This has emerged after last month’s massive explosion at the Duvha power station outside Witbank, Mpumalanga.
The February 9 explosion ripped through one of the turbines at the power station, causing extensive damage to the station’s infrastructure and immediately removing 600MW from the country’s electricity supply. That amount can power a city the size of Bloemfontein during peak hours.
It has now emerged that human error or lack of personnel caused the explosion, as it happened during a routine check.
Eskom is investigating whether the control room at the station was unmanned when all its safety mechanisms failed during a maintenance test on February 9.
The fiasco was caused by a faulty bolt which was supposed to have slowed down the turning speed of the turbine once it started spinning 10% faster than it was designed to.
Out of control
This failed to happen and the turbine spun out of control. The shut-down mechanism in the maintenance room also did not work when maintenance engineer Piet Bester, who was conducting the tests at the time, tried to shut the turbine down.
It appears that there was nobody in the control room to activate the emergency mechanism, which would have shut down the turbine immediately.
Four seconds later the turbine exploded, sending metal shrapnel tearing through the 30m-high roof of the turbine hall.
A witness said that absolute chaos ensued. One man, who had been showering at the time, ran outside naked.
Amazingly, nobody was injured in the explosion, which took place after working hours.
None of the other six generator units in the same turbine hall of the power station was damaged.
“This incident has happened at the worst possible time,” said Mike Rossouw, chairperson of the Energy Intensive Users’ Group (EIUG), a coalition of big manufacturers.
He said Eskom had already indicated that the power reserve margin was dangerously low and that there was little room to conduct routine maintenance.
Reliability of national grid
Rossouw said the explosion could have an effect on the reliability of the national grid, because scheduled maintenance at other stations was being delayed now that 600MW of generational capacity had been lost.
“We are worried that such a thing could happen again,” said Dirk Herman of trade union Solidarity.
This showed that Eskom’s personnel network could not handle the immense pressure, he said.
“Eskom’s investigation into the incident must be broadened to include an audit of the state of the network and the state of Eskom staff,” he said.
Eskom’s spokesperson, Hillary Joffe, said that the incident was a timeous warning to all South Africans to reduce their electricity consumption.
Two weeks ago Eskom presented a plan to government on how to force consumers to save electricity and on the issuing of fines to those who transgressed, she said.