Power cuts by state utility Eskom cost the South African economy up to 120 billion rand ($8.3 billion) last year and will probably persist for the next two to three years, research by the country’s national science council showed.

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

Ramaphosa has promised to break up Eskom to make it more efficient and granted it a series of mammoth bailouts to stabilise its finances, but its coal-fired power plants keep breaking down after years of mismanagement.