EasyJet says it wants to trial hydrogen fuel cell technology in one of its aircraft later this year, to increase efficiency, cut down on emissions, and reduce its rather large jet fuel bill.

Currently, after being pushed back from the gate by a tug, an aircraft uses its main engines (jets or propellers) to taxi to the runway. EasyJet estimates that the 20-or-so minutes of taxiing per journey accounts for about 4 percent of its annual jet fuel consumption. Jet fuel is expensive and produces a ton of carbon dioxide, and thus EasyJet is looking at alternative ways of puttering around the taxiway.

Enter hydrogen fuel cells. They can power buses and cars, so why not planes?

EasyJet's plan seems a little bit half-baked right now, but here's the general gist of it. Somewhere in the middle of the plane there would be a giant hydrogen fuel cell—probably something similar in scale to the 150kW fuel cells being used by buses in London and a few other cities around the world.

The fuel cell would produce enough electricity to power the aircraft's various systems while on the ground, and also drive some big ol' electric motors for moving the aircraft around the airport. The aircraft would be able to push back from the gate itself, and only have to start its main jet/propeller engines at the end of the runway.

That's not all, though. EasyJet says the exhaust from the hydrogen fuel cell—pure water—could be used to top up the plane's water tank. And, curiously, regenerative braking is also being looked at: a huge amount of energy could be captured and ferreted away into a battery, for later use by the aircraft's electrical systems. And when there's a big battery on board, you could also have solar cells on the top of the plane that feed into that battery. It isn't clear if all three of these systems would be used on the same airplane or not.

Anyway, you get the idea: EasyJet is looking at a bunch of new technologies with the hope of increasing efficiency. That aforementioned 4-percent reduction in jet fuel would equate to about £20 million annually, while not having to rely on a tug to push back from the gate could also result in time and money savings. Now EasyJet just needs to get some of those drop-in cabin modules that Airbus has proposed.