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Annual Energy Outlook 2021

Release Date: February 3, 2021  |  Next Release Date: January 2022  |  AEO Narrative
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The energy intensity of the U.S. economy continues to fall as end-use sector intensities decline at varying rates

Indexed total energy intensity of the U.S. economy

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Energy intensity declines across the entire economy

Total U.S. energy intensity—measured as the amount of primary energy consumed per dollar of GDP—continues to decrease slowly in the Reference case as real GDP increases faster than total energy consumption. In 2020, U.S. energy intensity is about half of what it was in 1990. In 2050, the ratio is about two-thirds of what it was in 2020. The U.S. economy becomes steadily less energy-intensive, although the rate of decrease is slower relative to recent history

Indexed delivered energy intensity by sector

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Declines in energy intensity occur in each end-use sector

Energy is used in the economy to provide specific end-use services. Activities that consume energy provide indicators of efficiency (energy intensity) for each economic sector in the United States and vary in the Reference case projection as sectoral activity, technology choice, and utilization interact.

Industrial sector

Energy intensity in the U.S. industrial sector—measured as the amount of energy consumed by industry per dollar of industrial gross output—generally declines at nearly the same annual rate between 1990 and 2050 because of a continuing shift toward less energy-intensive manufacturing industries. Energy intensity increases in 2020 in response to lower utilization, but thereafter returns to a steady decline.

Transportation sector

Energy intensities in the U.S. transportation sector—measured as the amount of energy consumed in transportation per passenger-mile traveled for rail, air, and bus modes and per vehicle mile traveled for light-and heavy-duty vehicle modes—have different pathways in the short term. The collapse in passenger traffic arising from the pandemic, as measured by average load factors, results in an increasing amount of energy per passenger-mile: an energy intensity spike in the short term. After air load factors return to 2019 levels in 2024, the trend in energy intensity per passenger mile returns to a steady decline as rail, air, and bus modes adopt energy-efficient technologies and practices. After 2020, the combined energy intensity for light- and heavy-duty vehicles declines throughout the projection period because combined travel growth is fully offset by increases in fuel economy. The rate of decrease slows toward the end of the projection period because current fuel efficiency regulations require no additional increases in fuel economy for new light-duty vehicles after 2026 or for new heavy-duty vehicles after 2027.

Commercial and residential buildings sectors

EIA calculates energy intensity in the U.S. buildings sector as either the amount of energy consumed in buildings per square foot of commercial floorspace or the amount of energy consumed per residential household. Currently established increases in efficiency standards, building codes, and incentives lead to energy efficiency improvements, especially those attributed to energy management controls and sensors associated with space heating. These improvements, along with growth in distributed electricity generation including onsite solar—partially offset the effects of growth in the U.S. population, households, and commercial floorspace, which decreases energy intensity.

Commercial building end-use intensities

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