Strategic analysis of energy efficiency projects: Case study of a steel mill in Manitoba

An analysis of energy efficiency opportunities at a steel mill were undertaken using two energy modeling tools, the RETScreen Clean Energy Project Analysis Software (RETScreen) and the Process Heat Assessment and Survey Tool (PHAST). A number of energy efficiency opportunities were found to be feasible in this analysis at Gerdau North America Long Steel-Manitoba Mill. The waste heat recovery opportunities included: (1) preheating combustion air in the ladle preheater, with an estimated energy savings of 22,000 GJ/yr and a payback period of 10 months; and, (2) preheating billets with an estimated energy savings of 60,323 GJ/yr and a payback period of three years. Changing natural gas space heaters to more energy efficient and safer models was both socially and economically beneficial, although having a longer payback period of 4.5 years. Oxy-fuel combustion was not deemed feasible as oxygen costs negated any natural gas savings and the productivity gains were not considered applicable. The strategic analysis showed that environmental, economic and productivity benefits were larger than the smaller concerns of: production interruption, the economic barriers of capital costs, as well as the risks posed by a downturn in the economy or by outsourcing.