Johannesburg - AngloGold Ashanti [JSE:ANG] and Sibanye Gold have lost about R481m after a power outage caused by a lightning strike at an Eskom substation last week forced them to close large operations, Business Day reported on Tuesday.
While the outage at the Midas substation near Carletonville, which supplies 400MW to the mines, is isolated, concerns are growing about Eskom's ability to keep the lights on if it does not commission its Medupi project by the end of the year.
On Monday Eskom said it had a national buffer of 500MW, due to unplanned outages of 7227MW at its plants. This was close to the margins that led to blackouts in late 2007 and early 2008.
The international standard for a reserve margin, a measure of capacity over demand, is 15%. In South Africa it is 1%.
If Eskom does not bring its Medupi plant on line by the end of the year, South Africa faces the real prospect of blackouts and load shedding next year.
AngloGold and Sibanye, formed after Gold Fields [JSE:GFI] unbundled three mines, could lose 32,646oz of gold production worth R481m at current prices due to the outage. Eskom has since restored 300MW of power to the area.
During the power failure, Driefontein mine used generators to hoist 400 people to the surface.
Follow Fin24 on Twitter, Facebook, Google+ and Pinterest.