Argument is the externalities of carbon emissions have (negative) value, so a tax would bring those two things in line and encourage that only people who really need to fly do so.
If we charged $100-200 per ton of CO2, which is supposedly more than recapture would cost, that would only be about $1-2 per 50 miles. From the numbers being quoted here, it sounds like that would do very little to bring prices in line.
Either charge for all the carbon, or start harshly dropping the quotas.
I'm 'commenting too fast' to reply, but show me any of your examples in flight please.
500+ miles range. Building it right now. Plus Wright Electric, Bye Aerospace’s eflyer 800, etc.
Why do people so easily and confidently claim something can’t be done?
EDIT: and YES this is true. Battery specific energy is 200-400Wh/kg. That is PER kilogram. And larger planes are NOT less efficient per passenger than smaller ones. Small and large jets or propeller aircraft have a out the same life to drag ratio. If anything, larger tend to be better due to Reynolds Number effects.
There is maybe not one misconception about electric flight that I’ve seen repeated most often by Internet skeptics than this false idea that “bigger is disproportionately harder for electric planes.” It is simply. Not. True.
Look at the specific energy of jet fuel compared to batteries on this page: https://en.wikipedia.org/wiki/Energy_density
And no, don’t switch topic to range. That is a known constraint. Focus on SCALE. It is scale-independent to zeroth and first order at least!
This comes up every single time, and I feel like I’m taking crazy pills. :D
I am only a lowly software engineer so I don't know that much about planes or batteries. If I'm wrong then I'm wrong, and I hope I am.
But both of these are second order effects. And they mostly cancel out.
I am a materials scientist with a background in physics and I have also developed electric motors for electric aircraft. I have a good understanding of how the systems scale. You were mixing up the exponential range equation with simple size scaling. if it were true, then large aircraft of any type would be much less efficient than smaller aircraft of the same type. This is most certainly not true. In fact, usually the efficiency increases with scale. A 777x is much more efficient than a Gulfstream or some smaller regional jet per passenger mile.
If you double the weight of "the plane", that includes the batteries and motors.
If you start with doubling just the structure, then you might need to add 50% more batteries, not "twice as much". Then to lift those batteries it takes another 30%. Then you add bigger motors which adds even more weight, etc. etc. By the time you finish, the total weight will be about 2x your initial weight.
There is difficulty in scaling planes, but it's not because more mass requires more fuel. A fixed percentage devoted to fuel works fine, if you're assuming the same route for both planes.
Also, the airplane manufacturer business is ripe for disruption. You have an extremely bureaucratic and dysfunctional Airbus battling an even more dysfunctional and mismanaged Boeing. Surely there is room for a hydrogen startup to come in and devastate these two monopolies. Often I wonder how much the world would be different if we had 100 Elon Musks instead of just one.
As far as disruption, the issue is that there is no opportunity for competition. Countries are rabidly protectionist about their airplane industries, and any newcomer even with a completely superior product (See: Bombardier C-Series) will get absolutely destroyed by sanctions, tarrifs, or even secondary export controls (Gripen, Avro Arrow, etc...). You cannot succeed unless you are American, and even in America Boeing has massive undue influence.
Also the SAFs are looking pretty good. Point is, I don't think we should decide that planes are bad of all sudden, that doesn't seem like a very wise thing to do given the massive benefits of air travel. Rail is also great but rail shines for cargo and large volume traffic between urban cores
Throw in all the current eVtol start-ups and I don't see that much difference between the US and Europe.
I do agree that an electric/hydrogen jet is the kind of disruptive tech that could upend the market, but due to the long lead times, stringent certification and very political markets it's an arguably even tougher market than cars or rockets.
The claim that larger size in particular is a problem is false. Efficiency, including structural efficiency, actually tends to improve with scale beyond 100 seats.
> We sadly cannot make large battery powered airplanes with a usable range and speed unless we get up the gravimetric density.
This, again, is often repeated but false from a technical standpoint. 9 seater and 100 seater, for the same range, scale just fine between them and with clean sheet design we can use existing 200-400Wh/kg gravimetric density. Scale. Isn’t. The. Problem.
Large planes tend to be used on longer routes, in fact. Smaller planes are needed for their granularity on short routes.
The reason we see 9 passenger electric planes first is pretty obvious: cheaper and faster to develop small planes than large. Big aircraft manufacturers are much more risk averse as well. A large new clean sheet aircraft can take literally decades to develop. Not true for small aircraft. And again, generally the granularity of small planes means they’re more useful than large planes for shorter routes. This all reinforces the false notion that there is some technical reason why we “CAN’T” make large electric planes when there really, truly isn’t.
For instance, consider the Learjet 70/75. 8 passenger, dry mass of 6 some tonnes. Over 700kg per passenger. 14 passenger Falcon jets do better at about 500kg per passenger. 737 Max8 with 210 passengers gets about 215kg/passenger. So if anything, overall structural efficiency improves with scale! At least up to ~200 passengers. (Caveat is that these are typically private jets with a different seating arrangement... but so are the example electric aircraft. So they'd similarly benefit from scale up to larger seat capacity.)
The 737 Max8 has a massive advantage over the LearJet of massively lower surface area per passenger. It's not comparable at all. In an electric aircraft where the bottleneck is the battery as far as weight goes this is not a relevant comparison.
You have two regimes. One where the dominant factor is structural efficiency is mass. One where the dominant factor is area. You cannot compare the two. It is simply a completely deficient comparison.
Do you want an actually correct comparison? Keep the 737 Max 8. Now compare it to a PAC P-750XL, dry mass of 1.6 tons over 9 passengers. That's 181kg per passenger, less than the Max-8.
Now that's the aluminium version. The Max-8 uses a massive amount of composites - the composite version of the P-750XL is expected to be significantly lighter still.
It's absolutely not a fiction. A 787 Max-8 consumes 18 liters (!!!) of kerosene at >60% thermal efficiency, per passenger, per hour. That's 175kW of useful energy consumption per passenger. To fly one hour at 400Wh/kg assuming 100% energy efficiency you need to add 437 kg of batteries PER PASSENGER.
The real key to making electric aircraft feasible is to increase the efficiency dramatically. (Also, jets don’t have >60% thermal efficiency if you use the HHV of the fuel.) just a swap out of the fuel for battery gets you to a few hundred miles of range at best. Enough maybe to compete with the California HSR, but not much more.
It’s like how a Tesla Model S is not a battery swapped sedan. It’s a custom clean sheet design. That’s why you can get 400 miles of range in it instead of just 150 miles.
Likewise, you need a clean sheet battery electric aircraft design. That’s why the Eviation Alice is able to get significant range. Incorporate 777x-like folding wingtips and possible truss braced high aspect ratio wings, natural laminar flow like sailplanes, you could increase L/D to about double current aircraft. Things like that allow 1000 mile range. Substantial enough for short haul trips, which are about half of all passenger miles.
A Tesla Model S doesn't have any more weight efficiency than a battery swapped sedan. It's just as heavy as a battery swapped sedan, it's just built to handle the weight better.
The main factor in the Alice having a lower L/D is flying at less than half the airspeed and thus drastically reducing parasitic drag. There are no easy gimmes. You're going to have to sacrifice range and speed.
So far electric airplanes are somewhat worse than piston aircraft. They will never rival jets until we drastically increase energy density.
The turbine efficiency of modern turbojets is actually around 60% and there are turbines with more than that. The overall efficiency is actually lower because of propulsive inefficiency, but electric aircraft have that exact same problem.
> All-electric designs have been demonstrated for small air vehicles. However, such prototypes have not been scaled up to more than ten passengers due to the specific energy (E*) limitations of current battery technology. [...] A significant proportion of the energy expenditure would be used to transport the mass of the batteries; this mass would not decrease during a flight as would that of conventional fuel.
Are these sources wrong, or too simplistic in their analysis, or am I misinterpreting what they're saying?
[1]: https://en.wikipedia.org/wiki/Electric_aircraft#Batteries
[2]: Structural Power Performance Targets for Future Electric Aircraft - https://www.mdpi.com/1996-1073/14/19/6006
I have no idea why people keep thinking that batteries would work worse for 100 seats rather than nine seats. The technology is independent of scale except in the trivial sense that you need proportionally more battery and cost since you’re 10 times larger. True the range is less, but we have built jets that can go 40,000km. We don’t need that much range to do short flights, comparable in length to the California HSR project. Existing battery technology is more than sufficient for that.
Even after carbon tax, electric aircraft is still a technology in its infancy, compared to electric trains. Are you proposing that the government should spend billions of $$$ on an experimental technology when a proven alternative exists?
We can? Present tense, certified, operational aircraft in service? Or do you mean that people are working on building them now and hope to have them in service at some point in the future?
And CO2 is good for plant growth, right?
https://e360.yale.edu/features/the-strange-case-of-the-liana...
It's entirely possible the externalities of having people (and goods) unproductive for longer periods of time is worse than simply getting them where they need to be.
Am I misunderstanding your position?
1) All people share one atmosphere 2) Well-reviewed science shows that individual decisions like taking a flight make the atmosphere less hospitable for all.
That type of problem is literally the reason the term externality was coined.
Markets are not efficient at considering externalities at all.
Maybe we could train more experts to avoid them needing to fly all over; buy and serve local.
A lot of efficiency options are left off the table sticking with the status quo.
Air travel is blamed for up to 3.5% of climate impacts; it's not an insignificant contributor...
No, the opposite of "effectively". That's like saying you can't plan an effective route because CSP, or you can't use SAT solvers to design things.
Markets aren't perfect, and that's all that proof manages to show. They could still be 99.99% accurate based on that logic. It's a cute thought experiment, not something practical.