What happens to this 300nmi range when the plane gets stuck in a hold or has to divert to an alternate? Is this 300 miles considering that possibility or can it literally only fly for 300 miles; if it’s the latter, that is basically useless for anything more than 20-30 mins of flying.

I have nothing against green stuff but it’s all PR until they actually make and fly an electric plane that can do 45 min turns and can fly as far as a normal plane. That’s a long way away.

frmrCapCadet wrote:

A 300 mile range would connect most of the small towns in 'flyover' country to a major/regional airport. I see 20-50 passenger, one pilot electric planes changing the economics of living in more isolated areas. Likely they would operate like our Washington State ferries - if a medical passenger needs immediate service the hell with schedule. And no one complains. They also do most of the marine emergencies in the central Puget Sound. Even stop for quicky burial services (cremains only!). Travel, normal medical, emergency ambulance, package cargo, tourism, AirBnB all fit well as a package.

I agree, and that is exactly the thinking at Harbour Air right next door in B.C. I'm sure you followed that thread as well, for those who missed it,
viewtopic.php?t=1418841

Dahlgardo wrote:

Nothing more than free publicity and spin to boost "green image".

Big electric powered planes are decades away, and battery technology needs more than a quantum leap to be a credible alternative both in terms of energy density and reliability.
And good luck getting them certified with the firehazards of the current battery technology.

How many kilos of batteries did that electric DHC-2 need to drag around to support a 750hp engine.
Can't recall, but it was a lot, and the range was not very impressive.

Electric airplanes will, in the short term future, run on Hopium and Unobtainium.

airnorth wrote:

frmrCapCadet wrote:

A 300 mile range would connect most of the small towns in 'flyover' country to a major/regional airport. I see 20-50 passenger, one pilot electric planes changing the economics of living in more isolated areas. Likely they would operate like our Washington State ferries - if a medical passenger needs immediate service the hell with schedule. And no one complains. They also do most of the marine emergencies in the central Puget Sound. Even stop for quicky burial services (cremains only!). Travel, normal medical, emergency ambulance, package cargo, tourism, AirBnB all fit well as a package.

I agree, and that is exactly the thinking at Harbour Air right next door in B.C. I'm sure you followed that thread as well, for those who missed it,
viewtopic.php?t=1418841

I did share this https://www.youtube.com/watch?v=kdLa0PdCB5w

can anybody tell me what does B.C. in the above stand for ?

767333ER wrote:

What happens to this 300nmi range when the plane gets stuck in a hold or has to divert to an alternate? Is this 300 miles considering that possibility or can it literally only fly for 300 miles; if it’s the latter, that is basically useless for anything more than 20-30 mins of flying.

I have nothing against green stuff but it’s all PR until they actually make and fly an electric plane that can do 45 min turns and can fly as far as a normal plane. That’s a long way away.

Good realistic questions that have to be answered first before getting excited about the concept.

william wrote:

767333ER wrote:

What happens to this 300nmi range when the plane gets stuck in a hold or has to divert to an alternate? Is this 300 miles considering that possibility or can it literally only fly for 300 miles; if it’s the latter, that is basically useless for anything more than 20-30 mins of flying.

I have nothing against green stuff but it’s all PR until they actually make and fly an electric plane that can do 45 min turns and can fly as far as a normal plane. That’s a long way away.

Good realistic questions that have to be answered first before getting excited about the concept.

wish the Wright brothers have thought of that, right ?

pune wrote:

airnorth wrote:

frmrCapCadet wrote:

A 300 mile range would connect most of the small towns in 'flyover' country to a major/regional airport. I see 20-50 passenger, one pilot electric planes changing the economics of living in more isolated areas. Likely they would operate like our Washington State ferries - if a medical passenger needs immediate service the hell with schedule. And no one complains. They also do most of the marine emergencies in the central Puget Sound. Even stop for quicky burial services (cremains only!). Travel, normal medical, emergency ambulance, package cargo, tourism, AirBnB all fit well as a package.

I agree, and that is exactly the thinking at Harbour Air right next door in B.C. I'm sure you followed that thread as well, for those who missed it,
viewtopic.php?t=1418841

I did share this https://www.youtube.com/watch?v=kdLa0PdCB5w

can anybody tell me what does B.C. in the above stand for ?

B.C., British Columbia; one of Canada's 10 provinces, straight across the border from the US State of Washington.

pune wrote:

william wrote:

767333ER wrote:

What happens to this 300nmi range when the plane gets stuck in a hold or has to divert to an alternate? Is this 300 miles considering that possibility or can it literally only fly for 300 miles; if it’s the latter, that is basically useless for anything more than 20-30 mins of flying.

I have nothing against green stuff but it’s all PR until they actually make and fly an electric plane that can do 45 min turns and can fly as far as a normal plane. That’s a long way away.

Good realistic questions that have to be answered first before getting excited about the concept.

wish the Wright brothers have thought of that, right ?

Doubt the Wright Brothers had to deal with ATC delays and holding patterns

Just had a line of thunderstorms come through Texas. All flights from DFW to Houston this morning were being directed southwest to Brownwood, then south near Junction, then west to Houston via San Antonio, more than "300" miles. If you want this concept to succeed, then you really want range issues fixed in the beginning of the development.

I think that if we first had electric powered aircraft and were then transitioning over to fossil fuel powered aircraft, we would be having very similar discussions, in general about how difficult it will be to switch fuels and motors, turn around times, and imagine putting thousands of gallons of fuel inside your aircraft?? Crazy!
This is discussed with cars in the following video, watch the first 5 mins or so, pretty thought provoking, and kind of funny!
https://www.youtube.com/watch?v=cXkRcuwoIm4

planecane wrote:

SQ317 wrote:

Aesma wrote:

How many of Easyjet flights are less than 300nm ?

I wonder if electric plane companies are not simply banking on batteries getting better and better, trying to have an airframe and engines ready when the batteries are.

What would be really interesting would be a normal ranged airplane, with an hybrid powertrain, but that's much more difficult to achieve.

I think this is a really valid point - think about how far batteries have come since 2010. The lead time for an airframe is much longer than batteries; the batteries will no doubt go through many iterations between 2023 and 2030.

They've gotten a lot cheaper but I don't think there's been any great leap in energy density.

Research seems to be in looking at lithium air batteries to reduce weight. However, those are nowhere near ready.

Perhaps not a leap but a steady increase.. take the Tesla Model S. The S85, introduced in 2012 had an EPA range of 265 miles. The S100D of today, with negligible weight difference once you consider the weight of the additional electric motor on the front axle, has an EPA range of 390 miles. That's a 47% improvement due to increased energy density and powertrain efficiency in 8 years.

SQ317 wrote:

planecane wrote:

SQ317 wrote:

I think this is a really valid point - think about how far batteries have come since 2010. The lead time for an airframe is much longer than batteries; the batteries will no doubt go through many iterations between 2023 and 2030.

They've gotten a lot cheaper but I don't think there's been any great leap in energy density.

Research seems to be in looking at lithium air batteries to reduce weight. However, those are nowhere near ready.

Perhaps not a leap but a steady increase.. take the Tesla Model S. The S85, introduced in 2012 had an EPA range of 265 miles. The S100D of today, with negligible weight difference once you consider the weight of the additional electric motor on the front axle, has an EPA range of 390 miles. That's a 47% improvement due to increased energy density and powertrain efficiency in 8 years.

The battery of the S85 was 85kWh. The 100D is 100kWH. At most, that would be a 17.6% improvement in energy density if the battery stayed the same weight. I can't find any good source for the weight of just the battery pack.

I'm not sure how they got all the additional range. If there was a major breakthrough in lithium ion technology by Tesla, they would publicize it for sure.

When it comes to improvements for use on electric aircraft, it must pretty much all come from energy density improvements in the battery. The "engines" are just electric fans and the technology of an electric motor is not going to improve much at this point. Possibly lighter materials will be developed to make the motors lighter but the core efficiency of an electric motor is unlikely to improve.

The other issue for battery powered aircraft is that they don't become lighter as they use energy. This hurts efficiency over the entire trip.

My opinion is that for electric aircraft to be viable, either they need to use fuel cells and liquid fuel to produce electricity or there needs to be a leap in battery technology (lithium air or something) that causes a vast improvement in energy density.

I can't wait for the day when electric aircraft are the norm. However, this just seems like a PR stunt. A radical new configuration is not going to be what makes electric aircraft viable. When battery energy density reaches a point where it can compete 1:1 with fossil fuels then we will see aircraft in much the same configurations we see today but with electric motors and batteries in the wings. I would much rather see the R&D dollars be spent towards the battery technology - once the technology is mature enough manufacturers will be falling over themselves to incorporate into existing planforms. Of course that isn't as sexy as pictures of V-tails and distributed propulsion, but to me this is like polishing the surface of your pinewood derby car to minimize aerodynamic drag, while the real issue is you're using square wheels.

Lingon wrote:

.. and the cynic in me can't help to think that the main purpose to have a V tail aircraft in these kind of pictures is for the futuristic look (read: marketing) ...

me too.. or else there would be allot more planes designed with it (aka C-Series, Tecnam P2102 Traveller, just to name a few recent cleansheet builds)..

planecane wrote:

SQ317 wrote:

planecane wrote:

They've gotten a lot cheaper but I don't think there's been any great leap in energy density.

Research seems to be in looking at lithium air batteries to reduce weight. However, those are nowhere near ready.

Perhaps not a leap but a steady increase.. take the Tesla Model S. The S85, introduced in 2012 had an EPA range of 265 miles. The S100D of today, with negligible weight difference once you consider the weight of the additional electric motor on the front axle, has an EPA range of 390 miles. That's a 47% improvement due to increased energy density and powertrain efficiency in 8 years.

The battery of the S85 was 85kWh. The 100D is 100kWH. At most, that would be a 17.6% improvement in energy density if the battery stayed the same weight. I can't find any good source for the weight of just the battery pack.

I'm not sure how they got all the additional range. If there was a major breakthrough in lithium ion technology by Tesla, they would publicize it for sure.

When it comes to improvements for use on electric aircraft, it must pretty much all come from energy density improvements in the battery. The "engines" are just electric fans and the technology of an electric motor is not going to improve much at this point. Possibly lighter materials will be developed to make the motors lighter but the core efficiency of an electric motor is unlikely to improve.

The other issue for battery powered aircraft is that they don't become lighter as they use energy. This hurts efficiency over the entire trip.

My opinion is that for electric aircraft to be viable, either they need to use fuel cells and liquid fuel to produce electricity or there needs to be a leap in battery technology (lithium air or something) that causes a vast improvement in energy density.

This may take time but will happen for sure. In cars, users are already voting with their wallets, the same is happening in energy markets whether it is australia or UK . If more energy markets are open to companies like Tesla you will see cleaner energy there as well.

https://www.solarquotes.com.au/blog/aem ... ty-prices/ or

https://electrek.co/2020/02/17/egeb-bri ... -illinois/

battery day with Tesla is around in April and it's possible he may make some announcements. While I agree that passenger aircraft may take a few years, but cargo aircraft I envison happening in 2-5 years at the very most.

Right now Magnix is the front-runner but if they don't capitalize and work on it, somebody else will. And their is real motivation for researchers since now the inventors have customers from variety of applications, not just car manufacturers. Also Government policies are also nudging people to use cleaner fuels (not hydrogen which is expensive and just as combustible as gas.) .

Sorry for bringing up an oldish thread but just saw this and hence had to share. Seems there are at least 10-15 odd manufacturers who are looking at electric aircraft.

https://www.youtube.com/watch?v=mz4rMq9yt7Y

airnorth wrote:

Interesting video on YouTube from the Canadian press on the Harbour Air Electric Plane:
https://www.youtube.com/watch?v=kdLa0PdCB5w

They interview both the CEO from Harbour Air and Magnix, they discuss the number of worldwide flights under 500 miles, and under 100 miles. I found the info they have to be quite an eye opener!.

Regarding the batteries, if I recall correctly, somewhere there is an interview with Greg McDougall, Harbour Air CEO where he describes the batteries they used in the test flight as being similar to the ones used by NASA, very heavy, but also very fail safe, which they needed to convince Transport Canada to allow this flight testing to go ahead. Sorry I cannot find that interview or article right now.
Anyway, here are a couple of entrepreneurs, who along with their teams, are convinced that electric planes are not only possible, but commercially viable, and they are putting their own money, and possibly reputation behind it. I think it is really amazing, hoping nothing but success.

Does the 5% of flights less than 100 miles include general aviation? I have coworkers that commute from riverside to coastal California.

As to <500 miles being 45% of flights, I can believe that. But what about passenger flights? All of my small plane flying was < 500 miles. Fun. But it would be more informative if percentage of passengers.

There is a market. 300 miles is enough.

Most of electrical flight is very cheap maintenance. If the battery cost per flight is about normal turboprop maintenance, these aircraft will do well.

Everyone should realize these planes compete with turboprops, not a narrowbody or even a regional jet.

Lightsaber

pune wrote:

Sorry for bringing up an oldish thread but just saw this and hence had to share. Seems there are at least 10-15 odd manufacturers who are looking at electric aircraft.

https://www.youtube.com/watch?v=mz4rMq9yt7Y

When the electric variant of an training plane costs $3 dollar an hour in fuel compared to $50 an hour for the old variant(see video on spot 15) the electric one will prevail even when it has more constraints.

People are to much focused on an one on one comparison for Battery powered vs Jet fuel powered. We will probably never have an 737 sized battery powered vehicle, but I believe there will be an huge 50 seater sub 500 miles market for electric planes with CASM that can compete with the A32xNEO's and 737Max's of this world due to much lower fuel and maintanance costs.

Like Lightsaber mentions, the props are the main target with the regionals being an close second.

JonesNL wrote:

We will probably never have an 737 sized battery powered vehicle....

OTH, there is a future possibility for hydrogen. Either combustion or fuel cells / electric motors. Not viable today or within short time, but I wouldn't rule it out.

JonesNL wrote:

When the electric variant of an training plane costs $3 dollar an hour in fuel compared to $50 an hour for the old variant(see video on spot 15) the electric one will prevail even when it has more constraints.

People are to much focused on an one on one comparison for Battery powered vs Jet fuel powered. We will probably never have an 737 sized battery powered vehicle, but I believe there will be an huge 50 seater sub 500 miles market for electric planes with CASM that can compete with the A32xNEO's and 737Max's of this world due to much lower fuel and maintanance costs.

Like Lightsaber mentions, the props are the main target with the regionals being an close second.

I agree. I saw another video today of another potential electric aircraft being made by a swedish start-up called heart airspace. Apparently a 2-seater trainer aircraft was recently certified although their goal is to get their 19-seater aircraft certified by 2025. As shared in the video, they are looking at regionals, although in Norway and Sweden. There is of course lot of excitement being generated by the leaked of a bigger size and more dense battery, if that is what gets announced on battery day 22nd September. That would have implications on car prices, manufacturing process as perhaps also aircraft . You can see the whole video at

https://www.youtube.com/watch?v=mBNIAxZ8MuE

The alleged battery leak has been explained in this video -

https://www.youtube.com/watch?v=94ZzLzFP5Zg

WPIAeroGuy wrote:

I can't wait for the day when electric aircraft are the norm. However, this just seems like a PR stunt. A radical new configuration is not going to be what makes electric aircraft viable. When battery energy density reaches a point where it can compete 1:1 with fossil fuels then we will see aircraft in much the same configurations we see today but with electric motors and batteries in the wings. I would much rather see the R&D dollars be spent towards the battery technology - once the technology is mature enough manufacturers will be falling over themselves to incorporate into existing planforms. Of course that isn't as sexy as pictures of V-tails and distributed propulsion, but to me this is like polishing the surface of your pinewood derby car to minimize aerodynamic drag, while the real issue is you're using square wheels.

I disagree entirely. 1:1 is not happening anytime soon, yet we will have electric aircraft long before that. In fact we have electric aircraft today.

Electric energy will be at a premium in an electric commuter/airliner, and as a result everything will be thrown at aerodynamic efficiency, weight reduction, etc. It's very likely they will look different from a 737. Another thing to consider is potential ATC gains (for example an electric aircraft could be given priority airspace).

reminds me of a project called Mars One

Aesma wrote:

WPIAeroGuy wrote:

I can't wait for the day when electric aircraft are the norm. However, this just seems like a PR stunt. A radical new configuration is not going to be what makes electric aircraft viable. When battery energy density reaches a point where it can compete 1:1 with fossil fuels then we will see aircraft in much the same configurations we see today but with electric motors and batteries in the wings. I would much rather see the R&D dollars be spent towards the battery technology - once the technology is mature enough manufacturers will be falling over themselves to incorporate into existing planforms. Of course that isn't as sexy as pictures of V-tails and distributed propulsion, but to me this is like polishing the surface of your pinewood derby car to minimize aerodynamic drag, while the real issue is you're using square wheels.

I disagree entirely. 1:1 is not happening anytime soon, yet we will have electric aircraft long before that. In fact we have electric aircraft today.

Electric energy will be at a premium in an electric commuter/airliner, and as a result everything will be thrown at aerodynamic efficiency, weight reduction, etc. It's very likely they will look different from a 737. Another thing to consider is potential ATC gains (for example an electric aircraft could be given priority airspace).

If those gains were even close to making up the difference then they would already be applied to existing aircraft. We have electric aircraft today, but they are significantly handicapped compared to their fueled siblings. They're being advertised as suitable for short hops (<1 hour). While its true that a 'typical' mission for that airplane may be short, the reality is most airplanes rarely spend their entire lives only ever going between two airports. What happens when there's a weather diversion? Or you have to go to a shop away from your home base for maintenance? Pipistrel's offerings can't even be used for a PPL long cross country without at least one battery swap.

My point is not that an electric airplane cannot fly. My point is that without substantial leaps in technology, electric aircraft simply cannot compete with fossil fuel airplanes, and simply coming up with more efficient shapes is not going to overcome the fundamental lack of energy capacity of current battery technologies.

"ETOPS" for the first larger electric planes could require favorable weather and the plane to be within 35-50 miles of an alternative airport. Close to Cessna 172 take off and landing speeds could make alternate airports easy.

frmrCapCadet wrote:

"ETOPS" for the first larger electric planes could require favorable weather and the plane to be within 35-50 miles of an alternative airport. Close to Cessna 172 take off and landing speeds could make alternate airports easy.

Not many airports nearby in the oceans.... and ETOPS is a certification for flying over oceans.

Have a great day,

First test flight by 2023... Entry into service by 2030... Date I'll fly 2050...

2175301 wrote:

frmrCapCadet wrote:

"ETOPS" for the first larger electric planes could require favorable weather and the plane to be within 35-50 miles of an alternative airport. Close to Cessna 172 take off and landing speeds could make alternate airports easy.

Not many airports nearby in the oceans.... and ETOPS is a certification for flying over oceans.

Have a great day,

I know that, but limited range electric planes flying over land will need a version of ETOPS. I see excluding inclement weather as a top condition. Flying short distances at relatively low altitude over the Cascades (or other mountainous areas for that matter) and no alternate airports available because of weather is the most common cause of aviation deaths. Interestingly, the electric conversions for flying from Vancouver to Victoria in British Columbia are seaplanes. Landing places available for the whole distance, weather allowing. LOL

Since an engine ie powered by combustion and a motor is powered by electricity, I am very interested in the type of “engine” that is being used.

WPIAeroGuy wrote:

Aesma wrote:

WPIAeroGuy wrote:

I can't wait for the day when electric aircraft are the norm. However, this just seems like a PR stunt. A radical new configuration is not going to be what makes electric aircraft viable. When battery energy density reaches a point where it can compete 1:1 with fossil fuels then we will see aircraft in much the same configurations we see today but with electric motors and batteries in the wings. I would much rather see the R&D dollars be spent towards the battery technology - once the technology is mature enough manufacturers will be falling over themselves to incorporate into existing planforms. Of course that isn't as sexy as pictures of V-tails and distributed propulsion, but to me this is like polishing the surface of your pinewood derby car to minimize aerodynamic drag, while the real issue is you're using square wheels.

I disagree entirely. 1:1 is not happening anytime soon, yet we will have electric aircraft long before that. In fact we have electric aircraft today.

Electric energy will be at a premium in an electric commuter/airliner, and as a result everything will be thrown at aerodynamic efficiency, weight reduction, etc. It's very likely they will look different from a 737. Another thing to consider is potential ATC gains (for example an electric aircraft could be given priority airspace).

If those gains were even close to making up the difference then they would already be applied to existing aircraft. We have electric aircraft today, but they are significantly handicapped compared to their fueled siblings. They're being advertised as suitable for short hops (<1 hour). While its true that a 'typical' mission for that airplane may be short, the reality is most airplanes rarely spend their entire lives only ever going between two airports. What happens when there's a weather diversion? Or you have to go to a shop away from your home base for maintenance? Pipistrel's offerings can't even be used for a PPL long cross country without at least one battery swap.

My point is not that an electric airplane cannot fly. My point is that without substantial leaps in technology, electric aircraft simply cannot compete with fossil fuel airplanes, and simply coming up with more efficient shapes is not going to overcome the fundamental lack of energy capacity of current battery technologies.

The big problem with most people envisioning electrically powered flight, is that they see a Tesla and just try to translate it into an aircraft.
I drive an electric car and I love it. I personally can't believe that people still choose to burn dinosaurs to commute to work, because there is nothing more comfortable for daily commuting than an electric car.

However, applying the same idea for aircraft doesn't work and here's an example why:

Tesla's 85kWh battery pack weighs about 500kg.
You stuff an A380 with 500 of those instead of fuel for a total of 250 metric tons and 4.2 MWh which is about 15 GJ (GigaJoules) or 15 GNm.
A380 engines are rated for 350kN each, producing a total of 0.0014GN of thrust.
So at the engine's rated thrust, the batteries would be depleted after about 10 kilometers assuming that the energy stored in the batteries is converted to thrust at 100% efficiency by an electric fan.

Using 500 20kUSD Tesla Superchargers each connected separately to a pack, it would take 45 minutes to charge the 500 battery packs to 80%, 90 minutes to charge to 100%.
It would take 2 to 3 large wind turbines turning at their rated speed, or 10000 full size solar panels at their max output to power the charge of the single aircraft.

With this dimensional comparison, you can realise that battery-powered flight has too many limitations.

This being said, I guarantee you that by 2030, there will be electrically powered commercial aircraft at advanced stages of development, if not already in service.
It just won't be battery-powered aircraft. It may not even be hydrogen-powered.
There are other options and the first aircraft will probably only be partly operated by electric power.

Another one to follow is this diamond nuclear waste battery that people are starting to talk about.
Oxford Uni has worked on the project and among others, a company called NDB is working on this.

https://www.energylivenews.com/2020/09/ ... 20reactors.

https://ndb.technology/

Even without putting waste isotopes in lab-manufactured diamonds, there are solutions out there, right now, today, that can allow aircraft to be powered by renewable electricity.

Personally I think that it's foolish of Musk to go all-in on batteries when so many alternative solutions could replace batteries overnight.

Waterb........ , also of interest is what is happening in the Puget Sound with boats - very large vehicle ferries, fast passenger only, distances from just over a mile or so to 20 miles . Those ferries are high mass, and travel through a very high density medium, battery weights are not exactly the main problem. The state and counties have already determined that electric is the way to go. The largest ferries will replace one of two diesel drives with an electric motor and batteries. At the other end, the smaller boats going the shorter distance will be all electric. Those in between, it all depends on distance and size. The local power company is working on another hard problem, some of those ferries are on islands or peninsulas at the end of the distribution system. Over the next 5-15 years it will be done. There is some hybrid electric already on small boats.

The aviation connection to all of this 'boat stuff' is that for electric planes it all depends on size and distance, as well as location and electric grid availability.

Waterbomber2 wrote:

Tesla's 85kWh battery pack weighs about 500kg.
You stuff an A380 with 500 of those instead of fuel for a total of 250 metric tons and 4.2 MWh which is about 15 GJ (GigaJoules) or 15 GNm.
A380 engines are rated for 350kN each, producing a total of 0.0014GN of thrust.
So at the engine's rated thrust, the batteries would be depleted after about 10 kilometers assuming that the energy stored in the batteries is converted to thrust at 100% efficiency by an electric fan.

Using 500 20kUSD Tesla Superchargers each connected separately to a pack, it would take 45 minutes to charge the 500 battery packs to 80%, 90 minutes to charge to 100%.
It would take 2 to 3 large wind turbines turning at their rated speed, or 10000 full size solar panels at their max output to power the charge of the single aircraft.

Dear Waterbomber, a very good analyses, but one small error crept in. 500 Tesla 85kWh batteries hold 42MWh, not 4.2MWh.

Consequently your theoretical 100% efficiency fan plane would do some 100 km instead of 10 km. And charging would take a few dozen of the world's largest wind turbines. And of course a good and strong wind.

It is maybe easier to just look at the following: The energy created by one lb jet fuel in an airliner takes roughly 40 lb li-ion battery. So a jet airliner fueled for a ten hours flight would with equal mass battery do a 10h divided by 40 = 15 minutes flight.

Same with a Tesla. Convert it to diesel, load it with diesel fuel same mass as its 85kWh battery, and it will run 40 times longer.

There are hundreds of minor "what ifs" connected to that round figure 40. But what does it matter if the real figure is more like 25 or 60? Nothing. It has to be very low single digit to be interesting.

prebennorholm wrote:

Waterbomber2 wrote:

Tesla's 85kWh battery pack weighs about 500kg.
You stuff an A380 with 500 of those instead of fuel for a total of 250 metric tons and 4.2 MWh which is about 15 GJ (GigaJoules) or 15 GNm.
A380 engines are rated for 350kN each, producing a total of 0.0014GN of thrust.
So at the engine's rated thrust, the batteries would be depleted after about 10 kilometers assuming that the energy stored in the batteries is converted to thrust at 100% efficiency by an electric fan.

Using 500 20kUSD Tesla Superchargers each connected separately to a pack, it would take 45 minutes to charge the 500 battery packs to 80%, 90 minutes to charge to 100%.
It would take 2 to 3 large wind turbines turning at their rated speed, or 10000 full size solar panels at their max output to power the charge of the single aircraft.

Dear Waterbomber, a very good analyses, but one small error crept in. 500 Tesla 85kWh batteries hold 42MWh, not 4.2MWh.

Consequently your theoretical 100% efficiency fan plane would do some 100 km instead of 10 km. And charging would take a few dozen of the world's largest wind turbines. And of course a good and strong wind.

It is maybe easier to just look at the following: The energy created by one lb jet fuel in an airliner takes roughly 40 lb li-ion battery. So a jet airliner fueled for a ten hours flight would with equal mass battery do a 10h divided by 40 = 15 minutes flight.

Same with a Tesla. Convert it to diesel, load it with diesel fuel same mass as its 85kWh battery, and it will run 40 times longer.

There are hundreds of minor "what ifs" connected to that round figure 40. But what does it matter if the real figure is more like 25 or 60? Nothing. It has to be very low single digit to be interesting.

The energy density piece of 40:1 is about right for jet versus battery, but the battery is more efficient at converting that to useful work. In a diesel engine, you get something like 35-40% efficiency from the engine itself, then lose a bit more from accessories, off-peak power inefficiency, traffic, etc. Meanwhile, a Tesla converts something like 70% to useful work, and has fewer costs in the off-peak areas like coasting and braking (with regen). Once you bake all of those in, you're closer to 15:1 advantage. This Wired article from 2017 confirms this ballpark number: https://www.wired.com/2017/05/electric-airplanes-2/

I see electric being huge in GA, as most flights are shorter than 2 hours, and the overwhelming majority <3.