Unfortunately, the promises of efficient, clean, quiet power that fuel cells offer are balanced by extremely low power densities and great infrastructure-related challenges. Studies by government and industry have investigated their feasibility for primary propulsion in light aircraft. These studies have produced mixed results but have tended to rely on integrating fuel cells into existing airframes, with respectably-performing light sport planes being turned into underpowered show planes with horribly compromised range and payload capabilities.
Fuel cells today are in the earliest phases of technological development. As an aircraft propulsion system, they are as advanced as the Wright's reciprocating engine was a hundred years ago. And just as the Wrights had to integrate their propulsion system with an entirely new airframe concept, modern aircraft designers need to be able to integrate revolutionary propulsion systems with their designs, rather than simply “wedging” fuel cell systems where traditional engines previously sat.
Design processes for potential fuel cell powered personal air vehicles need to integrate all aspects of aircraft design rather than simply focusing on the powerplant. They should also be able to account for uncertainty in fuel cell development. In addition to power and weight, they should also be capable of modeling volume-related concerns that are often taken for granted in the powerplant area of traditional light aircraft design. Even more importantly, design tools should be sufficiently flexible that they can accommodate “backwards” design - allowing the technology to drive the airframe, rather than letting an airframe choice dictate the required technologies.