Inside a futuristic-looking dome that rises from the sandy wasteland of the high Mojave Desert, soldiers in plywood cubicles work at computers powered by solar panels and a towering wind turbine.
Plug-in cars shuttle the troops across the vast expanses here at Ft. Irwin in San Bernardino County. At night, tents lined with insulating foam provide a cool retreat at the end of a 100-degree day.
The desert base, which houses the Army's premier training center for troops deploying to Iraq and Afghanistan, has become a testing ground and showcase for green initiatives that officials estimate could save the services millions, trim their heavy environmental "boot-print" and even save lives in the war zones, where fuel convoys are frequent targets.
The Department of Defense is the single largest energy consumer in the United States. Last year it bought nearly 4 billion gallons of jet fuel, 220 million gallons of diesel and 73 million gallons of gasoline, said Brian Lally, deputy undersecretary of defense for installations and environment.
American forces in Iraq and Afghanistan are using more fuel each day than in any other war in U.S. history. When oil prices spiked last summer, the Defense Department's energy tab shot up from about $13 billion per year in 2006 and 2007 to $20 billion in 2008. The Army alone had to make up a half- billion-dollar shortfall in its energy budget, said Keith Eastin, assistant secretary of the Army for installations and environment.
"That was, I think, a grand wake-up call that we somehow had to get a handle on what is loosely called energy security," Eastin said.
Defense officials now consider reducing consumption and embracing energy alternatives to be national security imperatives. At Ft. Irwin, commanders are experimenting with ways to power the desert training area -- which replicates austere combat conditions -- using wind, solar and organic waste-to-fuel technologies.
When Brig. Gen. Dana Pittard took command of Ft. Irwin in 2007, he was stunned by the cost of housing troops in tents powered by generators, as they often are in Iraq and Afghanistan. A brigade of about 4,000 to 5,000 troops was spending about $3 million to rent the tents and keep the air conditioners humming during a month-long rotation, Pittard said. By building tents covered with two to three inches of insulating foam and a solar- reflective coating, they reduced the generator requirements by 45% to 75%, a technique that is now being used at some larger bases in the war zones.
Estimates are that a $22-million investment to replace all the rented tents at Ft. Irwin with insulated, semi-permanent ones would pay for itself within nine months and could save the Army $100 million over five years, said Eric Gardner, a logistics management specialist at the base.
By reducing generator use, Ft. Irwin also expects to cut carbon emissions by 35 million pounds each year -- equivalent to taking 3,500 vehicles off the road, Gardner said. This year, for the first time, the facility did not need a waiver allowing it to exceed the state of California's emissions standards in the training area, Pittard said.
Some kinks still have to be worked out as the base increases its use of alternative energy. Although there is plenty of sunshine in the desert to keep solar systems running through the day, the military needs ways to store that energy for nighttime use. And although there is plenty of wind, the Air Force has expressed concern that turbines could interfere with its radar systems.
Even so, Pittard, who left Ft. Irwin in March to become deputy chief of staff of the Training and Doctrine Command Headquarters at Ft. Monroe in Virginia, is convinced that within five years it will be possible to take Ft. Irwin off the electric grid. The nearby Naval Air Weapons Station China Lake, also in the Mojave Desert, already is powered completely by geothermal energy generated by hot water below the surface.
Producers and advocates of green technology are taking note. The Defense Department derives 9.8% of its power from alternative sources and is looking to expand use of wind, solar, thermal and nuclear energy. Some believe that the military has the potential to become a catalyst, helping to turn more expensive power sources into financially viable alternatives to coal and petroleum.
"If the military were to go green, I think that this really could achieve some environmental goals, for a very simple reason: the military is so big," said Matthew Kahn, an environmental economist at the UCLA Institute of the Environment.
Although that remains to be seen, Kahn noted that it would not be the first time the military has had a transforming effect on technology. Cellphones, the Global Positioning System and the Internet all have roots in the military.
Some in the green energy sector hope that as the military adopts alternative power sources, the technology will gain broader acceptance among political conservatives.
"Just hearing that their military is embracing this new technology that was thought of as left-of-center is going to swing people's thoughts" about using it, said David Melton, president of Albuquerque-based Sacred Power Corp., which installed some of Ft. Irwin's photovoltaic panels and wind turbines.
Military officials concede that changing an institutional culture that until recently was far from green has sometimes been an uphill battle. But at a time of shrinking defense budgets, they say, commanders are finding that making their facilities more energy-efficient and generating some of their own power can yield significant cost savings.
And there is financial impetus to act: President Obama's economic stimulus package includes $120 million to improve the energy efficiency of Defense installations and $300 million for military research into alternative power.
In a combat zone, reducing reliance on fossil fuels can save lives, officials said. The convoys that bring fuel to troops in Iraq and Afghanistan are among the most frequent targets of bombs and ambushes.
In an often-cited memo from Iraq in 2006, Marine Maj. Gen. Richard Zilmer, then commander of U.S. forces in Anbar province, made an urgent request for renewable energy systems to reduce casualties and free up the troops defending fuel convoys.
"Continued casualty accumulation exhibits potential to jeopardize mission success," he wrote tersely.
That same year, the Defense Department formed an Energy Security Task Force, which reports to Congress twice a year, to drive efforts to wean the military from fossil fuels. Each of the military services has also set up its own energy team.
So far, the department's greatest success has been improving energy efficiency on its many installations, which Lally said account for about 20% of its power needs. Gains have been made with steps as simple as putting in double-glazed windows, painting roofs white to reflect the sun, installing more efficient pumps and boilers, increasing natural lighting and using energy-efficient lightbulbs.
All the same, more research is needed to improve fuel efficiency and find alternative ways to power the military's biggest fuel guzzlers: aircraft, ships, tanks and other tactical systems.
Some military initiatives may even generate green energy for civilian use. Before Pittard left Ft. Irwin, he proposed building a 40-megawatt solar project, enough to cover the base's needs. Officials in Washington saw an opportunity to generate income by also spinning off electricity to the grid. The Army has now invited bids from the private sector to lease land at Ft. Irwin to build a 500-megawatt solar project.
The project has many hurdles to clear, including obtaining environmental approval, a process expected to take about two years. But Eastin believes that it could become a model for how to use one of the Army's biggest assets: land.
The Army has more than 12 million acres, including large tracts that cannot be used for military, residential or commercial purposes because they are intended as buffers between bases and the civilian population. Some of that land, Eastin said, would be ideal for a solar array, wind farm or geothermal project. Within 15 years, he predicts, the Army "will be a net energy exporter."
That could be good news for California, which aims to acquire 33% of its energy from renewable sources by 2020.
"We think the military's development of renewable energy will help contribute toward that goal," said Terrence O'Brien, the California Energy Commission's deputy director for energy facility siting. "They are an extensive landholder, particularly in the southeastern desert in California, where we have particularly good solar resources but also wind and geothermal."