The system consists of 242 solar receivers supplied by German manufacturer Schott and covering 484m². These track the sun to generate pressurised hot water at 180ºC. The hot water in turn powers an absorption chiller that produces chilled water which is circulated into the data centre to cool the IT equipment.
The Fresnel-collector with thermal peak power of 272kW is now connected to the district cooling system at MTN’s main office. Here, the concentrating solar thermal collector powers a 330kW double-effect absorption chiller.
The solar system was built within the DENA Solar Roofs Programme by the German Energy Agency (Deutsche Energie-Agentur GmbH). Launched in 2004, the DENA programme, co-financed by the Federal Ministry of Economics and Energy, supports German solar energy companies entering new markets. Within the framework of the programme reference and demonstration projects are installed on the roofs of designated institutions in different countries around the world. The installation is accompanied by comprehensive marketing and training programmes.
Solar cooling or solar process heat is not widespread yet in South Africa despite its huge potential for industrial applications. The radiation levels are significantly better compared to Europe. Although no government subsidies for the purchase of solar technologies are available, the economics are improving due to rising energy prices and decreasing system costs and investments in renewable energies become more and more attractive.