The Ingula Pumped Storage Scheme (previously named Braamhoek) is a pumped-storage power station in the escarpment of the Little Drakensberg range straddling the border of the

KwaZulu-Natal KwaZulu-Natal (, also referred to as KZN and known as "the garden province") is a province of South Africa that was created in 1994 when the Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu) and Natal Province were merged. It is loca ...

and Free State provinces,

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

. It is about North-East of

Van Reenen Van Reenen (pronounced "Fun Reenen") is a settlement in Uthukela District Municipality in the KwaZulu-Natal province of South Africa. It is located on the N3 national road at the top of Van Reenen's Pass on the Great Escarpment of the Drakens ...

Design

The pumped-storage

hydroelectric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...

scheme consists of an upper and a lower dam apart and connected to a power station by tunnels. The power station uses 4 Francis pump turbines rated at 333 MW each, giving it a total rating of 1332 MW installed capacity.

Construction

Notable contractors included CMC

Impregilo Webuild SpA (formerly Salini Impregilo SpA) () is an Italian industrial group specialised in the construction and civil engineering business headquartered in Milan. The company was formally founded in 2014 as the result of the merger by incorpor ...

Mavundla Joint Venture and

Concor Concor Holdings (Proprietary) Limited. is a South African construction and mining services company. It is active throughout Southern Africa, involved in mining, civil engineering, building and road projects. Concor returned as an independent br ...

on the dams. The scheme was built at a cost of US$3.5 billion ( R25 billion). Construction began in 2005 and the power station was scheduled to begin operations in late 2015. * The first two generators were commissioned March 2016. * The third generator was brought into commercial operation in August 2016. * The fourth and final one in January 2017.

Detailed breakdown

The

pumped-storage hydroelectric Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. The method stores energy in the form of gravitational potential ...

plant uses water from the upper reservoir to generate electricity during the peak demand periods of the day. At night, excess power on the grid generated by conventional coal and nuclear plants is used to pump water to the upper reservoir. *The upper Bedford Dam on Bedford stream, a tributary of the Wilge River, was completed in April 2011. It is a tall

concrete-face rock-fill dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...

. It has a water storage capacity of which can be used for power generation. *The lower Bramhoek Dam on Bramhoek stream, a tributary of the

Klip River The Klip River is the main river draining the portion of Johannesburg south of the Witwatersrand, and its basin includes the Johannesburg CBD and Soweto. The mouth of the river is at Vereeniging where it empties into the Vaal River, which is a tri ...

, was completed in November 2011. It is a tall

roller-compacted concrete Roller-compacted concrete (RCC) or rolled concrete (rollcrete) is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for Po ...

gravity dam A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation to oppose the horizontal pressure of water pushing against it ...

. It has a water storage capacity of which can be pumped up to the upper reservoir. *A long headrace tunnel connects the upper reservoir to the

underground power station An underground power station is a type of hydroelectric power station constructed by excavating the major components (e.g. machine hall, penstocks, and tailrace) from rock, rather than the more common surface-based construction methods. One or mor ...

which houses 4 x reversible Francis pump-turbines. The elevation between the two reservoirs affords a

hydraulic Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counte ...

head (water drop) of . *Water from the power station is discharged down a long tailrace tunnel to the lower reservoir.

Storage capacity

The energy storage capacity is 21,000 MWh or 15.8 generating hours.

References

External links