Medupi and Kusile power stations
In recent decades, South Africa has experienced a growing economy and an expanding population, and as a result the supply of electricity within the country has become insufficient, resulting in narrowing reserve margins and frequent load shedding. State electricity producer Eskom, who supply 90% of electrical power to the southern African electricity market, has started a number of initiatives to resolve this problem, and one of the most important steps has been to construct the Medupi and Kusile coal-fired power stations.
Both stations are larger than any station constructed in Eskom’s 92-year history. Medupi is a 6 x 800 MW station located near Lephalale in Limpopo Province, close to the border between South Africa and Botswana. Kusile is a largely similar, 6 x 800 MW station located in the industrialised Witbank area, in Mpumalanga Province, to the east of Johannesburg.
The Medupi and Kusile power stations use supercritical boilers, firing abundant, locally mined coal. To minimise the use of water, a scarce commodity in South Africa, both stations use air-cooled condensers, which are the largest of their type in the world.
The Medupi Power Station is being constructed, and will be commissioned, without flue gas desulphurisation (FGD) plants initially, but designs are being prepared to retrofit FGD plants during the first major overhauls of the six units, after 6-8 years of operation.
The Kusile Power Station is constructed with FGD plants, which will operate from the initial commissioning of the units. The station will use wet limestone gypsum FGD technology and to keep generating cost down, the FGD units will not use reheat.
Both the Medupi and Kusile power stations use two, 220-metre high reinforced concrete chimneys, each with three steel flues. All four chimneys have been constructed by a consortium of Karrena Africa, Concor and Beroa Deutschland. All 12 steel flues have an internal diameter of 8.9 metres and they have been internally protected with PennguardTM linings, using 51mm-thick PennguardTM Block 55.
