Eskom load-shedding catastrophe

Eskom’s “Medium-Term System Adequacy Outlook 2024 – 2028” report shows that load-shedding increased by over 700% in two years.

The newly released study reviews the anticipated electricity generation resources to meet South Africa’s forecasted demand in the next five years.

It revealed that South Africa will likely have a significant electricity generation shortfall over the next five years – even with moderate electricity demand growth.

As part of the study, Eskom released unserved energy data measured in gigawatt hours (GWh) for the last seven years.

When there is not enough electricity supply to meet remand, the system operator implements load shedding and curtailment to ensure a stable power system.

Eskom revealed that its electricity supply was so low over the last year that it was forced to cut 14,583 GWh (14.58 TWh) year to date.

Although it was much higher than the 8,116 GWh (8.12 TWh) in 2022, the year is not over yet, and the figure will, therefore, continue to rise.

The figure includes load-shedding and load-curtailment but excludes interruption of supply (IOS).

IOS refers to all contracted and mandatory demand reductions to maintain system frequency and security of supply within acceptable bands.

The chart below from Eskom’s Medium-Term System Adequacy Outlook 2024 – 2028 shows the catastrophic increase in load-shedding in recent years.

Eskom burning diesel to keep the lights on

Eskom extensively used its open-cycle gas turbine (OCGT) power plants to prevent even worse load-shedding in 2023.

Eskom’s OCGT costs increased by over 50% over the last year – from R15 billion in 2022 to R30 billion in 2023.

The power utility said the usage of OCGTs to balance supply and demand has increased significantly since 2019.

“The 2023 year-to-date use is higher than the full year 2022 and is likely to increase further into the summer months,” Eskom said.

The high use of OCGTs, which use diesel to power the generators, was slated by many stakeholders as wasteful.

The reason is easy to see. It costs R472 per MWh for coal-powered generation and R7,077 per MWh for diesel-powered OCGTs.

Electricity Minister Kgosientsho Ramokgopa defended the extensive use of OCGTs, saying it was needed to bolster the ailing economy.

The chart below from Eskom’s Medium-Term System Adequacy Outlook 2024 – 2028 shows the increased OCGT use in recent years.