Fuel Cells Seen as Potential Way to Lighten Soldier Loads

More efficient portable power sources are needed to help lighten the load of soldiers and Marines, military experts agreed on Jan. 30.
“We have to get the combat development process to align with the individual combatant’s [priorities],” said George Solhan, deputy chief for naval research for expeditionary maneuver warfare at the Office of Naval Research.
One of the biggest problems at the Defense Department currently is that it focuses more on big systems like vehicles, radar and missiles over equipment for dismounted troops, said Solhan at the 6th Annual Soldier and Marine Modernization Meeting in Arlington, Va. 
A major issue that the Defense Department needs to solve is lightening the load, and one way to do it is reducing the need for multiple batteries to power the various pieces of gear a soldier wears, he said.
“The users of power — all the sites, all the sensors, all the communications devices — need to start designing in high-energy efficiency right up front,” said Solhan.
Patrick McGrath, a science and engineering technical advisor at the Defense Advanced Research Projects Agency (DARPA), said one solution to reduce gear weight and increase fuel efficiency may be the solid oxide fuel cell.
The fuel cell, which has been tested by DARPA for various missions, including increasing fly time for small unmanned aerial vehicles, would be an ideal way to charge portable electronics, he said.
“We are looking not just at the promise of fuel cells that people have been talking about for decades, but getting fuel cells into real missions and accomplishing things in the field,” said McGrath.
The solid oxide fuel cell is a cross between an engine and a battery. The electro-chemical device does not burn energy, but rather uses a chemical reaction with hydrocarbons to “suck” electrons out of the fuel, he said.
“It’s more efficient than an engine, you’re able to make it smaller than an engine, it’s very quiet, and you are able to get much greater energy density than you would out of a battery,” said McGrath. “Hydrocarbons are magical for storing and moving energy. They are safe, they are convenient, and they store a lot of energy.”
While fuel cells can help recharge batteries for longer periods of time, McGrath said, it is unreasonable to think that troops would be able to carry around dozens of wires to connect the power source to their gear. Wireless charging is necessary.
DARPA has been looking at devices to charge gear using magnetic fields, McGrath said. While it would only be able to charge devices within a few centimeters of the source, studies have shown that it has a 90 percent efficient power transfer, he said.
“It gives you the ability … to take the high-energy density source that is on the dismount and use that power to create a hotspot around that solider or Marine,” said McGrath. “You can power that scope, power the night vision goggle [and] power the radio.”
Martin Drake, a science advisor at U.S. Central Command in Tampa, Fla., agreed that the Defense Department must do a better job of solving the energy issue.
“We are tremendous users of power, energy power, and the burden that we put on our soldiers, sailors, airmen and Marines when we send them down range is significant,” said Drake. “CENTCOM is a big supporter of trying to get our arms around what we as a department need to do with regard to solving the energy power problem.”
Photo Credit: Defense Dept.

Topics: Defense Department, Energy, Power Sources, Science and Engineering Technology, DARPA