Homes in the United States have become much bigger, more plentiful and jam-packed with electronic gadgetry over the past three decades, but improvements in energy efficiency have largely offset the amount of energy U.S. households consume.
That's the conclusion of a new report from the U.S. Energy Information Administration titled "Drivers of U.S. Household Energy Consumption." Specifically, it estimates that energy efficiency has offset consumption growth by 70 per cent since 1980, with per-household energy use dropping by 24 per cent and declines per square foot falling by 43 per cent.
"Gains from energy intensity improvements would have been larger if it were not for consumer preferences for larger homes and increased adoption of home appliances and electronics," according to EIA economists. "In this period, the average home size grew by about 20 per cent. With increased square footage came adoption of more and larger devices such as more televisions, with larger screens and new or expanding end uses such as computers, networking equipment and home entertainment devices."
Specifically, the number of households increased by 33 per cent and total floor space grew by 52 per cent. The EIA estimates that without the energy efficiency improvements that took place over the years, U.S. homes would have required another 3.6 quadrillion British thermal units of energy in 2009, the equivalent energy in 162 million tons of coal.
The results raise an interesting question: How much of the increase in home size and device use is because of energy efficiency? In other words, without observed improvements in energy efficiency would U.S. home sizes still have grown, on average, by 20 per cent and would every room be filled with a TV, computer, game box and smart phone all connected via in-home wireless networking?
The answer depends on how much weight you put into the so-called rebound effect, also known as the Jevons paradox. The argument here is that energy efficiency reduces the costs of manufacturing, purchasing and using products, and therefore drives more consumption and energy use.
As I pointed out recently, groups such as The Breakthrough Institute, an energy think tank based in California, believe the rebound effect can erase a majority of the gains achieved through energy efficiency. In a blog post last October, Breakthrough analyst Alex Trembath argued that such a position is supported by a recent report from the International Energy Agency, which concluded, in Trembath's words, that “ efficiency rebounds can and do reach at least as high as 60 per cent."
The American Council for an Energy Efficiency Economy (ACEEE) counters this argument, suggesting the rebound effect averages about 20 per cent. “The truth is that for 40 years energy efficiency has had a dramatic effect on worldwide energy consumption,” ACEEE executive director Steven Nadel wrote. “In the United States, if we were to use energy today at the rate we were in 1974, we would be consuming more than twice the amount that we are actually using.”
The reality probably lands somewhere in the middle.
