Preliminary estimates show that the total U.S. manufacturing energy consumption increased about 3.7% between 2010 and 2014, according to the U.S. Energy Information Administration. This is the first measured 4-year increase in manufacturing energy consumption since 2002 (Figure 1). Energy source shares have changed modestly since 2002, with natural gas rising from 29% to 33% of all manufacturing energy consumption. Conversely, during this same period, the share of delivered energy to manufacturing from coal, coke and breeze declined from 10% to 8%, while the share of fuel oils and naphtha together decreased from 7% to 5%.
Fig. 1 Manufacturing energy consumption has increased for the first time since 2002
While manufacturing energy consumption did increase overall from 2010, the increase was not as large as the increase in manufacturing output during that same period, implying a decrease in energy intensity. The data represent energy demand for year 2014 as reported on the U.S. Energy Information Administration’s (EIA) Manufacturing Energy Consumption Survey (MECS).
Natural gas consumption in manufacturing increased 2% between 2010 and 2014. The price of natural gas continues to be low relative to many other available alternatives [2], and it has the lowest carbon content of the fossil fuels. In fact, several manufacturers reported renovation projects in 2014 that would permanently convert residual fuel oil equipment, a common alternative, to natural gas. They cited lower natural gas prices and preparation for expected changes in federal or state environmental regulations in their rationale to switch fuels.
While natural gas consumption has increased, coal, coke and breeze consumption in manufacturing decreased 1% between 2010 and 2014. Along with coal-derived coke, Figure 1 shows that this energy source continues to be phased out as less carbon-intensive energy sources, principally natural gas, become more prevalent and more price-competitive.
Manufacturing gross output rose 12% from 2010 to 2014. That rise outpaced the 3.7% increase in energy consumption, implying a decline in energy intensity. The output index represents gross output as a measure of an industry's sales, including sales to other industries as well as final users. Over the long term, manufacturing energy consumption has decreased in intensity, but the relationship between gross output and energy consumption is sometimes uneven (Figure 2). In fact, between 2010 and 2014, there was a 7% reduction in energy intensity [4], the ratio of a unit of energy consumption per unit of output [5]. Once final 2014 MECS results are released, more data will be available to determine what factors and manufacturing activities are contributing to the intensity decline. For example, besides real efficiency gains, the overall manufacturing intensity decline may be attributable to a change in the proportion of high energy-intensive industries (e.g., primary metal manufacturing) to lower ones (e.g., textiles and machine assembly).
Fig. 2 Manufacturing total energy consumption does not follow output levels between 2002 and 2014 suggesting energy efficiency gains
The data shown in Table 1 represent the first release from the 2014 Manufacturing Energy Consumption Survey. As the data are preliminary, the information may change somewhat as more detailed data tables and analysis of the 2014 MECS are released in 2017.
