Fuel cells promise significant advantages in terms of weight, coupled with cost and logistics benefits. Military applications for fuel cells vary but power and energy demands associated with the Objective Force and the Future Combat System requires a revolution in power. We have projected fuel cell missions for small man portable 1- 500 watt systems with 180 - 12,000 Watt-Hrs of stored energy to mobile auxiliary power units (APUs) in the 0.5 - 10 kW power range. Military power sources must be robust and capable of powering equipment under all environmental and operational conditions. Fuel cell power sources have been demonstrated for several military applications and are being investigated as possible power sources for the Soldier System, Robotics, Sensors and APUs.
CECOM's Power Division's efforts have been focused on small battery replacement and hybrid fuel cell/battery systems. Examples include a hydrogen/oxygen unit developed in the mid 90s and currently under evaluation by NASA for future space missions; a 100 W fuel cell based battery charger and a 50 Watt fuel cell used to power remote sensor systems. Because proton exchange membrane (PEM) fuel cells provide quiet, vibration free and low signature operation, a future application for these power sources are as APUs for combat vehicles. Small APUs (0.3 -2kW) with Methanol Reformers are feasible now for SILENT WATCH. Although considerable progress has been made in reducing the size and weight of PEM fuel cells, a key technical barrier for military applications has been the fuel supply, hydrogen. The effective use of fuel cells in the military will require a safe, high energy dense, transportable, and reliable source of hydrogen. The Army's current and future research and development efforts are focusing on methods of either storing or generating hydrogen on the battlefield. Hydrogen storage technology is considered critical to small military and/or commercial fuel cell systems, and is being pursued in a host of commercial and government programs. CECOM, in a joint effort with the Army Research Office (ARO) and the Defense Advanced Research Projects Agency (DARPA), is developing several promising hydrogen generating technologies. The goal of this program is a safe, reliable hydrogen source that can provide rates up to 100 Watts with an energy density of 1000 Watt-hrs/kg. CECOM with the same group of co-sponsors, developed the world's first portable fully integrated Direct Methanol Fuel Cell (DMFC) prototype. It is presently being tested by CECOM.
For larger fuel cell units (>500 Watts), it is imperative that the fuel cell power units be able to operate on fuels within the military logistics systems. CECOM is currently conducting research on catalysts and micro-channel fuel reformers that appear to offer great promise for the reforming of diesel and JP-8 fuels into hydrogen, the fuel feed required by the fuel cell. In addition to research work on PEM fuel cells and enabling technologies, the Army is also conducting research on direct methanol and solid oxide fuel cells.