JOHANNESBURG (Reuters) – South Africa has endured its worst power cuts on record this year, research by the country’s national science council showed on Friday.

The power cuts by ailing state utility Eskom are one of the biggest challenges facing President Cyril Ramaphosa as he tries to revive investor confidence in Africa’s most industrialised economy.

Analysis by South Africa’s Council for Scientific and Industrial Research (CSIR) found that 1,498 Gigawatt hours (GWh) of energy had been shed so far in the first eight months of 2020, more than 1,352 GWh in the whole of last year and 1,325 GWh in 2015, the previous two worst years on record.

The CSIR estimates planned power cuts, known locally as load-shedding, cost the economy up to 120 billion rand ($7.2 billion) last year.

Eskom generates more than 90% of South Africa’s power but has struggled to meet demand for years because of faults at its coal-fired power stations. Some of these stations have not been properly maintained and two new ones have been hobbled by design flaws.

Ramaphosa has promised to break up Eskom to make it more efficient and has granted it a series of mammoth bailouts to stabilise its finances, but its problems have persisted.

Eskom last implemented planned power cuts last week.

The CSIR predicts load-shedding will continue for two to three years, depending on the actions the government takes to address the electricity shortfall.

($1 = 16.7032 rand)