A new plan for the Air Force energy diet

The U.S. Air Force rolled out new plans Wednesday to guide the energy-thirsty agency's programs to reduce oil consumption and use more renewable energy.

The Air Force spends a lot of money on energy -- $9 billion in fiscal year 2008 to power planes, vehicles and bases. But it has also for years been integrating renewable sources into its energy mix and experimenting with alternative jet fuel.

It's not hard to see why all this matters. The Defense Department is by far the biggest energy consumer in the federal government, accounting for 91 percent of federal petroleum consumption, the plan notes. And the Air Force accounts for 64 percent of total armed services' fuel costs, largely to meet its 2.5 billion gallon-per-year jet fuel needs.