It comes after the power utility wanted a nearly 20-percent tariff increase for the 2018/2019 financial year.

Nersa only granted it just over 5-percent.

Eskom wants the court to find this decision unlawful, irrational and procedurally unfair.

Eskom is arguing that Nersa didn’t properly apply its methodology when the regulator determined the tariffs for 2018/2019.

The power utility's advocate Matthew Chaskalson is arguing Nersa is trying to reverse engineer outcomes through misdirection.

Eskom is claiming electricity prices are too low, while Nersa says they're too high.

Chaskalson accuses the energy regulator of not taking into account reasonable operating costs and return on investment.

Judge Jody Kollapen has questioned how overstocking coal at Eskom contributed to its debt problems.

He also wanted to know if the regulator was compelled to consider Eskom’s cash flow status.

Eskom doesn’t dispute issues of state capture at the power utility but it claims this accounts for only 5-percent of its troubles while over 80-percent of its problems come from low tariffs.

What's more, it says low tariffs are partly responsible for load-shedding.

eNCA