South Africa’s renewable energy sector has taken a significant leap forward with the commissioning of the KaXu Solar One plant. Built by the Spanish multinational Abengoa, this 1,100-hectare (2,718-acre) facility is South Africa’s first concentrated solar power (CSP) project to employ parabolic trough technology. This innovative approach uses mirrors in a parabolic trough to concentrate solar energy onto a tube filled with a heat-absorbing fluid, generating steam to power a conventional steam turbine.
Featured in the African Power & Energy Elites 2023, KaXu Solar One is not just a technological marvel but a beacon of sustainable development. The plant boasts a 100 MW solar thermal capacity, integrating a two-tank, indirect, molten salt-based thermal storage unit. It comprises 1,200 parabolic trough solar collectors, each stretching impressively to 152.4 meters in length.
Situated near Pofadder in the Northern Cape Province, the name ‘KaXu’ aptly means ‘open skies’, reflecting the plant’s geographical advantage for harnessing solar energy. Each collector consists of ten modules with 28 pivoting concave mirrors, totalling an astounding 336,000 parabolic-shaped mirrors.
According to a report by ESI Africa, the CSP plant’s total output is secured under a 20-year power purchase agreement (PPA) with Eskom, South Africa’s state-owned power utility. This agreement was one of the first awarded under the Renewable Energy Independent Power Producers Procurement Programme in 2011.
The construction of KaXu Solar One, spanning over two years, created 4,500 jobs. Since its operational commencement in March 2015, it has maintained 80 permanent positions. The solar thermal field is expected to function until 2035.
With an annual output capacity of 320 GWh, KaXu Solar One can power 80,000 homes and significantly reduce carbon emissions by 315,000 tonnes annually. The plant is connected to Eskom’s Paulputs Transmission Substation via a 5 km-long 132 kV overhead transmission line.
One of the remarkable features of this CSP plant is its ability to store and discharge power at any time, ensuring uninterrupted operation during reduced sunshine. This capability allows the plant to continue power production for up to three hours after sunset at full capacity. Additionally, it operates with about a quarter of the water consumption required by similar solar plants, making it a benchmark in sustainable energy production.
