May 1, 2008  

Fueling alternatives

Air Force Capt. Rick Fournier made history March 19 when he flew a B-1B Lancer over Texas and New Mexico — marking the first time an Air Force aircraft had flown at supersonic speed using synthetic fuel.

The fuel, a 50-50 blend of synthetic and petroleum gases, is being tested as part of an ongoing Air Force research and evaluation program to explore alternative fuels. The fuel has also been tested on a B-52 Stratofortress and a C-17 Globemaster.

The goal, said Maj. Don Rhymer, of the Air Force Alternative Fuels Certification Office, is to have every aircraft using synthetic fuel blends by 2011 and to produce at least half of those fuels domestically by 2016. Though the Air Force cites fuel prices and environmental concerns among its motivations for the effort, its chief concern is “to find a source of domestically produced, assured fuels, which would be sufficient for the Air Force to perform its national defense mission if current, overseas petroleum sources are threatened.”

The Army has been exploring electric and hybrid electric technologies for combat vehicles for more than a decade. The chief driver of the Army’s interest is the critical need for more power on military tactical wheeled vehicles. “The Army is very interested in all-green initiatives, but they are also very interested in the vehicle performance aspect and what additional power you can get to the soldier,” said Marion Von Fosson, BAE Systems Inc. director for vehicle systems. “Everything you add on — gizmos, iPods, IED defeat systems — consumes power.”

Therefore, the types of technologies that BAE Systems and others are developing to retrofit into existing military vehicle fleets and to embed in future combat vehicles are focused on minimizing energy loss and maximizing energy transfer. Potential fuel savings seem relatively low — Von Fosson estimates 10 percent to 18 percent efficiencies. Even so, where fuel-thirsty combat vehicles are involved, a 10 percent reduction in fuel is significant. For example, the M1 Abrams tank gulps 3 gallons per mile.

Meanwhile, the Navy is working to bring hybrid electric ships to the high seas. The Office of Naval Research is developing propulsion systems based on fuel-cell technology that could help power future ships. Its focus has been on a diesel reforming system that extracts hydrogen from diesel fuel to create a cell-based distributed power system.