Defense Department should rethink energy-saving tactics.

• Author: Karbuz, Sohbet
• Position: VIEWPOINT

The Defense Department is working toward developing alternative fuels and propulsion technologies to decrease its energy dependency, and increase its energy security. The Pentagon's environmentalism, however, does not align much with reality.

It is a pity that most of the Defense Department's efforts are concentrated on electricity, which accounts for less than 12 percent of military energy consumption, and not on oil, which comprises 78 percent.

Since only liquid hydrocarbons can provide Defense with the properties needed for its transportation fuels in the foreseeable future, the Pentagon's search for alternatives focus on two areas--biofuels (such as ethanol and biodiesel) and synthetic fuels.

In fiscal year 2007, the two primary biofuels--E85 (85 percent ethanol and 15 percent conventional gasoline) and B20 (20 percent vegetable oil and 80 percent conventional diesel) accounted for 6 percent of total fuels consumed by the military's 193,000 non-tactical fleet vehicles. But biofuels are not yet used in tactical vehicles. And the U.S. military's real pain is its oil consumption in tactical vehicles.

Besides costs issues, biofuels have several shortcomings in military tactical vehicle applications. The Defense Department does not currently use biofuels in aircraft due mainly to their high cloud point--it may cause the fuel to gel and clog the engine as the aircraft climbs. The use of biodiesel in marine vessels is prohibited because of its hydrophilic characteristics--it may result in damage to engine fuel system components, accelerate fuel storage instability, and affect the fuel's cold weather operating properties. The use of biodiesel in Army ground tactical vehicles is prohibited largely because of fuel stability, vehicle performance and maintenance considerations.

However, there are several initiatives already in place that are adapting biofuels for use in selected tactical vehicles. For instance, the U.S. Army Tank Automotive Research, Development and Engineering Center's fuel efficiency ground vehicle demonstrator program evaluates technologies that can increase fuel economy and develop performance. The overarching goal of the program is to improve military vehicle technology to reduce fuel consumption on the battlefield, and reduce dependence on oil. "While many alternative ideas are technically feasible, the question remains whether they are or will be cost effective.

The Air Force faces tough challenges as well. The Defense and...