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As others have noted, electric flights require a major breakthrough in the battery technology. Here are energy density numbers for gasoline, jet fuel, and lithi

As others have noted, electric flights require a major breakthrough in the battery technology. Here are energy density numbers for gasoline, jet fuel, and lithium-ion batteries: Gas and jet fuel specific energy density ~= 45 MJ/kg; Lithium-ion specific energy density < 1 MJ/kg Even worse, a jet engine is much better at generating power. A modern high-bypass turbofan engine can generate 10 kW/kg whereas an electric motor is around 1 kW/kg. In short we need much better batteries and much lighter motors. This is not going to happen anytime soon. A more reasonable option is to create carbon-neutral fuels (biofuels, carbon sequestration, etc.).

gameswithgo 7y ago
Carbon sequestration and biofuels that are actually carbon neutral may be similarly implausible.
- guntars 7y ago
  What’s the reasoning behind your statement? I think both are already being done, the economics are just not there yet. Digging up free energy from the ground is just too cheap.
  - gameswithgo 7y ago
    The scale of co2 that would need to be sequestered is massive, I don't think anyone has a vaguely viable plan of how that would be done. Most attempts at biofuel are not even net positive on energy. if we did get there then the question is how much forest do we have to clear to grow biofuel AND eat, and what net effect does that have on co2. Hard problems all around.
    - JaRail 7y ago
      > if we did get there then the question is how much forest do we have to clear to grow biofuel AND eat Convert the beef/dairy farms. :D
- ars 7y ago
  It's not necessary to do that. We could reserve use of hydrocarbon fuel to airplanes, and it would be fine. It's not necessary to go to zero.
- adrianN 7y ago
  Making Methanol from electricity is not too hard. You can also make a kind of diesel with electricity as energy source. These processes have fairly terrible efficiency of course, compared to batteries, but are useful for applications where you absolutely need high energy density fuels.
stcredzero 7y ago
Electric motors can enable something which jet fuel and gasoline cannot: beamed power. There could be a new class of vehicles which only have a small onboard power store for emergency purposes. The weight savings would be about 20%.
- 0xffff2 7y ago
  Is this something that someone has actually fleshed out with real numbers? The infrastructure and efficiency problems involved seem at first glance to be extremely challenging.
  - stcredzero 7y ago
    I've seen numbers for microwave power transmission efficiency ranging from 75% to 84%. http://large.stanford.edu/courses/2011/ph240/shu2/ http://large.stanford.edu/courses/2011/ph240/shu2/
- newsoul2019 7y ago
  That is a fascinating idea, a plane being "handed off" from one beaming tower to the next, like a cell phone
  - anticensor 7y ago
    It would be very interesting to see airplanes powered by Tesla towers.
  - salawat 7y ago
    The ATC systems required would be prohibitive, rest in peace any birds that fly into\through the beam, maintenance of the towers, and emitter tracking would all be huge problems. Also, where/how is all that electricity getting generated/transmitted to the emitter, and what complications does that introduce? What about environmental conditions? How does that effect the efficiency? Does a storm front blowing through suddenly make regular ICE planes a better idea again? Oh, yeah, don't forget the security aspect. Those emitters are more than 'interesting' enough to be weaponized in the wrong hands. I mean, beamed power sounds cool and all, but you actually have to take into account a heck of a lot of variables first.
murkt 7y ago
1 kW/kg for electric motors looks a bit on the low side for me. Tesla Model S with the highest power rating has 581 kW, and I don't think that its motors weigh in for more than half a ton combined. I've found a statement that some version of their motors with 270 kW weigh 31 kg (70 pounds). Which amounts to 8.7 kW/kg and isn't far off from your 10 kW/kg estimate for modern turbofan engines. Also it's probably not the latest number for an electric motors, and newest motors have better power-to-weight ratio.
- namirez 7y ago
  I stand corrected. I also found Emrax 268 which has a power to weight ratio of 10 kW/kg. But these are good only for small aircraft. It's much harder to maintain this power-to-weight ratio for larger motors. Emrax 268 is only 20kg, but a single engine of 777 weighs 8200kg. The ballpark for large motors at powerplants is currenly around 1 kW/kg [1]. But who knows; there might be a breakthrough in motors too. [1] https://newatlas.com/siemens-world-record-electric-motor-aircraft/37048/ https://newatlas.com/siemens-world-record-electric-motor-air...
  - namibj 7y ago
    You can stack Emrax motors on a shaft. Also, the technology scales up in diameter. Not that you really want _that_ large props necessarily, if you can get away with smaller ones. This combination should be enough, I guess. Edit: I think I met the guy behind these. But I'm not sure, for lack of having asked for the name of the company. I certainly have seen a prototype that could have been the 348.
    - namirez 7y ago
      Generally you should prefer few large propellers over many small ones due to aerodynamic efficiency. Stacking up motors axially sounds like a very good idea though.
russdill 7y ago
There are a lot of things that electric planes will not be able to do unless there are drastic changes in battery technology. They can still fill a niche for short flights with very little cargo/person capacity.
Robotbeat 7y ago
This is constantly repeated, but it's not true. I work in the field of electric motors for electric aircraft, and the amount of nonsense constantly repeated on the Internet about how electric flight cannot be done without a breakthrough is breathtaking. Electric motors can achieve FAR greater than 1kW/kg. Here's one used sometimes on electric aircraft capable of 10kW/kg, same as a jet engine: https://emrax.com/products/emrax-268/ https://emrax.com/products/emrax-268/ The specific energy of lithium-ion is poor, but jet fuel's USEFUL specific energy is more like 10-15MJ/kg due to needing to be burned. There's also some efficiency improvement possible, i.e. from airliner lift-to-drag of 16-20 (and like 8-10 for a Cessna) to a more glider-like L/D of 25-35 (the best gliders can do 70). Additionally, improved modern materials means you can just have most of your take-off mass be battery, compensating for the poorer specific energy (general aviation craft are only like 10-15% fuel, but 777s can be almost 50% fuel, and electric aircraft could be 60% battery). So if you combine efficiency improvements and high battery mass, sure, electric planes still may have a tenth the range of jet liners. But jets like the 777 have a range of 10,000 to 15,000km. A tenth of that is still over 1000km! Quite doable for a very large portion of domestic flights. Since domestic flights often involve multiple hops anyway (due to hub and spoke model), you could fly basically anywhere up and down the eastern seaboard in just the typical two hops. And faster than high speed rail. But of course, there are already better lithium batteries that are available in small quantities, like lithium-sulfur, metal electrode lithium batteries, solid-state batteries, or batteries that combine those various features. ~1.5MJ/kg cells are already demonstrated and you can buy them on an evaluation basis. ~2MJ/kg is feasible as well, enabling single-hop flights all over the eastern seaboard and enabling multi-hop transatlantic flights (as low as 1200km is the minimum range needed for transatlantic flights if you really wanted to do it).
- Robotbeat 7y ago
  Transatlantic electric flights wouldn't be too hard. 1200km minimum hops could be done with next-gen battery tech and plenty of margin. ...Transpacific (i.e. reaching Asia from North America) wouldn't be too hard as you can hop along Alaska and the Aleutians, but reaching Hawaii is a major challenge. To get to Hawaii from LA takes 3800km (at the edge of what you can do with L/D of ~40-50 and 500Wh/kg batteries). Taking the long way from the Aleutians to Midway cuts that down to 2600km for the minimum hop distance, which is perhaps feasible with a sailplane-like L/D and the next-generation lithium-metal and/or lithium-sulfur batteries (that are already demonstrated at the lab scale). Lithium-air is the breakthrough in battery tech people want, which will enable much easier transpacific flights at transonic speeds (rather than the ~Mach 0.50 speeds you'd be limited to for the most extreme high performance airfoils), like what people are used to already. Lithium-air would also potentially enable long distance supersonic electric passenger aircraft.
trhway 7y ago
>Lithium-ion specific energy density < 1 MJ/kg i think battery swapping is much more realistic for planes than for cars and that would allow to use non-rechargeable or factory rechargeable batteries like the metal-air ones (my favorite is Al-air) which is order of magnitude better than rechargeable Li-ion, and that really gets us close to the gas/jet capabilities given the low thermodynamic efficiency (or extremely high price and complexity) of the combustion based engines. >In short we need much better batteries and much lighter motors. This is not going to happen anytime soon. this is exactly what is happening right now in front of our eyes :)
sunstone 7y ago
Your analysis would be more compelling if you added some $$$ here and there. The savings in maintenance and fuel are really what's driving this technology.
cheerlessbog 7y ago
Also during the trip, your fuel tank gets lighter but your battery does not.
Shivetya 7y ago
One interesting idea but not likely workable, have an electric launch platform that simply has the actual passenger plane as its cargo and once sufficient speed is reached it drops off to circle back on its own for another go. could work with either propulsion method of the plane being lifted.
audunw 7y ago
I think the biggest point that you and others that bring this up is missing, is not just how electric designs gives you higher efficiency and close the gap (as others have mentioned). The main thing you're missing is that modern jet planes have absolutely ridiculous range, and a huge number of flights use only a fraction of that range. Electric planes don't need to match modern jet planes to be viable. They just have to compete on cost at a range that covers a significant amount of routes. And electric planes have a potential for huge cost advantages. A related aspect is that electric planes are much more quiet. Being cheaper to operate and more quiet means you can fly smaller planes from smaller local airports to other small airports. You can create an entirely new market. Electric planes are not going to take over transatlantic flights any time soon. But they don't have to in order to have a huge impact. I do agree that carbon neutral fuels are important for long-haul flights for the coming decades. With batteries for land transport and short-range ships/ferries and planes and hydrogen for heavy trucks and ships, we might be able to sustainably make enough carbon-neutral fuels for long-haul planes.
- rootusrootus 7y ago
  Even medium range flying is tough to accomplish with near-term electric technology. A flight across the United States would involve 10 hours of flight time, assuming you did it in a single leg, which of course you cannot. Three stops, so probably 15+ hours total. People do seem willing to take one-stop jet rides across the U.S. now, but the gold standard is about 5.5 hours for a non-stop flight.
  - Misdicorl 7y ago
    Why would a transcontinental flight be the relevant comparison here? The real disruptive/comparitive market is the DC <-> NYC <-> Boston corridor. I'm sure there are similarly busy and small corridors in the EU.
    - adrianN 7y ago
      London to the major western European cities is 1-3 hours and quite busy.
jillesvangurp 7y ago
By this logic, the several products in that are currently in the process of being certified are physically impossible. The more reasonable explanation is obviously that your numbers are in fact wrong (or at least your interpretation of them) and that within two years from now, several companies will be shipping the battery powered planes with exactly the ranges, weights, and specs they are currently advertising and that they are working to get certified. E.g. the Eviation Alice carries ~8000 pounds of battery and provides its nine passengers a range of 650 miles. That's undeniably a lot of battery and the energy density is indeed not great. However, it doesn't prevent it from flying. Transporting 9 people over that kind of distance for the price of charging that battery is a very disruptive cost improvement over the state of the art that involves burning hundreds of dollars worth of fuel. It's the cost of fuel that's going to kill jet and piston engines. It doesn't matter how energy efficient they are when the cost difference with battery electric in the first generation is already two orders of magnitude. And while we have pretty much peaked in terms of fuel cost efficiency (order of magnitude improvements seem unlikely), that is definitely not the case for battery electrical. Cheaper and lighter batteries are basically happening. 2-3x seems to be likely within a decade or so. More may come after that. Electricity prices are also not a constant and seem to be dropping rapidly. So, if it's economical now, it's going to be far more economical in a few more decades. I think another two orders of magnitude cost improvements are likely. For the same reason, hybrid planes are not likely to be more than a stop gap solution. They'd still be burning a lot of fuel which would raise the cost relative to small battery powered planes. I do believe that they will have an important role for longer distances; for the simple reason they'd definitely provide better energy efficiency. Ultimately, synthetic fuels generated using dirt cheap electricity may help bring prices down here but this will take a while and is not likely to be a very efficient way of using electricity (compared to storing it in a battery and using it directly). As soon as battery powered planes are range competitive, which for short haul is happening right now, orders of magnitude cost improvement means game over for traditional planes. Here's some back of the envelope math for you for the Eviation Alice vs the A319. You can buy a state of the art A319 for about 110M $. That same amount of money buys you about 30 Eviations (at the announced price of 3M $). You only need about 18 to match the number of passengers of an A319 (160 passengers). The A319 is very popular on short haul flights that are well within the range of an Eviation Alice. The difference is that one burns thousands of dollars worth of fuel and the other has an operational cost measured in the lower tens of dollars. There are of course many other advantages replacing big A319s with small battery powered planes. E.g. they make less noise and they can fly to much smaller airfields. The point here is that we don't need an electrical version of the A319. Big planes are only interesting because of the fuel economy. Small electrical planes don't have that problem. The biggest bottleneck is actually not going to be batteries, engine efficiency, maintenance, or electricity cost but pilot wages and production volume of these new planes: we'll need a lot of them and with the cost of electricity already being low, pilot cost is going to be the dominant thing. As cost drops, ranges improve, and production volumes go up, the business case for operating an A319 will rapidly disappear. The Eviation arguably already challenges that. Autonomous flight, which is another thing Eviation is working on, will accelerate this. IMHO most A319s shipping today will be retired years or decades before their normal projected end of life because of their operational cost vs the cost of products like this. This is why Eviation has a full order portfolio. They'll be selling these things as fast as they can build them. Others will follow. This is only the first generation of their product. I expect great things from them and their competitors in the years to come.

gameswithgo 7y ago

Carbon sequestration and biofuels that are actually carbon neutral may be similarly implausible.

guntars 7y ago
What’s the reasoning behind your statement? I think both are already being done, the economics are just not there yet. Digging up free energy from the ground is just too cheap.
- gameswithgo 7y ago
  The scale of co2 that would need to be sequestered is massive, I don't think anyone has a vaguely viable plan of how that would be done. Most attempts at biofuel are not even net positive on energy. if we did get there then the question is how much forest do we have to clear to grow biofuel AND eat, and what net effect does that have on co2. Hard problems all around.
  - JaRail 7y ago
    > if we did get there then the question is how much forest do we have to clear to grow biofuel AND eat Convert the beef/dairy farms. :D
ars 7y ago
It's not necessary to do that. We could reserve use of hydrocarbon fuel to airplanes, and it would be fine. It's not necessary to go to zero.
adrianN 7y ago
Making Methanol from electricity is not too hard. You can also make a kind of diesel with electricity as energy source. These processes have fairly terrible efficiency of course, compared to batteries, but are useful for applications where you absolutely need high energy density fuels.

stcredzero 7y ago

Electric motors can enable something which jet fuel and gasoline cannot: beamed power. There could be a new class of vehicles which only have a small onboard power store for emergency purposes. The weight savings would be about 20%.

0xffff2 7y ago
Is this something that someone has actually fleshed out with real numbers? The infrastructure and efficiency problems involved seem at first glance to be extremely challenging.
- stcredzero 7y ago
  I've seen numbers for microwave power transmission efficiency ranging from 75% to 84%. http://large.stanford.edu/courses/2011/ph240/shu2/ http://large.stanford.edu/courses/2011/ph240/shu2/
newsoul2019 7y ago
That is a fascinating idea, a plane being "handed off" from one beaming tower to the next, like a cell phone
- anticensor 7y ago
  It would be very interesting to see airplanes powered by Tesla towers.
- salawat 7y ago
  The ATC systems required would be prohibitive, rest in peace any birds that fly into\through the beam, maintenance of the towers, and emitter tracking would all be huge problems. Also, where/how is all that electricity getting generated/transmitted to the emitter, and what complications does that introduce? What about environmental conditions? How does that effect the efficiency? Does a storm front blowing through suddenly make regular ICE planes a better idea again? Oh, yeah, don't forget the security aspect. Those emitters are more than 'interesting' enough to be weaponized in the wrong hands. I mean, beamed power sounds cool and all, but you actually have to take into account a heck of a lot of variables first.

murkt 7y ago

1 kW/kg for electric motors looks a bit on the low side for me. Tesla Model S with the highest power rating has 581 kW, and I don't think that its motors weigh in for more than half a ton combined. I've found a statement that some version of their motors with 270 kW weigh 31 kg (70 pounds). Which amounts to 8.7 kW/kg and isn't far off from your 10 kW/kg estimate for modern turbofan engines. Also it's probably not the latest number for an electric motors, and newest motors have better power-to-weight ratio.

namirez 7y ago
I stand corrected. I also found Emrax 268 which has a power to weight ratio of 10 kW/kg. But these are good only for small aircraft. It's much harder to maintain this power-to-weight ratio for larger motors. Emrax 268 is only 20kg, but a single engine of 777 weighs 8200kg. The ballpark for large motors at powerplants is currenly around 1 kW/kg [1]. But who knows; there might be a breakthrough in motors too. [1] https://newatlas.com/siemens-world-record-electric-motor-aircraft/37048/ https://newatlas.com/siemens-world-record-electric-motor-air...
- namibj 7y ago
  You can stack Emrax motors on a shaft. Also, the technology scales up in diameter. Not that you really want _that_ large props necessarily, if you can get away with smaller ones. This combination should be enough, I guess. Edit: I think I met the guy behind these. But I'm not sure, for lack of having asked for the name of the company. I certainly have seen a prototype that could have been the 348.
  - namirez 7y ago
    Generally you should prefer few large propellers over many small ones due to aerodynamic efficiency. Stacking up motors axially sounds like a very good idea though.

russdill 7y ago

There are a lot of things that electric planes will not be able to do unless there are drastic changes in battery technology. They can still fill a niche for short flights with very little cargo/person capacity.

Robotbeat 7y ago

This is constantly repeated, but it's not true. I work in the field of electric motors for electric aircraft, and the amount of nonsense constantly repeated on the Internet about how electric flight cannot be done without a breakthrough is breathtaking. Electric motors can achieve FAR greater than 1kW/kg. Here's one used sometimes on electric aircraft capable of 10kW/kg, same as a jet engine: https://emrax.com/products/emrax-268/ https://emrax.com/products/emrax-268/ The specific energy of lithium-ion is poor, but jet fuel's USEFUL specific energy is more like 10-15MJ/kg due to needing to be burned. There's also some efficiency improvement possible, i.e. from airliner lift-to-drag of 16-20 (and like 8-10 for a Cessna) to a more glider-like L/D of 25-35 (the best gliders can do 70). Additionally, improved modern materials means you can just have most of your take-off mass be battery, compensating for the poorer specific energy (general aviation craft are only like 10-15% fuel, but 777s can be almost 50% fuel, and electric aircraft could be 60% battery). So if you combine efficiency improvements and high battery mass, sure, electric planes still may have a tenth the range of jet liners. But jets like the 777 have a range of 10,000 to 15,000km. A tenth of that is still over 1000km! Quite doable for a very large portion of domestic flights. Since domestic flights often involve multiple hops anyway (due to hub and spoke model), you could fly basically anywhere up and down the eastern seaboard in just the typical two hops. And faster than high speed rail. But of course, there are already better lithium batteries that are available in small quantities, like lithium-sulfur, metal electrode lithium batteries, solid-state batteries, or batteries that combine those various features. ~1.5MJ/kg cells are already demonstrated and you can buy them on an evaluation basis. ~2MJ/kg is feasible as well, enabling single-hop flights all over the eastern seaboard and enabling multi-hop transatlantic flights (as low as 1200km is the minimum range needed for transatlantic flights if you really wanted to do it).

Robotbeat 7y ago
Transatlantic electric flights wouldn't be too hard. 1200km minimum hops could be done with next-gen battery tech and plenty of margin. ...Transpacific (i.e. reaching Asia from North America) wouldn't be too hard as you can hop along Alaska and the Aleutians, but reaching Hawaii is a major challenge. To get to Hawaii from LA takes 3800km (at the edge of what you can do with L/D of ~40-50 and 500Wh/kg batteries). Taking the long way from the Aleutians to Midway cuts that down to 2600km for the minimum hop distance, which is perhaps feasible with a sailplane-like L/D and the next-generation lithium-metal and/or lithium-sulfur batteries (that are already demonstrated at the lab scale). Lithium-air is the breakthrough in battery tech people want, which will enable much easier transpacific flights at transonic speeds (rather than the ~Mach 0.50 speeds you'd be limited to for the most extreme high performance airfoils), like what people are used to already. Lithium-air would also potentially enable long distance supersonic electric passenger aircraft.

trhway 7y ago

>Lithium-ion specific energy density < 1 MJ/kg i think battery swapping is much more realistic for planes than for cars and that would allow to use non-rechargeable or factory rechargeable batteries like the metal-air ones (my favorite is Al-air) which is order of magnitude better than rechargeable Li-ion, and that really gets us close to the gas/jet capabilities given the low thermodynamic efficiency (or extremely high price and complexity) of the combustion based engines. >In short we need much better batteries and much lighter motors. This is not going to happen anytime soon. this is exactly what is happening right now in front of our eyes :)

sunstone 7y ago

Your analysis would be more compelling if you added some $$$ here and there. The savings in maintenance and fuel are really what's driving this technology.

cheerlessbog 7y ago

Also during the trip, your fuel tank gets lighter but your battery does not.

Shivetya 7y ago

One interesting idea but not likely workable, have an electric launch platform that simply has the actual passenger plane as its cargo and once sufficient speed is reached it drops off to circle back on its own for another go. could work with either propulsion method of the plane being lifted.

audunw 7y ago

I think the biggest point that you and others that bring this up is missing, is not just how electric designs gives you higher efficiency and close the gap (as others have mentioned). The main thing you're missing is that modern jet planes have absolutely ridiculous range, and a huge number of flights use only a fraction of that range. Electric planes don't need to match modern jet planes to be viable. They just have to compete on cost at a range that covers a significant amount of routes. And electric planes have a potential for huge cost advantages. A related aspect is that electric planes are much more quiet. Being cheaper to operate and more quiet means you can fly smaller planes from smaller local airports to other small airports. You can create an entirely new market. Electric planes are not going to take over transatlantic flights any time soon. But they don't have to in order to have a huge impact. I do agree that carbon neutral fuels are important for long-haul flights for the coming decades. With batteries for land transport and short-range ships/ferries and planes and hydrogen for heavy trucks and ships, we might be able to sustainably make enough carbon-neutral fuels for long-haul planes.

rootusrootus 7y ago
Even medium range flying is tough to accomplish with near-term electric technology. A flight across the United States would involve 10 hours of flight time, assuming you did it in a single leg, which of course you cannot. Three stops, so probably 15+ hours total. People do seem willing to take one-stop jet rides across the U.S. now, but the gold standard is about 5.5 hours for a non-stop flight.
- Misdicorl 7y ago
  Why would a transcontinental flight be the relevant comparison here? The real disruptive/comparitive market is the DC <-> NYC <-> Boston corridor. I'm sure there are similarly busy and small corridors in the EU.
  - adrianN 7y ago
    London to the major western European cities is 1-3 hours and quite busy.

jillesvangurp 7y ago

By this logic, the several products in that are currently in the process of being certified are physically impossible. The more reasonable explanation is obviously that your numbers are in fact wrong (or at least your interpretation of them) and that within two years from now, several companies will be shipping the battery powered planes with exactly the ranges, weights, and specs they are currently advertising and that they are working to get certified. E.g. the Eviation Alice carries ~8000 pounds of battery and provides its nine passengers a range of 650 miles. That's undeniably a lot of battery and the energy density is indeed not great. However, it doesn't prevent it from flying. Transporting 9 people over that kind of distance for the price of charging that battery is a very disruptive cost improvement over the state of the art that involves burning hundreds of dollars worth of fuel. It's the cost of fuel that's going to kill jet and piston engines. It doesn't matter how energy efficient they are when the cost difference with battery electric in the first generation is already two orders of magnitude. And while we have pretty much peaked in terms of fuel cost efficiency (order of magnitude improvements seem unlikely), that is definitely not the case for battery electrical. Cheaper and lighter batteries are basically happening. 2-3x seems to be likely within a decade or so. More may come after that. Electricity prices are also not a constant and seem to be dropping rapidly. So, if it's economical now, it's going to be far more economical in a few more decades. I think another two orders of magnitude cost improvements are likely. For the same reason, hybrid planes are not likely to be more than a stop gap solution. They'd still be burning a lot of fuel which would raise the cost relative to small battery powered planes. I do believe that they will have an important role for longer distances; for the simple reason they'd definitely provide better energy efficiency. Ultimately, synthetic fuels generated using dirt cheap electricity may help bring prices down here but this will take a while and is not likely to be a very efficient way of using electricity (compared to storing it in a battery and using it directly). As soon as battery powered planes are range competitive, which for short haul is happening right now, orders of magnitude cost improvement means game over for traditional planes. Here's some back of the envelope math for you for the Eviation Alice vs the A319. You can buy a state of the art A319 for about 110M $. That same amount of money buys you about 30 Eviations (at the announced price of 3M $). You only need about 18 to match the number of passengers of an A319 (160 passengers). The A319 is very popular on short haul flights that are well within the range of an Eviation Alice. The difference is that one burns thousands of dollars worth of fuel and the other has an operational cost measured in the lower tens of dollars. There are of course many other advantages replacing big A319s with small battery powered planes. E.g. they make less noise and they can fly to much smaller airfields. The point here is that we don't need an electrical version of the A319. Big planes are only interesting because of the fuel economy. Small electrical planes don't have that problem. The biggest bottleneck is actually not going to be batteries, engine efficiency, maintenance, or electricity cost but pilot wages and production volume of these new planes: we'll need a lot of them and with the cost of electricity already being low, pilot cost is going to be the dominant thing. As cost drops, ranges improve, and production volumes go up, the business case for operating an A319 will rapidly disappear. The Eviation arguably already challenges that. Autonomous flight, which is another thing Eviation is working on, will accelerate this. IMHO most A319s shipping today will be retired years or decades before their normal projected end of life because of their operational cost vs the cost of products like this. This is why Eviation has a full order portfolio. They'll be selling these things as fast as they can build them. Others will follow. This is only the first generation of their product. I expect great things from them and their competitors in the years to come.