Demand on South Africa’s electricity system increased by 5% in the first half of 2021 relative to the same period last year – but it was still 2,2% lower than two years ago.

This is among the findings in the half-year update on utility-scale power generation from the Council for Scientific and Industrial Research (CSIR).

Coal continues to dominate the South African energy mix, contributing 81,8% to the national energy mix in H1-2021 as an additional coal unit at Kusile power station entered into commercial operation.

The contribution from renewable energy sources totalled almost 11% (solar PV, wind, hydro, Concentrating Solar Power (CSP) and others) while zero-carbon energy sources contributed 14,3% (renewables and nuclear).

Based on data originally published by Eskom, insights are provided on technology specific daily, weekly and monthly electricity production, actual loadshedding experienced in H1-2021 as well as flexibility needs of the power system.

South Africa experienced loadshedding for 650 hours in the first half of 2021 – which totals 15% of the time – wherein 963 GWh of estimated energy was shed in mostly Stage 2 loadshedding. This is 76% of the total loadshedding experienced during 2020.

The extent of loadshedding experienced was largely driven by a declining energy availability factor (EAF) of the existing coal fleet where overall the EAF was 61,3% for the first half of 2021, relative to 65% in 2020 and 66,9% in 2019.

A concerning shift of the unplanned outage component of the EAF has also been highlighted where unplanned outages of up to 15 300 MW were experienced and were greater than 10 000 MW for more than 80% of the period.