Melting pot In South Africa, the sun’s energy will soon be harnessed to power a very different manufacturing process – aluminium-smelting. It’s a process that is renowned for the amount of electricity it uses, which is why a group of German and South African researchers are currently developing an alternative system – one that uses a kiln. Basically a furnace, the kiln (which is not unlike the drum of a washing machine) rotates at a low speed while solar mirrors draw from the sun’s radiation to achieve inside temperatures of around 700°C. South Africa, which is one of the top 15 largest producers of greenhouse gases in the world per capita, relies on its metalworking industries for some 30% of its manufacturing sector. 23 June 2015 Image: Gallo/GettyImages