U.S. Energy Information Administration data indicates a significant decline in the amount of energy used per unit of gross manufacturing output in the U.S.
According to the data, total energy consumption in the manufacturing sector decreased by 17 percent from 2002 to 2010. Manufacturing gross output decreased by only 3 percent over the same period.
The significant decline in energy intensity reflects both improvements in energy efficiency and changes in the manufacturing output mix. Consumption of every fuel used for manufacturing declined over this period.
The manufacturing sector comprised over 11 percent of gross domestic product (GDP) in 2010. The manufacturing base in the United States is broad, producing everything from food to clothes. Manufacturing includes energy-intensive industries such as petroleum refining, chemicals, aluminum, iron and steel, paper, wood products and food, as well as less energy-intensive industries such as textiles, leather, apparel, furniture, machinery and electrical equipment.
U.S. manufacturing used over 14 quadrillion Btu (approximately 1055 joules) of energy as a fuel in 2010, a decrease of 13 percent from the 2002 level. Fuel consumption in the five most energy-intensive subsectors accounted for 81 percent of fuel use in manufacturing. Two energy-intensive subsectors (petroleum and coal products, and food) showed 3.5 percent increases in their fuel consumption from 2002 to 2010.
Feedstock energy use in U.S. manufacturing accounts for more than 6 percent of all energy consumed in the country. Although nearly all manufacturers use energy as a fuel, 99 percent of feedstock energy use occurs in only three manufacturing subsectors: primary metals, chemicals, and petroleum and coal products.
Although overall manufacturing output declined by 3 percent between 2002 and 2010, some manufacturing industries grew over the period. The gross output for the petroleum and coal products subsector grew by about 3 percent, while the gross output for the food subsector increased by 5 percent.
However, during this same period the number of employees in both subsectors fell, the petroleum and coal products subsector by 6,000 employees, and the food subsector by 115,000 employees. The reduction in employment, along with an increase in gross output signals an increase in labor productivity in these two subsectors.