Unmanned Air Vehicles (UAV) are usually the prototypes preceding manned ones, and hence new technologies have to be tested thoroughly before applied to manned, real-life situations. UAVs have been tinkering with fuel cells lately to show that they’re capable to perform flight for an increasing period of time.
Horizon Energy Systems, for example, announced its new dry fuel cell power system, which should improve the flight duration of an UAV up to 300 percent, being able to power 5 to 10kg mini-UAVs.
Even the Israel Aerospace Industries (IAI) adopted Horizon’s new Aeropak for its Bird Eye 650 UAV, without increasing the airplane’s weight. With Aeropak installed, the plane is able to 
achieve 6-hour flights, more than doubling the time when lithium ion batteries were onboard.
“The miniaturized power system makes it very easy to use as drop-in replacement for battery packs currently in service, eliminating costly airframe modifications,” says Horizon.
Aeropak has a capacity of 900 Wh and a weight of 4.4 lbs (2 kg), using dry fuel cartridges.
