Cape Town – The collapse of the silo at the Majuba Power Station has put Eskom and South Africa on the brink of an energy crisis, according to energy expert Chris Yelland.
Eskom has planned to run Majuba at half capacity for the foreseeable future. “We hope the plan works, we hope there are no other unforeseeable incidents, because if there are, the country is in serious trouble,” said Yelland, MD of EE Publishers.
Running it at half capacity leaves the country short of 1 800 MW “at a time when we need it most”, said Yelland, adding that it would take months before they could rebuild the collapsed silo. “Building a new silo is like building a new house,” he said. “It takes time and … will take several months undoubtedly.
“Hopefully, in the interim, they can limp on at least at half capacity and, by using energy sparingly, the country could get by,” he said. “I have little doubt that in coming months we are likely to see more rotational load shedding.”
Investigation of collapse
The silo, which was last inspected in September 2013, should not have collapsed, said Yelland. “It is basically steel and concrete,” he said. “If correctly designed and implemented, it should last a lifetime of the power station, something like 50 years. So the fact that it has failed after 20 years – it was constructed in 1994 – is very unusual.”
Yelland said a three-month long investigation into the collapse would probably take place to explain how it collapsed. The causes could include weakness in the concrete, corrosion in the steel, vibration-related issues, or stress caused by the conveyors.
However, Yelland said the general public would probably not see the investigation’s findings, due to legal issues.
“An incident like this that takes out all six units out of one of Eskom’s major power stations, in fact the newest power station in the current Eskom fleet, is an incident of unprecedented proportions,” he said.
“It was certainly not on their planning horizons in terms of Eskom making contingency plans,” he said. “To lose units simultaneously when this incident occurred is a major problem coming at a time when the system is already extremely constrained.”
Emergency operation a mammoth task
What should be a simple automatic process of feeding coal into the six units has become an impossible task. Now, operators have to manage a process of manually trucking in coal and loading it into the units.
“This is quite an arduous process logistically, which would require something like 30 trucks per hour feeding on to the two inclined conveyors,” he said. “That means one dump truck every two minutes on a continuous 24-hour basis.
“This unfortunately will not be able to keep the full power station operating,” Yelland said. “It will keep four out of the six units operating.
“So perhaps this can keep the power station running at about half … capacity.”