Eskom cuts power to BHP smelter to save energy
An agreement between state-run Eskom and BHP allows the utility to interrupt power to the latter's energy-intensive smelters if the national grid approaches a tipping point.
"We did interrupt supply to one of the BHP Billiton units for a time, but still have emergency reserves available," Eskom spokesperson Hilary Joffe said on Tuesday. She also said Eskom ran gas turbines that it activates when supply is tight.
Eskom said on Monday the power reserve margin for the evening was expected to be extremely tight at 29 megawatts (MW), or just 0.08% of available power.
The utility also has agreements with its other large customers as part of its "emergency resources" plan.
Eskom, which provides 95% of the power to the country, has been walking a tightrope for five years as it tries to bring overdue new power plants online. Increased demand during the southern hemisphere winter puts further strain on the system.
The country's electricity reserve margin slid to a perilously low 63MW or 0.2% last week, heightening concerns that South Africa is a hair's breadth from experiencing rolling power cuts.
The company warned earlier this year that there is a heightened risk of load shedding during winter as it will no longer defer planned maintenance of its power stations, a number of which have reached their technical and statutory limits.
Ideally, a power system should have at least 2 000MW in reserve.
According to Eskom, supply during the summer was limited by unplanned outages at Koeberg's unit one and an unreliable supply from the hydroelectric Cahora Bassa scheme in Mozambique, which can supply Eskom with 1 500MW. – Reuters, Staff reporter