jeremyp
Philosopher
We'll see. It all looks pretty speculative for now.
The point about the fuel tanks is not a straw man. If you want to be competitive with fossil fuel planes, you need comparable performance. That includes capacity.
Electric Planes
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We'll see. It all looks pretty speculative for now.
The point about the fuel tanks is not a straw man. If you want to be competitive with fossil fuel planes, you need comparable performance. That includes capacity.
smartcooky
Penultimate Amazing
For certain definitions of "speculative"
Meanwhile, in the real world, actual scientists are doing actual research - and as I pointed out, one company is about to go into production of solid state batteries, and Toyota, one of the world biggest car producers, has contracted them to do so.
This in itself is a strawman. No one here has claimed that electric planes will be 100% competitive with fuel powered aircraft across the whole range of use. What I, and others have said, is that they look very likely to become competitive over short haul routes. We have provided evidence to back up our claims opinions.
Also, see my earlier post about the Harbour Air DHC2. They have replaced the fuel tank area with Li-ion batteries but needed some installed outside the tank area. They did this four years ago, and already, battery technology and energy density has increased sufficiently that it would allow them to remove some of the batteries that are located outside the tank area. As the technology improves energy density will increase to the point where all of the batteries will be in the tank area.
Oh, and FYI, some information about relative energy density. (U)
Avgas has about 100x the U of the equivalent weight of lithium-ion batteries. This sounds bad for batteries, but this does not take into account efficiency. ICE engines are very inefficient at turning that stored energy into useful work, the biggest waste being heat production. And there is little that can be done to improve this. ICEs are typically about 15% efficient. However, electric motors are 75 -85% efficient in turning the stored energy of a battery into useful work. The MagniX motors fitted to the Eviation Alice are claimed to be 90% efficient, their excess heat is dealt with using airflow over heatsinks!
All up, this means the relative U between Avgas and li-ion batteries is about about 9:1. If solid state batteries are going be 2 - 2.5 times the U of Lithium Ion, the that ratio comes down to between 3.6:1 and 4.5:1
This would be a significant improvement.
Those who claim that something can't be done need to stop getting in the way of those who are actually doing it
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Ziggurat
Penultimate Amazing
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The fact that you're beaming is the same. But the aiming technology actually isn't, because there's a huge difference between aiming at an essentially stationary target and a quickly moving target. It's why you couldn't actually use the Hubble to spy on objects on the ground.
It might work for something like a launch vehicle, where the weight savings are even more critical, you're controlling the air space more tightly to keep it clear anyways, and a single transmitter (or transmitter array) suffices, you don't need a network. For planes, I don't think it's realistic.
Roger Ramjets
Philosopher
On the last flight I took from Westport to Wellington there was too much low cloud at the Wellington airport. After two failed landing attempts we headed to Palmerston North. But there were no flights from there to Napier so me and my brother were put on a flight to Auckland and then another one back to Napier. That was a long day!
The distance from Wellington to Palmerston North is 131 kilometers, so you would want at least that much in reserve for that trip. However the Kapiti Coast Airport is only 50 kilometers away. 132 km (Nelson to Wellington) + 50 km = 182 km. Of course none of this matters if you have a seaplane!
Roger Ramjets
Philosopher
But the lithium is only a very small proportion of the total material in the battery.
The biggest problem is not energy density, but cycle life. To get high capacity you need a very large surface area on the plates. This is achieved by using porous materials such as graphite and manganese/cobalt oxide. Problem is the lithium ions expand the material they combine with, causing stress fractures that gradually destroy its integrity. This becomes worse as the plate materials are made more porous.
So you need far more plate material than lithium. You also need relatively thick metal plates to transfer the electricity with low loss, an electrolyte, and an airtight container to hold it all in. A typical lithium-ion battery contains about 7% lithium, 7% cobalt, 4% nickel, 5% manganese, 10% copper, 15% aluminum, 16% graphite, and 36% other materials. IOW, 93% of the battery is not lithium.
There are other chemistries that promise higher energy density, but getting them to achieve a high cycle life is proving difficult. Solid state batteries theoretically solve the expansion problem, but have much lower power density. But a lot of progress is being made and we can expect to see big improvements in the near future. The only reason we haven't seen it until now is that there was no big incentive to do it.
The other (related) issue is cost. A battery with high cycle life may not be as cost effective as a cheaper one with lower cycle life, or vice versa. In a car the ideal battery would last the life of the vehicle, whereas aircraft might be better to use batteries that wear out faster but are cheaper. As the technology improves an aircraft's range will increase each time it gets a new battery!
novaphile
Quester of Doglets
Personally, I'm expecting hybrid planes that run on bio-fuels.
Note that there are already airlines that are running planes on bio-fuels only.
Bio fuels are close to carbon neutral (carbon dioxide taken out of the air when the plants grow, and put back when the fuel is burned).
Roger Ramjets
Philosopher
If only that were true.
Biofuel
Biofuels are not a green alternative to fossil fuel
Conventional biofuels are just another way to kick the can down the road and pretend we are doing something while not actually doing anything. Current implementation is worse than useless - allowing airlines to greenwash their operations with little if any positive effect. The only good that may come out of it is dramatically increased fuel costs that help push the industry towards real solutions.
Obviously, the amount of electricity produced by an ICE hybrid system would have to be somewhat greater than the amount of electricity produced by batteries of the same weight of the hybrid system.
Some of my best friends are plants, and they say - "Stop killing us to make bio-fuels, and give us more carbon dioxide".
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rjh01
Gentleman of leisure
One of the major roadblocks for progress are people who, if the facts contradict their belief, reject the facts, rather than alter their beliefs.
jeremyp
Philosopher
So you agree that there is a possibility that the flight might have to divert if something unexpected happens or the weather closes in. There has to be a safety margin and unless the quoted 200km is accounting for such a margin, that plane is not doing commercial flights of anything like that length.
Having been on that flight literally several dozens of times in the last 50 years, I can tell you exactly what happens... you see, in this country, we have a couple of things you may not have heard of. They are called "Weather Reports" and "Radio Communications"
If Wellington is socked-in, the flight does not take off to begin with. If on some one in a million occasion the fog suddenly and unexpectedly closes in during the 45 minutes after the flight has already taken off, it either turns back or diverts to Blenheim (an airport it overflies on the way to Wellington.
If your flight is much shorter than that, you have to wonder why you’re bothering and not using cheaper ground or water based transport.
smartcooky
Penultimate Amazing
Ground transport? Water transport? Cheaper? Really? Looked at map of New Zealand lately?
By air
Sounds Air: Nelson <> Wellington on the Cessna Caravan (45 min, NZ$141 return)
Sounds Air: Nelson <> Wellington on the Pilatus PC-12 (30 min, $195 return)
By Ground and Sea
Inter-City Bus: Nelson <> Picton (2hr 30 min. NZ$96.00 return)
Blue-bridge Ferry: Picton <> Wellington (4hrs 3 min, NZ$340 return)
6½ hours v 30m or 45 min
NZ$436 v NZ$141 or NZ$195
You should quit while you're ahead. You already know nothing about what you are discussing, it can only get worse from here on in.
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jeremyp
Philosopher
Really? So what should I think about your price for the ferry that includes taking a car across? Are you going to put that on your electric plane?
And you also need to understand that you can't make commercial passenger planes economically viable, if they only make sense for one route.
Ziggurat
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I rather suspect it does. I don't think you want to be landing a sea plane in thick fog either, and while you don't need a specific runway to land a sea plane, it's still got to be visibly clear of any obstructions to land safely. You also need somewhere to dock it, which means in practice you can't just land anywhere, even if you've got some additional flexibility in location. But you also can't really land a sea plane if there's high waves, whereas wind poses less of a problem for landing on a runway, so fog isn't the only kind of bad weather that can keep you from flying a sea plane.
Ziggurat
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By weight or by volume? Aluminum is about 5 times denser than lithium, the other metals even more so. If that's by weight, then there's more volume of lithium than any other metal by a good margin.
The incentives have been there for at least a few decades, and research on the topic has been ongoing that entire time. Electric vehicles are hardly the only thing which could use higher energy density batteries, portable electronics have wanted that for as long as they've existed. Progress is being made, but I wouldn't count on any big breakthroughs in the "near future", unless you've got a really expansive definition of what counts as near.
MRC_Hans
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(Highlighted) That is actually an interesting question in this context. Current batteries are optimized for both weight and volume, but for most applications on ground level, volume has precedence. Just see how many people worry about the range of their EV, rather than its weight.
However, for an aircraft, by far the highest priority is weight. There is usually room to spare in a plane. There might be room for some new battery designs here.
Hans
smartcooky
Penultimate Amazing
Nope, that is the passenger walk-on price at peak times. Of course if you are prepared to leave Nelson for Picton on the 11pm bus to catch to the 2am ferry to Wellington for your 10 am business meeting, then you can get it cheaper. Its NZ$506 return if you want to take your car
As I said... quit while you're ahead. You're not very good at this.
Evidence?
Ziggurat
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Simple logic. Nobody does it. It costs a lot to design and certify a plane for commercial passenger use, and then set up a production line for it. The lower the sales volume, the more of that cost needs to be recovered from each sale. If you're only flying one route, that's only a handful of planes. And that's going to make those planes absurdly expensive. I don't think any plane manufacturer is going to launch a civilian passenger product if they don't expect to be able to hit volumes in the hundreds over the lifetime of the plane. Look up production volumes for planes from Bombardier or Embraer, for example.
smartcooky
Penultimate Amazing
Firstly, no-one has claimed an aircraft should be developed for a single route... that's just another of jeremyp's many "reductio ad absurdum" strawman arguments. The Nelson <> Wellington example was just that, an example. And there are many others.
Secondly, Harbour Air (BC, Canada) are in the process of electrifying their DHC-2 seaplane fleet to fly many short routes in the area they serve. An argument could be made that this is developing an electric aircraft for commercial use over a specific number of specialist routes.
This is not some startup company trying to see if its innovation is going to work. This is a well established. successful local airline with a 40+ year history of commercial flying in the region. I would think they will be expecting what they are trying to do to become commercially viable, otherwise why would they even be trying to do it.
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Delvo
Дэлво Δε&#
An easy real-world example of the non-viability of a plane with too few routes is the A380.
It's the biggest passenger jet: the one that's two stories tall all the way from front to back, not just in front like the older 747. The project to create it seemed to make sense at the time because long flights were scheduled by the spoke-&-hub model: collect all the passengers you can at one place and send as many of them at once as possible on the biggest possible plane. A large jet was required not only for the number of people but also for the long range.
But while the A380 was finishing development & starting early production & collecting orders for it from the airlines, the following generation of passenger jets like the 787 and A350 was also in the works. Made largely of composites instead of metals, they're significantly lighter for their size, thus more fuel-efficient, thus longer-ranged for their size, which meant a smaller plane could still do longer flights, which caused a shift in how long flights were scheduled. They've shifted away from (but not completely 100% abandoned) the hub-&-spoke model for a more even distribution of direct smaller flights between smaller airports. This sharply reduced the number of flights that a giant like the A380 was appropriate for. As a result, although the plane itself is an engineering success, the concept & project that produced it is a financial failure for Airbus. Production stopped in 2021 with only 254 built. Production continues on the smaller A350 with about 600 so far and its Boeing counterpart the 787 with about 1100 so far, both with hundreds more still on order, both of which are appropriate for a much larger assortment of different routes.
And that's what happened to a plane with not just a single applicable route but merely 53, because what it needed to survive was not dozens but hundreds. (Over a thousand routes use A350, and twice that many use 787.)
It's the biggest passenger jet: the one that's two stories tall all the way from front to back, not just in front like the older 747. The project to create it seemed to make sense at the time because long flights were scheduled by the spoke-&-hub model: collect all the passengers you can at one place and send as many of them at once as possible on the biggest possible plane. A large jet was required not only for the number of people but also for the long range.
But while the A380 was finishing development & starting early production & collecting orders for it from the airlines, the following generation of passenger jets like the 787 and A350 was also in the works. Made largely of composites instead of metals, they're significantly lighter for their size, thus more fuel-efficient, thus longer-ranged for their size, which meant a smaller plane could still do longer flights, which caused a shift in how long flights were scheduled. They've shifted away from (but not completely 100% abandoned) the hub-&-spoke model for a more even distribution of direct smaller flights between smaller airports. This sharply reduced the number of flights that a giant like the A380 was appropriate for. As a result, although the plane itself is an engineering success, the concept & project that produced it is a financial failure for Airbus. Production stopped in 2021 with only 254 built. Production continues on the smaller A350 with about 600 so far and its Boeing counterpart the 787 with about 1100 so far, both with hundreds more still on order, both of which are appropriate for a much larger assortment of different routes.
And that's what happened to a plane with not just a single applicable route but merely 53, because what it needed to survive was not dozens but hundreds. (Over a thousand routes use A350, and twice that many use 787.)
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