The potential of hydropower in South Africa is relatively small, but with trans-boundary agreements and regional co-operation agreements in place, South Africa’s commitment to purchasing power from promising hydro sites in the sub-Sahara region makes their development a more viable option, said GIBB this week.
Commenting on the endorsement by heads of state in the region of 15 hydropower projects with an estimated value of $50 billion, Colin Logan, technical executive at GIBB, said: “Central Africa has huge hydropower potential to meet both its local and export requirements.
“The Congo and Zambezi river basins are estimated to be able to provide 774 TWh/year and 38 TWh/year respectively.”
Southern African hydropower projects
In Southern Africa, GIBB is involved with the 40MW Kabompo Gorge Hydropower Project located in the Kabompo River in the North West region of Zambia.
The hydro project is made up of a roller-compacted concrete dam, a 4km tunnelled water conveyance system and underground powerhouse and transformer caverns.
“The underground powerhouse and associated infrastructure will be accessed by the main access tunnel. The principal component is the Kabompo Dam, a 47.50m high RCC gravity dam wall constructed on a straight vertical upstream face and a 1.0V: 0.75H downstream slope with gross storage capacity of 398 Mm3”, Logan explained.
According to lead consultant GIBB, the site investigations, including the tender development and adjudication phases of the Kabompo Gorge hydropower project, have been undertaken by the Amanzi Consultants Joint Venture, supported by Knight Piésold and Royal Haskoning.
“A contractor has been appointed and is undertaking temporary construction activities on site under an Early Works Agreement. Amanzi has been appointed as the Owners Engineer specifically to undertake a design review function and is assisting the client, CEC-Copperbelt Energy Corporation, with negotiations on the main engineering, procurement and construction contract,” GIBB said.
Amanzi is now in phase 4 of the project, having completed:
- Phase 1- Desktop review of information and facilitates a survey
- Phase 2- Master plan study
- Phase 3 – Multi-criteria assessment
- Phase 4 – Preliminary geotech investigation
Luapula Cascade Scheme
Another GIBB project is the Luapula Cascade Scheme located on the boundary between Zambia and the Democratic Republic of Congo (DRC) with five potential dam sites to be developed along the Luapula River.
GIBB explains that each hydropower site is unique but the general location of the project sites have been grouped in two regions namely: Mumbotuta Falls and Mambilima Falls. Mumbotuta Falls has two possible hydropower project sites and Mambilima Falls has three possible hydropower sites.
Logan concluded: “As per the Master Plan Study (2013) conclusions and recommendations, the five dam sites will operate as run-of-river dams with installed capacity ranging from 84MW to 250MW and dam heights from the lowest at 26m x 1556m in length to the tallest at 80m high x 1880m long.”
Hydropower under REIPPPP
In addition to importing hydroelectric power from neighbouring countries, the South African department of energy recently awarded the country’s first hydropower project, the Kruisvallei 5MW hydropower project, under round 4 of the Renewable Energy Independent Power Procurement Programme (REIPPPP).
The South African state-owned power utility Eskom, has been battling to meet energy demand in recent months due to lack of water and diesel reserves, technical faults and damaged infrastructure resulting in rolling black-outs across the country.
(Homepage pic credit: GIBB)