Why battery-powered aircraft will never have significant range

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Vigilant1

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If we think GA has a PR problem now, wait until summertime home thermostats are auto-bumped to a "comfortable and efficient" 79F so there's enough energy to charge small electro-planes.
 

PMD

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If we think GA has a PR problem now, wait until summertime home thermostats are auto-bumped to a "comfortable and efficient" 79F so there's enough energy to charge small electro-planes.
The only things that will be charging will be training airplanes as with over 50 times the energy storage density, nothing will have enough range to get out of the pattern. I am constantly amazed that in a medium where we agonize of the extra weight of a metal prop over a composite equivalent anyone can seriously discuss something that needs literally a TON of battery to do what 50 lbs. of fuel can. Then...there is the environmental cost of the idiot LiPo batteries....never mind the risks.
 

tspear

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@PMD

With Pipistrel already having a plane which has one hour endurance and designed as a trainer, you do realize how out of touch you sound? If the battery tech increases by a factor of forty, what plane needs to fly non-stop for forty hours?

A simple double of the existing battery energy density from 144 kw/kg and it is viable as not just the in the pattern trainer but a full PPL trainer.

Tim
 

Rhino

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If we think GA has a PR problem now, wait until summertime home thermostats are auto-bumped to a "comfortable and efficient" 79F so there's enough energy to charge small electro-planes.
Where on earth do you live where anyone can "auto-bump" your thermostat? This ain't the Soviet Union. ....yet.
 

akwrencher

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California and Texas, apparently. At least, if you believe the news.

On a lighter note, the other day I got bored and decided to do some quick math. A little googling and some back of the napkin numbers showed that, to replace the reported gasoline consumption in the US would require roughly doubling our electricity production. Now, to be fair, I did not go so far as to factor in the inefficiency factors for gasoline vs electric, so it is a ROUGH calculation. Sill, thats a lot of juice to come up with any way you cut it.
 

PMD

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@PMD

With Pipistrel already having a plane which has one hour endurance and designed as a trainer, you do realize how out of touch you sound? If the battery tech increases by a factor of forty, what plane needs to fly non-stop for forty hours?
And you think that assuming a technology is going to improve by 4,000% in the foreseeable future is in touch with what???????????

BTW: there has already a "homebuilt" airplane with internal combustion engines that has flown non-stop around the world...and it took a lot more than 40 hours (216...I had to look that up). Much newer CI technology as well as some pretty neat stuff that has run in lab level testing can increase the thermodynamic efficiency of ICEs to almost double that of the SI engines that circled the globe 35 years ago.
 
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mcrae0104

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Where on earth do you live where anyone can "auto-bump" your thermostat? This ain't the Soviet Union. ....yet.
You can voluntarily sign up for that with Xcel Energy.

Denver is considering green building measures that may make it mandatory in the near future.
 

Aesquire

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Mom has that thermostat. It gives her a discount price if she allows the local power company to turn up her temperature on high demand hot days etc. She also clips coupons.

The temptation of that kind of power to micromanage everyone is quite appealing to some people, but that's a discussion about mental illnesses and politics we don't need. :)

The unpleasant bottom line is your motivation matters here.

Love bleeding edge tech? Want a quieter paramotor so your neighbors aren't annoyed as much when you fly out of your back yard? Have a clever design that is really hard or impossible with a gasoline engine? ( like multi rotor or tail props that would need a heavy & challenging extension shaft )

Then go forth and enjoy.

Think you'll save money? Nope. Not this year. Maybe with tax money given a few people, but not you, not yet.

Think it'll make you cool & admired?

Ok, I WILL be impressed if you .... " build a flying machine with a wrecked motorcycle out of ladders to a modified design by a French guy who couldn't coordinate his hands and feet & made a design so flawed it was banned then analyzed by the greatest minds in aviation on both sides of the English Channel & people argue about why it's dangerous to this day. " but your neighbors generally won't. Again, I will, but I like Pous and get your kink.

Want to save the planet because of a crisis you saw on tv? Then figure out how to turn the plastic gyre bigger than France into Jet fuel.

Enjoy.
 

Victor Bravo

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Nobody can argue against the fact that Electric guitars have all but replaced the previous non-electric instruments in most of the music business. A certain guitarist proved that things could be done with an electric guitar that were never possible before.

So with this theme in mind, I have no doubt that some of the proponents of electric airplanes on HBA just can't wait to say... "awww move over, Rover, and let Tesla take over!"

(sorry, it's late, I couldn't resist :) )
 

dog

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Some statements above try (badly) to conflate the decrepit state of the power grid to some sort of imposible barier to the adoption of electric power for cars and aircraft.
The plans bieng acted on to convert the transport sector to electric include wide scale
new solar and wind power plants with disrtibuted energy storage in the form of hydrogen and batteries.Regenerative fuel cells
are set to play a big part as they can 1 make hydrogen for storage or fuel for mobile fuel cells,2 use that hydrogen to provide grid power and charge batteries for mobile electric use.
These are a scalable solution that will fir in anywhere that there is a lot of existing roof space and lots of sun,which lo and behold coincides with the places facing summertime
energy shortages right now.
The hotter it gets the better it works.
Any new building going up now that isnt factoring in solar PV is throwing away money
and driving there own costs up,as solar PV is a solid money maker ,and lowers the cooling costs of the building its installed on.
New or existing hangers are excellent solar PV oportunities for small struggling airports to
become profitable,now.
 

John.Roo

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Interesting endurance trial going on down under.
Just one detail...
Organizers describe the support needed for the record flight:
The flight team and support crew will include three pilots, five on-the-ground support crew, a second support (petrol-powered) plane, and two vehicles carrying recharging equipment for the aircraft."
As a fan of electric airplanes I am not sure if this is good way how to promote electric aviation. Why?
Zero emission electric plane will need petrol powered plane + two cars following him with chargers. To fly 1 150 km distance will require 18 stops to recharge / replace battery = in average means landing every 63 km. Will this really convince pilots of ICE powered airplanes that electric propulsion is a future?
And... is environmental friendly if one electric airplane is followed by two cars + ICE powered airplane?
What about to try to finally implement charger into electric airplane?

I wrote text above already in e-soaring thread....
 

PMD

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Some statements above try (badly) to conflate the decrepit state of the power grid to some sort of imposible barier to the adoption of electric power for cars and aircraft.
The plans bieng acted on to convert the transport sector to electric include wide scale
new solar and wind power plants with disrtibuted energy storage in the form of hydrogen and batteries.
I work in this industry and can tell you that most of these distributed power options are expensive to build and VERY expensive to maintain.

What the entire "green" movement is doing is piddling away financial and natural resources at a huge cost to both PLUS with excessive associated environmental damage - just to find more expensive and usually far more polluting ways to do more of the things that are destroying the sustainability of the planet. I will take them seriously when the whole BS programme starts to realize we need to do LESS of these things, not more.

Regenerative fuel cells are set to play a big part as they can 1 make hydrogen for storage or fuel for mobile fuel cells,2 use that hydrogen to provide grid power and charge batteries for mobile electric use.
I agree that for portable energy needs, Hydrogen is a great choice. However, I have watched an R&D project that HAS really good liquid H2 storage tech and wanted to use fuel cells to provide transportation and operating energy. The energy cost to cool the fuel cells was as much as it took to simply feed the H2 directly to a CI or SI ICE and generate the electricity conventionally (and MUCH more economically). To start building airplanes around technologies that are so immature is fallacy in the extreme.
These are a scalable solution that will fir in anywhere that there is a lot of existing roof space and lots of sun,which lo and behold coincides with the places facing summertime
energy shortages right now.
The hotter it gets the better it works.
Any new building going up now that isnt factoring in solar PV is throwing away money
and driving there own costs up,as solar PV is a solid money maker ,and lowers the cooling costs of the building its installed on.
New or existing hangers are excellent solar PV oportunities for small struggling airports to
become profitable,now.
At what cost???? Maybe read what the IEEE had to say about PVs a while ago:

Then maybe find out what the US Academy of Science and National Research Council had to say at Senate hearings regarding the environmental cost of Lithium Ion cell production. By far THE most polluting method of powering a motor vehicle is plug-in battery (with Li based battery tech). Add to that: there is not enough known Lithium on the planet to come anywhere near the needs if we were to use today's extremely flawed technology to try to convert transportation from carbon based to lithium based.

And: why are we straying so far away from Carbon based fuels???? Because a lot of people who can make money from doing so are telling us it is important....even ESSENTIAL due to atmospheric emissions? Let's maybe stand back and LEARN a bit about how the global environment deals with carbon and when you do, surprise, surprise: we don't have a carbon EMISSIONS problem, we have a carbon ABSORPTION problem. Here is a good site for a quick read: (www.goesfoundation.com) they seem to be down right now, but basically, we have killed off so much plankton that the ocean (by far the largest sink for carbon) can no longer absorb at the rate we are emitting. The die-off is about 1% per year, and IF we stop destroying the ocean (with things such as the chemical discharge from building more PV cells) we can restore the ability to live in a carbon-balanced system.

The secret IMHO is to simply stop doing so many polluting things, not add endless layers of more. The BIG two are: stop killing the oceans and stop reproducing like rabbits. From our perspective, I get as big a bang out of sitting between a pair of 540s and punching some very expensive and very polluting holes in the sky, but one could easily just limit travel to needed travel and do so with a small engine that doesn't spew lead at the rate of a WWI machine gun.
 

BJC

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What the entire "green" movement is doing is piddling away financial and natural resources at a huge cost to both PLUS with excessive associated environmental damage - just to find more expensive and usually far more polluting ways to do more of the things that are destroying the sustainability of the planet. I will take them seriously when the whole BS programme starts to realize we need to do LESS of these things, not more.
and stop reproducing like rabbits.
I will take the “environmentalist” seriously when, as per your comment, they start focusing on the world’s population.


BJC
 

tallank

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I trust your math more than mine at in morning, especially before caffeine!
If they are really at 144, getting to 288 in the next few years sounds very doable with just a 2% increase a year from 250.

Tim
Looking on their website, they listed a battery with a nominal voltage of 345V and 30Ah and 72 kg. This works out to about 144 Wh/kg. In our application we use about 180. The current technology is around 250 if you push it. There are lots of news looking at 400-500 Wh/kg. So, if they went from 144 to 400, that would be quite a change and starts to get interesting. I'm guessing we'll get in the 500 Wh/kg range, but after that, who knows. Would probably require some big breakthroughs. Still not quite in the range that is practical to us unless we're talking ultralights and self-launch gliders, or short duration trainers.

Otherwise, with all the electrified stuff out there (cars, motorcycles, lawn mowers, busses, locomotives, drills, etc.), it's not like we're starting from scratch or alone in this endeavor. With about 500 designs (in eVTOL news), some flying, a crazy amount of money and effort (from some big names) is going into it.
You are confusing wh/kg with kwh/kg. 400 wh/kg IS 0.4 kwh/kg.
 

FarmBoy

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I trust your math more than mine at in morning, especially before caffeine!
If they are really at 144, getting to 288 in the next few years sounds very doable with just a 2% increase a year from 250.

Tim
While we won't know the end unit production specs of the new (Panasonic/Tesla) 4680 batteries, they are based on a 380Wh/Kg chemistry, are already in production, and will be going into all Tesla Model Y and Cybertrucks being built at the Texas Gigfactory this year. Of course an integrated pack will shave off a few percent, though conservative estimates indicate the new Tesla modules will carry around 307 Wh/Kg (a 16% increase from the current 265Wh/Kg modules in my 2020 Model Y).

I don't see this slowing down any time soon either - a tremendous amount of capital is being invested in these technologies and there are already chemistries in various phases of proof of production upwards of 600 Wh/Kg (and LiS has a theoretical limit of ~2,600) . While 600 Wh/Kg would only reflect a ~4x increase over the currently contested Pipistrel use case, 4+ hours in the air is probably the average desired amount of time before a pee break (or other form of rest) is desired while traveling and certainly meets almost any training use case. I have no doubt that other aerodynamic and systems design improvements will add to potential time aloft. I believe we will be seeing some air worthy news items this year that will surprise quite a few folks. :)
 
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dog

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I work in this industry and can tell you that most of these distributed power options are expensive to build and VERY expensive to maintain.
I have lived with a battery based PV power system for more than 10 years,and have multiply amortised my investment,and have a better up time than the grid AND can still sell my system used for good money.
Distributed power is efficient and cost effective
when taken out of mega corporate hands.
Gimi numbers,what ,when,where,who,how,why.
Solar is the best investment an indivual can make for financial stability and possible future
effects.
 
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