An easyJet/Cranfield University proposal to use a hydrogen fuel cell to haul its jets around taxiways to save fuel and fossil carbon emissions comes with numbers that could mean big savings on short haul routes like Sydney-Melbourne.
Just getting into position for takeoff can take an inordinate amount of time compared to the interval between lift off and touch down between close city pairs.
On some SE Australian flights the block time of 55 minutes or so for the actual flying comes with an extra 20-25 minutes of queuing and taxying depending on the congestion factor, making some trips slower than they were when Locheed Electra four engined turbo-props ruled in the early 60s.
Who hasn’t wondered, ‘Are we there yet’ when a flight to Melbourne from say the Qantas domestic terminal at Sydney is sent via that wonderfully daft and devious set of turns along taxiways to the far end of the third runway for a northerly departure.
These issues can be much worse on some European flights, which is where easyJet is hard at work undermining the likes of Lufthansa and BA with lower fares and roomier seats for those who pay for select rows on their jets compared to their legacy competitors.
The focus of the easyJet/Cranfield study is to replace the inefficient burning of fuel during the ground phase of a flight with electrical power stored in a hydrogen fuel cell routinely recharged by capturing the some of the energy wasted when the brakes are applied on landing.
There is more detail on this here.
The capture of such energy by fly wheels has been incorporated into some trolley cars and trucks for around 100 years, including in a pre-war trolley bus fleet in the Sandringham area of Sydney near its airport. Recovering part of the energy used to accelerate an automobile when it brakes has been integral to current and recent hybrid car designs.
The cost versus cash benefits of such designs has however been long disputed, and such technology is often seen as working best in a tax advantage or regulatory emissions reduction context where the rules reward such investments.
EasyJet will also have to get certification for such a modification, and practice tells the airline business that jet makers like Airbus or Boeing are needed to get on board to make such changes as intended at the regulatory and operational level.
It’s not as simple as the article in Business Traveller might suggest. The easyJet/Cranfield plan is also but one of many such proposals, including various studies aimed at similar outcomes by Airbus and Boeing.
But the potential savings to airlines, and the contribution that would be made to reducing emissions of fossil sourced carbon particularly in the case of short frequent flights could be very worthwhile.