Why battery-powered aircraft will never have significant range

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Appowner

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Yes, and I appreciate the lithium batteries in my drills. But we will wait for the "promised" new stuff that's ten times better. We've been promised way too many fantastic things over the years that never materialized. The fantastic stuff we have now, like that cellphone that can send you voice or pictures or videos or texts anywhere in the world, almost, was never promised like the new electric stuff (or flying cars) is being promised. If I had been told 30 years ago that I'd be carrying a tiny cellphone that could do all that and thousands more things I'd not have believed it. Too fantastic. But here it is, something we were never promised like so many other things are and have been promised that we're still waiting for.

If they do come up with batteries ten times better, very good. Electric flying will do much better than it has been, but those new batteries will also be more expensive until the patents run out.
WRT Cell phones. You never read Dick Tracy or watched Star Trek?

Cell phones have been promised for years. They just never generated the excitement flying cars have. And considering the number of irresponsible cell users out there, I'm kind of glad the flying cars haven't made it. Yet!

BTW, remember the Motorola flip phones? In the military we referred to them as BEMUS for Beam Me Up Scotty.
 

Dan Thomas

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WRT Cell phones. You never read Dick Tracy or watched Star Trek?

Cell phones have been promised for years. They just never generated the excitement flying cars have. And considering the number of irresponsible cell users out there, I'm kind of glad the flying cars haven't made it. Yet!

BTW, remember the Motorola flip phones? In the military we referred to them as BEMUS for Beam Me Up Scotty.
Science fiction does not constitute promise of fantastic new technology. Where, for instance, is Diet Smith's magnetic space capsule?
 

mrinnovation

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Yes, pleading guilty, I'm a smart a**. (For a living :) )

But, I ask that you look at it from the public's side as well as your own. Assuming you are a professional with any level of expertise, in almost any field, you certainly will have seen all manner of big claims, hyper-hyperbole, and grandstanding in that field. And you will have seen that it generates eye-rolling that is proportional to the size of the claims, and usually proportional to the square of really big bold claims that promise the moon.

In my lifetime only one guy ever actually promised the moon and delivered on the claim, and he got shot anyway.
I didn't make any claim other than to say there are many people who have prototypes of devices that will change the "battery paradigm", including our team. I don't need to show proof, nor could I without getting into trouble. So go ahead and roll your eyes, be a doubting Thomas, call me whatever you will, it's ok, I get called worse by my wife, so I'm used to it.
 

PMD

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What really makes me scratch my head (and that is easy as there is no longer much hair in the way to blunt effect) is that in a business and hobby where we fret about ounces - or careless people whole pounds - anyone at all would seriously discuss a power delivery system that costs TONS in extra weight to do what the currently available hardware does already?????

Secondly: in a community of people who are analytical by description - why doesn't anyone bother to mention the environmental costs of producing the ever-off-in-the-distance battery technologies that now depend upon rare earth metals that don't even have the known reserves to run all of the projected electric cars that governments are subsidizing into being????

When engine technology is as advanced as it is (and in ground transport is sure as heck IS extremely sophisticated) we can eschew this ridiculous trend of trying to virtue signal in our designs and work to simply focus on making far more efficient both aerodynamically and thermodynamically the things we all know so well work to do what we do?

From an hard core environmental perspective - demonizing carbon is really only an issue when we ignore that the real problem is that we are destroying the ocean's ability to fix carbon in it's natural cycle. While we shouldn't look at releasing more carbon, we should look at absorbing what we COULD absorb by stopping our efforts to screw up the carbon sink that can easily manage at least a globally sustainable level.

If we DO want to stop carbon emissions from our sources, the solution IMHO is to use liquid hydrogen as a fuel - VERY good energy storage density and easily burned in either spark ignition and/or compression ignition engines. Of course, sourcing the H2 will require some green-ness, thinking PV is best.
 

PMD

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Thx. Had some kind of tech glitch in account and could not reach anyone. Finally got an e-mail from site with a reply link and it is all well now. Great to be back. Hope everyone is well.
 

BBerson

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Of course, sourcing the H2 will require some green-ness, thinking PV is best.
PV requires a large amount of coal or oil to make. Perhaps more coal than the PV can give back in solar energy depending on the latitude.
I have read that silicon refining from sand requires 20 remelts in a zone furnace to make pure enough. And some 200 other processes.
 

Victor Bravo

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I'd like to ask a question of anyone who has a better technical understanding than I do about nuclear power (nuclear power to generate the electrical power that recharges our homebuilt aircraft batteries, of course).

I understand that one of the biggest issues is cooling the reactor, keeping the heat under control and transferring it safely out of the system.

So most everyone built nuclear plants near the ocean, or some big river system, and use the large bodies of water as the medium to absorb the heat out of some kind of heat exchanger. But as we saw in Japan, the ocean can get angry and cause some major issues.

If you built a reactor cooling system that used a much larger version of a finned "heat sink" (like what is used to cool computer processors) as the final stage of transferring the heat out of the powerplant... essentially an air cooled heat exchanger... just how big would that final heat exchanger have to be for an average sized nuke power plant? 500 x 500 feet? 2000 x 2000 feet? A square mile?

My idea is that a nuke plant in the middle of the desert would be able to take advantage of almost any size solid state air cooled heat exchanger that was required. If you had half a square mile's worth of steel or aluminum cooling fins radiating 150-180 degree heat into the air, you would be able to reject an awful lot of the excess heat.

Tsunami's wouldn't hurt it, and if it was designed properly an earthquake wouldn't hurt it either. You would have a lower number of failure points or brittle solutions. Even in the event of some unforeseen catastrophe, you'd be out in the middle of the desert, instead of near a major population center (you'd poison a bunch of rattlesnakes and coyotes, but you wouldn't kill ten thousand people, or wreck the world's supply of fish, etc.).

We are blessed in the western USA to have an abundance of uninhabited desert, where this would be viable. The land cost is still very low compared to anywhere near a coastline as well.
 

Voidhawk9

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I understand that one of the biggest issues is cooling the reactor, keeping the heat under control and transferring it safely out of the system.
Yes, there are a lot of good, workable ideas, many of them already tested and proven to work. Some also make it impossible to kill the rattlers even if everything goes wrong. But getting regulatory approval etc. makes getting your homebuilt certified look like a milk run.
 

BBerson

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I'd like to ask a question of anyone who has a better technical understanding than I do about nuclear power (nuclear power to generate the electrical power that recharges our homebuilt aircraft batteries, of course).
I am not an expert but I think water cooling is more practical or even required.
I think putting the reactor on a barge off the coast has been proposed. In a meltdown it can be lowered into the sea to cool. Other similar ideas, but the current US plants have more than adequate safety fallbacks. The political push to remove Diablo canyon is motivated by the oil industry working with Green groups and the governor. No scientific reason to remove it, especially if carbon pollution is a concern. Read the book Apocalypse Never by Michael Shellenberger, who was a Green anti-nuke activist that switched to pro-nuke.
His website is Enviromental Progress and his free newsletter here:Michael Shellenberger
 
Last edited:

BJC

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VB:

The cooling that you asked about is the primary waste heat in the power generation cycle. It is the energy removed from the steam that exits the power turbine (that drives the generator) to condense the steam so that it can be pumped back into the steam generator. The process is common to both nuclear generation and fossil fueled generation. Almost all condensers are water cooled, and, in many locations, that water needs to be further cooled before being returned to a lake, river or ocean. That further cooling typically is done with cooling towers that evaporate some of the water to cool the rest of the water. Where full time cooling is mandated, hyperbolic, natural draft towers are used. Those towers frequently are mis-represented by the news media as nuclear reactors.

There have been air cooled condensers in a few locations, but they are rare.

Note that, with either nuclear or fossil generation steam turbines, it is essential that the condensers operate effectively to attain both maximum generation and maximum efficiency.


BJC
 

Vigilant1

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If you built a reactor cooling system that used a much larger version of a finned "heat sink" (like what is used to cool computer processors) as the final stage of transferring the heat out of the powerplant... essentially an air cooled heat exchanger... just how big would that final heat exchanger have to be for an average sized nuke power plant? 500 x 500 feet? 2000 x 2000 feet? A square mile?
In the case of a failure of the primary coolant and the need for emergency core cooling, I suspect the issue would be inadequate heat flux through the solid heatsink material. Even a solid with very good conductivity (e.g. copper) can't move the heat quickly enough from the concentrated hot side to the larger cool side. If the heat can't move through the copper as fast as it is being added, it melts, or at least the temps increase on the hot side till something else gives.
Physical movement of fluids (liquid or gas) can transport a LOT more heat for a given size pipe.
Heat pipes (vapor and gasses moving inside a tube with condensation on one end, evap on the other, no pumps needed) can move MUCH more heat than a copper rod of the same size. IIRC, it is about 50 times more.
 

radfordc

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I'd like to ask a question of anyone who has a better technical understanding than I do about nuclear power (nuclear power to generate the electrical power that recharges our homebuilt aircraft batteries, of course).

I understand that one of the biggest issues is cooling the reactor, keeping the heat under control and transferring it safely out of the system.

So most everyone built nuclear plants near the ocean, or some big river system, and use the large bodies of water as the medium to absorb the heat out of some kind of heat exchanger. But as we saw in Japan, the ocean can get angry and cause some major issues.

If you built a reactor cooling system that used a much larger version of a finned "heat sink" (like what is used to cool computer processors) as the final stage of transferring the heat out of the powerplant... essentially an air cooled heat exchanger... just how big would that final heat exchanger have to be for an average sized nuke power plant? 500 x 500 feet? 2000 x 2000 feet? A square mile?

My idea is that a nuke plant in the middle of the desert would be able to take advantage of almost any size solid state air cooled heat exchanger that was required. If you had half a square mile's worth of steel or aluminum cooling fins radiating 150-180 degree heat into the air, you would be able to reject an awful lot of the excess heat.

Tsunami's wouldn't hurt it, and if it was designed properly an earthquake wouldn't hurt it either. You would have a lower number of failure points or brittle solutions. Even in the event of some unforeseen catastrophe, you'd be out in the middle of the desert, instead of near a major population center (you'd poison a bunch of rattlesnakes and coyotes, but you wouldn't kill ten thousand people, or wreck the world's supply of fish, etc.).

We are blessed in the western USA to have an abundance of uninhabited desert, where this would be viable. The land cost is still very low compared to anywhere near a coastline as well.
 

PMD

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@PMD

The answer is very simple. If we always used what was proven, then we would never advance anything.

Tim
There is a time to innovate, but there is also a time to renovate. Innovation that causes far more damage than the status quo (and in this case I mean LiPo batteries and the idiotic idea of putting a ton of batteries in a light airplane just to do a virtue signalling move) is hardly advancing anything except the pollution from rare earth mining and the fortunes of those who speculate in these information (read propaganda) driven markets. We can safely advance by doing things (such as STOP killing off the oceans) that we know - but not being herded like the sheeple from the interwebs to demonize carbon.

When we ignore the science and embrace the technology, I don't call that smart or moving forward.
 

PMD

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While I am heavily involved with energy businesses and work, I am a rank amateur at this nuke stuff. Yes, have worked in some plants, but that doesn't require expertise in nuclear science, just the technologies we work with.

From what I understand: the real future lies in subcritical mass, gas cooled reactors ("pebble bed"). For conventional (read ANCIENT) designs, we (i.e. Canada - formerly AECL) use a lot of thorium fuel rods - but they have to be salted with uranium to keep a stable chain reaction - otherwise the thorium doesn't run away (i.e. critical mass) but simply shuts down. Not sure if we can use uranium/thorium pellets (but don't see why not). Meanwhile, while we pontificate and debate, China simply goes full scale, full bore ahead producing new subcritical mass designs for series manufacture.
 

PMD

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PV requires a large amount of coal or oil to make. Perhaps more coal than the PV can give back in solar energy depending on the latitude.
I have read that silicon refining from sand requires 20 remelts in a zone furnace to make pure enough. And some 200 other processes.
I wonder how the design life of PV relates to its obviously intense energy use in manufacture?

Of course, the other thing I forgot was that we are so afraid of burning down a 767/777 that we don't allow much in the line of LiPo batteries in the storage hold, but we can SERIOUSLY put a ton of the damned things in a light plane? You can ignite these things with a hammer blow, and when they start to burn, they are virtually impossible to extinguish with anything a fireman has available. IMHO, flying, driving or sailing one of these things is parallel to Homer Simpson coming home with a live isotope in his pocket.
 
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