By Deborah Zabarenko
FORT BELVOIR, Virginia (Reuters) - To sustain themselves on Afghanistan's rugged frontlines, U.S. Army troops have learned to sip, not guzzle.
The liquid they must conserve is JP-8, a kerosene-based, all-purpose fuel the Army uses in aircraft and Humvees and to generate power for computers, lights and heat. Consumption of JP-8 - short for Jet Propellant-8 - often comes at a grim cost.
The fuel arrives by tanker trucks dispatched in heavily guarded convoys that are frequently attacked by insurgents. For every 20 convoys that roll across the harsh terrain, one U.S. soldier dies, said Colonel Peter Newell, head of the Army's Rapid Equipping Force (REF) at Fort Belvoir in Virginia.
Newell's operation keeps that statistic in mind as it aims to make troops more sustainable - meaning that as they live and work on isolated bases they consume an absolute minimum of fuel. It also means they spend less time guarding fuel convoy routes and more time on tasks like combat, security and communications.
Plans to gradually reduce the size of the U.S. force in Afghanistan, which is due to shrink to 68,000 by the end of the summer, have made fuel conservation more challenging. Soldiers are more spread out now, Newell said, and many work out of small outposts of 150 soldiers or fewer. These outposts are often put up and dismantled after just a few months of operations.
The remaining soldiers are "performing more and more missions," Newell said. "Now they're driving longer than ever." Newell's team is working this year with 15 to 20 outposts spread across Afghanistan.
The program is part of a larger Pentagon effort to improve energy efficiency and reduce U.S. military dependence on foreign crude oil. There's the Navy's "Great Green Fleet" plan to deploy naval ships powered by alternative fuels, and the Green Hornet F/A-18 fighter jet, fueled in part by biofuel.
Since 2008, the Army effort to reduce its "carbon bootprint" has been seen at distant outposts in Djibouti, Kuwait, Iraq and Afghanistan. The technology is being refined at Fort Belvoir, located south of Washington.
The Rapid Equipping Force may have more in common with a venture capital firm than with traditional military provisioning. It borrows ideas from industry, academia and retail businesses as it focuses on small-scale details of life at a combat outpost.
'FOAM IS A FOUR-LETTER WORD'
Solutions can be surprisingly low-tech, according to Bill Garland of REF. Take, for example, insulating foam.
At small combat outposts, a big energy challenge is heating and cooling leaky and poorly insulated structures that slurp JP-8, Garland said. To trim energy use, about four years ago the Army started spraying insulating foam on the outside of tents or plywood structures, cutting fuel consumption by 45 percent.
But the foam caused more problems than it solved.
Not all contractors used for the task knew how to apply foam to ensure adequate ventilation, Garland said. Sometimes, the foam melted. Disposing of foam-coated structures when outposts were dismantled was challenging.
In short, Garland said, "Foam is a four-letter word."
The folks at REF innovated: instead of foam spray, they turned to wallboard panels filled with polyurethane, transportable in flat packages by helicopter or ground vehicles. They could then be assembled into insulated warzone buildings.
At Fort Belvoir, Garland and his colleagues constructed a test version large enough to house eight to 10 soldiers in a grassy plot near their offices. The living space included refrigerators, air conditioners and heat, plus a tactical operations center with computers and other equipment.
Just like ready-to-assemble furniture, the building shot up in hours, Garland said. The next step is to equip it with a camouflage-painted hybrid generator that runs on JP-8.
Standard generators posed a challenge in the field. They produced 5 kilowatts of power, far more than small outposts needed. Letting the generators churn away drained JP-8, without recapturing their excess power.
"The biggest problem I had was not necessarily power production," said Army Major Bill Casey, a veteran of two tours in Iraq and two in Afghanistan who now works at REF. "What I had a problem with was power distribution" - making sure all the energy that was generated got where it needed to go.
REF developed a hybrid system that stores excess power in a battery, similar to ones used on luxury yachts. When the battery is fully charged, the generator shuts off. The system is boosted by a small solar array perched on top of a battery that can supply an additional 1.2 kilowatts.
A single kilowatt of power is enough for a surveillance tower, battery chargers, and a television or X-Box video game console, Garland said. These can be essential on the frontlines, along with Internet access, washing machines for clothing, heat and air conditioning, Casey said.
Sometimes even the best-sounding ideas go awry. A suitcase-sized, JP-8-fueled generator seemed ideal for remote forward posts. But they had to be recalled after soldiers found that if the JP-8 varied from U.S. specifications, the generators would not work.
Greater fuel efficiency has other benefits, Newell said. With fewer convoys, U.S. commanders can vary the convoy schedule and lower the risk of deadly insurgent attacks.
(Editing by Marilyn W. Thompson and Will Dunham)