Emissions obligations weigh as heavily on the state-owned power firm's bottom line as its customers' health and safety.
The Democratic Republic of Congo has halted mining expansion projects due to a power shortage that has it considering a "load-shedding" schedule.
President Barack Obama is due to announce on Sunday a $7-billion initiative over five years to double access to power in sub-Saharan Africa.
Southern African countries bear the brunt of ambitious plans gone awry, writes Roman Grynberg.
Limpopo residents on Tuesday filed a complaint with the World Bank about the $3,75bn loan sought by Eskom to help finance the Medudi power plant.
SA's power supply is seen as a serious concern from 2011 onwards until new power stations come on stream, Eskom said on Tuesday.