Photos: Running on hydrogen

The Hyfish is an unmanned aerial vehicle powered by a hydrogen fuel cell. The DLR Institute for Technical Thermodynamics in Germany flew the Hyfish for about 15 minutes, but the designers think they can boost that to 15 hours or so if the fuel cell is used in conjunction with a battery. UAVs are used for recon in battle. Thus, distance and time aloft are important.

Photo by Horizon Fuel Cell Technologies