New MOTOR?

[SHIPCHIEF]

http://www.electraflyer.com/
We've seen electric bikes with high tech motors, Chevy Volt electric car, 36V Dewalt nano lithium Ion power tools.
We all know this is comming. It might be great!
when it gets about 75 HP it might be enough for an RV-12, then it will really get noticed.

This link shows the motor installation http://www.flickr.com/photos/2722498...7605355156982/

[breister]

This is a great idea for those who just want to troll a few times around the patch. The bigger issue is that the batteries weigh almost 10 times as much as the same energy-value of gasoline.

Electricity is better suited to ground vehicles, where once inertia is overcome weight is not quite such a disadvantage.

[SHIPCHIEF]

Don't think in the past.
Think in the future. Battery power density is getting better, and does not require the weight of the gas engine's fuel system. The motor is lighter than the engine and can be designed to run at the optimal prop speed.
I know it's not here yet, but it's on the way.
Could be great for flight instruction. Should last as long as a lesson, and change the batteries for fresh-charged ones...maybe slide out with a big cannon plug?

[breister]

Originally Posted by SHIPCHIEF

Don't think in the past.
Think in the future. Battery power density is getting better, and does not require the weight of the gas engine's fuel system. The motor is lighter than the engine and can be designed to run at the optimal prop speed.
I know it's not here yet, but it's on the way.
Could be great for flight instruction. Should last as long as a lesson, and change the batteries for fresh-charged ones...maybe slide out with a big cannon plug?

I absolutely agree and am a huge proponent.

EEstor reportedly finally has a working prototype out to an independent laboratory for verification of their performance claims. Not only will their storage device hold more energy than the best Lithium Ion batteries, but it will cost less and, because it is a capacitor rather than a battery, should have a relatively infinite number of recharges. If it is successful, it will allow America to be energy independent within a decade (coupled with new production of geothermal, wind, and solar power generating stations). Imagine electric powered trains carrying hundreds of boxcars worth of electrical power from the Rockies to New York, using only a boxcar or two of that energy for the round trip. Cheap power from steam....

My only point was that for cross-country we are still quite a ways out or I would switch yesterday. The only candidate I see having even theoretical capacity to challenge gasoline will be carbon nanotube capacitors - and they have to figure out how to pack all those microtubes close enough without shorting each other out. But, the idea has been demonstrated in a lab so now it's just an engineering challenge.

[robpar]

Just a few things I checked into on the electric motor application to aircraft.
There are electric motors that can produce the approximate power of an IO-360 say 200 HP and they can be made for about the same weight. However an electric motor that operates at 2500 RPM AND producing 200 HP will be much heavier than and IC engine. That means a PSRU which many people have a hard time with.

Now the big problem. Energy storage. Super Caps are the holy grail but the military has been pouring billions into them and they are still too far off to consider viable. Of the batteries the one that has the highest energy to weight ratio is the Zinc-Air battery. Its specific power is 0.37 KW-h/Kg which by my quick calcs requires 300 Kg of battery to produce 112 KW (150 HP) for one hour. 300 KG is about 650 lbs. Lithium-Ion is about 1/3 to 1/2 the specific power of the Zinc-Air so would be 2 to 3 times heavier for the same power.

Unfortunately it is going to be awhile before electric power is available for aircraft.

My source for the specific power was WikiPedia which I know is not the most up-to-date or most accurate but it is close enough to show that a lot of development has to be done before this will happen.

I have contacts in the battery industry so I will try to get the latest on batteries.

Bob Parry

[Steve Brown]

Originally Posted by robpar

......Its specific power is 0.37 KW-h/Kg which by my quick calcs requires 300 Kg of battery to produce 112 KW (150 HP) for one hour. 300 KG is about 650 lbs. Lithium-Ion is about 1/3 to 1/2 the specific power of the Zinc-Air so would be 2 to 3 times heavier for the same power.

Unfortunately it is going to be awhile before electric power is available for aircraft.
........

Bob Parry

Recreational flying in a local area, yes, replacing the ICE for cross country flights, never.

You just described a 650 pound battery that replaces 72 pounds of 100LL. That ain't going to fly.

As Supercaps go up in energy storage per volume, they go down in discharge rate. Its inherent to the technology. Pouring another billion in won't change that.

Being an EE, I'm also a huge proponent of electric power. Besides the fact that I like all things that run on electrons, it allows getting energy from any source: solar, wind, tide, fossil, or nuclear.

This struggle is not new just because oil prices went up. Battery energy density has been strongly driven for decades because of mobile computing & communication, with some improvements via new materials.

Unfortunately, enthusiasm combined with strong desire won't change the physics. The only material that could solve this problem is unobtainium.

Hydrogen fuel cells have a chance, but their own problems which must be overcome. That's still a liquid fuel that you won't get from the wall socket in your hanger. Also, I'm not sure that it wouldn't just be better to burn the hydrogen in an ICE than make electric power from it.

Cars are a different story as one already pointed out. In that case the limited range or weight of battery solutions is not such a problem. Even if electric cars only replaced ICE for local driving that would take a huge burden off of gas demand.

Similarly, battery powered ultralights or motor gliders might make sense.

Jet aircraft, and hence Jet A, is not going away even in the wildly speculative future. The best future hope of GA is to use JetA. Diesel is the way to go.

[robpar]

[
Unfortunately, enthusiasm combined with strong desire won't change the physics. The only material that could solve this problem is unobtainium.

Hydrogen fuel cells have a chance, but their own problems which must be overcome. That's still a liquid fuel that you won't get from the wall socket in your hanger. Also, I'm not sure that it wouldn't just be better to burn the hydrogen in an ICE than make electric power from it.
.[/quote]

While I was in the Fuel Cell Industry (10 years at Ballard) we kept trying to order unobtainium but it was alway on back order.

My experience with Fuel Cells has been: Too many Systems, Too much Cost, Too much weight, Too much Money.

Bob Parry

[breister]

Originally Posted by robpar

[
Unfortunately, enthusiasm combined with strong desire won't change the physics. The only material that could solve this problem is unobtainium.

Absolutely false - Impossibilium and Improbantium will both do the trick!



Actually, there is one contender proven in the lab which MIGHT get there some day - carbon nanotube capacitors.

But don't count on it too soon. Getting the necessary level of energy density will require packing trillions of tiny nanotubes in parallel without touching each other (somehow insulated from each other so they don't short each other out), while still connecting the ends to a conducting substrate. While there have been some impressive scanning electron microscope photos of "carpets" of nearly perpendicular nanotubes grown in the lab, it is still a very long way from mass production at practical prices.

[SHIPCHIEF]

When I started this thread I was refering to local training flights. The power density of batteries / motors would be sufficient.
But your reference to unobtainium, impossublium, and improbantium quickly brought the solution to mind.
The RETROENCABULATOR!

[breister]

Yep - the other big winner will be powered or self-launching gliders. They only need a fraction of an hour of power to get going - and that will save hundreds of dollars in launch fees.