(CNN) — On Tuesday easyJet announced plans to trial the use of hydrogen fuel cells on their planes.

The concept, which could convert their entire fleet of ordinary planes into hybrids without having to purchase new aircraft, could save a potential 50,000 tons of fuel and corresponding CO2 emissions each year.

The concept relies on hydrogen fuel cells which would be stored in the aircraft hold, and would allow a plane to taxi to and from the runway without using any fuel.

Considerable savings

The cells would capture energy from the aircraft braking on landing, and would charge lightweight batteries when the plane is on the ground, negating the aircraft's need to use jet fuel when taxiing.

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As 4% of the airline's fuel is consumed during taxiing, that comes out as a considerable saving.

Ian Davies, easyJet's head of engineering, says the short-haul, budget carrier is particularly well-placed to trial this technology.

"Because of the fact we're a low-cost carrier, most people take hand luggage and our hulls are empty, so we have the space to do it," he explains.

EasyJet's pilots would also have total control of the aircraft speed, direction and breaking during taxiing, thanks to a combination of power electronic systems and power motors in the aircraft's main wheels, meaning there would be no need for tugs to maneuver the aircraft around the runway.

The only waste is clean water

"If we can taxi at the end of the runway without starting engines, the whole experience will change at the airport. They'll be more quiet, more pollution-free, and more socially responsible as well," adds Davies.

The only waste the hydrogen fuel cell would produce would be clean water, which easyJet could theoretically use to refill the aircraft's water system.

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"People use water on board for flushing toilets and washing their hands. We said, 'if there's a way we can utilize (the water byproduct from the cells), let's do it.' We're looking at a no-waste solution," says Davies.

Hydrogen technology has come a long way in the last five years, both in terms of how it's stored and how it's generated, notes Davies, which is what's enabling easyJet and other companies in the aviation industry to employ it in the push to bring down CO2 emissions.

"Capital costs of hydrogen fuel stations have come down by 75% in the last 10 years, so being able to make this in an economically sound way and with relatively little land mass is the here and now," he notes.

"There'll be a point when (the price of) fuel goes back up, and it will be cheaper to produce hydrogen than it will be to produce aviation fuel.

"If you invest early, I think you can adopt early, and for us, that is the main thing," he says.

The timeline

Though easyJet plans to trial the technology this year, Davies notes it's a long road ahead before the full easyJet fleet will be carrying the cells.

"We're banking on a three- to five-year proof of concept, and after that hopefully we can persuade mainstream manufacturers to adopt it in the next five to 15 years," he says.

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This hybrid concept's part of easyJet's goal to reduce its fuel emissions by 7% by 2020, but it's not the only measure the airline's taking.

Davies says that in the last three years, the airline has already reduced weight on board by more than one ton (and less weight equals less fuel).