Kinda surprised no one is talking about Siemen's new electric motor

Of course the other advantage is an electric motor won't have pistons banging in and out all the time and thus will lack the concomitant vibration. I suspect they will be considerably quieter, eliminating noise complaints from airport neighbors, and will probably not have to be taken apart every 2000 hours or so.
 
Sac Arrow said:
Except that petroleum fuels exceed a battery's energy density by orders of magnitude.
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I realize that, I was just pointing out that the energy density of batteries doesn't quite need to reach the energy density of petroleum simply based on the efficiency of an electric motor compared to an ICE.

JHW said:
that's all true. Now, where did the electricity come from? Does it just flow into the batteries from a magic plug in your garage ?
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Again, I'm not an electrical/mechanical engineer or any kind of chemist or physicist that can come up with some new magical power source. Or even a way to charge batteries more quickly.

My one and only point was that electric motors are more efficient than ICEs, therefore the energy density of a battery can be lower than petroleum but still get you the same output power from the engine it's feeding.
 
RJM62 said:
The thing is, Jim, that my 1985 Escort with a 1.6 L gas engine and a five-speed manual transmission averaged about 35 MPG, my 2001 Saturn with a 1.9 L gas engine and a 5-speed manual transmission averaged around 41 MPG, and my 2012 Kia Soul with a 1.6 L gas engine and a 6-speed manual transmission averages around 36 MPG (or 39 MPG if I use ethanol-free gas), all with a lot less complexity.

Granted, I'm a bit of a hypermiler, and I always beat EPA estimates by a significant margin. Even my 2006 Saturn Vue SUV got close to 30 MPG with some moderate hypermiling techniques. So I'm wondering how much more efficient the hybrid drivetrains really are.

My understanding is that where hybrids really shine is in the stop-and-go kind of traffic where conventional drive trains are inefficient. Even when I lived and worked in the NYC Metro area, I really didn't encounter very much of that. I was able to schedule most of my stops along schedules that avoided most traffic tie-ups. And where I live now, there simply is no heavy traffic. I'd have to drive a couple of hours to find some. So maybe my numbers don't represent a good comparison.

Also, my preference for manual transmission has to be considered. That adds a few MPG if you know how to use it, which not too many people do nowadays. :(

Nonetheless, I've never been all that impressed with the MPG of hybrids because as a group, they don't do much better than what I do with conventional drivetrains.

Rich
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Hehe, we sound a lot alike. Growing up, I had a succession of small Fiats, and later I had a fleet of Geo Metro wagons. I recall back in the 80s Geo/Sprint used the 55MPH speed limit signs to promote their fuel econ numbers on the 3cyl metro stick shift. But, back then the Metro weighed nothing. It was cheap tin, with cheap wheels, spartan interior, usually no AC, no airbags, and ran on pure gas with no Eth. Again, like you I could actually beat the 55MPG once in a while in winter with high tire pressure and some hypermile driving.

Now, we have to live with crumple zones with more steel around the cage, airbags and controllers, AC in every car, window motors, thicker insulation, and a host of other issues, and we have to use E10 most of the time. Also, speeds have gone up to 65-75 for highway which makes a heck of a difference due to drag.

I looked real careful at the hybrids before buying and now I have 3 - well, actually 2-1/2 because my 10 Saturn Vue is really a mild hybrid with just a small traction batt. The other two are Prius C models, and they are pretty amazing. First, you don't need to hypermile them to hit the book number. They will do ~53MPG in city driving if you are just a little careful with accel. And they will do close to 50 on the highway if you aren't using the AC or driving 80. Of course, higher speed and AC use will pull it down pretty quick.

My kids are driving the Prius C each and they report consistent ~50MPG numbers in mixed city/highway commute and trip driving. I can't get anything non-hybrid or non-diesel that will do that. They also get 9 airbags, elec windows, tilt wheel, AC, and a quiet ride. Tons better than my old Metro.

My 10 Saturn Vue green line is pretty amazing, and I hate saying that about a GM car. I get 30MPG if I drive careful and it has tons of room. I even can tow a small util trailer with it. It's comfortable, and shuts off the engine at a traffic light. Considering the size of it, the economy is pretty remarkable on E10. So, hybrids are doing something in the market. It's not a complete solution but it's pretty well baked. Most benefit is seen in commute conditions indicated by the Prius getting better MPG in the city driving mode than in the highway, when it's usually the other way around.
 
JOhnH said:
Uhhh,
not that I want to take Jimmy's side, but try making that VW diesel conform to modern epa and safety regulations. It would weight twice as much and power would be measured in MP (Mouse power; with apologies to the current new engine thread) instead of HP.
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A modern Jetta TDI can satisfy all those constraints.

Emissions doesn't have anywhere near the penalty you're assuming.
 
I'm very excited about this, actually. With the battery development that Tesla has been brewing being the first big steps in what I think will be a significant seachange in how we power motor vehicles, that naturally could/should transition into airplanes.

Envision a C172 with this motor installed, with battery packs behind it at the firewall and in the leading, inboard portion of the wings. Without doing the math, I'd bet you would have a great performing airplane (similar to a Hawk XP or new SP), with similar range and payload. If ramps started having Tesla Superchargers available, you could charge to about 50% in an hour or so, and 100% a little later. I can imagine chargers on the ramps in front of those $100 burger joints we all love so much, right?

We're not there yet, but it's coming and this is a good step in the right direction. Not only potentially less expensive GA, but also much, much quieter (to annoy our neighbors less, and lessen the overall attacks on GA from the great unwashed).

I was a huge skeptic about electric cars until I rode in a Tesla. I'm now a believer, and if we can do this in an airplane, sign me up.
 
timwinters said:
Vision...

The future of electric vehicles has to lie in standardized battery sizes that slide in/out and "recharge stations" that simply swap 'em out. You have a large vehicle? It might take four packs. A small one might take two.

Eliminates the charging downtime.
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The other possibility along those lines is to keep the batteries in place, but swap exhausted electrolyte for charged electrolyte at the filling station. That would require standardization around a particular electrolyte, but that's probably easier to achieve than standardization around a particular battery form factor.

Rich
 
steingar said:
Of course the other advantage is an electric motor won't have pistons banging in and out all the time and thus will lack the concomitant vibration. I suspect they will be considerably quieter, eliminating noise complaints from airport neighbors, and will probably not have to be taken apart every 2000 hours or so.
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Much of your noise comes from prop tips, and electric motors don't have uniform torque around the cycle. They will get smoothed out by the heavy prop in front, just like piston engines.

Listen to distant turboprop noise for a demonstration of prop noise. The engine is a turbine and sounds just like a jet. Especially with reflected sound, it's not hard to separate the two noises.

If your pistons are banging, you need an overhaul.
 
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RJM62 said:
The other possibility along those lines is to keep the batteries in place, but swap exhausted electrolyte for charged electrolyte at the filling station. That would require standardization around a particular electrolyte, but that's probably easier to achieve than standardization around a particular battery form factor.

Rich
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I doubt that to be the case for Li-Ion.....else the 787 would be a no brainer.

Unfortunately Li-Ion chemistry is not easy or straightforward. Charge/discharge profiles are very important as well as charge/discharge states......:mad2:

Folks....this is gonna get real interesting. :goofy:
 
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JHW said:
you're spot-on, and that concept is already proven to work great. In boats. The system also has the advantage of taking the place of a little of the hundreds of tons of ballast that they use.
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Except displacement boats are very efficient at carrying lots of weight up to hull speed. a small 50hp diesel is adequate power for a 20,000lb boat
 
Checkout_my_Six said:
I doubt that to be the case for Li-Ion.....else the 787 would be a no brainer.

Unfortunately Li-Ion chemistry is not easy or straightforward. Charge/discharge profiles are very important as well as charge/discharge states......:mad2:

Folks....this is gonna get real interesting. :goofy:
Click to expand...

Who said the battery has to be LiOn? This company seems to be making progress with Nano-network flow cells.

Rich
 
Lagoon Sailboats was cutting edge a few years back with a diesel hybrid 42 where a Generator charged the batteries...people paid extra for a slower, heavier inefficient, fuel sucking yacht. They have all for the most part been converted back to straight diesel motors...if you cant make it work in a 30,000 pound sailboat its going to be hard in a airplane.
 
I'm excited about this motor! One more piece of the puzzle solved toward the goal of an electric Mooney. Admittedly it's the super easy corner piece of the puzzle, but a step closer none the less. For me, the electric powered airplane can't come soon enough.

I know, super long extension cord. Ha ha. Tee hee. :rolleyes2: It'll never work and never fly.

Everyone always assumes that the electric vehicle of the future will be powered by batteries. I guess it's just because that's what we've mostly seen so far.

So how much does that hydrogen fuel cell weight anyhow? It already works, maybe it can be made lighter too. Imagine the fuel you put in your plane makes it lighter! Just the opposite of now, as you fly, your airplane gets heavier.:D

All you geeks put away your slide rules and step back from the keyboard. I realize the amount of lift from hydrogen in a storage tank would be itty bitty and of no factor. It was just a funny idea too me.

Anyhow, thanks to the OP for posting the article. Every step closer to the electric plane makes me happier.:yes:
 
MAKG1 said:
A modern Jetta TDI can satisfy all those constraints.

Emissions doesn't have anywhere near the penalty you're assuming.
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But you are comparing a modern car to a modern car.
I was responding to a comparison of a modern car to "an old VW diesel".
 
ettsn said:
I'm very excited about this, actually. With the battery development that Tesla has been brewing being the first big steps in what I think will be a significant seachange in how we power motor vehicles, that naturally could/should transition into airplanes.
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Can you link me to what battery development Tesla has brewed? So far, all I know is they get ~60 miles per hour of charge at home. There are some fast charging systems that will give ~150 miles for 30 min of charge at a super high amp station. for an airplane, most trips are +150 miles so one would need the ground support to charge the battery at least half way up to go that 150 miles.

If you have some other info from a source that's reliable I'd like to hear it. I've been considering a Tesla but so far, the battery limitations are too great.
 
RJM62 said:
Who said the battery has to be LiOn? This company seems to be making progress with Nano-network flow cells.

Rich
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That might be the worst website I've ever seen. I can't tell what it is, where it is, how it's sourced, or any usable info. But the graphics and vid are top, top notch.
 
Tesla gets ~270sm range from their 85kw setup.
http://www.teslamotors.com/fi_FI/blog/driving-range-model-s-family

If cruising/hypermiling, users have gotten significantly more. Consider normal cruise in an airplane with the prop pitch dialed up, and the ranges you see here aren't crazy (you eat FAR more energy in takeoff and climbout than maintaining cruise, obviously) and airplanes power consumption resembles highway miles much more than city miles.

graph1.jpg


Using the Tesla Supercharger, the battery can return to 80% in 40 minutes, and 100% in 75 minutes.
http://www.teslamotors.com/supercharger

I have several friends with Teslas, and more than one of them have described highway journeys in excess of 300 miles on a single charge. (anecdotal, yes, but demonstrative)

Combine with a microturbine generator running off something like household grade LP as a range extender, and you could see significant range. The infrastructure would need to be in place, just as it is with the cars of course, but it's not a total pipe dream to think it could happen. http://www.mtt-eu.com/
 
Fredbob711 said:
Correct me if I'm wrong here,[...]
So battery energy density doesn't quite need to reach that of current fuels, just needs to reach the point where a given volume (? might not be the right word) of input energy medium, be it gas or battery, gives you equivalent energy output from the engine.
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You are correct - below I provide one way to estimate the real-world difference in energy per unit mass for the two systems.

Subsea said:
It would be interesting to see the comparison of the efficiency of gas vs electric /power to weight.
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Sac Arrow said:
Except that petroleum fuels exceed a battery's energy density by orders of magnitude.
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ettsn said:
Tesla gets ~270sm range from their 85kw setup.
http://www.teslamotors.com/fi_FI/blog/driving-range-model-s-family
Click to expand...

OK, so I'm working on the assumption that we can get a rough estimate of effective energy density ratio by comparing the miles per pound a pure electric car can travel versus a pure internal combustion engine car of similar masses traveling at similar speeds. I did some net searching and came up with the following (there is probably a better match than the Cadillac, but I didn't want to spend too much time on something that is only a rough estimate anyway):

2015 Cadillac CTS-V
19 mpg highway (EPA highway avg is ~50 mph)
6.1 lb/gal
3.1 miles/lb
Curb weight 4217 lbs
$69,900

Tesla Model S
Battery weight 1200 lbs
330 mile range at 50 mph (per chart)
0.275 miles/lb
Curb weight 4785 lbs
$69,900

So the ratio of energy density (in miles/lb) for these two ground vehicles yields about a factor of 11.3; basically one order of magnitude energy density difference for estimation purposes. At least it isn't several orders.

By the way, a careful read of the news article linked in the OP indicates a factor of 2 improvement over other electric motors in power density. The factor 5 is over non-electric engines.

You can buy electric motors for electric ultralights from places like Joby Motors. Their power density is maybe half that of the Siemens motor, but still good enough for experimenting on electric aircraft. Joby's site has a link to a Youtube video of an electric Lazair that uses their motor; it is worth watching for anyone interested in seeing what is possible today.

Battery energy density is going to be barrier for the indefinite future as a primary energy source. On the other hand, one might argue for electric hybrids for the following reasons:

  • You can run electric motors for brief periods well over their continuous duty ratings, something not easily done with internal combustion engines, allowing STOL or even VTOL operations otherwise not possible. Getting over the proverbial 50 ft obstacle would require only 6 secs of overdrive duty at an avg 500 fpm ascent rate and 1 minute to get to 1000 ft AGL at an average 1000 fpm. Batteries would need to store only enough energy for such operations.
  • You can easily run an electric motor in reverse with no added mechanical complexity, which would make for some interesting possibilities for STOL operations of small planes.
 
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It's easier to just look on wiki.

http://en.wikipedia.org/wiki/Energy_density

Gas 32.4 Mj/L

Li-ion batt 1-3 Mj/L

So, orders of magnitude. All this adds up when the conversion efficiency of the fuel is so low, and other things taken into account. Batteries are still crap when it comes to energy storage. Sorry.
 
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