The 1.08GW Kariba North hydroelectric power station is located on the bank of Zambezi River at Kariba in the southern province of Zambia. It includes the Kariba North Bank (KNB) (720MW) and Kariba North Bank Extension (KNBE) (360MW) power plants.
The KNB power plant was developed between 1969 and 1976 as part of the Central African Power Corporation’s (CAPC) development programme.
The KNBE power station was developed by Kariba North Bank Extension Power Corporation Limited (KNBEPCL), a special purpose vehicle (SPV) owned by Zambia Electricity Supply Corporation (ZESCO). It was inaugurated in December 2013.
Kariba North hydroelectric power station location details
The Kariba North hydroelectric power station is located on the northern bank of Zambezi River, 130km south of Lusaka at Kariba in Zambia.
The hydro station sources water for power generation from Kariba Dam located on the Zambezi River at the border of Zambia and Zimbabwe. The dam has a water storage capacity of up to 185 billion cubic meters (bcm).
The Kariba South power station located on the southern bank of Zambezi River belongs to Zimbabwe. It was initially developed with a capacity of 750MW and later expanded to 1050MW by the addition of two 150MW units in March 2018.
Kariba North power project make-up
The Kariba North hydroelectric power station comprises of four vertical shaft Francis-type turbine generating units of 150MW capacity each producing a total power of 600MW. The four turbines operate at a head of 92m with a rated discharge 186.79m3/s.
Under a rehabilitation programme executed between 2004 and 2009, the capacity of the power plant was expanded to 720MW. The expansion project was completed in June 2010.
The KNBE power station consists of two 180MW vertical-shaft Francis turbines with a rated discharge 227.6m3/s operating at a head of 89m for each single unit. It has two intake chambers for water at an elevation of 458m. The underground powerhouse is 24m wide and 51m in length.
The power generated is transmitted through a 130km long, 330kV transmission line from KNBE power station to the existing Kafue west substation.
Power purchase agreement details
The power generated from Kariba North power station is purchased by ZESCO under a 20-year long-term power purchase agreement approved by the Energy Regulation Board (ERB) in April 2011.
The plant operates with an average operating time of 3.5 hours a day under the regulation of PPA.
Financing of Kariba North power station extension
ZESCO initiated the extension of the KNB power project with an estimated investment of £338.2m ($421.1m).
China’s Export-Import Bank provided a syndicated loan of £253.47m ($315.6m), while the remaining £84.73m ($105.5m) was funded by Development Bank of Southern Africa.
Sir Alexander Gibb & Partners (Gibb) was awarded the contract for engineering work to construct the 600MW Kariba North hydroelectric power station. The main civil construction contract was awarded to Mitchell Construction Kinnear Moodie Group in January 1971.
Energoprojekt was engaged by the government of Zambia to complete the work of Kariba North power station after Mitchell Construction went into receivership.
EDF Hydro Engineering Centre rendered project ownership services for the project.
In 2003, the Government of Zambia signed a letter of intent (LOI) with Sinohydro Corporation in partnership with ZESCO for the 360MW extension of KNB power station.
Rehabilitation of Kariba Dam
The Kariba Dam is undergoing a restoration scheme since 2017 to reshape the plunge pool and the refurbish the spillway gates. The project will increase the life of the dam and is anticipated to be completed by 2025. It will ensure interminable water supply to both Kariba North power station and Kariba South power station.