Johannesburg - South African power utility Eskom said on Thursday the reserve margin between forecast demand and capacity in the evening was only 132 MW or less than 0.4 percent of available power.
Eskom is battling to keep the lights on in Africa's largest economy with the approach of the southern hemisphere's winter.
Earlier in May, the national grid came within a hair's breadth of overloading, when the gap between demand and supply was only 0.06 percent. - Reuters