Company Announcement - Forecast demand for electrical energy in the sub-Sahara Africa region has led to heads of state endorsing the investigation of the 15 most promising hydropower projects, with an estimated worth of $50-bn. South Africa’s own demand for energy according to the National Development Plan will require by 2030, a 29,000MW addition to current capacity to meet development targets and provide electricity to 100% of the population. If retired stations (10,900MW) are taken into account, this equates to an additional new build of 40,000MW. Some 20,000MW of which has been earmarked as renewables, which in addition to solar and wind, includes hydropower.

According to leading black-owned engineering consulting firm GIBB, 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. “Central Africa has huge hydro power 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. We are involved in several projects from studies to inception,” said Colin Logan, GIBB Technical Executive.

Logan’s insight comes from working on numerous hydropower projects for GIBB over the past 10 years, most notably in the role of Chief Supervisor on the Ingula Pumped Storage Scheme, a joint venture with Knight Piésold and Royal Haskoning DHV to supply detailed design, tender documentation, design monitoring and construction supervision. The rated generating capacity of the scheme is 1 332MW with an energy storage capacity of 21 000MWh.

Some of the hydropower projects that GIBB is involved with in Africa, include:

Kabompo Gorge Hydropower Project
This site is located on the Kabompo River, with the dam located at the top of the Kabompo Gorge. Located in the North West Province of Zambia, the proposed 40MW hydropower project comprises a roller compacted concrete (RCC) dam, tunnelled water conveyance system and underground powerhouse and transformer caverns. The 4km long tunnelled conveyance system includes D-section headrace and tailrace tunnels and a steel lined penstock section.

“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,” explained Logan.

Site investigations, including the tender development and adjudication phases of the Kabompo Gorge hydropower project, have been undertaken by the Amanzi Consultants Joint Venture, comprising GIBB as the lead consultant supported by Knight Piésold and Royal Haskoning DHV.

“A contractor has been appointed and is undertaking temporary construction activities on site under an Early Works Agreement. Amanzi have been appointed as the Owners Engineer specifically to undertake a design review function and are assisting the client, CEC-Copperbelt Energy Corporation, with negotiations on the main engineering, procurement and construction contract.

Luapula Cascade Scheme
This project is also in Zambia on the Luapula River a tributary of the Congo River which begins at the outlet of the Bangweulu Swamp and at this point, becomes the boundary between Zambia and the Democratic Republic of Congo (DRC).

Five dam sites along the Luapula River are being considered for hydropower development. 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.

“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,” said Logan.

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

Expertise
GIBB has also recently completed a 12 month long pre-feasibility study to investigate the viability of the proposed 1,200 MW Monont’sa Pumped Storage power plant in Lesotho, entrusted to the firm by the Lesotho Electricity Company.

“Our approach is comprehensive where we examine not only the technical issues but also environmental and social, sustainability and economic consequences. Hydro power has the potential to provide sustainable energy solutions in many countries in Africa,” concluded Logan.