The Orange River has been useful to farmers for decades. They have grown their crops along its banks, using its water and fertile soil to produce citrus, grapes and other cash crops.
But in modern times, the river’s use has been extended beyond the agricultural sector and into green industries. Electrical Engineers are now using its waters to generate and supply electricity for generations to come. The Kakamas Hydro Electric Power (KHEP) project in Northern Cape will make use of the river’s kinetic energy to generate 10 megawatts (MW) of electricity. The project is a run-of-river design that will be constructed at the existing Neusberg Weir, which feeds water to the Neusberg Power Plant.
Although the plant has an installed capacity of 12.57MW, the Department of Energy had limited its output to 10MW, which is in accordance with constraints placed on small hydroelectric power plants. The energy modelling for the project is estimated at 69.25 gigawatts per hour of net electricity generation per year. The output could light up as many as 5 000 homes.
Australian engineering company Hydro Tasmania partnered with the Industrial Development Corporation, Hydro SA, Old Mutual, Kakamas Hydro Community Trust and Nedbank to construct the KHEP.
Christoff le Grange, manager of new markets for Entura (the design division of Hydro Tasmania), says the project will be the largest mini hydro plant to be developed under the national Department of Energy’s Renewable Energy Independent Power Producers Procurement Programme. “When operational, it will make history by being the first independent power producer to deliver clean energy via a run-of-river mini-hydro in South Africa.”
The KHEP is the first of three plants proposed for the region. These will be Riemvasmaak, near the Augrabies National Park, at Boegoeberg Dam and Orange Falls. The project forms part of the government’s larger strategy to supply 17 800MW of electricity through renewable energies by 2030, and to reduce greenhouse gases by 34% below the current level by 2020.
The powerstation infrastructure is made up of stop-log gates, 1 410 metres of open canal waterway, three buried steel penstock pipes, a partially buried powerhouse, a 200m long tailrace canal that runs from the powerhouse back to the river, and infrastructure for connection to the Eskom distribution network.
The Neusberg Plant has a 15m drop on to its hydro turbine, which will capture kinetic and potential energies and subsequently drive a turbines connected to a generators. The energy created will turn into electricity. The plant guarantees 70% efficiency at all times, making it more reliable than the Kalahari sun.
Construction of the plant will take 21 months, and is scheduled to be completed by January next year. The capital investment for the project amounted to R560-million.
Advantages of hydro power
According to Mercia Grimbeek, KHEP’s economic development manager, the electricity produced will be supplied to the national grid. It is estimated that greenhouse gas emissions will be reduced by 467 782 tons in the first seven-year crediting period. Emissions of harmful substances into the atmosphere such as flue ash, oxides of sulphur, and nitrogen will be reduced.
Besides the decrease in greenhouse gases, Grimbeek says there are several other benefits that come with the project. These include the creation of 200 jobs during construction and four jobs for the operation phase. Furthermore, local businesses benefit from the procurement of goods and services locally. In addition, the Project Design Document states that sales of carbon credits will also increase foreign direct investment.