Electric power required for UAV flight traditionally comes from it’s battery. So the flight time is relating to the battery capacity but also limited by its weight. Using an adaptive fuel cell to reload the battery while in the air is changing that game.
Now the battery is only needed for peak consumption at startup and as a fail-safe backup. This allows the use of smaller and lighter batteries. The fuel cell can deliver constant energy to extend the flight time by a factor 20 and above.
Dr. Sascha Kühn is holding one of the tubes which are generating that electrical energy at a very high efficiency. A scalable stack of the tubes – depending on the estimated power needed – is providing the energy flow for any size of UAVs.
The adaptive fuel cell stack itself can run on propane/butane liquid gas or hydrogen. Limitations to operation time now scales only with fuel and fuel tank weight, which is tremendously more efficient than the correlation between battery capacity and its weight.