EasyJet and post-grads at Cranfield Uni have unveiled a concept that could save the airline 50,000 tonnes of fuel and associated CO2 emissions per year.
The zero emissions hydrogen fuel system is part of the airline’s environmental ambitions to slash fleet CO2 emissions per passenger kilometre by 7%. Set for implementation by 2020, the airline currently clocks up 81.05g of CO2 per passenger kilometre.
For the hybrid plane concept the airline looked to students at Cranfield University, who were asked to develop concepts that could come to fruition in 20 years time. Beating this timeframe by some margin, easyJet will now set to work with its industry partners and suppliers to apply the technology and test it later this year.
The hybrid plane concept uses a hydrogen fuel cell stowed in the aircraft’s hold. This system allows energy to be captured as the aircraft brakes on landing and is used to charge the system’s lightweight batteries when the aircraft is on the ground.
The energy can then be used by the aircraft without having to use its jet engines. This would be particularly beneficial during taxiing, given that the airline’s aircraft average 20 minutes of taxi time per flight, and the procedure itself accounts for 4% of the company’s annual fuel consumption.
Each aircraft would have motors in their main wheels and power electronics and system controllers would give pilots total control of the aircraft’s speed, direction and braking during taxi operations. The system would also reduce, if not remove altogether, the need for tugs to manoeuvre aircraft in and out of stands.
Wastewater from the fuel cells could then be used to refill the aircraft’s water system throughout the flight.
Ian Davies, easyJet’s engineering director said: “The hybrid plane concept we are announcing today is both a vision of the future and a challenge to our partners and suppliers to continue to push the boundaries towards reducing our carbon emissions.
“It’s also a great example of the benefits of our strategic relationship with Cranfield University.”
Dr Craig Lawson, lecturer, Centre for Aeronautics, Cranfield University, added: “Our students have showcased some exciting ideas for the 2035 vision of the airline industry through The Future of Flight competition, presenting environmental solutions, operational improvements and ideas to enhance the customer experience. We’re looking forward to developing this concept further.”
EasyJet and Cranfield University signed a three year strategic partnership agreement last year to share innovation and knowledge.
As part of easyJet’s 20th birthday activities, students at Cranfield University were asked to compete in four categories; cabin design, aircraft design, airport experience and in-flight experience.
Judges at easyJet and Cranfield received several advanced concepts, including dynamic wings which change shape in flight, a ‘shark skin’ coating to reduce surface drag and, in the cabin, ultra-light weight seats carbon fibre seats incorporating wireless phone and tablet charging panels.
Not understanding the “clever” part of this. The whole concept of electric drive taxiing is understood. It seems from the article this is just the notion of using a fuel cell instead of the aircraft’s own generators to deliver the power.
As far as the “greenness” is concerned, there are several unanswered questions.
1-What quantity of fuel, if using the on board generators, would be used?
2-What percentage of the total fuel saving does that amount in Q1 represent, and therefore what is the actual advantage in fuel saving of the hydrogen generator?
3-What extra fuel is used to transport the hydrogen and its fuel cell around the world?
4-Do the answers to the above questions indicate that, say, >99% of the saving is based on using electric taxiing and <1% is the use of a hydrogen powered generator for the electricity?
If the answer to Q4 above indicates that the fuel cell and water top up ideas are tiny proportions of the overall package of fuel saving delivered by electric taxiing, then isn't the article a triumph of style over substance? If so, can we have more scrutiny by the journalists at Engineering Towers and less reproduction of corporate press releases? Perhaps a section in an article such as this with some clear mathematical basis would provide better understanding of what is and is not being achieved.
MB made valid points, an engineering article should contain more detail. The system is supposed to achieve kinetic energy recovery but it is hard to see how to “charge” a fuel cell. Electrical energy could perhaps be used to hydrolyse the “waste” water mentioned to produce hydrogen for the fuel cell, but it would appear easier to charge “ordinary” batteries.
I would think that landing produces a lot of energy, very quickly…so charging batteries with a lot of energy in a short period just doesn’t work. In this design a lot hydrogen could be created at once and stored to power the Fuel Cells. However, without seeing any schematics or information on energy produced, I am just making an educated guess.