Hartmut Winkler
Over the past few months, South Africa’s power generation sector has performed better than expected.
Four factors explain this: an acceleration of solar power installations, less frequent breakdowns at power stations, a less restricted supply of diesel and the return to operation of some units at Kusile coal-fired power station.
Throughout most of this year, South Africa experienced prolonged and damaging electricity shortages, making 2023 the worst year to date.
The power utility Eskom confirmed this in its annual results presentation, in which it said: “Eskom’s generating plant availability reached the lowest levels ever, due to unprecedented levels of unplanned unavailability.”
The percentage of functional power-generating capacity, which was typically around 90% in the 1990s, has dropped over the past few years. It was between 50% and 60% for most of 2023.
Kgosientsho Ramokgopa, the country’s minister of electricity (a post created recently to deal with the electricity problems) has declared that the worst of the crisis is over and that power cuts will soon be a thing of the past.
Is he right? Is the government’s optimism justified?
There is certainly reason to be pleased that the 2023 winter electricity shortfalls were less grave than expected and that Eskom has booked some recent successes in its efforts to stave off further declines.
But it’s too early to claim a turnaround, which requires fundamental medium-term measures and reforms.
Mitigating factors
In the last year, a number of factors have assisted in mitigating the power crisis.
Firstly, an acceleration of private solar power installations. The acute power shortfalls triggered a long-overdue drive towards private solar rooftop installations. The move was boosted by government-promoted tax incentives and loan schemes.
According to estimates provided by Eskom, the capacity of private solar installations has risen by 349% between March 2022 and June 2023.
The total peak generating capacity of these was in June 2023 expected to be almost 4 500 megawatts. As solar energy generation is limited to daytime sunny conditions, this translates to about 1 200MW on average.
Secondly, less frequent breakdowns at the coal power station fleet, apparently linked to a decrease in sabotage activity.
The previous Eskom CEO claimed to have uncovered evidence of massive sabotage at power plants. While the scale of such sabotage is uncertain, it is likely that at least some has occurred.
There have been several arrests. Instances of breakdown have been lower in recent months (although breakdowns are still extraordinarily high). Together with plant repairs, the effects have been to reduce unplanned outages by about 2 000MW.
Thirdly, a less restricted supply of diesel.
In 2022 the power crisis deepened when Eskom ran short of funds to purchase diesel. The power stations where electricity is generated from burning diesel are only envisaged as a back-up during acute shortages but have been kept running longer than intended.
Assisted by the government taking over half of its debt, Eskom has a much higher budget of R27.9 billion for diesel purchases (about $1.6bn) for the current financial year. Half of this amount has already been spent.
In October last year, Kusile lost three of its units, or 2400MW, due to a collapse of the flue ducts. Two of these were restored in the last month, albeit with much higher than usually permitted emission levels. These additional 1 600MW now available, and the 2 400MW from the remaining three units projected to come into service in the coming year, are the main reason for the minister’s optimism.
On the downside, lengthy closures will be needed at some point to properly fix the flue ducts.
The biggest threat is that the ageing and overworked coal plant fleet remains vulnerable to breakdowns.
Secondly, the life extension project for the country’s sole nuclear power plant, Koeberg, is progressing far too slowly. Calls for its closure are gaining traction.
Winkler is a Professor of Physics at the University of Johannesburg. This is an edited version of his article that was published first in www.theconversation.com