The damage caused by an explosion at the Medupi power station on Sunday night will cost between R1.5 billion and R2 billion to fix and increase the risk of load-shedding for up to two years.
Eskom said the explosion at the Unit 4 generator at Medupi was so significant that the disturbance caused Unit 5 at the power station to trip.
A preliminary investigation suggests that during a process to find a leak, air was introduced into the generator when hydrogen was still present in high quantities.
The hydrogen and air mixture created a volatile mix which ignited and resulted in the devastating explosion.
Eskom said that it appears there was a deviation from the procedure for carrying out this activity.
It has placed those employees responsible for managing and executing this work under precautionary suspension pending the conclusion of the investigation.
The explosion caused significant damage to the generator. It now has to be replaced, which comes at a tremendous cost.
Eskom CEO Andre de Ruyter told Fin24 that repairs to unit 4 at Medupi could cost anything between R1.5 billion and R2 billion.
He estimated that the repairs could take up to 24 months to complete, which increases the chance of load-shedding during this period.
Energy expert Chris Yelland said there is an option to replace the damaged generator with unit six from the Kusile power station, which is not used yet.
It is a complicated task to move the generator from Kusile to Medupi, but it is quicker than building and importing a new unit.
Yelland said losing two 794MW generators at the Medupi power station is a big blow to Eskom and will increase the likelihood of load-shedding.
South Africa’s power grid is already under severe strain, and Eskom relied on the Medupi power station to relieve some of the pressure.
The explosion comes less than a week after Eskom announced that the last of six generation units of the Medupi power station attained commercial operation.
“This milestone marks the completion of all building activities on the 4,764MW project, which commenced in May 2007,” Eskom said on 2 August.
Eskom applauded the team at Medupi for their great work, despite the project being years late and having cost far more than budgeted for.
Photos of the damage at Medupi unit 4
Damage at the Medupi Power Station
The video below provides an overview of the damage at Unit 4 at the Medupi Power Station.