Energy consumption is expected to grow 1.3% annually during the next two decades, rising from 98 quadrillion Btu in 1999 to 127 in 2020, according to the U.S. Energy Information Administration, in its latest yearly energy outlook. Future economic growth will be more robust than the EIA projected last year, prompting government analysts to raise energy consumption estimates in the latest forecast. Energy consumption in 2020 will be 6 quads, or 5%, more than the EIA's previous annual forecast. The figure assumes a 3% average annual U.S. economic growth, as measured by gross domestic product. The agency had based its forecast on 2.1% annual economic growth, a year earlier. The upward revision is due in part to "a more optimistic view of long-run economic growth" and to "statistical and definitional differences in the National Income and Products Account," the EIA says. "The outlook is a glimpse of what might happen during the next decades," says EIA acting administrator Mark Mazur. "It is not a forecast of what is most likely to happen. We're trying to put together a set of plausible assumptions for how the energy sector will evolve." The agency suggests world oil demand will grow to 117 million barrels per day in 2020, from 76 million in 1999. The 2020 figure is 5 million barrels per day more than the previous-year forecast. In the U.S., demand will be 25.8 million, up from 19.5 million, led by 1.8% annual growth in the transportation sector. "This is the fastest growing of all our sectors," Mazur says. Residential-sector growth is expected to average 1.2% annually; commercial-sector, 1.4%; and industrial-sector, 1.0%. In transportation, advanced technology vehicles, such as fuel cells and hybrids, play a very small role in the forecast. "We do see these technologies showing up in the marketplace, but the dominant form of transportation is the petroleum-fueled vehicle," Mazur says. By 2020, new-car fuel efficiency will gain less than one mile per gallon, and new-truck efficiency, two.