The cumulative cost of load shedding to South Africa's economy in 2019 was between R59bn and R118bn, according to a new presentation by the Council for Scientific and Industrial Research.

This presentation was developed by CSIR principal engineer Jarrad Wright and senior engineer Joanne Calitz. The CSIR is a non-partisan scientific research institution.

According to the research, South Africans experienced 530 hours of planned power cuts in 2019, as Eskom reduced the load on the national grid to stop it becoming overloaded. While this was lower than in 2015 - when SA experienced a total of 852 hours of rotational power cuts - the intensity of the cuts were higher in 2019. This included the unprecedented implementation of Stage 6 load shedding in December.

According to Wright and Calitz, 1352 Gigawatt hours (GWh) of energy was shed in 2019, compared to 1325 Gwh in 2015.

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The report also noted that Eskom's energy availability factor (EAF) - the percentage of time power plants produce electricity - has been in decline since 2001 when it was over 90%. EAF was just 67% in 2019, its lowest average yet.

"Historical fleet EAF decline seems irreversible," stated the presentation's authors.

The CSIR said load shedding is expected to continue for two to three years depending on key decisions and actions by government.

"An urgent response is necessary to ensure short-term adequacy and set South Africa on a path towards long-term adequacy in the 2020s," they said.

The presentation set out various scenarios for South Africa to ensure the supply of power in the current decade. The authors highlighted that, in the short term, a key response to start to close the "energy supply gap" is let businesses, private citizens, mins and farms produce their own electricity.