In June, the utility applied for an undisclosed tariff hike but now four months later the National Energy Regulator of South Africa (Nersa) has rejected it.
Gas energy generation licences approved despite environmental concerns.
Turkey-based Karpowership, one of the world's largest floating power plant operators, in March won a government tender to supplement South Africa's fragile electricity supply with gas-to-power projects at three ports.
'The bad news is that we will probably have to have a greater increase in electricity tariffs in order to make up for a series of adverse Nersa decisions which we have successfully challenged in court,' Eskom CEO Andre de Ruyter said.
The city was compelled to raise its billing in line with Nersa's guidelines and will bill customers through something called 'inclining block tariff methodology'.
The amendment will make it easier for independent power producers to make electricity and sell it into the grid.
The Nersa approval allows the Department of Mineral Resources and Energy to procure additional energy beyond, but not excluding, Eskom and including renewable energy.
The high court has given Eskom the go-ahead to claw back R69 billion over the next three years from customers in the form of higher electricity tariffs.
Eskom can now file a new application within 60 days to recover the costs next year.
Nersa wrapped up hearings in Midrand on Monday where the public was given a last chance to voice their views.
Energy expert Lungile Mashele said that Eskom needed all the money it could get.
The National Energy Regulator of South Africa (Nersa) has filed court papers in response to those of Eskom, which has called for the High Court to review and set aside the regulator's tariffs decisions.
In a statement, Eskom said that in keeping with a board decision reflecting the poor performance of the business, no performance bonuses had been paid to employees in the past two years.
Experts are warning that the tough economic times may lead to more uncertainty about the country's investment market.
The party hosted a press briefing at Bruma in Johannesburg on Monday.
The National Energy Regulator of South Africa has approved a tariff hike of 9.41% for this year.
Eskom CEO Phakamani Hadebe has pleaded with the National Energy Regulator of South Africa (Nersa) to consider the power utility's uncertain financial situation.
Eskom CEO Phakamani Hadebe says that if the price of electricity is not increased over the next three years, the institution will struggle to improve its financial position.
