The US Energy Information Administration (EIA) says that Americans consumed about 105 exajoules (EJ) in 2006, and predicts that energy consumption will exceed 120 EJ by 2025. That projection looks unrealistic. Here's my attempt to do better.

EIA records show that US energy consumption has increased almost every year for a long time. A look at the period between 1950 and 1973 shows each year's increase in energy consumption was even greater than the year before.

High energy prices caused energy use to decline between 1973 and '75 and again between 1979 and '83. When growth resumed after the second energy crisis there was a difference: Each year's increase was less than the year before.

If the trend established in 1980-2006 were to continue then US energy consumption would crest around 2015 before starting to decline. Consumption in 2025 would be about the same as in 2006. This projection is much lower than the EIA's, but I still think it unrealistically high. A more likely scenario is an immediate reduction in energy consumption in response to high energy prices, as occurred in the previous energy crises. A 1.2% annual decline in energy consumption, sustained until 2025, would bring the nation back to consumption levels of the mid-1980s.

Renewable sources currently provide just 7% of the nation's energy. The EIA predicts this will be up to 11% by 2025. Just as the EIA appears to have overestimated the availability of non-renewable energy sources in the near future, it appears to have underestimated the contribution of renewables.

A coalition of business, labor, and environmental groups is calling for plans to increase renewable energy production to meet 25% of the nation's energy consumption by 2025. The 25 by '25 vision has its opponents, particularly now that the corn ethanol push is widely recognized as an environmental, social, and financial disaster. Sooner or later, though, the nation and the planet must return to 100% renewable energy.

What might a 17 year transition to a 25% renewable energy economy look like? One scenario would involve a 30% reduction in non-renewable energy use coupled with a doubling of hydro, biomass and geothermal energy use and 12 and 24-fold increases in wind and solar energy use, respectively. That might have some pretty serious economic, environmental and social ramifications, but it would get us to 25%. The rate of decline in renewable energy use would be pretty similar to the rate of increase that got us where we stand today.