-Finally- an honest assessment of electric airplanes

Baked Potato said:
Well it's a good thing that planes don't need infinite energy!

Weird stating that something will never happen. That's a lot of conviction.

Especially since electric planes actually exist, today. Just not with the specs or price that you need.
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They already exist, yet we’re discussing a statement by one of the leaders of the effort saying it’s not possible.
 
Salty said:
Weird that you claim that I stated something that I have never stated. I chose my words carefully. Read them.
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Ok, I did a few times and have not come to a better understanding of your statement. Apologies, but I'm unsure that we're making progress here.
Good discussion, all!
 
Baked Potato said:
Isn't that solid state batteries?
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Solid state battery research has been ongoing for decades. SSBs may eventually give us 2 or 3 times the energy density of currently fielded battery technologies, which would be around 0.3% of the energy density of gasoline. The real advantages of SSBs lie in the physical robustness of having a solid electolyte and the ability to charge them quickly. The SSB won't be a holy grail that magically enables electric aviation.
 
Half Fast said:
Solid state battery research has been ongoing for decades. SSBs may eventually give us 2 or 3 times the energy density of currently fielded battery technologies, which would be around 0.3% of the energy density of gasoline. The real advantages of SSBs lie in the physical robustness of having a solid electolyte and the ability to charge them quickly. The SSB won't be a holy grail that magically enables electric aviation.
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My understanding is that Li-Ion batteries have about 1% of the energy density of fossil fuels, so 2x or 3x that would be 2 or 3 percent. But point taken.

Also remember that the batteries (or fuel source) is only part of the equation though. There are also recent developments in engines that are much more powerful, and lighter, than our current piston or turbine engines. That will change the whole architecture of the power plants that we're currently used to and will enable configurations that are not currently on the market.

And also keep in mind that Tecnam is far from the only manufacturer that is (or was, in this case) developing electric aircraft.

Edit - per my link above, I, for one, am happy that US entities like MIT and NASA are developing these and we're not going to fall behind other countries in new tech like this.
 
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Salty said:
They already exist, yet we’re discussing a statement by one of the leaders of the effort saying it’s not possible.
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The article is about an electric twin engine plane.
Here's a certified electric plane:
Velis Electro - Pipistrel (pipistrel-aircraft.com)

Half Fast said:
Solid state battery research has been ongoing for decades. SSBs may eventually give us 2 or 3 times the energy density of currently fielded battery technologies, which would be around 0.3% of the energy density of gasoline. The real advantages of SSBs lie in the physical robustness of having a solid electolyte and the ability to charge them quickly. The SSB won't be a holy grail that magically enables electric aviation.
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SSBs may go beyond that 2 to 3x the energy density of current batteries too.
 
Salty said:
18 minutes of flight. Not practical. An experiment only.
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You haven't defined practical. Without a definition, your dismissal of the plane is meaningless.
Also, since you have told others that they read you post improperly, read the link again since the range is more than 18 minutes.

It's not experimental. They sell it as a certified aircraft.
 
Salty said:
Why assume there are no limits? ICE engines have also improved dramatically, but there are limits to their efficiency and output per pound of engine and fuel. Same is true of batteries. There is most certainly a physical limit, and to assume we are nowhere near it yet is ignoring the facts IMO. You can’t ignore physics just by wanting things to be true. Sure, a lot of things from Star Trek have developed, but far more of them have not.
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I'd never claim there are no limits. I do believe that we can't predict now what those limits will be.
Salty said:
Because, just as fuel contains a finite amount of energy, so does a battery. And the fact that with fuel you are consuming vastly more potential by breaking down the fuel completely rather than just moving electrons back and forth means it’s pretty safe to assume it will never come close.
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And here you touch on one thing that no one has mentioned, other than a passing tongue-in-cheek post by @ElPaso Pilot. The final solution may possibly be a vastly improved battery technology that we haven't hit on yet. It may instead be some other source of electrical power that we haven't even thought of yet.

Lest you think I'm some kind of sci-fi dreamer, no, I don't think we'll see some miraculous dilithium crystal power source... not any time soon, for sure. But I grew up in the 60s and 70s, and started a career in what we now call "IT" at the very dawn of the 80s. Most of what we have now would have been dismissed as wild fantasy and totally impossible back then, including driving my car (with heated and cooled seats and a couple hundred channels of 24/7 uninterrupted music) at 80 miles per hour while getting close to 30 MPG. I'm sure automotive engineers in the 70s thought they were getting close to the best that could be done, too.
 
Cap'n Jack said:
You haven't defined practical. Without a definition, your dismissal of the plane is meaningless.
Also, since you have told others that they read you post improperly, read the link again since the range is more than 18 minutes.

It's not experimental. They sell it as a certified aircraft.
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It’s an experiment. It is not usable in the real world. Nobody can make money or even break even with it yet. Pretend all you like. It’s not practical.
 
DaleB said:
I'd never claim there are no limits. I do believe that we can't predict now what those limits will be.

And here you touch on one thing that no one has mentioned, other than a passing tongue-in-cheek post by @ElPaso Pilot. The final solution may possibly be a vastly improved battery technology that we haven't hit on yet. It may instead be some other source of electrical power that we haven't even thought of yet.

Lest you think I'm some kind of sci-fi dreamer, no, I don't think we'll see some miraculous dilithium crystal power source... not any time soon, for sure. But I grew up in the 60s and 70s, and started a career in what we now call "IT" at the very dawn of the 80s. Most of what we have now would have been dismissed as wild fantasy and totally impossible back then, including driving my car (with heated and cooled seats and a couple hundred channels of 24/7 uninterrupted music) at 80 miles per hour while getting close to 30 MPG. I'm sure automotive engineers in the 70s thought they were getting close to the best that could be done, too.
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I’ve never said there is no tech we haven’t yet invented. With what we know now, batteries will not be that tech.
 
Salty said:
It’s an experiment. It is not usable in the real world. Nobody can make money or even break even with it yet. Pretend all you like. It’s not practical.
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A powered parachute is an experiment. you can only fly it in still air for a few minutes. Nobody can make money or breakeven with them. People fly them.
 
Salty said:
I’ve never said there is no tech we haven’t yet invented. With what we know now, batteries will not be that tech.
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Says the guy who doesn't know the basics of chemistry. Without that knowledge, all you have is a wrong opinion.
 
Finally? I’m pretty sure we had people here that knew this years ago. If only they had come here and listened.
 
Cap'n Jack said:
Says the guy who doesn't know the basics of chemistry. Without that knowledge, all you have is a wrong opinion.
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You mean all the things you’ve later agreed with in principal? Lol

never give up. Never surrender.

I’d be disappointed if you did.

meanwhile, I’ll get excited when something shows actual promise. Battery tech or otherwise. But if I had to place a bet today it would be on otherwise.
 
Cap'n Jack said:
And maybe more than 5x. I won't say there's no limit, but I won't say such a low limit either.
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Sure, pick any number you like. The higher the number, the lower the probability of achieving it. The probability of gasoline equivalence is near zero. I suspect the probability of getting to 25% of gasoline is not much better.
 
Half Fast said:
Sure, pick any number you like. The higher the number, the lower the probability of achieving it. The probability of gasoline equivalence is near zero. I suspect the probability of getting to 25% of gasoline is not much better.
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I think you’re being optimistic.
 
Half Fast said:
Sure, pick any number you like. The higher the number, the lower the probability of achieving it. The probability of gasoline equivalence is near zero. I suspect the probability of getting to 25% of gasoline is not much better.
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That's the thing though - equivalence in energy density is not necessarily a prerequisite to commercial feasibility.
 
ElPaso Pilot said:
Nuclear fusion battery, anyone??

1608559472-homer-nuclear-1608559439.gif
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download (2).jpeg
 
Half Fast said:
Sure, pick any number you like. The higher the number, the lower the probability of achieving it. The probability of gasoline equivalence is near zero. I suspect the probability of getting to 25% of gasoline is not much better.
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With the current efficiencies in ICE, 25% is all you need for a battery equivalence. Most of the energy burned in an ICE is thrown away as heat.
 
Salty said:
You mean all the things you’ve later agreed with in principal? Lol

never give up. Never surrender.

I’d be disappointed if you did.

meanwhile, I’ll get excited when something shows actual promise. Battery tech or otherwise. But if I had to place a bet today it would be on otherwise.
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I like the Pipistrel. A couple of hours flying time and charge it when you land. That's practical for me.
 
Cap'n Jack said:
With the current efficiencies in ICE, 25% is all you need for a battery equivalence. Most of the energy burned in an ICE is thrown away as heat.
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Yes, and there's almost no chance of achieving it with batteries.
 
Cap'n Jack said:
Says you. IIRC, you didn't think a 700-mile electric car was possible either.
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Is there a sedan I can go buy today that has a 700 mile range?

How many days does it take to do a full recharge? I own an EV, even with a ton of capacity there are issues to deal with.
 
Salty said:
Is there a sedan I can go buy today that has a 700 mile range?

How many days does it take to do a full recharge? I own an EV, even with a ton of capacity there are issues to deal with.
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You seem to be the only one with issues with your EV.
You know, if you have a ton of stuff in it, try reducing the weight you carry. You'll get better range.
 
Cap'n Jack said:
You seem to be the only one with issues with your EV.
You know, if you have a ton of stuff in it, try reducing the weight you carry. You'll get better range.
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Nope. I just don’t pretend they are perfect. Sometimes you even admit it.
 
Salty said:
Nope. I just don’t pretend they are perfect. Sometimes you even admit it.
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I never said they were perfect. Even the Leaf with 100 mile of range would cover 99% of my driving. Likewise, the electric Pipistrel would be a fun and practical plane for me.

Back to your EV- try taking some of that ton of capacity out and your range will improve. Any vehicles' range will improve with less weight. Do you really need to carry a ton of stuff?
 
Cap'n Jack said:
I never said they were perfect. Even the Leaf with 100 mile of range would cover 99% of my driving. Likewise, the electric Pipistrel would be a fun and practical plane for me.

Back to your EV- try taking some of that ton of capacity out and your range will improve. Any vehicles' range will improve with less weight. Do you really need to carry a ton of stuff?
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I’m talking about battery capacity. And yes, more batteries causes the other problems I was referring to.
 
Salty said:
I’m talking about battery capacity. And yes, more batteries causes the other problems I was referring to.
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Take a look at what you posted earlier. "Tons" isn't a unit of battery capacity. Ampere hours, Watt-hours, or kilowatt hours are appropriate units.
Salty said:
Is there a sedan I can go buy today that has a 700 mile range?

How many days does it take to do a full recharge? I own an EV, even with a ton of capacity there are issues to deal with.
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Cap'n Jack said:
Take a look at what you posted earlier. "Tons" isn't a unit of battery capacity. Ampere hours, Watt-hours, or kilowatt hours are appropriate units.
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Sorry for your misunderstanding.
 
Salty said:
Is there a sedan I can go buy today that has a 700 mile range?

How many days does it take to do a full recharge? I own an EV, even with a ton of capacity there are issues to deal with.
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The S450 we had would have went 700+ if we drove it the speed limit. Driving above it around 80, we had a 650 mile range and that was in terrain.
 
Baked Potato said:
Well it's a good thing that planes don't need infinite energy!
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No, but they need a lot more than cars do. Cars typically cruise at 25 or 30% power. Airplanes have to cruise at more than twice that, or they don't stay up. They burn considerably more fuel per hour because of that.

And "improved airframes" sure would fix that some, but where are they? There is already plenty of reason to improve them, but the best we see are slick composites that still need a lot of power.

The Pipistrel. We had a debate on this over on HBA some time ago. Pipistrel makes both electric and gasoline-power versions of their airplane, which leads some people to think they are equivalent. They are nowhere near equivalent.

The numbers for the Pipistrel Alpha trainer, powered by an 80 HP Rotax:

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The numbers for the Pipistrel Alpha Electro:

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Th electric has
-20 MPH less max speed
-Cruise range is 81 NM, and that's at 80 kt, not the 75% power's 108 kts. The gas version has a range of 324 NM. The 81 NM electric's range would be less at 75% power
-Note that there are no numbers shown for the electric's Rate of climb or service ceiling. I can't find the ROC but did earlier. The HP is the same, so the electric's ROC should be the same, but at full power for more altitude the range would suffer. The service ceiling will be low due to the limited battery capacity
-"Endurance" implies minimum-power level flight, and that's one hour plus the reserve. The best endurance speed appears to be the 80-kt cruise, based on the range at 80 kts.

I can't see these selling that well.
 
Dan Thomas said:
I can't see these selling that well.
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Yet they've been around for some years now. I don't think they've upgraded the batteries since introduction, but using current battery technology would improve range.
 
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