Johannesburg - Power utility Eskom said it would start implementing rolling blackouts on Sunday after a silo containing tonnes of coal cracked and affected supplies to all six units of the Majuba power station.

In March, the utility was forced to impose rolling blackouts for the first time in six years to prevent the national grid from collapsing, a situation that underscored just how precarious the balance is between South Africa's power supply and demand.



Eskom said in a statement late on Saturday that it had lost 1,800 MW at the Majuba station when a silo holding 10,000 tonnes of coal cracked. That plant was now operating at a reduced capacity of 1,300 MW.



The load shedding would start at 8 a.m. local time (0600 GMT) and run till 10 p.m. Eskom estimates between 600-800 MW will be affected on Sunday.



"Teams are on site and are in the process of dispatching mobile coal feeders to site. In the unlikely event that this contingency is unsuccessful, it may impact the full supply from the power station," the utility said.



Eskom, which produces virtually all South Africa's power, has struggled to overcome electricity shortages as labour strikes and shoddy workmanship delayed new generation coming on stream.



Because of the impact on growth and on key sectors such as mining, the government is keen that Eskom bridge its wide funding gap, estimated at around 225 billion rand ($20.4 billion), over the next four to five years.



Last month, the national Treasury said it would inject 20 billion rand ($1.8 billion) into the utility, and may also convert its existing 60 billion rand subordinated loan to equity.



This was after it approved a financial package in September that includes the company raising 50 billion rand in additional debt, over and above its original plan of 200 billion rand.

Reuters