Fuel Cell System for Solar-Powered Airplane
In 1998 AeroVironment began working under contract to NASA to produce a fuel cell system for Helios, the 247-foot wingspan solar-powered airplane. The proton exchange membrane (PEM) fuel cell system would enable Helios to fly for six months continuously. As a result of the NASA work, AeroVironment acquired expertise designing the balance-of-plant, testing a large variety of fuel cell stacks, and performing system integration.
AeroVironment developed a state-of-the-art fuel cell monitoring system that includes proprietary software and incorporates proprietary Fuel Cell SmartGuards and BSC system. Fuel Cell SmartGuard is a 20-channel module that, when coupled with BSC, monitors voltage and temperature of each cell. Multiple SmartGuard modules are used to monitor large stacks. The energy storage system for Helios uses the sun to power a PEM electrolyzer that splits water into hydrogen and oxygen. The hydrogen and oxygen gases are stored in AeroVironment designed, lightweight high-pressure tanks. At night, the PEM fuel cell combines the hydrogen and oxygen to provide power for the aircraft propulsion, avionics and payloads.