South African power supplier Eskom warned on Thursday it might be forced to resort to rolling blackouts again to ease pressure on the shaky national grid after a conveyor belt feeding coal into its Medupi generation units failed.

The State-owned utility, which provides some 95 percent of the country’s electricity, has effected loadshedding intermittently for more than a decade as its ageing infrastructure has struggled to generate enough to meet demand.

The company is also beset with financial problems blamed on years of mismanagement by executives who have since left.

On Thursday it said the incident at its Medupi power station meant that the four generation units in service were not able to take in the requisite amount of coal to generate electricity.

“This puts further strain on Eskom’s ability to fully supply electricity over the next 24 hours,” it said.

“While Eskom teams are working round the clock to repair the conveyor belt, which is expected to take the better part of the day, any further breakdown elsewhere in the generation fleet, would necessitate the implementation of Stage 2 loadshedding at short notice.”

Stage 2 loadshedding entails suppressing 2 000 megawatts of electricity demand at any given time to avoid overwhelming the grid and making it trip.

“Eskom will continue to communicate should there be any further changes as the system remains unreliable and vulnerable,” the company said.

Last week group chief executive André de Ruyter suspended the managers at Eskom’s Tutuka and Kendal stations pending disciplinary inquiries after breakdowns which forced the utility to ramp up rolling blackouts earlier in the week.

The state firm said a previous culture of weak consequence management would no longer be the norm and would no longer be tolerated at Eskom.