Monday, August 23, 2010

The Most Energy Efficient Economy in History

The top chart shows that the U.S. had the most energy-efficient economy in history last year (data here), based on the amount of energy consumed to produce each real dollar of Gross Domestic Product (GDP). In 2009, it required only 7,290 BTUs of energy (petroleum, natural gas and other energy) to produce each real dollar of GDP, an all-time record low, and less than half the energy required in the mid-1970s to produce a dollar of output.

Just one example of many that contribute to the remarkable increases in energy efficiency over time is illustrated in the next graph showing energy consumption trends for household appliances from 1990 to 2009 (data purchased from the Association of Home Appliance Manufacturers). Since 1990, the energy consumption per unit for five of the most common household appliances has fallen so consistently over the last twenty years that today's household appliances use between 20% (air conditioner) and 73% less energy (clothes washer) than in 1990.

Using a slightly different measure of energy efficiency provided by the AHAM ("energy factor") that accounts for changes over time like the average tub volume of  clothes washers (27% larger today than in 1990), the next graph shows the dramatic improvements in the "energy factors" since 1980 - from between a 43% improvement in energy efficiency for the room air conditioner to more than 200% for the refrigerator.

Amazingly, the EIA report also showed that total U.S. energy consumption in 2009 (94.66 quadrillion BTUs) was less than the total energy consumed 12 years ago in 1997 (94.76 quadrillion BTUs). 

See previous CD post here.

Update: We did save some energy in 2009 because output (GDP) fell by 2.44 percent due to the recession, but energy consumption fell by about twice as much (4.81 percent) last year, which lowered energy consumption per dollar of real GDP for the 18th consecutive year to an all-time historical record low.

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