Why Gas Engines Are Far From Dead - Biggest EV Problems

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PMD

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Martensville SK
Well, as much as I dislike the idea of electric power for random direction/routing transportation, I DO think it has a place in SOME rail and city commuting. BUT: while the "gas engine" IMHO is pretty much at its peak of development, the future for diesel in cars, trucks, boats and ESPECIALLY airplanes is quite bright.

The HUGE difference in energy density between petroleum liquids and current battery tech is no where near compensated for by the difference in efficiency. While an electric MOTOR may have efficiencies in the 90s you still need the efficiency of the batteries (including the required heating and cooling requirements), the charging system and the power delivery....LESS the vehicle requirements for heating (as this is "free" from internal combustion systems). Now, the near 30% thermal efficiency of an SI (spark ignition = gasser) still doesn't measure up to an electric car (MAYBe 80%, but I think overall probably less) diesels available today are capable of near 50% (opposed piston) with some research reaching over 70%. Pretty much makes next gen diesel close to next gen sparky stuff.

In the world of aviation where on this very forum everyone worries (for good reason) about an extra 20 lbs. making one engine unacceptable compared with another, just think about how ridiculous it is to speak of systems that require 2x or 3x the entire propulsion system weight to get the same job done.

In OUR world of aviation where a $10k Kia can get far, far more useful range (especially in inclement weather) than a $100k with subsidies Tesla are we ready for 2x or 3x the propulsion system costs?

See how utterly ridiculous electric airplanes actually are?
 
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dog

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Well, as much as I dislike the idea of electric power

The HUGE difference in energy density between petroleum liquids and current battery tech is no where near compensated for by the difference in efficiency.

Yet

See how utterly ridiculous electric airplanes actually are?

I see electric airplaines as the most interesting and
promising direction that aviation is going in.

Hereis one tidbit.
Counter rotating electric motors with variable pitch propellers are easy,and they can do things no other syatem can.Variable pitch and speed with two different diameter props.
The contraction of the airstream(see multiple threads on Bernoulie) after the first prop then enters the disk of the second slightly smaller and faster rotating prop,resulting in something like an
open air ducted prop.This is easy to try electricaly
and almost impossible to build with "conventional"
engines.
Firewall?whats that?
No need to put the electric "fuel"at the cg as there is no weight change.
Opens up configurations that are impossible with
a liquid fuel.

Physics is awesome!
 

lr27

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PMD: If I'm not mistaken, a Kia won't get much further than a Tesla without using a gas station, just as a Tesla won't get all that far without a charging station. So this isn't really an example of the inherent limitations of the technology. Obviously, it's a little different in the air.
If it's possible to store a reasonable amount of hydrogen in a tank that's not too heavy, and fuel cells don't pan out, we can always burn hydrogen in internal combustion engines.
 

pictsidhe

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PMD: If I'm not mistaken, a Kia won't get much further than a Tesla without using a gas station, just as a Tesla won't get all that far without a charging station. So this isn't really an example of the inherent limitations of the technology. Obviously, it's a little different in the air.
If it's possible to store a reasonable amount of hydrogen in a tank that's not too heavy, and fuel cells don't pan out, we can always burn hydrogen in internal combustion engines.
Hydrogen storage is very heavy. It makes hydrogen a poor fuel for aircraft.
 

Vigilant1

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Hydrogen storage is very heavy. It makes hydrogen a poor fuel for aircraft.
Yes, and there are many other problems with hydrogen. It is famously difficult to store (leaks through most common gasket materials/sealants, causes embitterment of steel, copper, and several other metals), and rather than being "clean" it is commercially produced using natural gas as starter stock, with considerable loss of energy compared to just burning the natural gas. (Producing hydrogen using electrolysis would considerably increase the price). Hydrogen might appear to be a useful means of transferring/storing power for electric motors, etc, but on a large commercial scale it is a road to nowhere. The "hydrogen economy" envisioned by some people was, and remains, impractical. More here:https://www.thenewatlantis.com/publications/the-hydrogen-hoax
 

dog

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Dec 29, 2019
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=very simple...
Yes thank you.
Made a mistake and was thinking of two gas engines,not one.
I watched the videos you provided links to before.
Awesome.Want!
And in full honesty that is one of the very few ideas
that can help to give some life to internal combustion powered planes.
Whats the catch?It seems that having symetrical
thrust offers enough advantages, no need to
offset the rudder ,with the losses there,and presumably a much smoother airflow over the fueselage,smaller propeller diameter nessesary to absorb the power, and also shorter landing gear and with less weight,knock on for landing gear attach points(ya, ya, tiny)The increased propeller efficiency of have the second propeller operating in
an reduced pressure and higher speed flow has to be significant.
Must be more!
The whole lunch might not be free,but it sure looks like the desert is on the house.
Still ever so slightly easier with electric motors.
 

Dan Thomas

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I suspect a future bottle neck on the world's supply of lithium, cobalt and nickel, will moderate the transition from internal combustion to EV. Wonder if some future Greta Thunberg may be reading up on lithium and cobalt mines in "developing countries" even now. Maybe hydrogen fuel cell technology can improve to point it overtakes lithium battery technology. But, I'm betting I'll be able to get full use out of my IO-360. The question is will it still be burning 100LL?
I read somewhere (on the internet of course) that if everyone in Europe bought an electric car, the world's known reserves of lithium would be entirely consumed. From https://www.livescience.com/28579-lithium.html

  • Lithium and another battery component, cobalt, could become scarce as demand increases, Stefano Passerini and Daniel Buchholz, both at the Helmholtz Institute Ulm in Germany, said in a statement describing their analysis of the future availability of those elements published in 2018 in the journal Nature Reviews Materials. In addition, both are concentrated in less politically stable countries, the study revealed. As such, the researchers urged the development of new battery technologies based on other, non-toxic elements.
  • The United States has one lithium mine, in Nevada, according to the USGS. Chile and Australia produce the most lithium in the world.
So, imagine what happens to the prices of lithium and cobalt as the demand for vehicle batteries skyrockets and supplies tighten. Just imagine. As if aviation wasn't already expensive enough.
 
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Dan Thomas

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Was stated as LTA in the first mention,the fact is that electric flight is viable now,limited missions
granted.There are deap pockets working on electric
turbine hybrids for regional comuter planes and the same thinking applies to light aircraft.

Phisics is always fun.
Man-powered airships have also always been possible. The LaFrance is absolutely no indicator of the coming success of electric airplanes.
 

lr27

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Hydrogen storage may not be heavy forever, though. And electrolysis may be more expensive right now, but I think it's hard to say where things will be in a few years. People are also working on other kinds of fuels made with electricity instead of oil. I seem to recall someone is making methane with electricity, from atmospheric carbon and, presumably, water.
 

Dan Thomas

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Sep 17, 2008
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I see electric airplaines as the most interesting and
promising direction that aviation is going in.

Hereis one tidbit.
Counter rotating electric motors with variable pitch propellers are easy,and they can do things no other syatem can.Variable pitch and speed with two different diameter props.
The contraction of the airstream(see multiple threads on Bernoulie) after the first prop then enters the disk of the second slightly smaller and faster rotating prop,resulting in something like an
open air ducted prop.This is easy to try electricaly
and almost impossible to build with "conventional"
engines.
Firewall?whats that?
All of that stuff you propose is possible with IC engines. All of it. Counterrotating constant-speed props have been used on light twins since the 1970s, when I learned to fly. Tandem props have been seen on various airplanes longer than that. Study some actual aviation history.

Firewall? Maybe one would be advisable between that massive lithium battery pack and the occupants? After all, Teslas have offered spectacular fireworks fairly regularly when their batteries explode into an inferno for no discernible reason.
 

Dan Thomas

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PMD: If I'm not mistaken, a Kia won't get much further than a Tesla without using a gas station, just as a Tesla won't get all that far without a charging station. So this isn't really an example of the inherent limitations of the technology. Obviously, it's a little different in the air.
If it's possible to store a reasonable amount of hydrogen in a tank that's not too heavy, and fuel cells don't pan out, we can always burn hydrogen in internal combustion engines.
Ranges are vastly different, as is the time to "refuel."
 

Dan Thomas

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Hydrogen storage may not be heavy forever, though. And electrolysis may be more expensive right now, but I think it's hard to say where things will be in a few years. People are also working on other kinds of fuels made with electricity instead of oil. I seem to recall someone is making methane with electricity, from atmospheric carbon and, presumably, water.
Sounds like simple electrolysis. An onboard aircraft system would be heavy, and you still have to tolerate losses in converting the electricity to methane and then burning the methane instead of using the electricity directly.

Methane is better known as natural gas, and the earth has plenty of that.
 

Victor Bravo

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Various shrill denouncements of electric propulsion and the introduction of Gretta are questionable though.
Speaking of shrill, a shrill voiced, clearly theatrically trained child that is essentially being used as a political operative... does not give the electric vehicle or environmental movement any added credibility with me. I've seen plenty of amateurs coached and trained on how to be a media darling, and I can smell it a mile away.

Being spoon-fed carefully scripted sound bites, or having every other situation comedy on TV serving as a political infomercial, is getting on my nerves. Sorry for the OT rant...
 

lr27

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Ranges are vastly different, as is the time to "refuel."
Last time I checked, the average gasoline fueled car could go somewhat over 300 miles on a tank. The range for the Tesla I"ve seen quoted is comparable, but let's say it's only 200 miles. Currently, it takes a while to charge a Tesla, but I own batteries that can be charged in 15 to 30 minutes. Personally, after driving for several hours, I like to stretch my legs and eat something. So electric ground vehicles, or at least cars, are practical NOW. Especially plug in hybrids.

As I said, in the air it's another matter.

Dan Thomas:
The whole point of methane would be to leave what you call an onboard system on the ground. The use model is a tank in the vehicle which you fill with a hydrocarbon and burn in an ICE engine. That ought to sound familiar. If methane requires an excessively heavy tank, I"m sure that chemists can make a liquid fuel with it. At the moment, there is a problem with excess electricity from renewable sources at times. This would be a way to use it, and produces a fuel which borrows carbon from the air rather than introducing mire from underground.

pmaf: What history teaches is getting into politics. My observation is that history usually "teaches" people things they're already inclined to learn. One thing I've "learned" from history is that when there's a broad consensus among many scientists, that conclusion tends to be close to the truth.
 

BJC

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It is prudent to keep in mind where the electricity comes from.

upload_2020-2-17_13-3-24.png
As you can see, about 3% is from wind and solar combined.


BJC
 

lr27

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That's changing quickly. Prices are way down. And other countries are ahead of us. We will change with alacrity once seawater reaches the Capitol steps, but I'm not so sure about before that. ;-)
 
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