The Democratic Alliance (DA) on Thursday formally referred the National Energy Regulator of South Africa (Nersa) to the Public Protector for investigation over the R54-billion error made in its recent Eskom tariff determination.

Nersa agreed to a court order that Eskom can collect an extra R54-billion in tariffs over the next few years, as a result of errors made by the regulator in its sixth multiyear price determination (MYPD6) revenue decision.

DA spokesperson for Electricity and Energy Kevin Mileham said the party also wanted a reconstitution of the Nersa board with “competent professionals”.

The DA said it was outraged by what it termed the “most staggering regulatory failure in recent memory”, noting that the error, admitted to in writing by Nersa chairperson Thembani Bukula, would directly result in higher electricity tariffs for South African households and businesses, with increases now projected at 8.76% in 2026/27 and 8.83% in 2027/28.

Last week, the party wrote to Bukula demanding public accountability and answers.

In a letter to the DA, Bukula conceded to errors in Nersa’s calculations, citing a “clerical error” and a “version control issue”.

The letter to the DA also said a remedial process to find the origin of the errors was underway, and that consequence management would also take place to ensure accountability.

“Instead of defending its decision in court, Nersa chose not to oppose Eskom’s judicial review and quietly settled for an additional R54-billion in allowable revenue over the MYPD6 period. This deal was struck behind closed doors, without any public consultation, despite the fact that it will directly impact the cost of living for millions of South Africans,” stated Mileham.

On Wednesday Nersa appeared before the Parliamentary Portfolio Committee on Energy and Electricity, over the error, where the committee confirmed that Nersa knew of the error before finalising its decision in January 2025 — yet failed to correct it before publishing the Reasons for Decision in June.

“This is a textbook case of maladministration. Furthermore, the leadership of Nersa has ‘passed the buck’ - blaming employees and failing to take ownership of their own role in approving an incorrect determination without verifying its correctness,” Mileham said.

He said this exposed “deep institutional rot” at Nersa, that highlighted governance failure, a transparency deficit and capacity gaps.

“The R54-billion debacle at Nersa is not an isolated blunder; it is the clearest evidence yet that the system is failing the very people it is meant to protect,” Mileham said.