A fuel cell jacket light enough for a civil drone
The jacket has to hold heat at start-up, release it once the stack is stable, and still weigh almost nothing.
A fuel cell converts chemical energy to electricity directly, with high conversion efficiency, flexible siting and short build times. In a drone it complements the airframe: the cell gives endurance, the airframe gives reach. The difficulty is thermal, because a fuel cell has to be kept warm at start-up and cooled once it stabilises, and every gram of insulation is a gram removed from payload.
Working with a material supplier, a cell manufacturer and the end user, we spent more than a year on material selection and sewing process before reaching a small-batch trial. The jacket is split into a stack cover and a reformer cover. Insulation has to be enough for a short hold, not so much that it traps heat, and the assembly has to stay light and flexible enough to fit around the stack hardware.