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UK Team Tests Hydrogen-Powered Drone

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First Flight of Hydrogen-Powered Drone with Water Vapour Exhaust (excerpt)

(Source: New Scientist; published Feb 5, 2016)

It only lasted 10 minutes and the guys in woolly hats and high-vis jackets looked like any other drone enthusiasts. But this short flight was the first by an aircraft wholly powered by solid hydrogen.

The experimental drone runs on pellets that emit only water vapour when they burn. The drone’s fuel is also three times as light as a comparable lithium battery. One day the technology could help make commercial aircraft lighter and cleaner.

“The idea was simple: stick solid state hydrogen fuel into a drone and fly it – but it’s tricky to do,” says Phil Anderson, head of Marine Technology at the Scottish Association for Marine Science in Argyll, UK, where the flight took place.

Just as hydrogen fuel-cell cars have been eclipsed by electric vehicles, the idea never really took off with aircraft either. Previous efforts such as the Cryoplane project from Airbus used large tanks of liquid hydrogen kept at super-low temperatures. But these tanks proved too big and cumbersome to be practical. Storing hydrogen as a pressurised gas is also not very efficient.
Drone on and on

The new system, designed by UK firm Cella, uses around 100 solid pellets packed into a cartridge. The 1-centimetre-squared pellets are made from a chemical compound that produces a steady stream of hydrogen as they are gently heated. This gas is then converted into electricity in a fuel cell that runs the drone’s rotor. The inclusion of a polymer stops the compound melting and helps it release hydrogen at a lower temperature.

The test flight lasted for 10 minutes and flew at an altitude of 80 metres – although it could have gone for two hours with the fuel it had on board, says Anderson. “Unlike with a battery, if you put in twice as much fuel you can go twice as far.” (end of excerpt)

Click here for the full story, on the New Scientist website.