Truncation error in embodied energy analyses of basic iron and steel products

An input–output study of the energy requirements for the manufacture of basic iron and steel products by the Australian steel industry is presented. The basis of this study is a decomposition of the total energy requirement per mass output of steel into partial requirements from industry sectors supplying the steel industry. A separation into different order requirements shows that lower order energy requirements for basic iron and steel, chosen from the supplying industries identified in a recent process analysis, are 19 MJ/kg, and that the total energy requirement is 40.1 MJ/kg. This proportion demonstrates that truncation error in this process analysis, that is, the omission of higher order energy contributions, is of the order of 50%.