WSJ's environmental blog has a post about the US Army Green efforts. In it they mention 85% of Army's diesel is used to provide cooling for

the troops and computer equipment.

About 85% of the diesel hauled up to forward areas goes straight into air-conditioning, both for tired soldiers and to keep communications equipment cool. That means more, larger, and more vulnerable supply lines targeted by insurgents. Just spraying foam insulation on Army tents cut energy loss by 45%, Reuters reports.
And just as Baghdad is installing solar-powered streelights to improve security, clean energy could mean immediate security for American troops, and not just eventual energy independence for the American people:

“If we can reduce consumption on our forward operating bases by using renewable energy, let’s say wind or solar instead of a diesel generator outside the tent … then we can reduce the number of these supply convoys that need to come forward that are getting hit by these IEDs,” [said the Pentagon’s Deputy Assistant Secretary for environment, safety, and occupational health Tad] Davis.

The Pentagon is among the country’s biggest users of electricity and transport fuels, and the run-up in oil prices has led to a four-fold increase in the Pentagon’s gas bill since the Iraq war started. Most of its environmental initiatives so far have been like those of any other big, multinational firm—simple measures that reduce energy use and save money, and thus free up resources for other uses.

And even the Army is thinking Green.

Army Green: U.S. Military Gunning to Curb Carbon ‘Bootprint’

Posted by Keith Johnson

Expensive supply lines (AP)
The U.S. military has been trying to green up its operations in response to skyrocketing energy bills, toying with everything from biofuel for Air Force planes to solar panels at air bases.
On the ground, the lean green fighting machine is now trying to live up to all its name implies—and save lives in the process.
Reuters reports on the U.S. Army’s latest initiative to cut its own greenhouse-gas emissions by 30% in 2015—its carbon “bootprint.” One of the biggest opportunities? Slimming down the massive and vulnerable supply convoys carrying fuel for the mobile and energy-hungry U.S. forces operating in forward areas of Afghanistan and Iraq.