Airplane galleys consume a huge amount of power. Additional power units may soon come to the rescue: housed inside trolley carts in the galleys, these units deliver both supplemental power and thus uncouple the power to the cabin and the kitchen from power supplied to the rest of the aircraft. In addition, the cart does not need new approval every time the airplane gets a retrofit or a facelift.

Housed in a trolley cart, the additional power supply for airplanes is easy to stow. (© 2014 Diehl Aerospace GmbH)

The innovation relies on fuel cells: they not only generate power efficiently, but quietly as well. Because hydrogen can only be stored in pressurized containers, they pose a considerable risk in the airplane’s cargo hold. Propylene glycol was chosen since it is a liquid substance and requires no pressurized containers.

The liquid becomes non-flammable when mixed with water and, in addition, is non-toxic and is already being used in airplanes as a coolant and de-icing agent.