The Council for Scientific and industrial Research (CSIR) has confirmed that 2021 surpassed 2020 as South Africa’s most intensive load-shedding year to date, as the performance of Eskom’s coal fleet continued to deteriorate.

Load-shedding occurred for 1 169 hours, or 13% of the year, with an upper limit of 2 521 GWh, representing a 40% increase compared with the 2020 load-shedding upper limit of 1 798 GWh.

The energy availability factor (EAF) of Eskom’s coal-heavy fleet fell to 61.8% for 2021, from 65% for 2020, 66.9% for 2019 and 71.9% in 2018.

There has been little sign of a marked recovery in the EAF during 2022, despite an intensification of planned maintenance in recent years. For the year to end March, the State-owned utility reported an overall EAF of 62% but load-shedding has intensified since then with the coal fleet’s EAF dipping well below 60% at times.

South Africa’s Integrated Resource Plan of 2019 (IRP 2019), which outlines the technologies needed to ensure supply security to 2030, assumes an EAF of 70%, rising to 75% by mid-decade, and an immediate shortfall of supply of about 2 000 MW.

The supply deficit is currently considered to be far larger, with Eskom calculating the shortfall to be between 4 000 MW and 6 000 MW.

Mineral Resources and Energy Minister Gwede Mantashe announced last week that Cabinet had decided to review the IRP 2019, which is regarded as being outdate on more than only its EAF assumptions.

Mantashe also said the plan would extend beyond 2030, but he did not provide a specific timeframe for the completion of the review.

The CSIR indicates that the intensification of load-shedding could be attributed largely to the increase of unplanned outages across Eskom’s coal fleet, a trend that has continued into 2022.

Eskom has indicated that there could be as many as 104 days of load-shedding this winter and another 191 days during the summer months.

“Load-shedding in 2021 overtook 2020 as the most intensive year of load-shedding to date, with load-shedding concentrated in October and November, and dominated by Stage 2 load-shedding overall,” the CSIR states.

During the first half of the 2022 calendar year, rotational power cuts have been implemented up to Stage 4, or 4 000 MW.

The statistics also show that, in 2021, the total system demand increased by 6.5 terawatt hours (TWh), a 3% increase compared with total system demand in 2020. However, total system demand last year was still 5.3 TWh, or 2%, lower than pre-lockdown levels of 2019.

Coal still dominates the South African energy mix, providing 81.4% of the total system load. The contribution of renewable energy technologies increased in 2021 to a total of 5.7 GW installed capacity and provided 6.6% of the total energy mix.