nately, the trend reversed between that period and 2006–2007, attributable mainly to the shift from cars toward less-efficient sport utility vehicles, pickup trucks, and minivans (EPA, 2007a). This shift to less-efficient vehicles, together with a greater number of vehicle-miles driven, resulted in a 31 percent increase in U.S. gasoline consumption during 1986–2006 (EIA, 2007b).
EISA included the first significant advance in fuel-economy standards in more than 30 years. Assuming that these standards are met, the average fuel economy of cars and light trucks combined will reach at least 35 mpg in 2020, a 40 percent increase.24 It is estimated that the new CAFE standards will save 1 million barrels per day of gasoline by 2020 and 2.4 million barrels per day by 2030 (ACEEE, 2007). These estimates account for the “rebound effect,” that is, the increase in travel demand due to the reduction in the cost per mile driven as vehicle fuel economy improves. This effect is generally thought to be real but small (Greene, 1998; NRC, 2002; Small and Van Dender, 2007).
Appliance efficiency standards, first enacted by California, New York, Massachusetts, and Florida during the late 1970s and early 1980s, were followed by national standards in 1987. These standards led to dramatic improvements in the energy efficiency of new refrigerators, air conditioners, clothes washers, and other appliances. For example, the combination of state and federal standards resulted in a 70 percent reduction in the average electricity use of new refrigerators sold in the United States from 1972 to 2001 (Geller, 2003).
In 1992, minimum efficiency standards were extended to motors, heating and cooling equipment used in commercial buildings, and some types of lighting products. In 2005, standards were adopted for a variety of “second-tier” products, among them torchiere light fixtures, commercial clothes washers, exit signs, distribution transformers, ice makers, and traffic signals. With the addition of these products, national minimum efficiency standards were in place for better than 40 different types of products.
National appliance efficiency standards saved an estimated 88 terawatt-hours (TWh) of electricity in 2000, or 2.5 percent of national electricity use that year (Nadel, 2002); based both on the time required to turn over the appliance stock