Green Tech

"If we were to sum this up in a bumper sticker, it would say something like: 'America, the U.S. military gave you the Hummer. Now we're taking it back."

Dennis McGinn, a retired vice admiral in the Navy and former commander of the U.S. Third Fleet, spoke those words Monday during a teleconference.

McGinn is on the military advisory board of the not-for-profit Center for Naval Analyses. The group issued a report (PDF) on Monday, stating the U.S. military must, as a matter of national security, work to reduce its dependence not just on foreign oil, but on natural gas, coal, and an increasingly unstable U.S. electrical grid.

"We believe in the study that national security, energy security, and climate change are interdependent. We've come up with a list of findings and priorities, a challenge to the DOD, an opportunity to lead," John Napman, a retired admiral, said during the teleconference.

McGinn added: "We're heavily dependent on a global petroleum market that's volatile, but it's not just restricted to oil. Natural gas and coal also ran huge spikes in the last year."

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The transfer of wealth (via fuel purchases) to nations associated with terrorism has essentially put the U.S. in the position of financing both sides of conflicts and has been a wake-up call to the military, according to McGinn.

To some degree, the Department of Defense has already made strides toward increased use of electrical vehicles for light-use and of some hybrid and alternative fuel vehicles for other uses, according to Gordon Sullivan, a retired general and former U.S. Army chief of staff.

"Throughout DOD installations, you'll find a lot of the pick-up trucks. (There's a lot of) natural gas being used. And I think in the administrative fleets, you'll see a lot of that. And some of these things that look like John Deere Gators or whatever. They're like golf carts fueled by natural gas," said Sullivan.

But reducing foreign oil dependence is not enough, according to the report.

Military installations "are almost completely dependent on commercial electrical power delivered through the national electrical grid," according to the report signed by 12 former U.S. generals and admirals, and sponsored by the Bipartisan Policy Center, the Energy Foundation, and the Grayce B. Kerr Foundation.

Considering the military's increased reliance on computers to analyze data, provide tactical support to troops, and remotely fly UAVs like the Predator, the "outdated, fragile, and overtaxed national electrical grid is a dangerously weak link in the national security infrastructure," said the report.

The report also recommended a slowdown of the development of coal-to-liquid fuels for the U.S. Air Force in favor of fossil- and alternative-based blends. It pointed to DARPA's $100 million in research and development toward JP-8 blends from nonfood crops such as algae and other plant-based biomass as an area in which the DOD has already expressed interest.

By addressing its own needs with regard to developing electrical smart grids, fuel efficient vehicles, and even jet fuel, the Department of Defense can influence the general market as it did with the invention of the Humvee, according to both Sullivan and McGinn.

Only this time, that crossover vehicle from military to civilian drivers will likely be a lot more fuel efficient.

The Army plans to install a 500-megawatt solar thermal power farm at a Fort Irwin, Calif., base as part of its bid to reduce a $3 billion annual energy bill, spent mostly on installations.

Nellis Air Force Base solar panels.

(Credit: U.S. Air Force photo/Senior Airman Larry E. Reid Jr.)

The Mojave Desert plant would feed electricity to the grid by 2014 for savings of $21 million and 4,015,000 tons of carbon dioxide over 25 years. Construction is set to begin in 2012.

The Army's solar thermal system would eclipse the 14 megawatts at Nellis Air Force Base near Las Vegas, the largest U.S. solar photovoltaic installation.

"By making greater use of alternative and renewable energy, Army initiatives will bring energy savings and security to the Army, reducing the risk of power disruption," said Keith Eastin, the Army's assistant secretary for Installations & Environment, who is charged with reporting the progress of energy projects to Army Secretary Pete Geren.

The solar project is close to the scale of the 550 megawatts planned to come online by 2013 by OptiSolar of Hayward, Calif., for what would be the world's largest thin-film photovoltaic plant. Utility Pacific Gas & Electric inked a deal with that company in August to use electricity from the target site in San Luis Obispo County.

The Army's Monday announcement came as it establishes an energy council to advance a collection of projects, including:

• A joint geothermal initiative with the Navy to provide 30 megawatts at Hawthorne Army Depot, Nev., by 2012.
• Biomass-to-fuel demonstrations at six Army posts: Forts Benning and Stewart in Georgia; Fort AP Hill, Va.; Fort Bragg, N.C.; Fort Drum, N.Y.; and Fort Lewis, Wash. A one-year test will begin in 2008. Waste for potential conversion for use as diesel or jet fuel would come from wood and grass clippings and cardboard.
• Plans to buy 4,000 electric vehicles for maintenance and operations at Army posts, replacing 800 petroleum-powered vehicles. The Army aims to phase in the vehicles over three years, reducing the use of more than 11 million gallons of fossil fuel.

Saving on fuel isn't a question of conservation for the military. It's about saving lives.

The U.S. Army is testing two prototype generators in Iraq that run on garbage, rather than diesel fuel.

The Tactical Garbage to Energy Refinery (TGER, pronounced "tiger"), was co-developed with Purdue University and deployed in May at Victory Base camp in Baghdad, where it will be tested until August.

A waste-to-energy generator being tested by the U.S. military in Iraq.

(Credit: U.S. Army)

The purpose of the unit is to cut down on the amount of diesel fuel used and to cut down on the amount of garbage that camps generate, which are both security risks.

"Those convoys that carry fuel are also known as targets," said James Valdes, scientific adviser for biotechnology at the U.S. Army Research, Development & Engineering Command. "Officers say 'We don't calculate the cost of fuel in dollars, we calculate it in blood.'"

Handling garbage is a logistical challenge, too, because the Army hires contractors who need to be followed.

Right now, the Army's trash goes up in smoke by burning it. The problem with incinerators, though, is that they require a lot of energy to run and many people to operate it.

TGER uses a variety of technologies to fuel a standard 60-kilowatt electrical generator.

People put trash into a chute and then the wet waste--like food slop--is separated from the rest. The cardboard, plastic, and other dry trash are crushed and pelletized.

Those pellets are then put into a gasifier, which heats them until they turn into synthetic gas--fuel for the generator.

Developers found that the relatively low-grade fuel from the trash over-heated the generators and maxed output at about 40 kilowatts.

So it created a system to convert the sugar-rich wet wastes (apparently, U.S. soldiers drink a good amount of Kool-Aid) into a form of ethanol. The wet waste is treated with enzymes and then fermented into hydrous ethanol--a mix of 85 percent pure ethanol and water, Valdes explained.

That ethanol is blended in with the synthetic gas, which boosts the generator's output to 55 kilowatts.

Starting up the contraption takes 6 hours and still requires 5 percent of the diesel the generator usually uses, or about 1 gallon per hour.

Compared to an incinerator, TGER is far more efficient at converting garbage to usable energy, said Valdes, who also said it runs at 90 percent efficiency. And it significantly cuts down on the amount of garbage that needs to be trucked around.

"Ultimately, what we would like to do is have a clean-sheet design so that you could automate it more. So you literally put trash in one end and electricity comes out the other," Valdes said.

If the TGER units work well in the harsh Baghdad conditions, he envisions the generator will be deployed in smaller camps, where the higher percentage of food waste can improve efficiency.

Valdes said the portable generator could also be used in disaster-relief situations where there is a lot of trash and the need for generators. The U.S. Navy has shown interest in the unit as well.

Trash, as it turns out, is an attractive feedstock. There are several commercial companies developing technologies that use wastes as fuel.

Cellulosic ethanol companies convert agricultural or forestry residues into ethanol, while portable generators use similar feedstock, such as wood chips, to make electricity.

A number of companies are also trying to convert municipal solid waste into ethanol using a range of processes.