Duvha Power Station. Exterior of the Duvha coal-fired power station, Witbank, Mpumalanga, South Africa. The 300 metre chimneys (lower centre) of this power station are the second and third tallest structures in Africa (as of 2016). In 1993 Duvha Power Station was the first power station in the world to be retrofitted with pulse jet fabric filters on three of its six units. These filters reduced air pollution by removing 99.9 percent of the fly ash produced by the power station, which would otherwise be released into the air through the chimney's.