In 1980, energy efficiency researchers formed the American Council for an Energy-Efficient Economy (ACEEE). As we turn 35 years old this year, we thought it would be useful to look at energy efficiency progress over the past 35 years and to also look at possible and recommended pathways for the next 35 years (i.e., through 2050). We find that the energy intensity of the US economy has steadily improved since 1980, with the majority of this improvement due to energy efficiency. Each of the major sectors has shown gains. Many factors have driven these efficiency improvements, including market forces, policy impacts and the interplay between the two. On the other hand, energy prices have not been a major driver, since energy prices today are either similar to or less than 1980 prices after the effect of inflation is removed.
While much progress has been made, there are large and cost-effective energy efficiency opportunities that collectively can reduce 2050 energy use by 40-60% relative to current forecasts. Specific opportunities are discussed. In order to realize these energy-saving opportunities we need to harness and transform markets, make efficiency a key strategy for the utility of the future and expand federal, state, and local policy efforts.