Fire at Kriel Power Station

Eskom may have experienced another generating unit explosion, this time at its Kriel Power Station in Mpumalanga.

According to an X (formerly Twitter) post from Limpopo Current Affairs (@BlaqSlav), the power station’s unit 6 generator caught fire at around 17:30 on Sunday, 3 November 2024.

The power station features six coal-fired generation units with a combined capacity of 3,000MW.

“Load-shedding might come back in full swing,” the post adds.

Energy expert Chris Yelland retweeted the post. However, he doesn’t believe the fire will necessarily cause load-shedding to return.

“Not so sure about load-shedding coming back in full swing, but it looks like a pretty serious explosion and fire at Kriel power station yesterday late afternoon,” said Yelland.

Yelland said he received quick feedback from Eskom spokesperson Daphne Mokwena, who confirmed the fire had been extinguished.

“It was an oil pipe that burst, but all safe now. We are still assessing,” Eskom reportedly said.

However, Yelland noted that one of the videos showed a large hole in the top of the generator hall.

“I am somewhat surprised that a burst oil pipe and associated fire would cause such a gaping hole… Looks more like a massive explosion to me,” he said.

Eskom subsequently issued a statement on the matter, emphasising that the incident won’t impact its current generation capacity, nor will it lead to load-shedding.

“Unit 6 at Kriel Power Station correctly tripped following the loss of hydraulic oil to the turbine valves,” it said.

“A preliminary investigation revealed that an oil pipe had broken, causing oil to spill on the hot surfaces of the turning, which triggered a fire.”

Eskom noted that Kriel Power Station Unit 6 contributes 475MW to the grid.

“With this unit temporarily offline, total unplanned outages stand at 8,483MW — still 4 517MW below the base case for summer 2024,” it said.

Medupi Power Station’s unit 5 generator tripped on Sunday, 8 August 2021, and the next day, Eskom explained that it had tripped due to its unit 4 generator exploding.

Fortunately, no power station staff were injured, and all employees and contractors were accounted for. However, it noted that emergency services attended to seven staff suffering from shock.

A few days after Eskom’s confirmation, Yelland explained the sequence of events that led to the explosion.

The unit was scheduled for maintenance, which required technicians to purge oxygen from the generator using carbon dioxide. Once completely purged, technicians can then pump in air.

Mixing hydrogen and air can create an explosive mixture. According to Yelland, technicians never properly purged the hydrogen generator, and the mixture of air and hydrogen ignited, causing a massive explosion.

The generator was completely destroyed.

“This generator cannot be repaired — it has to be replaced,” Yelland said at the time.

Eskom confirmed Yelland’s explanation of the events that resulted in the explosion.

“It also appears that there was a deviation from the procedure for carrying out this activity,” it added.

Former Eskom CEO André de Ruyter later revealed that bringing the unit back online would cost around R2.5 billion and take approximately three years.

He had previously said that repairs would cost between R1.5 billion and R2 billion.

The three-year timeframe meant Eskom was targeting August 2024 for the return of Medupi Unit 4. However, this didn’t go as planned.

In mid-October 2024, Yelland warned that Eskom had delayed the return of the unit until March 2025. It also delayed the return of Koeberg Unit 2 until December 2024.

“Until the above are successfully completed, Eskom is reluctant to say that load-shedding is finally over in SA,” he added.

MyBroadband contacted Eskom for comment about the fire at Kriel, but the power utility did not immediately respond.