The Ingula pumped storage scheme in South Africa is the largest hydro power scheme in Africa, and it recently began generating electricity for the national grid.
The pumped storage scheme consists of an upper and a lower dam, each capable of holding approximately 22 million cubic metres, which is around 5.28 billion gallons of water.
The dams, which are 2.9 miles apart, are connected by underground tunnels passing through a subterranean powerhouse with four 333 MW generators, and the power station is able to respond to increases in demand on the national grid within two and a half minutes.
Here are the 13 things you probably didn’t know about Africa’s largest hydro power scheme.
Sources: IndependentOnline, EyeWitnessNews, LadysmithGazzette, EngineeringNews.
The scheme is officially the largest on the African continent, while it is the 14th-largest pumped storage scheme in the world. It is capable of delivering just over 3% of the South Africa’s current generation capacity.
To generate electricity during peak demand times, water is released from the upper dam, passing through the turbines into the lower dam. During times of low energy demand, the water is pumped from the lower dam back to the upper dam.
The scheme will pump 10,400 Olympic-size swimming pools of water up the hill at night and then let it all run down the next day, using the gushing power of the water to spin four of South Africa’s biggest electrical motors.
Power utility Eskom is able to quickly release some of the water down a 2.9 mile-long tunnel beneath the mountains. As it tumbles down towards a second dam in Kwa-Zulu Natal, the water rotates turbine blades spinning at more than 205mph, which then drives massive electric motors.
The project was first known as ‘Braamhoek’, but was officially changed to ‘Ingula’ in March 2007. The name ‘Ingula’ describes the creamy contents at the top of a milk calabash, and was inspired by the mountains and foamy river-waters in the area.
The pumped storage scheme has taken many years to build, and as such the cost for the massive infrastructure has been huge. Around $3.5 billion (R25 billion) has been spent to create the project.
Over 90 locations were investigated since 1981 before the Ingula site was decided upon 31 years ago. The new Ingula power station is located on the border between the KwaZulu-Natal and the Free State provinces in the Drakensburg.
Apart from the dams and power lines, very little of the power plant is visible from outside. Most of the power station is deep beneath the mountain in a central chamber housing four generators each weighing 230 tons.
Around 6.6 million pounds of dynamite was used to blast and remove three million tons of rock to allow for the completion of the Ingula project, creating the world’s largest single-span machine hall in mud-rock.
Over 300 bird species have been seen at Ingula and the surrounding areas, including the Wattled Crane, which is among the critically endangered birds in terms of regulations issued in the National Biodiversity Act. The wetland is recognised by BirdLife South Africa as an ‘Important Birding Area’ (IBA), and is therefore protected.
Almost 20,000 acres around the Ingula power station has been declared a nature reserve, called the Ingula Nature Reserve. The conservation area protects the moist, high altitude grasslands of the eastern Free State and northern KwaZulu-Natal.
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Unfortunately tragedy struck the project in 2013, when six workers lost their lives in a platform collapse. Eskom reported that a working platform in the incline high-pressure shaft, which connects the top dam to the powerhouse, failed, leaving six dead and several injured.
In July this year South African president Jacob Zuma visited the site to officially open the plant. The scheme first began construction 11 years ago, and it is nearing completion at this point.