Aluminum energy semi-fuel cell systems for underwater applications: the state of the art and the way ahead

Fuel Cell Technologies Ltd. (FCT) is developing high endurance aluminum energy (AE) semi-fuel cell systems for various underwater applications. One system under development is a novel aluminum/hydrogen-peroxide pressure-compensated semi-fuel cell system that will deliver 80 kWh at 300 W for a deep-sea autonomous underwater vehicle (AUV). This will permit over 11 days of uninterrupted full-power operation without a pressure hull. A second system under development is an aluminum energy system for a diver heating application. This underwater cogeneration fuel cell system will provide both electrical power and heat to divers while decompressing during their ascent from deep cold-water dives. The proof of concept of this system completed pool trials in March 2001, and FCT is now developing the Advanced Development Model for field trials. This paper summarizes the principle issues associated with the design and proof of these high performance underwater energy systems and reports on the current status of system evolution as well as the planned way ahead for this technology.