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Airbus and Boeing are exploring the viability of electric planes

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Re: Airbus and Boeing are exploring the viability of electric planes

#121

Post by maccam94 »

ShorsHammer wrote: post #94
lumberjack wrote: post #48

It would make infinitely more sense to look into carbon neutral hydrocarbon fuels that could be used in conventional turbofans. Some more material on this topic: https://aviation.stackexchange.com/questions/26910/could-an-...

Another SE link of interest, how much electrical power needed to run a 747 engine: https://aviation.stackexchange.com/questions/19569/how-many-... The consensus is ~90 MW. That's a lot of energy, electric air travel is certainly possible, but it will likely come at a severe cost to speed and endurance. If we are going to travel slowly would personally prefer autonomous airships.

I think we'll see smaller capacity VTOL aircraft for shorter flights before we get batteries with enough energy density for long-range flights. You'd just need to have a fast charging rate or potentially swappable batteries at landing pads. Daisy-chaining VTOL trips carrying 10-20 passengers ~100 miles at a time could be faster and more flexible. Uber has done some research on this too: https://www.uber.com/info/elevate/

Re: Airbus and Boeing are exploring the viability of electric planes

#122

Post by toomanybeersies »

Airbus actually made a prototype electric ducted fan plane: https://en.wikipedia.org/wiki/Airbus_E-Fan

The core problem with it though was the poor energy density of batteries. Hopefully electric cars will drive more innovation in this area, although the aviation industry is usually at least 20-30 years behind the automotive industry as far as engine technology goes, so we're probably 40 years away from getting widespread adoption of electric aircraft.

Re: Airbus and Boeing are exploring the viability of electric planes

#123

Post by bigiain »

GuB-42 wrote: post #77
savrajsingh wrote: post #25

It’s just a question of the energy density of batteries vs. fuel. We need a couple more battery breakthroughs before we get a fully electric commercial airliner.

There is more than that. Planes become lighter as they burn fuel, batteries don't become lighter as they drain. Lighter planes are more efficient, and most airliners are not designed to land with their tanks full. They have a option to jettison their fuel in case of emergency. It means that just matching the energy density of fuel is not enough, batteries must exceed it. Jet engines are also quite efficient: around 4…

I'm pretty sure the "emergency fuel jettison" is for "I'd rather it not splash about everywhere and catch fire in the case that I put this plane down hard enough to split the tanks open" rather than "It's impossible to land this plane safely at the same weight as it took off".

(Not that I'd want to be hurtling at the ground barely in control with many tons of fully charged LiPo battery on board either...)

Re: Airbus and Boeing are exploring the viability of electric planes

#124

Post by rootusrootus »

bigiain wrote: post #123
GuB-42 wrote: post #77

Earlier quoted context omitted.

There is more than that. Planes become lighter as they burn fuel, batteries don't become lighter as they drain. Lighter planes are more efficient, and most airliners are not designed to land with their tanks full. They have a option to jettison their fuel in case of emergency. It means that just matching the energy density of fuel is not enough, batteries must exceed it. Jet engines are also quite efficient: around 4…

I'm pretty sure the "emergency fuel jettison" is for "I'd rather it not splash about everywhere and catch fire in the case that I put this plane down hard enough to split the tanks open" rather than "It's impossible to land this plane safely at the same weight as it took off". (Not that I'd want to be hurtling at the ground barely in control with many tons of fully charged LiPo battery on board either...)

It's true. Take a 787 Dreamliner as an example. The maximum take-off weight is over 100,000 pounds more than the maximum landing weight.

Re: Airbus and Boeing are exploring the viability of electric planes

#125

Post by greglindahl »

toomanybeersies wrote: post #122

Airbus actually made a prototype electric ducted fan plane: https://en.wikipedia.org/wiki/Airbus_E-Fan The core problem with it though was the poor energy density of batteries. Hopefully electric cars will drive more innovation in this area, although the aviation industry is usually at least 20-30 years behind the automotive industry as far as engine technology goes, so we're probably 40 years away from getting wides…

If you'll recall, Boeing used pretty modern LiIon batteries in the B787 and it caused a few fires. That appears to have been a design mistake that no car manufacturer has made, but it still sets a standard for what aviation needs to do if they want to be closer to the bleeding edge.

Re: Airbus and Boeing are exploring the viability of electric planes

#126

Post by CuriousCosmic »

vilmosi wrote: post #115
adventured wrote: post #107

Earlier quoted context omitted.

US wind energy production has increased eight fold in 12 years. The US has greater wind energy production capacity per capita than Norway does for example. Hydro power is an impossible resource to perpetually manufacture more of. The US has heavily tapped out its potential in hydro. First it's difficult/undesirable to manufacture a new source of hydro once you reach saturation, and second it's arguably a terrible ide…

Wouldn't a country with vast access to hydro power be inclined to not invest in wind? And why cherry pick wind power anyway?

I believe they specifically mentioned wind because that was the specific form of renewable energy the grandparent was talking about.

As for why a country with vast access to hydro would prefer wind energy, Hydro requires large investments, is excruciatingly difficult to upgrade, interferes with local water flow and ecosystems, and in the case that either it is improperly maintained or a major accident occurs, can be very dangerous and deadly.

Re: Airbus and Boeing are exploring the viability of electric planes

#127

Post by Retric »

toomanybeersies wrote: post #122

Airbus actually made a prototype electric ducted fan plane: https://en.wikipedia.org/wiki/Airbus_E-Fan The core problem with it though was the poor energy density of batteries. Hopefully electric cars will drive more innovation in this area, although the aviation industry is usually at least 20-30 years behind the automotive industry as far as engine technology goes, so we're probably 40 years away from getting wides…

> behind the automotive

That's far from true, large aircraft engines are vastly more efficient than automotive engines. Small aircraft are such a tiny market they effectively get zero R&D.

Interestingly hybrid cars could be significantly improved fuel efficiency using turbine engines though at increased costs. Plug in hybrids may actually see the adoption due to lower weight and lower useage making those tradeoffs less meaningful.

Re: Airbus and Boeing are exploring the viability of electric planes

#128

Post by greglindahl »

savrajsingh wrote: post #25

It’s just a question of the energy density of batteries vs. fuel. We need a couple more battery breakthroughs before we get a fully electric commercial airliner.

So you're boldly predicting that you can't even build a short-range electric plane. Which is what everyone's trying to do.

Your criticism is similar to what many people said about electric cars and electric trucks. Well, surprise, commercial short-range cars and trucks became viable before longer-range cars and trucks.

Re: Airbus and Boeing are exploring the viability of electric planes

#129

Post by seanmcdirmid »

kzrdude wrote: post #10

Norway is in an ideal position; a surplus from oil money and excessive access to hydro power. I would hope they can use their current oil prosperity to prepare for a hydro (and other green energy) powered future, in all kinds of new places. After I typed that I realized that the whole world could be said to be in oil prosperity still, so the same applies to us all: with less evenly distributed oil prosperity, and not…

Washington state gets 90 or so percent of its electricity from hydro. It isn’t that unusual, there are already a few hydro states in the world besides Norway, and one or two thermal states as well.

Re: Airbus and Boeing are exploring the viability of electric planes

#130

Post by greglindahl »

lumberjack wrote: post #48

It would make infinitely more sense to look into carbon neutral hydrocarbon fuels that could be used in conventional turbofans. Some more material on this topic: https://aviation.stackexchange.com/questions/26910/could-an-...

Is it impossible to develop 2 things at the same time? In fact, both are under development.
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