Technical issues and opportunities for fuel cell development for autonomous underwater vehicles

The efficiency and quietness of fuel cells make them attractive power sources for the autonomous underwater vehicles of the future. However, several technical issues must be addressed before fuel cells can surpass the performance characteristics of batteries, including efficiency, reliability, durability, standby operation and storage, changes to orientation, and high shock loads. Improvements to the storage of the fuel (hydrogen or hydrogen sources) and oxidizer (oxygen) make the biggest impact on the size, weight, and utilization of fuel cell systems. Proton-exchange-membrane fuel cells (PEMFCs) are the most attractive fuel cell system and already have been successfully demonstrated for use in Autonomous Underwater Vehicles (AUVs). AUVs of the future may utilize direct-methanol fuel cells (DMFCs) or solid-oxide fuel cells (SOFCs) which can use liquid methanol or diesel fuel instead of hydrogen.