and the economy. But far less is known about the effect on people’s sleep.
As sleep scientists and members of the South African Society for Sleep and Health (SASSH) we are interested in studying, and raising awareness about, the importance of sleep to people’s well-being. People usually sleep within a specific window of time, and if their sleep is interrupted they get less sleep. Fragmented sleep and low sleep duration have been associated with poor health and cognitive outcomes, including higher cardiometabolic risk (diabetes, high blood pressure and heart problems), lower cognitive performance (attention, executive function and learning), higher risk of developing depression or anxiety, and chronic pain.
Sleep is easily disturbed by the world around us, including light, noise, temperature and worry. Loadshedding changes all of these at once. We wanted to gain insight on how loadshedding affected the sleep of university students in particular. This seemed an important group to study as they already tend to sleep poorly, keep irregular hours and carry heavy workloads. Any extra disruption could, therefore, have an impact on both their health and their studies.
Between August and November 2023 more than 1,100 students at the University of the Witwatersrand in Johannesburg completed our anonymous online survey. We asked how loadshedding affected their sleep, whether they had access to backup power, and how outages affected their studying and grades. Specifically, we wanted to understand how access to alternative power sources might make a difference to sleep.
Overall, around a quarter of the participants said power cuts affected their sleep. Poor sleep had an impact on their studies and grades.
Loashedding has eased, but South Africa’s grid remains under pressure. Our study raises important considerations for universities, not only in South Africa, but any country that faces unreliable electricity generation and distribution.
What we found
Nearly three in four students considered their sleep affected by loadshedding. Of those, four in five said it made their sleep worse. The most common complaint was broken sleep, with students waking more often during the night.
The reasons students gave were revealing.
Almost half lay awake worrying about appliances such as fridges, phones and internet routers not being powered, and keeping food fresh, or having internet connection. Nearly a third were anxious about security in the dark. A similar number found their bedrooms too hot or too cold as they couldn’t power fans or heaters. About a third said they took longer to fall asleep with disrupted daily and sleep routines, as well as more generator noise pollution affecting sleep onset.
Timing mattered. Students reported that outages between 8pm and half an hour past midnight were the most disruptive. This period covered the evening routine of cooking, washing and studying, and included the average bed time for these students of 11pm, which they reported in our study.
Not everyone slept worse. About one in five affected students said they slept better. Most of them said this was because screens and wifi were switched off and their rooms became darker and quieter.
Backup power lessens those effects, but not equally
Backup power made a difference, but not all backup power was equal. Students with an alternative supply had roughly 60% lower odds of reporting worse sleep, after we accounted for factors such as age, sex and where they lived.
About half of the participants lived in family or private housing, away from the university. The other half lived in university residences or dormitories. At the time, the university had a generator fleet that partially powered on-campus residences.
Among those with backup power, generator and battery inverter users reported worse sleep about half the time. Among solar users it was fewer than one in four. Generators are loud and cycle on and off, which can break sleep. Access to backup power was also uneven. Only 40% of participants had access, with those living in university residences having more than those living at home.
Sleep and studying
Poor sleep and poor studying went together. Two thirds of students said loadshedding had affected their studies, and more than half of these reported a drop in grades. Students who slept worse were more likely to report lower grades and to arrive late for class.
More than four in ten said they simply studied less during outages.
Sleep plays a central role in learning. Sleep helps the brain store what
was learned during the day and remove unnecessary memories “to start afresh” the next day.
Our study cannot prove that loadshedding caused grades to fall, but the pattern fits what sleep research already shows.
Why it matters
Our study offers some of the first evidence on how planned power cuts affected sleep in young people.
Planned outages are still part of daily life across sub-Saharan Africa and in countries such as Nigeria, Ghana, Zambia and Pakistan.
The findings raise practical considerations for universities, energy planners and households. They suggest that quieter backup options such as solar may protect sleep better than generators.
They also suggest that late evening outage slots carry a particular cost.
For students, keeping a regular sleep routine during outages may help, rather than filling the dark with phone screens. The lights may come back on, but sleep lost while they are off is harder to recover.
Joshua Davimes receives funding from the National Research Foundation (NRF) South Africa. He is affiliated with and serves as the Chair of the Science Committee for the South African Society for Sleep and Health (SASSH).
Karine Scheuermaier receives funding from the Wellcome Trust and the South African National Research Foundation. She is the Chairperson of the South African Society for Sleep and Health (SASSH, https://sassh.org.za).
Original source: https://analysis1.mil-osi.com/2026/10/22/power-cuts-and-sleep-students-link-loadshedding-to-anxiety-disrupted-rest-and-lower-marks/