Long Endurance Fuel Cell System for Small Unmanned Aerial Vehicles

The warfighter requires long flight duration, hand-launched, small Unmanned Aerial Vehicles (UAVs). Batteries are expensive and provide limited flight duration. A viable alternative to batteries, that could provide higher gravimetric and volumetric energy density, and lower life cycle cost, are hybrid battery/fuel cell systems with hydrogen stored as chemical hydride, which, when reacted with water, generates the required fuel as-needed. AeroVironment’s (AV’s) Phase I effort determined it would be feasible to develop an integrated fuel cell/battery hybrid energy storage system for the AV-designed and manufactured PUMA UAV, The 9-ft wingspan PUMA has a flight duration of three hours on rechargeable batteries, but will be able to fly for 6-8 hours with the fuel cell-based energy storage system. In phase I we worked with several fuel cell system developers and conducted a bench top demonstration of an integrated fuel cell/battery hybrid system using a Protonex fuel cell and hydrogen storage system. In Phase II, we will optimize and build a fuel cell-based energy storage system and conduct several tests to demonstrate achievable flight duration. We will also perform feasibility studies for adding advanced solar cells on the PUMA wings and integrating a similar energy storage system into the Raven UAV.