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Electric Planes Usher in the Second Great Age of Aviation

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Re: Electric Planes Usher in the Second Great Age of Aviation

#51

Post by trhway »

venomsnake wrote: post #19
sokoloff wrote: post #2

I drive an electric car and fly piston airplanes. I don't see electrics replacing internal combustion in aviation in my flying lifetime. Why? Weight. The specific energy (energy per kg, edited per masklinn) of batteries sadly lags the specific energy of gasoline or kerosene, and the airplane carries that weight for the whole flight for an electric airplane. (My gas airplane gets lighter and lands as much as 1000 poun…

A fuel cell that carries only hydrogen and harvests oxygen from the atmosphere ... is viable. * *the whole membrane degradation thing excluded

metal-air fuel cells are in many respects even better. And with metal content around 50% they become weight comparable or better than 30% efficient ICE.

Re: Electric Planes Usher in the Second Great Age of Aviation

#52

Post by stcredzero »

elektromekatron wrote: post #48
stcredzero wrote: post #43

Earlier quoted context omitted.

If you could run cargo planes on beamed power, you wouldn't have to haul your power storage (fuel) to altitude. Also, given the extreme simplicity and reliability of electric motors, such an infrastructure would save huge amounts of money and also avoid externalities like atmospheric pollution. The big question, of course, is the ability to build such an infrastructure with enough reliability.

Perhaps an orbiting network of solar powered satellites that can each manage large numbers of directed power beams. Though maybe that would be a non starter due to the large number of non-civilian applications.

Satellites? I doubt it. Too expensive. Long-duration high altitude aircraft, maybe?

Re: Electric Planes Usher in the Second Great Age of Aviation

#53

Post by sokoloff »

coryrc wrote: post #28
sokoloff wrote: post #2

I drive an electric car and fly piston airplanes. I don't see electrics replacing internal combustion in aviation in my flying lifetime. Why? Weight. The specific energy (energy per kg, edited per masklinn) of batteries sadly lags the specific energy of gasoline or kerosene, and the airplane carries that weight for the whole flight for an electric airplane. (My gas airplane gets lighter and lands as much as 1000 poun…

Electric planes could stop GA poisoning everyone with lead. You could also choose a different fuel. Toy planes (general aviation) are responsible for the majority of lead pollution: www.emagazine.com/earth-talk/lead-in-aviation-fuel

The FAA certification process is the largest limiting factor for bringing an unleaded fuel to the market. There are about 9 different formulations of unleaded fuels flying in experimental aircraft right now. I have my own "favorite", but it's unclear when, if ever, that will be available for sale to non-experimental aircraft.

The magazine article you reference says that 70% of aircraft could use (a lower octane) unleaded fuel available today. That's true, but paints an incomplete picture. That's 70% by aircraft, not 70% by flight hours or fuel consumed.

Cape Air and similar and other turbocharged piston aircraft are the ones that can't use the available unleaded "mogas". Those are also the aircraft that fly the most hours and thereby use the most fuel. Fixing the 172s and Cherokees doesn't move the needle much on TEL emissions.

I want to get rid of the lead from my aviation fuel, both for environmental reasons and for practical reasons. (Practically, it's a pain to deal with on the supply chain side, is expensive, there's only one manufacturer of TEL worldwide, it tends to gunk and foul plugs, etc.)

The FAA is the regulatory body that is presiding over this, much more than the EPA. End running the FAA to get the EPA to make another "lead is bad" proclamation won't do any good, IMO.

My engines can't burn any available and certified unleaded fuel.

Re: Electric Planes Usher in the Second Great Age of Aviation

#54

Post by venomsnake »

trhway wrote: post #51
venomsnake wrote: post #19

Earlier quoted context omitted.

A fuel cell that carries only hydrogen and harvests oxygen from the atmosphere ... is viable. * *the whole membrane degradation thing excluded

metal-air fuel cells are in many respects even better. And with metal content around 50% they become weight comparable or better than 30% efficient ICE.

In that case you have lithium oxide to take care of and you have heavier plane with each second (of course most of the fuel is wasted on lifting the plane, so it may be better)

Re: Electric Planes Usher in the Second Great Age of Aviation

#55

Post by melling »

sokoloff wrote: post #2

I drive an electric car and fly piston airplanes. I don't see electrics replacing internal combustion in aviation in my flying lifetime. Why? Weight. The specific energy (energy per kg, edited per masklinn) of batteries sadly lags the specific energy of gasoline or kerosene, and the airplane carries that weight for the whole flight for an electric airplane. (My gas airplane gets lighter and lands as much as 1000 poun…

How old are you? 50 years from now the world will be a lot different. It'll probably change as much as it did in the last 100, which to put into perspective:

http://www.aerofiles.com/gallaudet-c2-1915.jpg

Re: Electric Planes Usher in the Second Great Age of Aviation

#56

Post by maxerickson »

melling wrote: post #55
sokoloff wrote: post #2

I drive an electric car and fly piston airplanes. I don't see electrics replacing internal combustion in aviation in my flying lifetime. Why? Weight. The specific energy (energy per kg, edited per masklinn) of batteries sadly lags the specific energy of gasoline or kerosene, and the airplane carries that weight for the whole flight for an electric airplane. (My gas airplane gets lighter and lands as much as 1000 poun…

How old are you? 50 years from now the world will be a lot different. It'll probably change as much as it did in the last 100, which to put into perspective: http://www.aerofiles.com/gallaudet-c2-1915.jpg

45 years ago:

http://www.museumofflight.org/747

Re: Electric Planes Usher in the Second Great Age of Aviation

#57

Post by greedo »

simonsquiff wrote: post #47
masklinn wrote: post #16

Earlier quoted context omitted.

> I'm not sure it's ignoring everything - as this article states, electric planes exist today Prop toys exist, not "future of aviation" anything. Props being an other issue, electric planes means no turbofans. > Batteries are also improving Batteries are not improving at a rate which would increase their specific energy by 2 orders of magnitude (the difference between the specific energy of the best batteries availab…

The original supposition was that electric planes are the future - albeit a future very far way - because electric means no oxygen concerns, which means higher altitude, which increases efficiency and / or speed. Now, electric doesn't mean battery. Fuel cells, solar, or even hybrid might all play a part. I believe a large proportion of energy consumption is during takeoff - what if you could draw take off power needs…

How is a turbofan/turboprop engine going to work in the thin air at these high altitudes? True jet engines work because of the combustion of jetfuel, but those are not really used much...

Re: Electric Planes Usher in the Second Great Age of Aviation

#58

Post by melling »

maxerickson wrote: post #56
melling wrote: post #55

Earlier quoted context omitted.

How old are you? 50 years from now the world will be a lot different. It'll probably change as much as it did in the last 100, which to put into perspective: http://www.aerofiles.com/gallaudet-c2-1915.jpg

45 years ago: http://www.museumofflight.org/747

You probably should have gone with 46 years ago: https://upload.wikimedia.org/wikipedia/commons/1/11/Concorde...

What was your point? Here's a computer from 1965:

http://www.columbia.edu/cu/computinghistory/a10.jpg

Not all technology is increasing at the same rate. Adoption is another problem. Take this bullet train from 1964. Still won't find that in America.

http://cdn.gaijinpot.com/wp-content/uploads/sites/4/2014/10/...

Re: Electric Planes Usher in the Second Great Age of Aviation

#59

Post by trhway »

venomsnake wrote: post #54
trhway wrote: post #51

Earlier quoted context omitted.

metal-air fuel cells are in many respects even better. And with metal content around 50% they become weight comparable or better than 30% efficient ICE.

In that case you have lithium oxide to take care of and you have heavier plane with each second (of course most of the fuel is wasted on lifting the plane, so it may be better)

the electric planes, at least at first, isn't about just swapping ICE for electric. It is about building different planes. The current planes have evolved significantly under the limitations of ICE. The electric planes, at least initially, is about short-hoppers ("flying car" like functionality) where ICE is a no-go because of cost and noise. The electrics are well suited to build STOL and VTOL (multi-copters). With years the electrification can make its way through various hybrid schemes into much more efficient long-haulers.

Re: Electric Planes Usher in the Second Great Age of Aviation

#60

Post by maxerickson »

melling wrote: post #58
maxerickson wrote: post #56

Earlier quoted context omitted.

45 years ago: http://www.museumofflight.org/747

You probably should have gone with 46 years ago: https://upload.wikimedia.org/wikipedia/commons/1/11/Concorde... What was your point? Here's a computer from 1965: http://www.columbia.edu/cu/computinghistory/a10.jpg Not all technology is increasing at the same rate. Adoption is another problem. Take this bullet train from 1964. Still won't find that in America. http://cdn.gaijinpot.com/wp-content/uploads/sites/4/2014/…

Given your example, I thought you were talking about aircraft, so the diminishing returns in the recent 50 years seemed salient.
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