Why battery-powered aircraft will never have significant range

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Jay Kempf

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Solar ain't much of a range extender in the end. What you need to carry with you to take advantage of solar cells.
Studies on the internet do not replace market forces. If "wind" power was a significantly lower cost of delivery than other energy sources, the the suppliers of the energy product would run (not walk) to provide that product. They would not need to be dragged into the market by government incentive - the ability to provide a product with higher profit margins would be all the incentive needed.

That's the beauty of capitalism - it is the "truth" behind human nature. If wind or solar was "cheap", it would be the primary energy source for the planet. But it's not.
Salesmanship works this way: for Tesla, you can market breathtaking acceleration, then you can market huge endurance, how many chargers there are , and unbelievable R&D and planet stewardship... but the marketer implies that all those things can coexist. The customer assumes they do cause they were all in that one sentence together. The engineer knows they aren't and don't coexist.

For wind turbines you can say that they can output some continuous power number but they don't run continuously or even consistently except in a very few places. So what difference what their output per unit time is. What matters is what is their output when they can be synchronous with the grid on a day when the wind is favorable integrated over a standard year or something. Same with solar. And you just leave out storage of that energy cause you don't want to have to explain how you are going to do it and when.

I'm waiting for improbability drives to become reality. Then I can power all my devices with unfavorable odds.
 

pictsidhe

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European renewable energy mandates are a very real form of subsidy to these schemes. They wouldn't be built without them. There are lots of ways to put a thumb on the scale . . .
I take you have been getting your numbers from Facebook etc.
The reality is that in the UK, onshore wind costs 6c/kWh to generate. That is before any subsidies. It also happens to be less than both nuclear and coal. I don't have recent numbers for gas. But I seriously doubt gas is much if any cheaper.
Maybe you think nuclear and fossils should be subsidised and wind should not. But that is well into the realms of politics.
 

Vigilant1

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The cost of production is one data point. More important is the difference between the cost of production and the market value that the power commands at the time it is produced.
Distributing power and maintaining a stable grid also has costs. Intermittent, unreliable power produced without respect for actual demand drives up the cost of the grid as a whole, and govt mandates disproportionately push those costs to the remaining steady sources of electricity.
There would be no need for renewable energy mandates and other giveaways if these power sources made economic sense in their own right because then the utility companies would build them anyway. They want to make money and know how to do it.
Yes, other forms of power have had subsidies, too.
If we want to explicitly price in externalities (pollution, climate impact, etc) then our system should be explicit about it, rather than just random efforts in fits and starts with poorly supported rationales and vaguely defined objectives. And we should be honest about the costs. Expensive energy reduces the standard of living of those who pay for it.
 
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Voidhawk9

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The reality is that in the UK, onshore wind costs 6c/kWh to generate.
Is that installed capacity or actual? To rephrase, per maximum potential capacity, or what is actually generated, taking into account calm conditions etc.
 

emotodude

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The subject of the controversies around electricity production is really tiring every time it comes up on this forum. If only we could restrict ourselves to the electric airplanes themselves...
Right you are. I didn't realize what a rabbit hole this would become. I'll try to remain on topic :)
 

starrtit

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My 90 yr old brain seems to remember of a trial aircraft [model?] being kept in the air across Canada by beaming electrical energy from strategically placed electronic units on the ground. In Canada we have an enormous amount of electric power available so don't knock electric flying just yet.
 

mcrae0104

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Right you are. I didn't realize what a rabbit hole this would become. I'll try to remain on topic :)
No worries--that wasn't directed at you in particular. Glad you're here, emoto. BTW. I enjoyed your interview on the SonexFlight podcast.
 

Vigilant1

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Right you are. I didn't realize what a rabbit hole this would become. I'll try to remain on topic :)
Sorry for any ruffled feathers, I appreciate the way you presented your position. That the subject brings out strong opinions is just a sign of "bigger challenges" in our public discourse.
 

Dan Thomas

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The debate about electricity generation is valid. If we get it wrong, electricity will get really expensive, maybe even rationed, and now you have a problem. You end up with an expensive electric airplane and no legal/affordable fuel for it.

A parallel is the past (maybe present?) water shortages in some California cities, where washing your car or watering anything in your yard is outlawed.
 

pictsidhe

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Is that installed capacity or actual? To rephrase, per maximum potential capacity, or what is actually generated, taking into account calm conditions etc.
Total cost for generating electricty over the life of the installation. Building it, running it, scrapping it. Yes, including financing fees. Don't forget, fossil fuel prices as well as electricty keep on rising.
You can play with various numbers. Wind loses to fossils when you consider installation, but beats the pants of everything for running costs.

Total cost is the very bottom line.

Wind does make economic sense in windy places, like the UK. Privately financed wind farms were proliferating in Wales when I left. Look at the actual numbers, you can see why. They make a great 25 year investment. Arizona? You're better off looking at solar...

Unstable demand and supply? Try combining a national TV network, an unusually popular TV show with no breaks for an hour, in a nation of tea addicts.

A robust electricity network can handle power stations going off line, sudden demands in certain places. When you look at wind power over a large area, the variation drops considerably. The changes are also much slower. No problem to adjust the more traditional stations for.
January may suck for solar, but it is great for wind. A mix allows diversity and robustness. A fossil supply disaster? Good thing there are other types of fuel in use.
 
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berridos

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May i ask what are the important characteristics a generator should have, for example RPM, torque wise.....? My honda generator looks boring normal.
 

WINGITIS

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NEW PRESS RELEASE TODAY FROM NEW ZEALAND...


Unlimited range electric/solar.......very ambitious...!

They made it onto the main evening news show, local Mayor in tow etc etc.

Also with the Minister Of Innovation in toe, so they will be getting some government funding one assumes....

Brings back memories of the Martin Jetpack, money in not much out!!!!!!!!!!!!!!!!!!!!!!
 
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WINGITIS

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Some more info:



HMMMMMMMM, flying at 65,000 feet, that is a potential air density issue, although its roughly the same density as the NASA helicopter will see on Mars and NASA have sent that up in the latest package to Mars...so they think its possible to get lift at those densities...

There are no plan views that I can find from which I can abstract the chord from the 32 Meter span and do some calculations to ascertain whether at 90KG it can have lift at that air density!
 
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Jay Kempf

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It's actually been designed, built and tested more than once. Higher altitudes are possible as well. The aero and power budgeting is well known for HALE aircraft and there are a few players working on that particular design point. Spent some time working for one of those players a few years back. Far from a practical man carrying corner of the flight envelope though.
 

Speedboat100

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Solar ain't much of a range extender in the end. What you need to carry with you to take advantage of solar cells.

Salesmanship works this way: for Tesla, you can market breathtaking acceleration, then you can market huge endurance, how many chargers there are , and unbelievable R&D and planet stewardship... but the marketer implies that all those things can coexist. The customer assumes they do cause they were all in that one sentence together. The engineer knows they aren't and don't coexist.

For wind turbines you can say that they can output some continuous power number but they don't run continuously or even consistently except in a very few places. So what difference what their output per unit time is. What matters is what is their output when they can be synchronous with the grid on a day when the wind is favorable integrated over a standard year or something. Same with solar. And you just leave out storage of that energy cause you don't want to have to explain how you are going to do it and when.

I'm waiting for improbability drives to become reality. Then I can power all my devices with unfavorable odds.

I disagree battery+solar could give 6 + 6 hours flying time....in an efficient aeroplane....nowadays it don't have to look like Solar Impulse...as it is not soaring across the oceans.
 

Dan Thomas

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Far from a practical man carrying corner of the flight envelope though.
Yup. Carrying cameras isn't quite the same as carrying a human. And at 65,000 feet the solar energy will be far higher than at recreational flight levels. The density of air at 65K is 1/13th sea level density. Presumably, and someone can correct me, that means the solar energy filtered out by the atmosphere will also be about 1/13th as much, allowing solar cells to generate considerably more power. That airplane would need plenty of batteries to get up there, too.
 
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