The African continent might not be as developed as the rest of the world, but it has many things of great value. In this case, it’s the power of the sun all year round, which makes it perfect for solar power projects. In 2010 South Africa launched it’s own development project to increase the presence of solar power and establish 9 600 MW of power by 2030. The reasons behind this project are three-fold. Firstly, to fix the strain on supplying South African with power. Secondly, it’s a global movement that can’t really be avoided. Last but not least, the continual decrease of prices for panels meant it became a more affordable option.
South Africa currently has several solar farms, most of them funded by private companies under the special procurement program created by government. However, Eskom also has a few. At the moment the solar farms are making use of photovoltaics (PV) panels and concentrated solar power (CSP) technologies. PV is the most popular, due to the affordability and efficiency. In basic terms, the PV process is when light energy is absorbed by materials and directly transformed into electrons.
One of the most basic PV solar farm designs in South Africa can be found in the Northern Cape, near Kimberley. It’s called the Droogfontein Plant and the panels are fixated at a certain degree and face the midday sun. A more advanced design can be seen in the Sishen Plant, which is also located in the Northern Cape. The panels use single-axis tracking technology to make up for the efficiency loss, but the Herbert and Greefspan (Northern Cape) plant takes it one step further. These panels use a two-axis tracking system, so it’s always facing the sun directly. Even though the two-axis motor system is more expensive, the plant captures a lot more energy, which makes up for the additional cost.
Concentrated Solar Power
With CSP technologies the sunlight is re-directed to a single focus point. This is usually done through mirrors. The heat from the focus point gets transported to an electricity generating unit through fluids, where the water is boiled and the heat drives a turbine. It’s pretty much the same concept of coal getting burnt to create heat, but without the pollution. Khi Solar 1 is a plant that is being built with this foundation and one that’s already operational can be found near Pofadder, called KaXu. At least two plants that are in development will also use CSP.
There is one case where a hybrid system is being used, namely the Touws River plant in Western Cape. This is when the collection point of energy directed by the mirrors, which is fluid, gets replaced with a PV receiver. Whether this hybrid method will be used again in the future remains to be seen.