The Standard Industrial Classification (SIC) system has been replaced by the North American Industry Classification System (NAICS). Since the Bureau of the Census has collected the information necessary to classify establishments on both an NAICS and an SIC basis, the same 1998 data can be shown on both the old and the new basis in bridge tables that allow comparisons between the two systems. These data are hereby produced for the last time on an SIC basis for 1998 at the national level only.

The estimates presented in this table are for the total consumption of energy (formerly total inputs of energy) for the production of heat, power, and electricity generation, regardless of where the energy was produced. Specifically, the estimates include the quantities of energy that were originally produced offsite and purchased by or transferred to the establishment, plus those that were produced onsite from other energy or input materials not classified as energy, or were extracted from captive (onsite) mines or wells.

During manufacturing processes, it is possible that the thermal energy content of an energy input is not completely consumed for the production of heat, power, or electricity generation. Hence, residuals of that input may remain. Those residual leftovers may be subsequently consumed for fuel purposes, whether onsite or offsite at another manufacturing establishment (for example, blast furnace gas as a byproduct recovered from coke and other inputs that were not completely consumed). In such cases, double counting of inputs cannot be avoided, and the "Fuel Consumption" estimates will be inflated.

Source: Energy Information Administration, Office of Energy Markets and End Use, Energy Consumption Division, Form EIA-846, '1994 and 1998 Manufacturing Energy Consumption Surveys.'