DOD tests fuel-cell technology for ground, UAV uses
The Defense Department is stepping up efforts to provide warfighters with reliable, long-lasting and low-weight portable power.
Specifically, the military is working with companies to integrate fuel-cell technology into mobile and off-grid power applications. Fuel cells would complement conventional batteries or eventually replace them.
The Air Force Special Operations Command is evaluating technology from SFC Smart Fuel Cell to reduce the battery weight special forces carry into the field and eventually power unmanned aerial vehicles.
Meanwhile, the Army is working with UltraCell to develop fuel-cell systems for mobile applications and increase the performance of equipment that must operate at high altitudes and temperatures.
A fuel cell directly transforms chemical energy into electrical energy with no intermediate steps or moving parts and no significant loss of energy, said Peter Podesser, chief executive officer of SFC.
The company designed its Jenny fuel cell for use by special forces. It can be worn or connected to devices to power remote applications. A warfighter carries it along with small fuel cartridges that contain certified ultra-pure methanol. The system can power devices such as night-vision equipment, Global Positioning System devices, radio systems and rugged laptop PCs.
The Jenny 600S connects to a secondary battery and monitors its voltage continually. When necessary, it automatically turns on to recharge the battery. Once the battery is recharged, the Jenny reverts to silent standby mode.
SFC said the Jenny weighs a little more than 2 pounds and can reduce the weight a soldier must carry by as much as 80 percent compared to traditional batteries.
“What we are trying to bring to our users is a lightweight, low-emission energy source,” Podesser said. “The biggest advantage of our system kicks in [when] working as a hybrid together with batteries, reducing the weight for a 72-hour mission by 70 to 80 percent compared to a mere battery solution.”
That type of weight reduction is one reason the Air Force Special Operations Command is interested in the technology, said Lt. Mark Roosz, who works on fuel-cell technology at the Air Force Research Laboratory.
The service’s special operations forces work with the other military branches’ special forces units to coordinate air strikes on hostile targets. For that purpose, they carry computers, range finders, radios and satellite communications equipment — a host of electronic devices that the typical ground soldier does not have, Roosz said.
“We identify fuel cells as a way to mitigate the amount of weight we have to carry,” he said. The Air Force is testing Jenny in simulated battlefield exercises, and so far it has performed well, he added.
However, the technology must be more reliable before it can be used in an operational environment, Roosz said. “Fuel cells are becoming a mature technology. However, they are not at the reliability level that compares with batteries, where 99.5 percent of the time you get that power,” he added.
“We have matured our platforms in civilian markets, like leisure and industrial applications,” Podesser said. The company is working with DOD on ruggedization and temperature range requirements.
SFC is getting valuable feedback from the tests, he added. Two of the company’s portable fuel-cell systems won first and third places last year in DOD’s wearable power competition, Podesser said. In both systems, the hybrid battery was still fully charged, with substantial amounts of fuel left in the cartridge, at the end of the 96-hour test, he added.
The Air Force is not limiting fuel cells to ground applications but is also testing the technology on the service’s UAVs, which have typically run on batteries, Roosz said. By using fuel-cell technology, the Air Force has been able to demonstrate big advances over traditional batteries in UAVs, he added.
Fuel cells can be used with or directly mounted on military vehicles as a charging unit in the field, Podesser said. The systems can silently generate power, unlike typical generators that can be detected by their noise or temperature signals, he added.
Meanwhile, the Army has entered into two contracts with UltraCell that involve developing and producing fuel-cell systems based on the company’s XX25 reformed methanol fuel cell technology.
UltraCell officials said they will develop 30 fuel-cell systems for the Army’s Agile Integration Demo and Experimentation, part of the Army's Research, Development and Engineering Command.
The systems will provide higher energy density, a longer operating life, increased performance at higher altitudes and a greater threshold for maximum ambient temperature than previous portable power solutions, they said. Soldiers will field-test the units for about three months, with the contract extending through March 2010.
Additionally, UltraCell is working with the Army’s Communications-Electronics Research, Development and Engineering Center to build fuel-cell systems capable of delivering more than 50 watts of continuous power for a 72-hour off-grid mission. The contract with CERDEC will extend through March 2010.
The systems will be capable of recharging batteries in the field and powering portable electronic equipment such as radio and satellite communications devices, remote and mobile surveillance systems, and laptop PCs. UltraCell will initially build five units for use by ground forces in the Army and Air Force, company officials said.