Original URL: http://www.theregister.co.uk/2007/11/05/fuel_cell_uav/

Fuel-cell UAV achieves 'record' distance

Tech could replace battery whisper-drones

By Lewis Page

Posted in Science, 5th November 2007 10:01 GMT

A fuel-cell company has announced a "record-breaking" flight by an unmanned aerial vehicle (UAV) propelled by one of its fuel cells.

Horizon Fuel Cell Technologies of Singapore revealed on Friday that the Pterosaur UAV had made a 78-mile flight in California. Lots of UAVs have flown further than this, but Horizon claim it is a record for a "micro" UAV, which they define as one weighing less than 5kg.

Here's the obligatory YouTubage:

While Horizon developed the hydrogen fuel cells which powered the aircraft, the remaining systems integration came from partner organisations including universities in America and Singapore. The fuel cell itself, according to Horizon, offered power density better than 480 Watt-hours per kilogram.

That's good compared to batteries, but pretty poor compared to conventional aviation fuels. Horizon are probably right to be focusing on very small UAVs, which are sometimes battery powered - typically for reasons of stealth. Thus far, the besetting sin of small electric sky-spies used by soldiers and cops has been poor endurance, and such customers might pay well for an equally silent little hand-launched plane which could stay up for longer.

The plods and soldiery certainly wouldn't want to cart troublesome pressurised hydrogen around with them to fuel up small skydroids; but Horizon have that in hand. The existing Pterosaur runs on pressurised hydrogen, but Horizon have a joint venture with Millennium Cell, whose hydrogen-on-demand™ fuel cartridge tech stores hydrogen in the form of sodium borohydride.

This sort of application isn't going to change the world overnight, but it is interesting. Following generations of kit might be useful to workaday customers too, rather than just the military-security world.

The Horizon release is here (pdf). ®