31/05/2022
The second interesting finding is that the quantity of the power cuts is small relative to the total delivered energy. Over the week 12-19 May 2022, Eskom delivered 4,271 MWh of electricity and cut 70 MWh, which is only about 1.6% of the energy generated, as shown in the image below.
I’m making this point to show that power cuts could get much worse, unless the rebuild programme begins soon. One reason that the power cuts attract high media attention is that consumers bear a disproportionate share of the energy cuts relative to Eskom’s anchor customers.
For instance, under level 4 where power cuts can last for over five hours in a day, lower end users have power for only 67% of the day – meaning 33% of their power supply is cut. But the total energy saving across the whole system is 10%. This suggests that Eskom deliberately preserves supply for its anchor customers – large industrial users and essential services – even during the power cuts.
The final issue is that Eskom could get more capacity from its pumped hydro schemes. These schemes use excess power at night to pump water to high storage dams, from which the water is released during the day to meet the higher demand during daylight hours. During the week 12-19 May, capacity utilisation of pumped hydro was only about 38%.
The chief operating officer of South Africa’s electricity utility, Eskom, warned in May that the government should urgently start building new generating capacity. He was referring to a n…