The energy-utilization over a 10-year period (1994–2003) has been analysed for the South African
industrial sector, which consumes more primary energy than any other sector of the economy. Four
principal sub-sectors, namely iron and steel, chemical and petrochemical, mining and quarrying, and
non-ferrous metals/non-metallic minerals were considered in this study. Primary-energy utilization
data were used to calculate the weighted mean energy and exergy efficiencies for the sub-sectors
and then overall values for the industrial sector were obtained. The results indicate that exergy efficiency
is considerably lower than energy efficiency in all the sub-sectors, particularly in mining and
quarrying processes, for which the values were approximately 83% and 16%, respectively. The performance
of exergy utilization in the industrial sector can be improved by introducing various conservation
strategies. Results from this study were compared with those for other countries.