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London-Paris electric flight 'in decade'
- koolba 10y agoI'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 https://en.wikipedia.org/wiki/Energy_density
- aphexbr 10y agoFTA: "The company is relying heavily on innovation in battery technology continuing to improve at its current rate. If not, the firm will not be able to build in enough power to give the plane the range it needs." So, it presumably can't work now but they're putting their money on the idea that it will in the near future.
- jacquesm 10y agoAt which time everybody and their brother will be doing the same. The hard part is the batteries.
- 6stringmerc 10y agoSee also: Moeller Air Car
- tankenmate 10y agoThe equation isn't just energy density; it's also the efficiency of harnessing that energy. Good electric motors are way more efficient than a turbofan.
- dredmorbius 10y agoThat buys you roughly a factor of three. Subtract again for the fact that you're not shedding half your takeoff weight in fuel over the course of a flight. You land with as much battery as you started with. More if you're using metal-air batteries.
- koolba 10y agoNot 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.
- JustSomeNobody 10y agoThat sounds like something that could go very wrong and either cause the plane to crash or hurt/kill people on the ground.
- J-dawg 10y agoSpeaking 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 reunited with the parent aircraft.
- kgabis 10y agoI would also add safety and the fact that 70% of our planet is covered in water/not easy to retrieve batteries from.
- dredmorbius 9y agoThe aircraft in question is being offered for a relatively short-range flight (London-Paris), 345 km (215 mi). Odds are good this flight configuration wouldn't be used on long-distance trans-oceanic flights. Though it might be best-suited to short hops between islands, islands and mainlands, or across deep peninsulas. That's a somewhat limited set of markets. For travel between heavily-populated continental points, ground-based rail would almost certainly be more efficient and practicable, and even in the case of the suggested London-Paris route, there is a ground-based alternative.
- blutack 10y agoElectric motors would need to be orders of magnitude more efficient than turbofans (which they aren't). You also need to compare the overall efficiency developed as thrust, not just thermal efficiency. There's also the issue of the mass of batteries not going away during the flight, unlike fuel, which will require maximum landing weight to equal maximum takeoff weight - this will impose a structural penalty versus IC aircraft.
- cjrp 10y ago> There's also the issue of the mass of batteries not going away during the flight Excellent point; currently as fuel is burned off, planes can climb to higher, more efficient altitudes (known as a step climb). What's the performance penalty for not being able to do this as your batteries aren't getting lighter as the flight progresses.
- neolefty 10y agoMaximum efficiency is ... 100%. So if a turbofan is 30% efficient, then the best you can do is about 3x.
- ericd 10y agoGood point, but something to keep in mind is that the efficiency of the motors in turning stored energy into motion is only one part of the efficiency of the aircraft. If a plane is able to fly much higher due to the engines no longer being air breathing, that would also change the equation, as drag would be much lower with the thinner atmosphere.
- Gravityloss 10y agoAlso you can tune the location and amount of propulsors, and have a high efficiency rotation rate with direct drive electric motors. The current turbofan engines are close to the size limits in relative fan size and bypass ratio without a gearbox, which adds cost and mass. (Only one manufacturer is in the process of introducing a geared turbofan.) Because of no high speed jet exhaust and large area thrusters, these aircraft have the potential to be able to take off really steeply and to be really quiet.
- fdej 10y agoThat'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 is needed to make it economical (we want to haul some useful payload, not just the batteries). [1] https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft
- JustSomeNobody 10y agoWhat's the turnaround for the aircraft though? If they can't turn around an aircraft in 15-30 min, we'll need more aircraft or prices will skyrocket (no pun).
- notahacker 10y agoAny sensible proposal for electric systems for commercial aircraft is going to aim for batteries to be safely swappable in 10-15 minutes. (Though they can still make delays from unexpected diversions to airports without a stock of batteries worse)
- dx034 10y agoAnd then charge overnight and be used as energy storage for the time they're not in use. As flight times are very predictable, they should be a good use case for battery storage.
- jpm_sd 10y agoThe structural penalties for making "most of the weight of the aircraft" removable will probably lead to a plane that doesn't fly.
- JustSomeNobody 9y agoHmmm... I wonder. Let's say they design the aircraft around an existing battery (size/weight). If later technology allows for a lighter battery, would they they have to add the weight back in order to keep the cg correct?
- jakozaur 10y agoMaybe we should think outside of the box. What if, aircraft doesn't need to store all of the required energy on-board? E.g. transmit energy wirelessly through microwave and just have enough fuel for emergencies.
- wlll 10y agoPlanes 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.
- brians 10y agoDurability is a problem here too: these things fly through hailstorms and thunderstorms, and it'd be nice to have power coming out the other side.
- gambiting 10y agoIt 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 of the airplane. For simplicity sake, let's say only half is in full view of the sun - so 107 square meters. Even if we assume magical solar panels that can actually convert 100% of the energy into electricity, and assume that the plane is flying in full daylight, that's only ~100kW. The aircraft uses two PW100 engines, each producing....3700kW, so the total output of the aircraft is around 7400kW. So even if the conditions were ideal, we had magical solar panels, and covered every inch of the aircraft, they would produce....less than 1% of power necessary to fly it. To be fair, a normal 2.0L petrol engine produces more power than what those solar panels would produce. In reality, those panels could maybe power the onboard lights and computers? Just about? [0]http://www.supersonicinstitute.org/docs/Q400SurfaceAreaReport_Final.pdf http://www.supersonicinstitute.org/docs/Q400SurfaceAreaRepor...
- polshaw 10y agoYes the idea for this will be v. short haul for now which is why they talk about London to Paris; ~215 miles. 25 times further (50x lower energy density, 2x better engine efficiency) would be under 5,400 miles. Looking at the empty weight, the weight of max fuel capacity and range[1], it seems realistic to fly 200-300mi on batteries without any kind of jettisoning. So it seems feasible, the next question is where could it be in terms of commercial viability. 1. https://en.wikipedia.org/wiki/Boeing_777 https://en.wikipedia.org/wiki/Boeing_777
- macspoofing 10y ago>A new start-up says that it intends to offer an electric-powered commercial flight from London to Paris in 10 years. There is no way a startup without any experience in aviation will design, build, certify and sell a commercial 150-seat airplane in 10 years. Not even mention the immense R&D groundwork required to even prove the concept of using batteries to power short haul flights. Why do they put out bullshit like this? It just hurts their credibility.
- nether 9y agoBut they do have experience in aerospace, since they're made up of engineers from Boeing, Cessna, and NASA.
- deleted 9y ago[deleted]
- tankenmate 10y agoSpaceX? I realise that the world has very few Musks about, but it is possible; highly unlikely but it is possible.
- raverbashing 10y agoSpaceX was still using "conservative" technology. It was more like a business model innovation than technological per se. And the reusable parts are being developed by steps It's an important difference.
- throwaway2048 10y agoMagical thinking is a very effective VC cash magnet, especially when you have entered the "fear of missing out" stage. Uber is a company that has a 60 Billion dollar valuation contingent on the idea that it will somehow both develop driverless cars, and maintain a monopoly on them (dispite having zero expertise in this area whatsoever, and competing against entire industries that do) before they run out of money losing 2 Billion+ a year. Theranos had promises of technology that was not physically possible, and they knew it. Yet the billions still poured in. Magical thinking is powerful.
- thriftwy 10y agoWhat's the point if you can just take an electric train? Isn't it basically 'a flight' on rails? They should have chosen a better city pair.
- notahacker 10y agoTell 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.
- lorenzhs 10y agoEurostar have around 80% market share on Paris–London for good reason. At 2hrs 15mins from city centre to city centre it's faster, less hassle, and more comfortable than flying. Security is less strict (you can take liquids) and you don't have to check your bags. Two large items of luggage are also included for every passenger. It's not even more expensive than flying if you book in advance if you include the price for airport transfer. London–Paris is just an example in the article to demonstrate the range of that hypothetical aircraft. It could also be useful as a demonstrator.
- aninhumer 10y agoI assume that's just market share of travel specifically between the two cities? There's also the market of connecting flights to consider.
- selectodude 10y agoThere aren't any flights to anywhere in the world out of London that would connect through Paris unless you require a flight on Air France.
- mcintyre1994 10y agoI think the parent might mean eg. travel from the UK outside of London to Paris, and France outside of Paris to London. In that case you'd probably spend longer traveling to the Eurostar in your own country than on the Eurostar. The same would be true if you traveled to an airport in London/Paris to fly, but there's the alternative of flying from a regional airport direct to London/Paris instead.
- ptaipale 10y agoTL;DR: If I read things right, the BBC article is highly misleading and the plane still uses jet fuel. Longer version: The article mentions "removing the need for jet fuel" but does not explain how the engines of this "electric" plane work. Propellers run by electric motors, or what? No. Wright Electric's own site is scant on technical details and concentrates on praising the great team in its blog. From browsing other sites [0] it appears that the engines are still using conventional jet fuel to generate the thrust; it's just that the external systems (pressurization, de-icing, landing gear mechanics, fuel pumps etc) that are powered by electricity are using battery power instead of generator in the current jet engines. This may be a step ahead in energy efficiency but is not that revolutionary, and calling it "electric flight" is simply wrong. I hope I misunderstood, but Wright Electric really should tell how their electric plane is supposed to work if it is really electric. https://electrek.co/2017/03/22/electric-plane-startup-150-seat-battery-powered-plane/ https://electrek.co/2017/03/22/electric-plane-startup-150-se...
- IanCal 10y ago> TL;DR: If I read things right, the BBC article is highly misleading and the plane still uses jet fuel. I don't think there's a clear description of the plane, so I don't think you can say what it "does" use. Their blog says they'll go all-electric if batteries progress fast enough or they describe taking a hybrid approach "like a chevy volt". > From browsing other sites [0] it appears that the engines are still using conventional jet fuel to generate the thrust; it's just that the external systems (pressurization, de-icing, landing gear mechanics, fuel pumps etc) that are powered by electricity are using battery power instead of generator in the current jet engines. The clip I think you're referring to comes from this: https://drive.google.com/file/d/0B5dHV3MyeeBjN1BoU3hHclFYd3M/view https://drive.google.com/file/d/0B5dHV3MyeeBjN1BoU3hHclFYd3M... which is not describing their proposal but they bring it up in one of the reports as a side opportunity for electric aviation.
- alex_duf 10y agoI think the image you can see on the electrek article is from this blog post: https://weflywright.com/2017/02/12/wright-weekly-weport-feb-12-2017/ https://weflywright.com/2017/02/12/wright-weekly-weport-feb-... The legend for that image is: >This image shows the potential subsystems that could be powered electrically. (Note: an fuel plane can also install electric subsystems – for example the 787 is making headway in this direction – but the subsystems in an electric plane will be all electric!) From what I read from the blog, it looks like they are going all electric. So I'm not sure what magic they intend to use in order to propel the plane, but I'll assume propellers until proven wrong.
- CalRobert 10y agoThey picked the one city pair already served well by rail??? One where there will be substantial time lost to immigration queues anyway, thus reducing the relative benefit of high speed travel? SF-LA, London-Dublin, etc would have made a lot more sense.
- pale-hands 10y agoGood point, but this is just the BBC giving an example of a distance that its audience can easily grasp.
- jacquesm 10y agoI hope the took the requirements of two alternates to heart in their range calculations otherwise - bad pun - this won't fly.
- jlebrech 10y agowe could save a lot on fuel if they reordered flight plans into a grid, you might not be going direct to somewhere far and popular but they overall impact or the environment would be huge.
- charlesdenault 10y agoWhat do you mean by a grid? Long-haul direct flights offer many benefits, such as lower drag at cruising altitude, engine efficiency at altitude, etc. [1] Biggest fuel savings are going to come from more efficient engines and weight reduction (composites). 1: https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft
- jlebrech 10y agoyou find the optimal distance for a flight and create a mesh out of those flights. and stop lines from crossing.
- baldfat 10y agoAdd it to the list of 10 years from now 1) Dozens of new battery technology 2) Graphine will change our world 3) Genetic cures for thousands of diseases and birth defects 4) Linux Desktop :(
- notahacker 10y agoIt's good to see YCombinator funding some ambitious and really hard projects, but I'll believe the "in a decade" when I see it. Even if a decade's worth of battery technology improvements allows it to get off the ground, there's still a lot of painful certification processes to work through (and certification authorities likely to be less-receptive than average due to it being a new entity and having less commonality with previous generation aircraft) A little surprised they seem to be going after the ultracompetitive A320/737 market rather than the shorter-haul, lower-speed, turboprop market as well (closer to their starting point, less competition, even more fuel price-sensitive, airline customers less conservative etc.)
- jlebrech 10y agowhat about passenger gliders?
- jakozaur 10y agoI appreciate Y Combinator at grabbing ppl attention. We need to do more of this ambitious projects. However, I'm rather disappointed lack of even fundamental technical vision. I get that if you shoot to fly in a decade you can optimistically base your model on other technical advances (e.g. better batteries), but too much short-term hype can be deceiving. It will take many years to get there and probably it would be easier to create first small turboprope electric plane. Something like: https://en.wikipedia.org/wiki/Bombardier_Dash_8 https://en.wikipedia.org/wiki/Bombardier_Dash_8
- tuna-piano 10y ago"Second flight will be after the battery recharges, approximately 10 years after the first flight"
- anovikov 10y agoWhy 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, must be easily possible. Airbus works on a 1000km battery powered regional plane (catch is, it's probably a turboprop) by 2030, by the way.
- kgabis 10y agoYou've contradicted yourself by saying that batteries are both less and more dense than jet fuel...
- anovikov 10y agoLOL energy density is much much lower, but volumetric density is several times higher. Meaning, they take less space for same weight -> airframe can have smaller profile and have less air resistance.
- kgabis 9y agoI don't think that's true, both volumetric and mass densities for lithium ion batteries are very low (https://upload.wikimedia.org/wikipedia/commons/c/c6/Energy_density.svg https://upload.wikimedia.org/wikipedia/commons/c/c6/Energy_d...).
- fridek 10y agoCurrently 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 central (2x15 min) and you can easily hop on train even five minutes before the departure - although I usually plan at least another 15 min buffer. That is a total of a little over 3 hours. I don't pretend to know enough about economy of future trains vs future electric flights, but it looks like short distances will always be a tough sell for airplanes. Personally I also find trains more comfortable and I was never given a free massage for carrying scissors in my pocket when boarding one.
- dx034 10y agoThe better idea for the first electric flight is probably LCY-AMS. It's a 35-40 min flight but there's no alternative to it (train 4+ hours, ship 8+ hours). There's a lot of demand for that route, you have more than 15 flights per day across all London airports.
- fridek 10y agoI was just looking for a route London - Rotterdam and found exactly what you mention - no good alternative to flights :)
- Symbiote 9y agoThe ferry is OK if you're travelling overnight, I've done it a couple of times. It's possible to buy a train ticket which includes the ferry, and trains at both ends. (e.g London to Rotterdam.) The ferry itself is from Harwich to the Hook of Holland.
- TorKlingberg 10y agoI wonder why there is no fast London - Amsterdam train. It's not that much farther than Paris.
- D_Alex 10y agoI 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 other land-based petroleum consumers such as trucks, agricultural equipment, mining machinery etc. Airplanes are so far down the list of things we can easily swap over to batteries that it is not yet worthwhile to work in this field.
- gambiting 10y agoOn 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.
- ams6110 10y ago> 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.
- woodandsteel 9y agoI could be wrong, but I am guessing that batteries + electric motors will be both cheaper and need a lot less maintenance than jet engines plus fuel tanks and pumps.
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- 6stringmerc 10y agoOkay, I had to stop reading and chuckle for a moment at this bit of logic: >Wright Electric said by removing the need for jet fuel, the price of travel could drop dramatically. Note to self: Bring back Zeppelin travel.
- m-j-fox 10y agoWhy not hydrogen? Stuffing a Mirai's guts into a turboprop is a project we could do today. Solves the waiting/hoping for battery technology problem and saves Toyota's $billions invested in r&d from the toilet.
- gjjrfcbugxbhf 10y agoHow do you store the hydrogen?
- yongjik 10y agoI wonder if any company is seriously considering nuclear-powered planes? The energy density alone would make it extremely competitive. And, let's be honest, in case of a crash, I'd rather walk away (or be hauled away without a limb or two) to die of cancer ten years later, than be burned to crisp in a huge fireball. Fear of radiation is overrated.
- nether 9y agoWell, I don't think there's much consideration of nuclear power in the first place by most countries. A nuclear-powered B-36D (large bomber) was explored in the '60s though. Complications included the weight of the lead shielding to protect occupants, and that doing some routine operations in the radioactive areas required a remote controlled robot. The reactor was never used to power the aircraft, and test flights just explored the effects of radiation on everything.
- deleted 10y ago[deleted]
- asteli 10y agoI see some back of the napkin calcs happening here, and feel compelled to point out that in addition to in-flight fuel, current regs require planes to have reserves sufficient to: * maintain a holding pattern for 30 minutes (45 for recip. engines) PLUS * perform a missed approach at destination, climb out again, and perform a landing at an alternate PLUS * contingency fuel (5% of trip fuel)
- lutusp 10y agoAirlines that switch to electrics will have to resolve a logistical issue -- do you switch batteries between flights, or do you need to buy twice as many aircraft, so half are flying and half are charging? I suspect that battery-switching will be the answer, even though the batteries will be a significant percentage of the aircraft's volume.
- rz2k 9y agoIt's already possible to swap the battery pack on a Tesla Model S faster than a gasoline car can be refilled.[1] That is special equipment, but presumably modular batteries that are quickly bolted into a large cavity on the underside of a plane would be possible. It might only make sense in hubs, or highly traveled routes to put the equipment in place, though. Slower charging when the plane is on the ground overnight at a regional airport for example probably wouldn't be a problem.
- verulito 10y agoMaybe I don't understand combustion well enough but why isn't there more hype about fuel cells? They seem so much more compelling, in cars or otherwise. Just seems like if Elon Musk decided to pursue fuel cell cars rather than electric cars that those might be more dominant on the market today.