Why battery-powered aircraft will never have significant range

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Dan Thomas

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Even if a particular region's power comes from petrol burning utilities, a gallon of petrol burnt to power a utility to power a battery electric car still yields twice as much range as burning the fuel directly in an combustion car. Depending on what state you're in, a battery electric car gets 2-5 times the range on an equivalent gallon of gas, and is considerably cheaper to fill up.
Now. Tell us how adding several stages to the process, each with its losses, can possibly be more efficient. I'd really like to know that secret.
 

Dana

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i have posted the images of planes for sale in the other post, here you have ready to buy

pipistrel velis, alpha an taurus and more to come
OK. Electric motorgliders make sense as I said earlier. Training planes, I wonder how many they will actually sell? I suspect schools and FBOs will find themselves unhappy with the dispatch rate, especially if they're intended to be used as rentals as well as training. Maybe the numbers will make more sense in Europe where avgas is so much more expensive and the distances are shorter... IF fast recharging is available at all likely destinations.
 

Saville

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"fizzle, post: 614855, member: 107199"]
No one has the duty to enlighten you or anyone,

No one asked you to enlighten anyone. You were asked to enlighten yourself on what people are actually saying.

It's abundantly clear that you didn't even read the last couple sentences of my reply.

Someone writes a little skepticism and your eyes roll into the back of your head and your respond to the title of the thread, as if that was remotely relevant to the discussion.

And then you start calling people names.



you have a working brain and i won't answer to your nonsense, you can read the links by yourself.

Not interested in whether you answer or not - though you seem to be unable to prevent yourself from doing so.

Also I can publish an entire library with incidents regarding the development of petrol internal combustion aircrafts during the 1900s with crashes, deaths, design and engineering errors,

Strawman. No one said ICE didn't have teething pains and everyone expects EV to have them too. It's part of technology growth.

Do you have ANY idea what the discussion is about?


decades with billions wasted in research, etc and also about the problems and limitations of that technology and now you can fly with a petrol ice aircraft with some relative security until the oil field is empty and the waves flip over your beach house.

Translation of the above paragraph: I have no rational reply so I'll resort to silliness.
 
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fizzle

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Have you calculated how large a solar panel you need to power a man carrying aircraft?
this is the graph of solar irradiance vs altitude

Solar irradiance vs the altitude ASHRAE Model-Diffuse-solar-radiation-W-Knaupp-and.ppm.png


to make a solar panel with more output you can use two or more cheap silicon bifacial solar cells, this kind of cells are called multi junction solar cell and usually have exotic solar cells or a combination of various solar cells and so are expensive or unavailable in the market.


with bifacial in tandem you can multiply the panel output per m2, and also at high altitudes there are low temperatures that increase the panel output as well, also a tensed mylar aluminum fabric can be used to reflect light as spoilers located behind the panels doing roll movements without creating much drag
 
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Saville

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you can make it at home, private companies are constrained by patents rights, labor costs, components purchases, high cost machinery, they apply obsolete technology instead recent research, etc

go for it if you are so concerned about some specific requirements and price. isn't this a homebuilt forum? because all i heard here is corporate "success" bias, a problem that has also boatdesing.net.

there are many people living offgrid with solar panels and batteries with continuous energy, you can use your phone continuously with a solar panel because you use batteries, it's pretty obvious.

The above comments avoid the question..which was:

"So, successful electric aircraft... what's out there? Show me a PRACTICAL aircraft for any of today's real world missions."

and this one:

"Again, name one electric aircraft available today that's practical for a real world mission. Note that "practical" also includes being at reasonably close pricewise to a comparable gasoline powered model."

And this one:

"Really? Please cite practical, existing examples as proof. Not wishful- thinking CGI stuff."
 

Saville

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Dana's question to fizzle:

Have you calculated how large a solar panel you need to power a man carrying aircraft?

fizzle's answer to this question is below and it can be summed up in one word:

No.




this the graph of solar irradiance vs altitude and latitude

View attachment 114834


to make a solar panel with more output you can use two or more cheap silicon bifacial solar cells, this kind of cells are called multi junction solar cell and usually have exotic solar cells or a combination of various solar cells.


the with bifacial in tandem you can multiply the panel output per m2, and also at high altitudes there are low temperatures that increase the panel output as well, al aluminum fabric can be used to reflect light behind the panels without creating much drag
 

Topaz

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Just deleted two posts for heading into personal attack territory. You know who you are. If you can't stick to the HBA Code of Conduct, it gets less friendly from here.
 

tspear

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OK. Electric motorgliders make sense as I said earlier. Training planes, I wonder how many they will actually sell? I suspect schools and FBOs will find themselves unhappy with the dispatch rate, especially if they're intended to be used as rentals as well as training. Maybe the numbers will make more sense in Europe where avgas is so much more expensive and the distances are shorter... IF fast recharging is available at all likely destinations.
The press reports says Pipestrel is back ordered on the Elektro over a year, and this matches with the answer when I called the US Sales reps. Toward the end of 2020 they were supposedly on pace to make about 3 a month, and expecting to more than double production rates in 2021 and double again by 2022.
Per the sales lady, there is/was a flight school in Florida that has ten on order and is already flying a couple, there was one out west with twenty on order. Recharge time is basically one for one (one minute flying, one minute charging); which works for many flight schools.

Tim
 

Aesquire

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Ten pounds of Plutonium has far more easily extracted energy than a hundred pounds of gasoline or a million pounds of solar cells.

the gasoline needs a complex mechanism with many carefully machined moving parts to get useful power for airplanes. The solar cells need complex electronics, electric motors made with rare Earth elements.

The plutonium only needs a few chemicals, careful machining, and a few electronic parts. Maximum speed is quite high, but making the aircraft safe when exposed to higher temperatures than the surface of the Sun does present as yet unsolved technical issues. :)
 

Saville

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Ten pounds of Plutonium has far more easily extracted energy than a hundred pounds of gasoline or a million pounds of solar cells.

the gasoline needs a complex mechanism with many carefully machined moving parts to get useful power for airplanes. The solar cells need complex electronics, electric motors made with rare Earth elements.

The plutonium only needs a few chemicals, careful machining, and a few electronic parts. Maximum speed is quite high, but making the aircraft safe when exposed to higher temperatures than the surface of the Sun does present as yet unsolved technical issues. :)

All the timing requirements - system clocks and GPS stuff etc. means that each aircraft should have a Cesium clock. ;)
 

ElectricFlyer

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Wow -- what a great debatable topic this has turned into. Lots of passion on both sides.

I recently just started thinking about it again. I was just ground testing my Simonini 202 getting ready for my 1st solo. As I watched it shack the sh!t out of itself during ideal, apparently its normal, I was thinking I cant wait for better batteries!

Later on someone pointed out a little play in the proper -- it is looking like a bearing issue with the redrive. This could easily have been an electric drive unit with the bearings needing replacement. Electrics will definitely have issues, will they save the environment aside, but IMHO the issues will be considerably fewer and far less between times of fail and they will be easier to repair.

I think I previously pointed out that my needed flying time will be an occasional 1hr in the evenings for the next long while. So electric is looking good for me for now while we wait for that. The hardest part of getting the electric conversion is getting my wonderful wife who is the bread winner of the house to open up the funds.😁
Think I am going to have to agree to some OT at work to get this.

Cheers
 

Dusan

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The CHP cycle are a lot more efficient than Otto cycle. The multiple small losses do not compare to the single massive loss.
I don't want to get into arguments, but facts are facts. Our current gasoline car engines have one of the lowest thermodynamic efficiency out there, about 20% to 35%. Taking into account also that the gasoline needs to be refined and transported, it is much better to use the oil to power a modern electric power plant, efficiency about 60%. Loses to transport electricity, conversion and charge/discharge batteries are under 5% overall, much smaller than transporting fuel.
 

Aesquire

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Arguments on complexity that favor electric vs. gasoline engines are also arguments for 2 stroke vs. 4 stroke.

No fancy valve train... Unless it's disc valve, which scrape themselves to paper thin shards, or feed valves, which vibrate apart. But both are in cool parts of an engine so don't need exotic alloys. Disc valves need synchronized drive gears or chains or belts, like a 4 stroke, but don't have reciprocating masses trying to tear themselves apart.

so no poppet valves banging into valve seats thousands of times per minute. Basically 3 moving parts,piston, connecting rod & crank.

And for generations of mechanics a solid knowledge base on how they work. It's a different circle on the Venn diagram for mechanics with understanding of electronic motor controls.

Now electronic motor controllers don't have any moving parts! Yea! But the parts are heated by resistance and depend on quantum physics. That's another circle for your Venn diagram.

And then there's Wankel engines. Few moving parts!

Ok, so we look at moving seal surfaces...

The point is by cherry picking your aspects of design you can make good sounding arguments for lousy designs, or put down good designs you don't like. I'll ignore efficiency claims that are more science fiction than an African American Billionaire building reusable orbital boosters.

New Electric Car Charger Is More Efficient, 10 Times Smaller Than Current Tech
7% losses at one of many steps. The new one is 2.5% losses, and I'm actually quite impressed.
 

BFE_Duke

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I don't want to get into arguments, but facts are facts. Our current gasoline car engines have one of the lowest thermodynamic efficiency out there, about 20% to 35%. Taking into account also that the gasoline needs to be refined and transported, it is much better to use the oil to power a modern electric power plant, efficiency about 60%. Loses to transport electricity, conversion and charge/discharge batteries are under 5% overall, much smaller than transporting fuel.
Yes, this exactly. Gasoline car engines may have peak 35% efficiency (~38% efficiency with Atkinson cycle, in the Prius), but are not always running at ideal RPMs, especially in stop-and-go traffic. Add to that the driveline losses, and we're looking at about 22-23% tank-to-wheel efficiency. Electric motors are typically mounted on the diff, so there is low driveline loss. Combined cycle power plants are on the order of 50-60% efficiency. CHP cycles are 70-80% efficient.

Now in some regions a hybrid can get pretty close to battery electric, but if you're in somewhere with a high percentage of renewables like California, or upstate New York, it's not even close.
 

Aesquire

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or upstate New York
Niagara Falls... ( step by step...) & Nuclear Power. Both renewable, and both ultimately gravity power. The Uranium in the reactor does take a bit longer to be created by nature than the lighter elements in the water flowing downhill. And I don't think it will be recycled unless the Big Bang is cyclic. Both the used Uranium and the minerals in the water should still be on the frozen cinder of a planet after the Sun swells and cools to a dwarf. The water will probably be blown away in the Solar wind as the planet is scheduled to be inside the Red Giant at one point. "Red Hot Fog" I believe is the term for conditions then.

The philosophic origins of the power in the grid that will charge your electric thingee are many faceted. Ultimately, there is a lot of labor and big holes in the ground for EVERY form of power. The gigantic oil & coal infrastructure is well documented. ( I recommend the book "The Prize" by Daniel Yergin. ) The Solar photovoltaic industry is quite nasty, too. If only sand was needed, the Sahara would be the center of the Energy world. Ditto for all the electric motors, ( Cobalt, Rare Earths ) wire, ( Copper ) and everything else, there's a mine or a well to get the chemicals.

I have no doubt that Asteroid mining will be picketed by Astronomers, even if they get a distributed telescope 3 A.U. across out of the deal.

Even my hang glider uses stored Power to drive to the mountains, since I'm not willing to pedal a bicycle from pre-dawn to get there. Even my Bicycle uses stuff from a mine.

So feel free to feel self righteous about how you move about on the planet. As a buddy often says, "I support your right to your delusions even if I don't share them." But Anyone else can feel free to puncture your ego.

I honestly don't know how efficient the flow of power from the Nuclear plant up on the lake into my mother's Prius Prime Battery is. I will bet a Wendy's meal that the Toyota 115 volt charger unit that's the size of a happy meal box ( plus cords & plugs ) isn't 5% efficient at the job. But I don't need to bet.

Once I was called a "know it all" by some fellow who was arguing stupid stuff on the Internet. ( not here, btw ) I replied, that, "Duh!, you are arguing on the internet. I can take your argument, cut & paste it on a search engine, find your source material, make a reasonable judgment as to it's bias, find a better source, with more accurate data, and post a rebuttal showing what a fool you are by the time you sound out the words on the next dumb thing you copy to make your argument." Yeah, that was a bit blunt.

Charger efficiency.

A comparison of electric vehicle Level 1 and Level 2 charging efficiency So... 10-15% losses from wall to battery. Then there's from the generator to the transformers, up & down in voltage, and the miles of wire to your home or hanger.

I'll certainly believe you if you are measuring total loss to heat from fuel tank & battery to wheels in IC and Electric cars.

That doesn't count the oil tankers, the pipelines, the pumps, the conveyer belts, and the entire system from "I think I'll sell power" to your bill.

And I don't think that argument is relevant to anything except more argument. If in another 20 years as promised for my whole life we get Fusion from Seawater and room temperature superconductors to carry the power to your wall, people will argue the Rarite used is environmentally Bad.

What matters is How much does enough energy to fly weigh? That's not going to be a single number. And today's answer won't be much different than tomorrow, but hopefully by next decade, it will be.

That tells you what's possible, then you need to ask how much it costs.
 

Topaz

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OK. Electric motorgliders make sense as I said earlier. Training planes, I wonder how many they will actually sell? I suspect schools and FBOs will find themselves unhappy with the dispatch rate, especially if they're intended to be used as rentals as well as training. ...
Obviously where you are it may be different, but all the flight schools around here have most of their fleet sitting, most of the time. There are other issues keeping dispatch rate down, and if an electric airplane could recharge in an hour, I doubt anyone would notice.
 
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