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London-Paris electric flight 'in decade'

bbc.co.uk

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Re: London-Paris electric flight 'in decade'

#101

Post by kgabis »

J-dawg wrote: post #42
koolba wrote: post #27

Earlier quoted context omitted.

Not necessarily! Imagine a system where the plan actually jettisons the spent batteries along the way. They could glide/parachute down to a collection depot to be recharged and sent back to the airport for installation.

Speaking as someone with no aviation knowledge at all this seems like an awesome idea. The plane could take off with battery packs slung under the wings which are jettisoned and become drones, gliding down to a depot. I'm now waiting for someone who actually knows what they're talking about to point out the flaws. One that springs to mind is the logistics of collecting the drone-batteries and transporting them to be…

I would also add safety and the fact that 70% of our planet is covered in water/not easy to retrieve batteries from.

Re: London-Paris electric flight 'in decade'

#102

Post by kgabis »

anovikov wrote: post #71

Why not, a jet powered plane can fly 17,300km, electric plane must have about 2x energy efficiency (70-80% vs 35-40% overall) because it's not a heat machine, so with 50x less energy density it translates to 700km. Actually it can be more because batteries are a lot denser than jet fuel so plane will be thinner, thus having a lot less air resistance, so 800km is possible. As you can see they are shooting for 500km, m…

You've contradicted yourself by saying that batteries are both less and more dense than jet fuel...

Re: London-Paris electric flight 'in decade'

#103

Post by fridek »

baby wrote: post #88
fridek wrote: post #72

Currently the shortest LGW-CDG flight is 1h. There is LCY-CDG lasting 1h 20m. For both cities it takes 30 - 60m to get to the airport from central location and you should be there at least 1h before the departure (for a total of 2-3h non-flight time). This makes total travel 3h - 4h30m. For comparison, the fastest train is 2h 25m. I guess you need to travel to and from the train station too, but it's definitely more…

What you're saying. The only reason to take a plane vs taking a train for this distance is the price. Usually planes are way cheaper. But the hassle of taking a plane is really making it a tough sell as you say.

Train tickets are anywhere between 60 and 300 pounds for this route. The cheapest plane tickets for the same route I've found were 80 pounds and there is no upper limit. I don't see much difference in price to be honest (+ getting to the airport is usually way more expensive).

Re: London-Paris electric flight 'in decade'

#104

Post by jsjohnst »

J-dawg wrote: post #42
koolba wrote: post #27

Earlier quoted context omitted.

Not necessarily! Imagine a system where the plan actually jettisons the spent batteries along the way. They could glide/parachute down to a collection depot to be recharged and sent back to the airport for installation.

Speaking as someone with no aviation knowledge at all this seems like an awesome idea. The plane could take off with battery packs slung under the wings which are jettisoned and become drones, gliding down to a depot. I'm now waiting for someone who actually knows what they're talking about to point out the flaws. One that springs to mind is the logistics of collecting the drone-batteries and transporting them to be…

The risk of puncture would likely cause the safety precautions required to make this cost prohibitive. That's just one battery specific reason, there's hundreds more why jettisoning isn't done except with military aircraft and even then only rarely.

Re: London-Paris electric flight 'in decade'

#105

Post by jsjohnst »

gambiting wrote: post #98
wlll wrote: post #61

Earlier quoted context omitted.

Planes I've been on regularly fly above the clouds, I wonder how much energy could be generated by covering the entire top of the aircraft with solar panels? I don't work in this field so as far as I know it could be a drop in the ocean. Clearly only possible during the day though.

It is a drop in the ocean. 1 square meter of surface receives at most 1kWh of energy from the sun, and that's only at the equator, on clear day, and without taking any conversion losses into equation. But for the sake of fun - For a Bombardier Q400(that was the only reliable data I could find)[0], the total surface area is ~213 square meters. That's obviously total surface area, so it includes both the top and bottom…

> In reality, those panels could maybe power the onboard lights and computers? Just about?

Doubtful. I don't have the exact numbers handy, but the power draw there is much higher than you think. That said, if you're unicorn farting skittles scenario was actually possibly (100kW solar per plane), which we know it isn't, then sure, it's enough power for that.

Re: London-Paris electric flight 'in decade'

#106

Post by ams6110 »

gambiting wrote: post #89
D_Alex wrote: post #75

I am really quite confident that no serious development of electric passenger aircraft will take place during the coming decade. And it is not a question of feasibility, but rather of priorities. There is so much low hanging fruit to be collected! By the end of the decade, if all goes well, we will be in the middle of replacing petroleum fuelled cars and busses with electric ones, and maybe turning our attention to o…

On the other hand, the majority of the cost of almost any flight is the fuel. Electricity won't be free, but should be considerably less than tonnes of kerosene(I'd love to hear how much less exactly) - which means that obviously airlines can pocket the difference as profit, and they do love that. There's already loads of short connections in EU, so an aircraft like that should be hugely attractive.

> airlines can pocket the difference as profit

Air travel is intensely competitive in most areas, and customers generally have very little "brand loyalty" and buy almost entirely based on price. The difference in expenses should result in lower fares.

And it is yet unknown whether the extra cost of flying tons of batteries around (they weigh the same when depleted, as opposed to jet fueled aircraft which become lighter as they use up fuel), and the extra cost of those batteries, and maintenance/replacement of them, will net out to be significantly cheaper than using conventional jet fuel.

Re: London-Paris electric flight 'in decade'

#107

Post by TillE »

fridek wrote: post #103
baby wrote: post #88

Earlier quoted context omitted.

What you're saying. The only reason to take a plane vs taking a train for this distance is the price. Usually planes are way cheaper. But the hassle of taking a plane is really making it a tough sell as you say.

Train tickets are anywhere between 60 and 300 pounds for this route. The cheapest plane tickets for the same route I've found were 80 pounds and there is no upper limit. I don't see much difference in price to be honest (+ getting to the airport is usually way more expensive).

I did a quick search for both April and June, and found the prices very similar. EasyJet is cheaper when buying well in advance, but it's not a massive difference.

Of course, budget airlines will also take you all over Europe for low prices. But for the narrow case of just London-Paris, the Eurostar is competitive, which is quite a bit cheaper than I'd remembered.

Re: London-Paris electric flight 'in decade'

#108

Post by notahacker »

ulfw wrote: post #64
notahacker wrote: post #29

Earlier quoted context omitted.

Tell that to the double-digit number of airlines already flying between London and Paris... It's a [hypothetical] aircraft, not a hyperloop. It can fly other routes.

Please list that 'double digit' number of airlines that fly between Paris and London. I get to max 7 (British, Air France, easyjet, Vueling, Transavia, flyBE, cityjet)

There's no shortage of other airlines selling the BA, AF or Vueling flights under codeshare agreements as a leg of another journey, which is one of the main reasons why demand on that route exists. Iberia and airBerlin sell others' LON-PAR flights under their own code as a point-to-point flight too. Not to mention the daft indirect itineraries you can buy if there's really no other alternatives

Re: London-Paris electric flight 'in decade'

#109

Post by cprayingmantis »

D_Alex wrote: post #75

I am really quite confident that no serious development of electric passenger aircraft will take place during the coming decade. And it is not a question of feasibility, but rather of priorities. There is so much low hanging fruit to be collected! By the end of the decade, if all goes well, we will be in the middle of replacing petroleum fuelled cars and busses with electric ones, and maybe turning our attention to o…

I agree, I've been thinking about it for years but I really want automated electric farm equipment. Torque and weight wise it all works out.

Re: London-Paris electric flight 'in decade'

#110

Post by mikro2nd »

fdej wrote: post #26
koolba wrote: post #2

I'm not at the forefront of this field so maybe I missed some great advances in battery technology or airplane efficiency, but how could this possible work when the energy density of a battery (.3-.9 MJ/kg) is 50x less than that of jet fuel (46 MJ/kg)[1]? Or is that simply enough for (very) short haul flights? [1]: https://en.wikipedia.org/wiki/Energy_density

That's correct, but note that an electric motor is about twice as efficient as a combustion engine, reducing the factor to about 25x (at least ideally). Typical medium range aircraft burn about 3 kg fuel per km [1], so to fly 1000 km you would need about 3 * 25 * 1000 kg = 75 tonnes of batteries. This should be in the ballpark of what we can pack into an aircraft already, but I guess at least another 2x improvement i…

There are other considerations, though... The thought of a Li fire on board an aircraft is something that would keep me awake nights.

I'd guess that anybody wanting to put Li technology batteries aboard aircraft is likely to spend the next 10 years jumping through regulatory hoops, so unless rechargeable battery technology is "ready to deploy" right now on aircraft, I don't see any way this is happening within a decade.

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