Wind and solar energy generation contributed more electricity to Eskom’s grid than nuclear power in 2020.
This was revealed in the Statistics of Utility-scale Power Generation in South Africa in 2020 Report compiled by the Council for Scientific and Industrial Research (CSIR).
Overall, electricity demand declined by 5.1% from 2019, which saw significant reductions in the contribution of coal and nuclear energy, while others like solar PV and pumped storage showed increased production.
Notably, variable renewable energy in the form of wind and solar power contributed 5.6% – or 12.4 terawatt-hours (TWh) – of the total system demand in 2020.
This was compared to just 11.5TWh or 5.2% of the electricity demand provided by nuclear energy from Koeberg Power station.
This significant increase on the part of variable renewables was due to 415MW of wind and 558MW of solar PV becoming operational during the past year.
Combined with other renewable energy such as hydro plants and pumped storage this supported 10.5% of the total system demand in 2020, equating to 23.1TWh of electricity.
Coal energy still on top
Wind power achieved a maximum peak power production of 2,114MW at the start of December, while solar PV hit 1,929MW towards the end of November.
The maximum instantaneous contribution of wind, solar PV, and concentrated solar production (CSP) was 16% at one point in late December.
Electricity generated by coal still contributed to the majority of system demand, with 184.4TWh of generation providing 83.5% of South Africa’s electricity.
The remaining generation came from diesel and open-cycle gas turbines, which provided just under 1% of the demand.
The chart below shows the portions of the generation contribution of each energy source in South Africa’s electricity mix.
Increase in contribution
The CSIR also provided a graph that showed how the annual energy produced by solar and wind on the South African grid increased from 2013 to 2020.
This revealed a gradual climb in generation over seven years – from 0.1TWh to 12.4TWh.
The contribution of wind energy had remained fairly similar over the last three years, while CSP’s contribution had also held steady at 1.6TWh.
Solar PV, however, saw a big increase from 3.3TWh to 4.1TWh over the last year.
The changes in annual energy produced by variable renewable sources can be seen in the chart below. Figures are in TWh.
South Africa had 51.6 GW of wholesale/public nominal electricity capacity by the end of 2020.
When looking at the total installed capacity of renewable energy compared to coal and other sources, it would appear that wind and solar should actually be contributing more to the energy demand.
Wind generation capacity stood at 2.5 gigawatts (GW), solar PV at 2.0GW, and CSP at 0.5GW.
Combined, this means they make up around 9.7% of the installed capacity.
However, since the performance of these power sources can vary greatly depending on environmental factors, their overall impact is lower.
Coal constituted the vast majority of the capacity at 37.9GW, followed by diesel pump stations at 3.4GW, and pumped storage at 2.7GW.
The table below shows the total installed nominal capacity of each different type of electricity generation source on Eskom’s grid as of the end of 2020.
|Energy source||Nominal capacity||Portion of total capacity|
|Diesel and open gas cycle turbine (OCGT)||3.4GW||6.6%|