Global Warming: Electric/Hydrogen airplanes feasable?

[Charbax]

Hi, I am a big fan of cheap airlines in Europe, I use Ryanair, Easyjet and Sterling a lot.

Specially the last few years, I have been able to travel around europe to film festivals, between my mother in Denmark and my father in Switzerland, I have also been able to go to several computer tradeshows, also in the USA, which I made video-blogs from at http://video-blog.eu

But I am afraid of rising oil prices, and global warming. I feel kind of bad of the pollution that the airplane does, and oil not being a renuable energy source, I wonder if there is a chance some airlines soon switch over to some renuable energy technology.

I wonder if it would be feasable to fly the same sized airplanes, even some A380s, using a different, renuable and non-polluting source of energy. Would a big electric engine with big batteries be enough? Has hydrogen been tried?

[chornedsnorkack]

Originally Posted by Charbax

But I am afraid of rising oil prices, and global warming. I feel kind of bad of the pollution that the airplane does, and oil not being a renuable energy source, I wonder if there is a chance some airlines soon switch over to some renuable energy technology.
I wonder if it would be feasable to fly the same sized airplanes, even some A380s, using a different, renuable and non-polluting source of energy. Would a big electric engine with big batteries be enough? Has hydrogen been tried?

Batteries aren´t good.

A big problem with airplanes is that in order to get off the ground in the first place, they have to have a large ratio of power to weight, and in order to fly any reasonable range, they have to have a large ratio of energy to weight.

Generally, a battery weighs more than oil that gives the same amount of energy. Boeing recently fley a man on a battery-powered plane, but I do not think very far.

And electricity has to be produced somehow. For example, from oil.

Hydrogen is more sensible. The problems are, for one thing hydrogen is cold. For another, it has very low density. A given weight of hydrogen gives much more energy than the same weight of oil - but a given volume of hydrogen gives much less energy than the same volume of oil.

Which is why A-380 sized and bigger airplanes are excellent for hydrogen power. A lot of space for the lightweight hydrogen fuel, and you do not need so much heat insulation.

[Charbax]

Allright! So Hydrogen would be feasable? That's great news..

Does anyone know of test flights using hydrogen? Aren't Airbus and Boeing testing that?

So how long time until Ryanair, Easyjet and Sterling switches over to hydrogen?

[chornedsnorkack]

Originally Posted by Charbax

Allright! So Hydrogen would be feasable? That's great news..
Does anyone know of test flights using hydrogen? Aren't Airbus and Boeing testing that?
So how long time until Ryanair, Easyjet and Sterling switches over to hydrogen?

Not soon. Hydrogen has a lot of technical challenges.
What is an advantage of hydrogen is that the large amount of energy per unit mass allows longer range with hydrogen. Provided that the airframe is built for this!

[Gaspasser]

The technical issues of running future designs of turbine engines on hydrogen could probably be overcome quite easily by redesign of burners and combustion cans.
The real problem is the logistics of making hydrogen refuelling available at key airports, and to be able to do this safely.
There is also the issue of legacy equipement that will continue to use jet fuel.
I guess to be realistic jet fuel will be around for the next thirty years its just whether it is produced from alternative sources than crude oil such as biomass, gas to liquid technology etc.

[Charbax]

Nice, so.. could ethanol be used to fuel airplanes without needing to tweak the current engines very much? And would that provide a solution for the pollution problem?

[chornedsnorkack]

Originally Posted by Gaspasser

The technical issues of running future designs of turbine engines on hydrogen could probably be overcome quite easily by redesign of burners and combustion cans.

If you do, you also have to put in place insulation for the fuel talks. What you get is a plane with short range that is overweight in very many places.

What you need to do is design the whole airframe around the density requirements of hydrogen.

[Rainboe]

I should stop listening to all this propaganda! Global warming is not our fault. The world is never stable- it is always cooling down or heating up. But it is long term stable- otherwise life would never have got this far. Europe will go through another Ice Age after a bit of warming up. The sum total of human pollution compared to a really big volcano isn't worth bothering with- there haven't been any damn good volcanos lately, so don't worry about it. There is plenty of oil, more is being discovered and more efficient ways of extracting oil from shale developed. What is the problem? Oil is expensive for political reasons. As oil gets more expensive, other power sources will be developed. Meanwhile, that seat of yours on the aeroplane will be going anyway. Without your ass in it, what a waste of resources! So travel and enjoy it and don't feel guilty. Sometimes these 'green' organisations are more 'political' than 'green'. They don't want any progress, they want us to live in villages and wear sacking for clothing while we farm our one cow and chickens, and only buy food that is grown locally. I like mangoes and strawberries (in the winter), and vegetables from Kenya (it actually gives the growers money). I don't know why so many people listen to this 'green' nonsense- the world will restore itself and then go the other way, then swing back again. All we shoud worry about is not polluting with poisons- PCBs and other chemicals (like womens, birth pills in the water supply). So fly and enjoy it- I do. And take your holidays wherever you like- have you seen the bikinis in Brazil?`

[tribekey]

rainboe-utter rubbish. The link between the amount of co2 in the atmosphere and the average temperature of the Earth is beyond doubt,it's not even difficult science, co2 reflects infra-red radiation back to earth, as does water vapour, methane etc. Given that the levels of co2 in the atmosphere have, beyond doubt been increased by man's activities then we do have a problem. Granted, no-one can say categorically exactly which parts of the planet may (or may not )suffer, but that's hardly the point is it? Surely,we can't afford to wait and see,gamble as it were?
Yes, there are natural cycles of warming and cooling, usually over thousands of years,probably linked to various factors(levels of radiation from the sun vary,for example) but it doesn't seem wise to add our own into the mix!
oh, and like it or not ,oil will soon be a diminishing resource,fact.Watch for 'peak oil' over thenext few years,we don't have to run out of the stuff to have a problem,when demand exceeds supply then just watch the world's economy wobble, that will be the thing that cuts down on expanding aviation.

[Rainboe]

Well, thank you, Sir, for the verdict of 'utter rubbish'! I find all this 'green' spin total nonsense! I do not think driving us out of our cars into filthy polluted trains/buses is going to make one iota difference! Not being able to travel will change nothing. This 'peak oil' nonsense will come to nothing- we were repeatedly told we would be running out of oil at the turn of the Century- the price is actually falling fast now. Sticking up all these awful wind turbines and killing all those birds with them won't help. We can expect efficient nuclear power, they are just discovering all the coal reserves we have quietly been ignoring for years. Watch my lips....'there is NO energy crisis'. The world previously had far, far more carbon dioxide in the atmosphere than it has now. The carbon dioxide down to us is irrelevant- it goes up and down all the time, and ultimately the world has a restoring element to keep things under control. Once the world was all volcanos and lava and very hot. It's managed to become the balmy place we all know and love now. Life adapts to climate change- maybe one day we'll all grow hair again. Instead of attacking and blaming ourselves for everything and demanding I stop eating Kenyan runner beans and Spanish strawberries, these 'green' organisations should stop the natives cutting down trees and poisoning us with insecticides. But FOE and Greenpeace just like attacking anything we do for political ends.

[seacue]

I've long been convinced that the last drop of the Earth's liquid fuel will power an aircraft.

Alternatives would seem to fit stationary uses and ground transportation much more easily.

But the "renewable" energy sources often use non-renewable energy today.

Dams must take decades to pay back the energy cost of their construction - and there is often a significant local climatic effect.

Wind and sun power require energy to create the installations and aren't "24/7" reliable..

Batteries require energy to mine and process the components and the components aren't "nice" in many cases.

Biofuels must be grown which takes fertilizer, today coming from non-renewable sources.


Simple answers to difficult problems are usually wrong. (I wish I could remember the actual quatation.)

[The SSK]

Rainboe, you can rant all you like but you’ve lost the plot. Look at what’s happening in the airlines – BA, Air France Virgin, they aren’t fighting environmental regulation, they’re trying to manage it. Look at what’s happening in the organisations – IATA, AEA, ICAO, ACI, ASD, Eurocontrol – the talk is of little else.
Your arguments are food and drink to the radical greens, they merely point and say ‘look – the airline industry’s in denial again’.
The fact is, it doesn’t matter what the truth is – the politics and the perception have moved on, and there’s no putting the clock back.
There are far more aviation professionals in Europe who are actively working to find solutions to this dilemma than there are those who deny that it is a dilemma in the first place.
As for the original question, forget hydrogen. Even if it were technically feasible, it would just replace CO2 emissions with more-damaging water vapour.

[TSR22]

First of all, Hi Guys!
I am as guilty as the rest of you for tootling around and polluting our upper atmosphere but I have to say, I am one of those people that would really like to see a green solution to our problems. Trouble is, even if we did manage to find a workable solution such as hydrogen/electric cells (very unlikely - how on earth would they provide the necessary range/power/thrust?) - we often only end up shifting the burden to another source. Hydrogen requires energy to produce it - this will probably come from a non renewable source - fossil fuel.
Rainboe - with the greatest of respect, denial is a dangerous activity . When the planet has cycled its atmosphere and climate, it took (in most cases - not all), thousands or millions of years. We have seen the largest and fastest changes in pollutant levels caused by human activity and it is unlikely that in the short term (within the lifespans of possibly hundreds of generations) the planet would be able to respond. Sitting down and doing nothing is not an option, because if we do - we will be sitting in some very deep water in the next couple of decades. The changes that are happening now are profound and will be long lasting and far reaching. Lets hope that a solution can be found, and fast. Three cheers for Mr Branson

[barit1]

Originally Posted by Gaspasser

The technical issues of running future designs of turbine engines on hydrogen could probably be overcome quite easily by redesign of burners and combustion cans...

I believe current engines would NOT require internal changes at all - H2 combustion would take place in a small fraction of the volume of present burners. (Future improved engines could have shorter combustors, shorter shafting between turbines & compressors, and thus lighter overall)

The big change would be in plumbing, pumping, metering, and fuel nozzles, to handle a MUCH larger volumetric flow of cryogenic fuel.

And of course there's the elephant in the room - the HUGE tankage required. Most of the fuselage volume would be necessary for a cryogenic tank for very low-density liquid H2.

[Load Toad]

OK - how are we going to make all this hydrogen we need?

[Rainboe]

Well folks, I am not 'in denial'. But I just don't believe all the doomsayers and lies put out by 'green' organisations. There are a lot of very dodgy statements of 'truth' put out by people. One of them is here:
"We have seen the largest and fastest changes in pollutant levels caused by human activity and it is unlikely that in the short term (within the lifespans of possibly hundreds of generations) the planet would be able to respond." I would say 'show me proof!' They are trying to scare us all by saying the atmosphere will be unsustainable- well after several billion years of torture, it's managed to sustain life quite happily. Drastic forecasts of running out of oil have been made for years- we're doing quite nicely thankyou with plenty all over the world, and more still be discovered, and a lot of previously uneconomic supplies becoming viable for processing. The melting of the glaciers....they naturally come and go. One day Europe will be under 2 miles of glaciers again...guess what- it won't be our fault! It's a natural process. All we need to do is plant lots of trees and cut down on the chemicals. The 'greens' can fret about peak oil and nuclear technology all they like- it really won't make much difference because these crises are still a lot further away than they think. So if you don't travel by air because you are worried about pollution, then it's a false argument because in practice you will be shifting the pollution to other forms....unless you walk!

[chornedsnorkack]

Originally Posted by barit1

I believe current engines would NOT require internal changes at all - H2 combustion would take place in a small fraction of the volume of present burners. (Future improved engines could have shorter combustors, shorter shafting between turbines & compressors, and thus lighter overall)
The big change would be in plumbing, pumping, metering, and fuel nozzles, to handle a MUCH larger volumetric flow of cryogenic fuel.
And of course there's the elephant in the room - the HUGE tankage required. Most of the fuselage volume would be necessary for a cryogenic tank for very low-density liquid H2.

Or else you can make the wing bigger, and lighter.

But wouldn´t hydrogen burning generate higher maximum temperatures?

[TSR22]

Hi Rainboe!

I knew you would ask for proof! A government document was released about 2 weeks ago indicating that the pollutant (CO2) levels have risen drastically in the last decade (showing an almost exponential rise) - unfortunately, I cant put my hand on the document right now..
I know that there are a lot of men (and some girls!) with beards, sandals and little bits of spittle in the corner of their mouths who proclaim doom, but there IS a lot of compelling evidence published every month in respectable journals such as Nature or New Scientist (the latter being a bit more popular but less "hard" science). I tend to read a lot of these things (mainly because the medical stuff is so boring that I normally have to read!) and then discard the articles so I can't quote anything directly. There have, however, been some very hard hitting documents published recently and the governments of the world have started to sit up and listen. Jut look at the weather changes that we are seeing.. (I know that there is natural variation in this anyway - just observe the difference in winter temperatures from those of the 1940s).
I think that one of the other major problems is that CO2 and other pollutants such as lead tetra-ethyl, chloroflourocarbons etc are often long lasting and will continue to cause huge problems for hundreds of years to come. One fact I do have, is that if the Great Western ice sheet collapses, then the world sea level will rise in the order of 4.3 metres..(I got that from a "popular science" book but it is well researched and worth reading: "A short history of nearly everything by Bill Bryson - it's quite funny too in places! )
I'm not a green campaigner by any stretch of the imagination but I am quite concerned about the long term future of life as we know it. I do like walking though!!
I looked at your profile - 747s eh! Only in my wildest dreams (and if the money doesn't run out!!!!)

[barit1]

Originally Posted by chornedsnorkack

...But wouldn´t hydrogen burning generate higher maximum temperatures?

Yes, the peak temperature within the burner would be higher, but it would be diluted down to normal turbine entry temperature by cooling airflows in the aft part of the burner.

[haughtney1]

I'm of the opinion that there WILL come a time when a hybrid, or even completely new propulsion (hydrogen powered perhaps) for aircraft will come to fruition. Is that day coming anytime within the next 15-20 years? No... Why not? because the current technology still has a theorectical 30-40% left worth of improvement in it..thats why.

As for aviations impact on the environment, it depends on who you talk to, perhaps more telling is the overall 2-3% of global C02 emissions that aviation currently produces. Opinion is divided on the basis that no one has put in detailed research (despite what the local green loonies/soothsayer's/fundamentalists spout from there carbon emitting bodies) as to the effect of high altitude carbon emissions (again there are plenty of popular theories about..but very little real data) the jury is still out. Aviation as an industry has recognised that politically it has to move with the times..which it will continue to do.

Aviation is an easy, highly visible, and high profile target for the green lobby. Given this, it is perhaps surprising (and telling) that more effort isn't concerntrated in the area of the average western household, where with a few simple steps, the overall carbon footprint can be reduced by around 40%, which would equate to an overall reduction in emissions worldwide of 25% or so (or 8 TIMES the emissions of the aviation sector)