State-owned power supplier Eskom will make more power cuts this week as it struggles with capacity shortages that threaten to stymie President Cyril Ramaphosa’s efforts to boost investments and economic growth.

Eskom supplies more than 90% of the power in South Africa but has suffered repeated faults at its coal-fired power stations, along with low water levels at hydroelectric plants and diesel shortages.

Ramaphosa told eNCA television on Monday that the power cuts were very worrying and authorities were working every hour of the day to restore power.

The situation worsened on Saturday after Eskom lost its electricity imports from the Cahora Bassa hydroelectric system in Mozambique, which contributes more than 1,000 MW to the South African grid, after a powerful cyclone.

Eskom said late on Sunday it would continue to implement rolling blackouts on Monday and Tuesday with 4,000 megawatts to be cut from the grid on a rotational basis.

Businesses have been disrupted, particularly the small- and medium-sized firms which do not have access to backup power sources such as diesel generators. Vincent Xaba, a manager at Tsa Africa Restaurant in Johannesburg, said he had to throw away about 15 kilograms of tripe and 10 kilograms of pigs’ trotters worth about R8,000 after his freezer stayed without power for too long.

“We’re losing a lot of money and a lot of customers. Our meat is getting spoiled, our drinks are getting warm. Everything is in a big mess,” Xaba said inside the dark, empty restaurant. Jacob Munthali, an employee at Harvey Refrigeration & Air Condition, said the situation was stressful.

“We can’t check or fix appliances without electricity,” Munthali said. “I’ve got a family to support so if the boss is not getting anything that means me too as an employee won’t get anything.”

 Eskom’s power station performance has deteriorated steeply in part because of delays to critical maintenance work.

Long-term neglect means there are no quick fixes. The power cuts, known as “loadshedding", have also prompted frustrations among ordinary people ahead of an election in May.

“We get ‘loadshed’ twice in a day,” said 32-year-old Johannesburg resident Lukhanyo Ceza. “When leaving the office, traffic lights are not working, it’s havoc, it takes 20 minutes to drive one kilometre.

"I can’t cook because there is no power and I am forced to get takeaway and it’s expensive.”

Eskom’s ageing power plants, that are between 37 and 50 years old, could come under further strain in the South African winter which begins in earnest in June.

“I don’t know if Eskom will fix the problem in future, maybe I must vote EFF,” said panel-beating shop owner Charles Hutamo, referring to the radical leftist Economic Freedom Fighters party.

The Ministry of Public Enterprises, which oversees Eskom, said in a statement late on Sunday that the utility would be assisted to fast-track the procurement of essential goods and services required to rehabilitate and repair power generating units.

To supplement its ageing power plants, Eskom is developing the Kusile and Medupi projects, but both are years behind schedule and tens of billions of rands over budget. The few units at Kusile and Medupi that are online perform unreliably.