The amount of energy used at our mines is a function of the amount of material we mine, the hardness of the material, the distance from the mine to processing facilities, the type of processing, and many other site-specific factors. Direct energy consumption includes fuel for our haulage / mine fleet, vehicle transportation, heating and aviation uses. At some of our mines, direct energy consumption (Diesel/Light Fuel Oil or Heavy Fuel Oil (HFO) also includes self-generation of electricity for camp and processing needs. At other sites, we purchase electricity from external suppliers (shown below as indirect energy consumption).
During 2013, we consumed 17.4 [A] million gigajoules (GJ) of energy (i.e., purchased electricity and fuels), compared to 16.6 million GJ in 2012. This 4.9% increase in total energy consumed was largely due to the 3.3% increase in the tonnes of ore processed year-over-year.
Energy intensity, the amount of energy consumed per tonne of ore processed, is a key measure of efficiency. Typically, energy intensity increases as mines mature. For example, at some mines the ore is harder as the depth of excavation increases, and, at all mines, the haulage distances increase as the active mining areas move deeper. Since 2011, the first year after acquisition of the Tasiast and Chirano mines in West Africa, our total energy intensity has been relatively steady. In 2013, a small decrease in direct energy intensity was realized.
Total Energy Consumption
(gigajoules x 1,000)
Energy (Direct and Indirect) Intensity Rates
(megajoules/tonne of ore processed)
2013 Total Energy
Consumption by Type