A South African court on Tuesday sided with State power utility Eskom in a dispute with energy regulator Nersa over electricity tariffs in the 2018/19 financial year.
The court "set aside" Nersa's tariff decision and granted Eskom leave to apply to Nersa for additional expenses it incurred in 2018/19, a copy of the judgment seen by Reuters showed.
The court found that Nersa's treatment of coal and employee costs resulted in the deduction of billions of rands from Eskom's projected revenue.
It said decisions taken by Nersa were "procedurally unfair, irrational and unreasonable".
A Nersa spokesperson said the regulator would issue a statement on the court judgment.
Eskom has argued that Nersa's tariff decisions are one of the major reasons why it is in a financial crisis and it has challenged several of those decisions.