The breakdown occurred on 25 July, and since then the dam operating company, Hidroelectrica de Cahora Bassa (HCB) has only been operating at 70 per cent of its production capacity.
The breakdown affects the smoothing coil, a key piece of equipment which regulates the transmission of the direct current electricity produced at the HCB power station installed inside the dam.
According to HCB technical director Gildo Sibumbe, the breakdown occurred precisely when the company was procuring a spare coil, a procedure which normally takes six months.
The matter is now urgent, and so last week HCB asked a team of German specialists to come to Songo to carry out a viability study on replacing the damaged equipment. The HCB managers estimate that repairing the damage could take about 30 days.
Sibumbe said that contacts are under way with the South African authorities for the loan of a coil similar to the damaged equipment. Since the South African electricity company Eskom is far and away the largest client for Cahora Bassa power, it is certainly in South Africa’s interest that the situation should be normalised as quickly as possible.
“Contacts are under way with our other partners to acquire the coil with utmost urgency”, said Sibumbe. “To remedy the situation we are expecting at any moment confirmation from out South African partner, who is willing to lend us a piece of equipment with similar characteristics to ours”.
In principle, this equipment could be in Songo in a few days – but the problem is tranporting it, since it is exceptionally heavy. The coil weighs around 150 tonnes. Enormous vehicles would have to be used to take it from South Africa to Songo. Not only would transport be slow, but it poses a threat to the roads used.
“We are negotiating with the National Roads Administration (ANE) to find a way out, so as to avoid destroying the roads, and particularly the bridges”, explained Sibumbe.
He said that HCB has hired a specialist company to study the best route which the trucks carrying the coil should take. That company is advising transport from Pretoria, through Zimbabwe, and entering Tete at the Cuchamano border post. Using this route, the truck would pass over just one major bridge, crossing the Mazoe river.
“We will have to work with the ANE to see how the bridge can be strengthened to support the truck and the equipment”, Sibumbe said.
While it would be possible to put the coil on a ship to the port of Beira, the route from Beira to Songo involves many more bridges, including the Samora Machel bridge over the Zambezi, in Tete City, “and so that’s out of the question”, he added.
Post published in: Africa News