Post oil: Pentagon "Green Hawks" see energy security in biofuel (VIDEO)

"Green Hawks" at Pentagon see energy security in biofuel alternatives for a post-oil world.

Six twin-tailed F-18 Hornets rolled toward the end of the runway at the Naval Air Station Patuxent River, taxiinging with the pent-up energy of hooded hunting falcons. It was the annual Labor Day Air Expo along Maryland's western shore, and whether they knew it or not, thousands of spectators were going to watch the Navy's Blue Angels conduct an experiment at hundreds of miles an hour.

Last year, the jets burned dead dinosaurs – petroleum-based, combat-tested jet fuel. This year, the six jets were burning a 50-50 blend of dead dinosaurs and the byproduct of a plant that counts broccoli and Brussels sprouts among its distant kin. One minute-long maneuver would bring four craft to within 18 inches of one another, wingtip to canopy – no margin for even a split-second engine hitch.

Rear Adm. Philip Cullom, who heads the Navy's energy and environmental readiness division, called it "the ultimate test" of a fuel blended to help the US military wean itself from reliance on uncertain oil supplies and their volatile price swings.

For a glimpse of what the road to an oil-free, more energy-efficient future might look like, look no further than the US military. In a movement that has gained momentum during the past decade, active and retired officers dubbed the "green hawks" have been beating the drum for increased energy efficiency and wider use of renewable fuels for civil­ian and military needs. It's an urgent matter of national security, they argue.

Many credit James Woolsey, a former undersecretary of the Navy and former CIA director, for raising the issue's profile to a strategic level. No bearded Birkenstocker he. In interviews he has credited the gas lines during the 1973 Arab oil embargo with opening his eyes to America's vulnerability and firing up his interest in renewable energy.

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The issues of energy efficiency and renewable fuels have taken on added gravitas with the wars in Iraq and Afghanistan. The US military burns more energy than any other domestic consumer, according to a Pew Project on National Security, Energy, and Climate study published in September. In 2009, the Pentagon's thirst for oil topped 375,000 barrels a day. Only 35 nations consumed more oil.

The long-term outlook for oil prices goes nowhere but up, even as federal budgets grow tighter. The US as a whole remains vulnerable to supply disruptions. And the price for delivering fuel to combat zones is dear in blood as well as treasure. Between 2002 and 2005, more than 3,000 soldiers and contractors were wounded or killed in Afghanistan defending fuel and water convoys supplying forward operating bases, Pentagon data show.

A shift to renewable fuels alone won't lead to fewer troops protecting fewer convoys, senior officers acknowledge. But when combined with a range of technologies – from simple foam insulation for desert tents to reduced air-conditioning needs to variable-cycle jet engines – alternative fuels are more efficient, reducing the number of convoys needed on sea or land to keep a battle group or a fighter wing running.

And the "Grown and Refined in the USA" label will ensure fuel is available. In August, President Obama announced that the Navy and the US Departments of Agriculture and Energy had agreed to provide a combined $510 million over three years to help jump-start private-sector production of advanced biofuels.

"This is a truly win-win-win situation: for the nation, in terms of moving off of fossil fuels; for the Navy, in terms of national defense; and for rural America and our farmers, in terms of job creation," says US Navy Secretary Ray Mabus, who sits squarely in the green hawks camp.

Indeed, what's good for the Defense Department may well be good for the economy, suggests Wal­lace Tyner, an agriculture economist at Purdue Uni­versity. "The military could be a significant ... stimulus to getting the cellulosic-biofuels industry going," he says. "Everybody wants to build a third, or fourth, or fifth production plant, [but] no one wants to jump in and build the first or second."

With the Defense Department as an anchor customer, especially if it enters into fuel contracts that span 15 years, investors will be more willing to pony up for those initial plants, he says.

Perhaps no branch of the service has outlined more aggressive plans for going green than the Navy. Mr. Mabus has directed the Navy and Marine Corps to draw fully half their energy needs from renewable sources, including biofuels, by 2020. The Navy currently is undertaking some 60 percent of all the Pentagon's renewable-energy projects, according to the Pew study.

Next year, the Navy plans to send its first green carrier strike group – typically an aircraft carrier, at least one cruiser, two destroyers, at least one submarine, plus support ships – to tour the world as the "Great Green Fleet." The strike group is to be fully integrated into Navy operations by 2016.

Beyond biofuels, the Navy launched its first hybrid ship in 2009, the amphibious assault ship USS Makin Island. Inside the engine room, efficient gas turbines for high-speed travel joined diesel-electric power plants for slower speeds. The combination saved 900,000 gallons of fuel on the ship's maiden voyage from a shipyard in Mississippi to its home port in San Diego.

The USS Makin Island "was the first experiment with hybrid-electric drive," Cullom says. Now, the Navy is preparing to install similar combinations scaled for destroyers. Think Porsche Carrera performance with the mileage of a Toyota Prius, he says.

The Defense Department's shift toward greener energy sources isn't without skeptics. In January, the RAND Corporation's National Defense Research Institute published a study indicating it remains highly uncertain whether biofuels can be made cheaply enough for the Pentagon to afford and cleanly enough for the environment to tolerate.

The authors said they saw no military need for the change, because in time of war the military gets first dibs on the nation's available fuel supplies.

But the report also makes one observation virtually everyone agrees with: A sustained alternative-fuels and energy-efficiency drive within the military could encourage a broader national cultural shift on energy and energy efficiency.

"The military is spending a lot more time getting individual soldiers to understand the importance of energy efficiency," says William Rogers, a research associate at the Center for a New American Security in Washington. "As they cycle back into society, there are ripple effects" as they take their new energy ethic with them.