It's South Africa's biggest polluter, but struggling power utility Eskom says it could take two decades to install the technology it needs to comply with stricter emission rules, that come into force in April.
The state-owned company applied last year to have these new limits on emissions, such as nitrogen oxide and sulfur dioxide, to be postponed, suspended or adjusted for some of its coal-fired power plants.
The company, already mired in a financial crisis and struggling to meet demand, argued that compliance wasn't realistic and could cost an exorbitant amount.
But that's angered environmentalists who blame Eskom and other big polluters for causing respiratory disease.
The Centre for Environmental Rights has called for Eskom's recent postponement request to be dismissed.
The organization has previously taken the government to court over air pollution in an area where 12 of Eskom's coal plants are located.
Eskom's environmental manager Deidre Herbst said in an interview that if authorities reject this application, the company might have to take 10,000 megawatts offline.
That, according to energy experts, could potentially trigger another round of severe nationwide power cuts.