easyJet puts its weight behind plans for electric planes

According to the Beeb, Easyjet is backing plans to develop commercial passenger aircraft powered by electric batteries instead of conventional aero engines.

If they can pull it off, it would be an amazing feat. The energy density of batteries is still much lower than jet fuel, but maybe there will be enough advances in the next 10-20 years in battery technology to compensate for that. I hope so.

Pointless unless they commit to powering with 100% renewable energy.

Will this drop the price? Surely elec is cheaper than jet fuel? Will there be longer times between flights? cant imagine charging being faster than refuelling.

Since we’ve just had the announcement of the Tesla truck which in some ways is similar, I thought I’d make a comment on here as well.

@hiphopopotamus, the Tesla semi that’s just been announced can charge fully in 30 minutes off the latest generation chargers that are going to be rolled out. Already that’s not too far off the time it takes to fuel up a diesel truck.
I could imagine that a plane with a split battery charge system (charge multiple sets of batteries individually) in the future could be recharged within even the quick 30 minute turnaround times for some planes.

Presuming we can get electric engines to produce the thrust required and we have the batteries to power it, there is a big point that has to be considered. Passenger jets (especially on long haul flights) lose almost half of their weight during the flight. Batteries empty or full weigh (practically) the same amount which limits the range compared to a traditional jet, even if you’ve theoretically got the same amount of energy to play with when you set off.

Hopefully the cost difference between jet fuel and electricity is enough to stop this being a problem when we get that far.
From a quick calculation earlier, kerosene is currently about $0.045/kWh whereas solar bids in Abu Dhabi have got down to around $0.025/kWh recently. I doubt that’s enough but we’re getting there!

Batteries empty or full weigh (practically) the same amount which limits the range compared to a traditional jet, even if you've theoretically got the same amount of energy to play with when you set off.

Maybe I’m an optimist, but with increasing improvements to solar panels, hopefully we’ll see this gap between combustibles narrow as the plane is able to partially recharge while in the air.

Maybe I'm an optimist, but with increasing improvements to solar panels, hopefully we'll see this gap between combustibles narrow as the plane is able to partially recharge while in the air.
With the megawatts of power that jet engines require, even if we could get every single bit of solar radiation and turn it into energy (a vanta black plane anyone?) then that's apparently only a theoretical 1.4kW per m2. For more efficient light aircraft/drones then maybe but for a passenger plane, the size to weight ratio of the planes themselves will likely make it impossible for solar to really ever have any effect.

Hmm good point. The wing area of a 747 is 524m2, so even if we’re generous and double it by saying we can have panels on the fuselage too, we’re still only getting a maximum of 1.45242 = 1.5MW of power. This stack exchange topic reckons you’d need about 90MW to get a 747 airborne, so we’re quite a way off, even with a perfect solar panel.

That’s just for take off though. I can’t immediately find data on how much energy is used when cruising at altitude though, but I imagine it’s much less. And apparently a 747 is notoriously fuel inefficient, so maybe there’s still hope. #optimist :slight_smile:

Hmm good point. The wing area of a 747 is 524m2, so even if we're generous and double it by saying we can have panels on the fuselage too, we're still only getting a maximum of 1.4*524*2 = 1.5MW of power. This stack exchange topic reckons you'd need about 90MW to get a 747 airborne, so we're quite a way off, even with a perfect solar panel.

That’s just for take off though. I can’t immediately find data on how much energy is used when cruising at altitude though, but I imagine it’s much less. And apparently a 747 is notoriously fuel inefficient, so maybe there’s still hope. #optimist :slight_smile:


Haha, I read that same thread yesterday! Yeah maybe there’s scope for a few extra miles at cruising altitude.
Considering planes do also fly at night though, you’d still have to be able to go the whole distance without any solar generation.

Electric power with batteries is probably practical for light planes, but It is probably more practical for large passenger planes to carry on using liquid fuel (even the kerosin we use already). The trick to green flight is how you get the kerosin - out of the ground as done presently or synthesised from the CO2 in the air and the hydrogen from sea water plus a lot of electricity from re-newable or nuclear sources. You may only achieve 30% efficiency out of the 50% theoretical maximum, but you now have a 30 year carbon cycle or thereabouts and not 300 million years. Food for thought…

Robert had some thoughts on the planes in one of his news eps. https://www.youtube.com/watch?v=yaC1qgXaRvE

@TheeEngineer Or even a hybrid combination of battery and kerosene may be an option that’s being considered. Battery motor for take-off and kerosene once it reaches an altitude, will reduce the localised emissions from a plane taking off.

@“Rob at Bulb”, I suspect if viable, that’s the most likely first step as it reduces the big issue of noise which currently limits the times planes are allowed to take off and land.