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 Energy Departments are jointly working to develop, test, certify, and use jet fuels that are derived from coal, natural gas, and oil shale (via the Fischer-Tropsch process and coal liquefaction). Production of jet fuels from these sources is feasible, but a number of technical hurdles remains. These include improving the lubricity, seal swell and storage stability of these fuels and their combustion performance.
As the Defense Department’s largest consumer of oil, the Air Force has already taken the lead in evaluating, supporting and testing synthetic fuels. The first tests were run on B-52 bombers.
The first B-52 flight used a synthetic fuel-blend fuel that was 50 percent derived by natural gas and 50 percent conventional crude-oil based JP-8. A C-17 cargo and passenger jet flew with synfuel blend in one tank. In December 2007 the first transcontinental flight using synfuel blend by a C-17 was realized. In March 2008, a B-1B Lancer became the first aircraft to fly at supersonic speed using synfuel blend. The Pratt & Whitney F100 engine, the power plant for the F-15 Eagle and F-16 Fighting Falcon, was tested on synfuel in May 2008. In August, the F-22 Raptor performed aerial refueling using a synthetic fuel.
By early 2011, all Air Force aircraft will be tested and certified to fly on a domestically-produced synthetic fuel. The Air Force has a goal of fulfilling 50 percent of its continental U.S. aviation fuel requirements from a synthetic fuel blend that is produced domestically by 2016. At current consumption, this equates to some 325 million gallons to a 50/50 blend.
The problem is that synfuel that is derived from natural gas does not assure the service a dependable supply of jet fuel, since U.S. natural gas production is insufficient to meet the country’s future needs, unless Congress radically changes its stance on exploration of the outer continental shelf and arctic. A major technological breakthrough is also needed on how to use methane hydrates.
There are two other domestic sources to derive synthetic fuel: oil shale and coal. The former is prohibitively expensive and realization of the latter is extremely difficult.
In any case, the Air Force is working with the civil aviation industry to expand the demand for synthetic jet fuel and to make it more economical to produce. But entrepreneurs want guarantees in terms of a fixed price and a long-term contract with the military. And current legislation allows a maximum 10-year contract, and a fixed price is budgetary suicide. (See “Coal-to-Liquids Promise Big Profits, But Obstacles Remain,” by Michael Frodl, National Defense, October 2008).
Synfuel tests have also become a Pentagon propaganda tool. Officials proclaimed that synthetic fuel burns much cleaner and emits no sulfur dioxide compared to conventional JP-8. However, a full-cycle greenhouse gas emissions assessment from mine-to-turbine discloses considerable pollution results from converting coal to synthetic fuel, according to a June 2008 report by the Congressional Budget Office.
Moreover, the 2007 Energy Independence and Security Act prevents the Air Force from buying synthetic jet fuel unless it is proven to emit less carbon over the life of the substance than petroleum. It is yet to be seen whether the Air Force’s synfuel ambition is wishful thinking or a cure to ease its oil pains.
In the U.S. military, oil has been and will continue to be the traditional fuel for mobility for tactical vehicles. It is extremely unlikely that synthetic fuels and biofuels are capable of fully replacing oil.
This does not mean that the Pentagon should stop looking for alternatives. On the contrary, it should direct its efforts to areas where it can make a change, and should avoid wasting time and money where it cannot, such as on hybrid-electric armored vehicles. The Defense Science Board’s energy task force recommended that the Defense Department establish a “fully burdened” cost of fuel and require its use as a factor in all analyses of other energy sources.
Unfortunately, the Pentagon does not have a coherent and viable long-term strategy on energy. Its efforts on energy concentrate on three issues: supply oriented (alternative and renewable fuels and nuclear); demand oriented (energy efficiency technology options such as turbine and engine technologies, material and aerodynamic design etc); and cross cutting technologies (conversion of waste to energy).
Efficient use and conservation of energy deserves much more emphasis. The Air Force’s efforts to increase the use of flight simulators, modifications to flight routes, efficient cargo loading, more en route fuel stops instead of in-flight refueling, and culture change constitute good examples. Similar efforts should be adopted by the other services. Sohbet Karbuz is a former official at the International Energy Agency, based in France. He currently works for an energy industry association as head of its hydrocarbons division. The views expressed in this article are solely those of the author.