Why battery-powered aircraft will never have significant range

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Vigilant1

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I might buy an economy one or two seat electric car. None available.
The battery replacement cost depends on the weight of the battery. So driving a five seat vehicle with one person is costly.
A (cheap) tiny electric car might have utility. It is tough to make a very small vehicle safe on a one-car crash, impossible to make it reasonable in a head-on crash with the now ubiquitous SUVs. It's just the F=ma thing. Not much value in seat belts etc if the driver's head pops off the stalk.
Motorcycles aren't safe in a crash, but from years of street riding I believe that, if responsibly used, their superior acceleration and ability to squeeze between cars can help riders avoid crashes. If a small electro-cycle was as nimble as an IC motorcycle, that might be an option for short range, fair weather errands. OTOH, if it is a slug I'd never want to ride it in traffic.
 

Hot Wings

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A (cheap) tiny electric car might have utility.
My current ideal ground transport would be a hybrid Messerschmidt KR 200 clone with a 50+ hp combined output.............and a trailer hitch.
My aviation projects (Quickie:AV-361) seem to follow the same pattern.

Emotion is involved in those choices. An old Cushman Truckster would probably have the same utility, but not the style of a Messerschmidt clone.
And we all know that HBA, other than Toobuilder's, are just for fun.
 

BBerson

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impossible to make it reasonable in a head-on crash with the now ubiquitous SUVs.
I don't think so. The 900 pound Edison 2 passed the crash tests. So does the tiny Smart car.
I want big and light weight for more crumple zone. Two seat tandem could have enormous side crumple zone. (two feet). It needs four wheels spaced wide like Edison 2, but doesn't need four seats that the X-prize required.
If X-prize did a two seat contest it would have enormous return for economy and actual sales to the masses not just the wealthy.
 

Bille Floyd

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Having lived off grid on solar for more than 10
years I can say ,you are wrong on all points,as of right now the sun is going down,I can hear my deapfreez running,just watered the horse,
3/4hp 220v ac jet pump, running from a split
phase 220 v inverter operating from a 400ahr,
48 v dc battery bank.
My up time is better than the grid.
Solar power is now officialy the cheapest power ever built and run.
Solar pv production will more than double over the next two years.
Many many billions of dollars are going into just the research for the next gen solar.
And just to yank your chain.
There is an little known variant of photo voltaics that might interest you Dan, as it runs
on gasoline,useing a pv panel that has been tuned for one specific wavelength of light and built into a cylindrical shaper, then fuel is burned inside the resulting tube and the coulor temp of the flame is regulated to match the
photo voltaics.
Do you use Wind , as well ; was thinking you might know
how that , would fit in the efficiency rating for gathering electricity ?
That question, does loosely fit , in the Topic of discussion.

Bille
 

Vigilant1

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I don't think so. The 900 pound Edison 2 passed the crash tests. So does the tiny Smart car.
The frontal crash tests (both NHTSA and IIHS) simulate crashes against vehicles that have similar weight to the tested vehicle. This is frequently overlooked.. If you test any small car in a head-on crash with a considerably heavier vehicle, the occupants in the lighter car do comparatively poorly.
Link to tests between vehicle sizes:IIHS used car lists help families choose safer, larger vehicles for teens
The 2008 Smart for 2 and the 2008 Mercedes C-Class both got top IIHS
ratings for frontal crashes (because the ratings assume they crash into a similar size car). Here's how they did against each other:
Even if you can keep the passenger compartment of the little car intact, it is still coming to a stop and reversing direction while the heavier car just keeps moving forward. Lots of Gs, very tough on the head/neck of those in the lighter car.

When our daughter was looking for her first car, we offered to help pay for it, with some conditions. We wanted good crash test results an a minimum weight of 3000 lbs. Kinda arbitrary, but there had to be a line somewhere.
 
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Vigilant1

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My current ideal ground transport would be a hybrid Messerschmidt KR 200 clone with a 50+ hp combined output.............and a trailer hitch.
My aviation projects (Quickie:AV-361) seem to follow the same pattern.
That's cool. I liked the GM "Lean Machine" that was displayed at Epcot for many years.
https://www.hemmings.com/stories/2020/03/26/had-gm-produced-the-lean-machine-wed-now-be-able-to-drive-the-ultimate-self-isolation-vehicle
But swapping things to have a single rear wheel and two in front simplifies things (no differential needed) and improves handling, especially braking in a turn.

A motorcycle rider's eyes are above the other car rooftops or at least within the glazing zone of most vehicles (even pickups and SUVs). This improves situational awareness a LOT compared to being down low, and also helps other drivers see you (if they bother to look). Any small vehicle that puts the driver's head down low gives up a significant crash avoidance mechanism.
 
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BBerson

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Link to tests between vehicle sizes
True but weight is only half of F=MA
The article said : "is determined in part by the vehicle's own weight".
Need a bit more front and rear crumple zone to equalize. I am not a teen either, and speeds over 55 are on divided interstates.
 

dog

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Do you use Wind , as well ; was thinking you might know
how that , would fit in the efficiency rating for gathering electricity ?
That question, does loosely fit , in the Topic of discussion.

Bille
Not useing wind.Have a rather large wind turbine project that was gifted to me.
Bergey 10kw with tower and electronics,sans
blades ,hence a project.
 

dog

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Depends on where you live. Warm sunny place is good. Where I live, nope. Between the low sun angle and short days in the winter, the snow covering the panels and the sometimes -30C stuff, solar in only useful for about half the year. But that is helpful at least, just payback time on the investment is doubled.
I live almost exactly on the 45th parallel,half way to the pole.Winter here sees weeks on end with low light.
The price of PV panels alows designing the system for those months and the rest of the year is gravy.
Lots of snow,lots of ice,lots of wind,plenty cold.
Just design for that,and for someone useing grid tied solar there just isnt a down side.
Here in Canada they will let you roll a chunk of your RRSP's onto your roof,no tax,and rebates.
 

dog

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Yeah, reliably absent over 50% of the time.

Solar has a place in the mix. Wind, too. But until very cheap and reliable storage is actually fieldable, they will be bit players. Power produced when it isn't needed isn't very useful right now. And theoretical power production that isn't available when demanded is a cruel joke to folks who need to keep their house warm.
Intermittent power sources drive up the cost of electricity by requiring extra (truly reliable) power generation to remain in existence and ready to go, but not producing. Then, solar proponents point to those sources and say "look how expensive they are per kilowatt that you produced! Buy more cheap solar and wind!' Yeah, cheap.
Solar and wind accounts for 11% of us energy production.
A 800 mw off shore wind plant just got aproval.
just off Marthas Vinyard.
Size of an average nuke and runs on air.
 

Vigilant1

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Solar and wind accounts for 11% of us energy production.
Solar power: Utility scale PV constituted just 2.2% of US electrical generation in 2020. If we add in all the rooftop PV systems, it's just another 1.5% (at the price of huge taxpayer giveaways). Altogether, just a drop in the bucket.
Wind: Another 8.4% of production, all of it totally unhitched from electricity demand and intermittent/fickle, so it drives up grid costs and costs of all the standby (reliable) generating capacity that has to back it up 24/7/365.

A 800 mw off shore wind plant just got aproval.
just off Marthas Vinyard.
Size of an average nuke and runs on air.
When it runs. "Becky, I feel a breeze outside! Maybe we can finally run the washing machine today."
 
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Dan Thomas

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I live almost exactly on the 45th parallel,half way to the pole.Winter here sees weeks on end with low light.
The price of PV panels alows designing the system for those months and the rest of the year is gravy.
Lots of snow,lots of ice,lots of wind,plenty cold.
Just design for that,and for someone useing grid tied solar there just isnt a down side.
Here in Canada they will let you roll a chunk of your RRSP's onto your roof,no tax,and rebates.
How much ground area does your solar array occupy?

Then we multiply that by the number of houses in a city and add in the commercial building needs, and maybe find that we need much more than another city's area for the solar panels.

Out here on the Canadian prairies, a solar thermal array was decommissioned and demolished recently near Medicine Hat. 'The Gas City' pulls plug on money-losing $13-million solar power project

And on the prairies as well as other places, hail is a big problem.

1620835917658.png
 

Starjumper7

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In all fairness, we have yet to see the limit to the stock market. Since its inception, when its composite value was below 100 points, to its all-time high of over 11,000, it has continuously been growing,
If you factor in real inflation, not the govt. advertised kind, then it's a joke.
 

rv7charlie

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In response to the Canadian winter [corrected] images...
How to make your energy supply unavailable (use natural gas & give full control of energy supply/delivery to profit motivated corps):
1620862320179.png
 
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BJC

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How to make your energy supply unavailable (use natural gas & give full control of energy supply/delivery to profit motivated corps):
A public utility’s behavior is mostly dictated by the state’s utility commission. Some states have effective, functional commissions; some are totally political.

REAs are quasi-governmental entities that, supposedly, are responsive to their “members”.

If you don’t think that your electric energy supplier is doing a good job, formally complain to the commission or the REA’s management. Many utility company executives have part of their performance compensation based on favorable commission ratings / absence of formal customer complaints. If the commission is lousy, elect different legislators and governors.

Some form of reliable electrical energy supply will be necessary for the electric homebuilts that will proliferate in about 30 years.


BJC
 
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