South Africa faces tight electricity supplies

07 January 2011

South African utility Eskom has warned of tight electricity supplies in the years ahead until new coal-fired generating capacity is brought on line. Meanwhile, unit 1 of its Koeberg nuclear power plant – on which it will depend for supply - has been taken out of operation due to suspected fuel defects.

Koeberg (Eskom)
Koeberg (Image: Eskom)
The company said, "The margin between electricity supply and demand is going to be very slim at times over the next five years, and especially over the next two years until the first units of the giant new Medupi [coal-fired] power station come on line in late 2012 and 2013." Eskom added, "The first unit of the sister Kusile power station will start generating power in late 2014."


"Unless steps are taken to address it, the gap between supply and anticipated demand is expected to lead to a shortfall of 6 terawatt-hours (TWh) in 2011/12 and 9 TWh in the subsequent year." The company noted that this gap is equivalent to the annual consumption of a large city such as Cape Town.


Company CEO Brian Dames noted, "Eskom has resolved not to return to the disruptive load shedding, and recognises it cannot achieve this on its own. However, that resolve will be tested during the next two years."


The company's position was not helped in mid-December 2010 by the unplanned shutdown of Koeberg 1 after higher than normal levels of radioactivity was found in the unit's primary coolant circuit indicated one or more defective fuel rods in the reactor. The company said at the time that the unit, which recently under went a refuelling outage, would remain offline for between 30 and 40 days to locate and replace the defective fuel.


The utility noted, "Although Koeberg is designed to operate safely with a limited number of fuel defects, this would result in increased levels of radioactive waste being produced by the filtration systems that keep the primary coolant circuit clean. Eskom believes that it is thus prudent to shut down the unit and replace the defective fuel."


Eskom has taken into account the temporary shut down of Koeberg 1 in its capacity planning and "is committed to ensure that sufficient generating capacity is available to meet the demand for electricity," although Dames said that  "the loss of half of Koeberg's generating capacity reduced our flexibility to do maintenance at our coal-fired power stations, and some maintenance has had to be postponed. This in turn increases the risk of unplanned outages at these stations."


Researched and written

by World Nuclear News