ENERGY EFFICIENCY EVALUATION OF COAL PRODUCTION

Coal is still the primary source of energy in the world. Coal mines are among the major energy companies. Coal production process is very complex and complicated. System components can be very diverse in terms of energy consumption. Inside the coal mine may be a high demand for electricity, heat, liquid fuels, etc. On the other hand, in addition to the same coal, mine can produce a range of products which can be used for energy generation directly or indirectly. These issues can have a potentially huge impact on environmental and energy efficiency of the hard coal production. For a complete evaluation of the activities of the coal mine, the energy efficiency indicator, based on the concept of total gross and net energy, has been defined. It takes into account all the energy needs of all coal production process together with efficiencies. It includes by-products and their impact on the overall energy and environmental balance. The energy efficiency indicator, defined in the manuscript, is useful for estimating the actual efficiency of the process of coal mining, but may be used for any complex technological chain in various type of industries as well. It can serve as an additional indicator for the analysis of LCA covering topics not included in its classical form.