Name and Location
Ingula pumped-storage scheme project, on the border between the Free State and KwaZulu-Natal, South Africa.

Client
Eskom.

Project Description
The Ingula pumped-storage scheme, located within the Little Drakensberg mountain range, 23 km north-east of Van Reenen’s Pass, will comprise an upper dam (Bedford) and a lower dam (Braamhoek). The upper reservoir site is located in the Free State and the lower reservoir site in KwaZulu-Natal. The escarpment forms the border between the two provinces.

The distance between the upper and lower reservoirs will be 4.6 km, with an elevation difference of about 470 m.

The dams will be connected through underground waterways using an underground powerhouse complex, which will house four 333 MW pump turbines with a total capacity of 1 332 MW, a machine hall, a transformer hall and associated tunnels, shafts and caverns.

The twin waterways, consisting of concrete and steel-lined headrace tunnels, pressure tunnels and shafts, will link the upper reservoir with the pump and turbines. Steel-lined extended draft tubes and a single concrete-lined tailrace tunnel will connect the pump and turbines to the lower reservoir.

The upper reservoir will be a concrete-faced rockfill embankment dam, 41 m high, with a total capacity of 22.6-million cubic metres and an active water storage volume of 19.3-million cubic metres. The 39-m-high lower dam will be of roller-compacted concrete (RCC), with a total capacity of 26.3-million cubic metres and an active storage volume of 21.9-million cubic metres.

The upper reservoir will store enough water to generate electricity continuously using all four units for 16 hours. Pumping the water back from the lower reservoir will take about 21 hours, giving an overall efficiency of 76% for the scheme.

Value
R23.8-billion. As at March 31, 2012, R11.1-billion had been spent.

Duration
The power station is planned to be fully operational in 2014.

Latest Developments
Eskom has reported in its New Build News for January 2014 that excavation and rock support works on the underground works have been completed and that civil works, together with the installation of the turbine units and other mechanical items, are under way. Civil works include the placement of about 500 000 m³ of concrete.

The civil works activity remains critical in terms of the overall project completion, owing to access requirements for the transformer and electrical packages. The intake and outlet structures have been completed.

Other major underground works packages under way include:
• the tailrace and concrete lining, which is 95% complete;
• surge chambers 3 and 4’s base construction, which is 92% complete;
• surge chamber 1 and 2’s base construction, which is 78% complete;
• the CAT portal structure, which is 75% complete;
• the main drainage gallery and dewatering sump, which is 98% complete;
• surge risers 1 and 2 are 30% complete, while surge risers 3 and 4 are 95% complete;
• the steel-lined incline shafts 1 and 2, which are 85% complete; and
• the steel-lined incline shafts 3 and 4, which are 77% complete.

Work under way at the 45-m-high machine hall includes:
• the spiral encasement Unit 1, for which the last pour has been completed and is awaiting the disassembly of pressure-test equipment;
• the ongoing compressor room installations at Unit 2 from the turbine floor to the generator floor; and
• Octagon Unit 2, for which the pour for lifts 1 and 2 has been completed with the pour for lift 3 in progress.

Key Contracts and Suppliers
The Braamhoek Dams joint venture (JV), consisting of Gibb, Knight Piésold and SSI (civil, mechanical and electrical engineering, detailed design, tender documentation, design monitoring and construction supervision); Murray & Roberts (civil works); Grinaker-LTA (access roads); CMI JV, comprising CMC di Ravenna, PG Mavundla and Impregilo (underground civil works); Afriscan (water supply, sewage treatment, small access roads and building temporary Eskom offices); B&E Quanza Group (aggregate quarry); Acer [Africa] (environmental consultants); Braamhoek Dam JV, comprising Concor Roads & Earthworks, Wilson Bayly Holmes-Ovcon (WBHO), Edwin Construction and Silver Rock (dam contract); Voith Siemens Hydro Power Generation (mechanical auxilary plant); Atlantis Drill (ventilation shaft) and Sandvik Mining & Construction (raiseboring manager); Deutsche Bank (R1-billion loan); ABB (electrical balance of plant, or eBoP, solution); NCC Environmental Services (independent environmental control officer services); Konecranes (heavy-duty cranes); Hitachi POwer Africa (boiler); Basil Read (main civils); Alstom (turbine); Roshcon (enabling civils); Aveng (access roads); African Construction (infrastructure); TBD (optic fibre and communications); and Siemens (generator transformers).

On Budget and on Time?
The first 333 MW unit was initially expected to be commissioned by January 2013; however, it will only be commissioned in the first quarter of 2014.

Contact Details for Project Information
ABB head of communications Harmeet Bawa, tel +41 43 317 6480, fax +41 43 317 6482 or email harmeet.bawa@ch.abb.com.
Gibb, Andre Bosch, tel +27 11 519 4600 or fax +27 11 807 5670.
Braamhoek Dams JV (Concor Roads & Earthworks), Eric Wisse, tel +27 11 495 2222.
CMI Mavundla JV, tel +27 36 638 6000 of fax +27 36 8 6017.
Eskom media desk, tel +27 11 800 3304/3309/3343/3378, fax +27 11 800 3805 or email mediadesk@eskom.co.za; or Katlego Nchoe, tel +27 11 800 3435 or email NchoeK@eskom.co.za.
Eskom national call centre, tel 0860 037 566.
Ingula Visitors Centre, tel +27 36 342 3122 or email fifi.meyer@eskom.co.za.
Impregilo, Giovanni Frante, tel +39 02 4442 2115 or email giovanni.frante@impregilo.it.
Voith Siemens Hydro Power Generation, Barbara Fischer-Aupperle, tel +49 7321 370, fax +49 7321 37 6180 or email barbara.fischer-aupperle@vs-hydro.com.
NCC, tel +27 21 702 2884, fax +27 86 555 0693 or email info@ncc-group.co.za.
Konecranes, tel +27 11 864 2800.