Eskom has increased its net profit for the year to March 2012 to R13.2 billion, the electricity utility announced on Thursday.
This was slightly above the R12.8 billion the company reported for the first half of its financial year to September.
It declared a net profit of R8.4 billion for the previous year.
Eskom said its business was seasonal, with most of its profit earned in the winter months, in the year's first half. This is when tariffs for large customers were higher and maintenance costs lower.
Public Enterprises Minister Malusi Gigaba said the results were pleasing.
"Eskom must continue to improve its financial health, so that it can invest to support economic growth and job creation, and improve the [people of South Africa's] quality of life," he said.
Eskom's CEO Brian Dames said the results would not have been possible without the utility's 43,000 employees.
"Electricity is very important to South Africa. It is the oxygen of this economy," he said.
Eskom had been able to keep the lights on despite tight supply. It had not achieved this on its own, but had worked with customers to do so.
Twenty-five fatalities were recorded during the year, mainly as a result of vehicle accidents and electrical incidents. Safety would be a top priority for the company in the current financial year.
By applying to reduce the tariff increase it had been granted from 25 percent to 16 percent, Eskom had returned R8 billion to the economy, Dames said.
The utility had made significant progress on its capacity expansion programme during the year. Two previously mothballed stations, Camden and Grootvlei, had been returned to service. The commissioning of a third station, Komati, was two-thirds complete.
A total of 5.8GW of new generating capacity, 3899km of high-voltage transmission lines, and 20,195 mega volt ampere of new transformer capacity had been installed since 2005, Eskom's financial director Paul O'Flaherty said.
Construction of the two new coal-fired power stations -- Medupi and Kusile -- was continuing.
"We are doing everything in our power to make sure we bring (the new capacity) online and within budget," he said. - SAPA