Pipe dream: Norway wants electric airplanes to provide passenger service

WUWT reader “Non Nomen” writes:

Norway now wants to electrify domestic air traffic by 2040.

Will they be able to recharge at every overhead power line?

If they are on medication, they’d better stop that.
If not, they’d better take their pills.


Medication aside, I don’t think these people understand the concept and difficulty of scaling up such technology.

Here is another video worth watching:

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ResourceGuy

The key word is short.

I suggest these be made mandatory for travel to attend climate policy meetings. No reimbursement for any other forms of travel and penalties for using fossil fuel modes.

Bill Powers

How about this for keywords blue sky pleasant if not ideal weather conditions? If a little head wind placed a toll on the battery power for an hour flight imagine what a typical Chicago day will do to your battery life. And forget about take off and landing that “Balsa Wood” Baby. Having spent most of my life between the U.S. Midwest and Mid Atlantic states Weather conditions that would stick that propeller in a tree can materialize out of nowhere despite the best Global Satellite eye in the sky. Until they can combine real weight wjtb realistic altitude and sustain flight in severe weather for prolonged periods this thing is cute but extremely limited in use and availability. They slightly past Amazon Delivery mode

Patrick

Even more reason to mandate it upon the CAGW faithful.

Bryan A

Given the 1 hour 20KW range of 135 kilometers or 83 miles and recharge time for refilling a 20KW battery, they had better leave a month ahead to fly to a COP in one of these. (or be able to land at a Tesla Supercharger station) Just another toy

James

You would not be able to fulfill the requirements to get your Private Pilot Certificate in the United States. The plane does not have sufficient range for the 200nm cross country. I doubt that you could do a VFR cross country flight in it legally, you would not have sufficient reserve capacity.

rocketscientist

“Small aircraft are the safest around as they can barely kill you.”
– an Old Test Pilot

Non Nomen

Steve Fossett never heard about that, obviously.

John from the EU

He was killed due to lack of mountain flying experience.

Non Nomen

“Small aircraft are the safest around…”

So small aircraft are unsafe in mountainous terrain?
Btw, Fossett was a highly experienced pilot, licensed for Zeppelin NT airships for example. Anyway, sh*t happens…old pilots, bold pilots but no old, bold pilots.

Bryan A

But it is true that smaller aircraft have killed fewer people and the smaller they are, the less likely death is.
I have yet to hear of even pilot death in any of these aircraft

MarkW

Small plane that didn’t have enough power to get him out of a tough spot.
Sounds a lot like these electric planes.

Electric planes dont have to be short of power. Its duration that is the problem.

On a ratio of people death to aircraft loss, smaller craft are a better bet, but you can still die in any crash that exceeds the parameters to life. Elevators are still the safest way to travel.

RayG

The software that controls elevators is subjected to extensive validation and verification unlike the climate models.

MarkW

How many places in the world have airports 1 hour apart?
And that’s one hour in ideal flying conditions, as well as a day that is neither too warm nor too hot.

I could see the usefulness of this as a trainer that never travels more than a few minutes from it’s home airport. Of course you would need to have charged up before hand, one set of batteries for every student you plan to take up that day, since there won’t be enough time to recharge between flights.
BTW, hope none of your students are a bit chubby. That’s gonna cut way down on training time.

Felix

The toy plane in the story clearly isn’t a regional passenger liner.

But a bigger, multiengine craft, especially if hybrid to start, isn’t outside the realm of possibility by 2040.

Marcus

“Multi Engine” means more batteries !! SPLAT !!

Felix

Please see performance of Solar Impulse 2. By 2040, it’s not outside the realm of possibility to improve its performance. In the meantime, the aviation industry is working on hybrid engines:

https://www.wired.com/2017/04/hybrid-jet-finally-make-electric-flight-reality/

Bryan A

Solar Impulse 2, the only solar powered plane to fly around the world at an average speed of 2mph (22,000 miles at 16 months)

Felix

Its top speed is 87 mph and cruise 56. It flew from Japan to Hawaii in 172 hours and 52 minutes. Night speed is obviously a lot slower than during daytime.

It then had to stay in HI for repairs for months. But even the longest flight in Norway would be only a fraction of that record-setting flight of nearly 4500 miles.

So for short to medium hops around Norway, it would work, if it could carry passengers, which of course it can’t. As noted above, Oslo to Bergen would take 3.4 hours, if it averaged its cruise speed. That’s at least twice as fast as driving.

For the next two decades, however, hybrid engines will probably have to suffice. Pure electric will require improvements in battery tech.

MarkW

173 hours. And you don’t understand why the rest of us are laughing.
And that’s with the trade winds. How long would it have taken if it had been going the other way?

Felix

It’s the principle. They laughed at the Wright Brothers.

Again, commercial electric planes aren’t proposed for trans-Pacific routes any time soon. As I keep noting, even the primitive Solar Impulse 2 could fly around Norway in a timely manner.

Airworthiness and load capacity may have to await improved batteries. But functional hybrids are flying already.

Felix

Heavier than air flight and nine other “scientific impossibilities” which proved possible, often embarrassingly promptly:

https://www.newscientist.com/article/dn13556-10-impossibilities-conquered-by-science/?DCMP=ILC-hmts&nsref=specrt15_p

Bryan A

Felix
Heavier than air flight and nine other “scientific impossibilities” which proved possible, often embarrassingly promptly

All thanks to the inherent high density energy found in Fossil fuels

jorgekafkazar

They laughed at Buck Weimer of Pueblo, Colorado, too.

markopanama

Actually, I don’t think informed people laughed much at the Wright brothers. They had petroleum fuel with very high energy density and only needed an engine light enough to put in an airplane. Engine technology has been on the steep part of the improvement curve ever since, right up to the Rolls Royce Trent engines of today.

When the Wright brothers were working, the leading alternative to internal combustion was the steam engine, which required heavy fuel and water loads, limiting range. Just like battery vehicles today.

Batteries need a 10X improvement in energy density to be considered revolutionary. Until then, there is an elegant alternative fuel – gasoline.

Felix

Yet people did laugh. Among them was Lord Kelvin, just eight years before the brothers succeeded in 1903.

Highly regarded S. P. Langley had failed to achieve heavier than air, powered flight.

https://en.wikipedia.org/wiki/Samuel_Pierpont_Langley#Aviation_work

The SW Ohio bicycle shop boys solved some advanced aerodynamic issues as well as building a lightweight engine.

Leo Smith

No. they didn’t solve any aerodynamic issues.They built a kite with propellors powered by a geared motorcycle engine.

It was an aerodynamic abortion. Aerodynamics only started to be understood by WWI.

Felix

Nope.

The Wright’s insights into aerodynamics were brilliant. They understood, confirmed by their wind tunnel experiments confirmed their profound insight that a propeller was an airfoil, like a wing.

https://airandspace.si.edu/exhibitions/wright-brothers/online/fly/1901/wind.cfm

It wasn’t just their engine but their keen grasp of aerodynamics that enabled them to achieve heavier than air flight where such scientific celebrities as Langley had failed.

I read your link. I stand by my statements.
Ships propellors were ‘understood to be hydrofoils’ some years before.

https://en.wikipedia.org/wiki/Propeller#History_2

Paul

Come to Dayton and see the museums to the Wright Brother’s work. They did a LOT of research into airfoils and engines.

Sam C Cogar

Felix – June 22, 2018 8:49 pm

The Wright’s insights into aerodynamics were brilliant.

It wasn’t just their engine but their keen grasp of aerodynamics that enabled them to achieve heavier than air flight

Shur nuff, ….. Felix, ….. the Wright brother’s insights into aerodynamics was no more brilliant than your not-so-brilliant insights concerning the evolutionary “path” traveled by our pre-human ancestors.

IMLO, the Wright brother’s “first flight” airplane was little more than a gasoline powered sail (kite).

Felix, ….. here ya go, …….. point out those “brilliant” aerodynamic designs you spoke of, to wit:

http://monovisions.com/wp-content/uploads/2015/02/Wright-Brothers-First-Flight-in-1903-08.jpg

Felix

For ground vehicles, thanks to relative efficiency differences and much simpler support systems, batteries only need to be about 30% as energy-dense as gasoline to meet weight- and range-equivalence with ICEs.

The situation with aviation is liable to be tougher, but IMO 2040, while on the optimistic side, isn’t crazy.

In the meantime, hybrid electric aircraft engines exist and are undergoing rapid development.

Felix

Short-haul prop planes would be closer to the ground vehicle efficiency regime than turbofan stratoliners, naturally.

Richard Patton

question: why use unfamiliar acronyms (ICE-which in the US usually means Immigration and Customs Enforcement) which bring the reader to a shuddering stop to figure out what you mean rather than using the words that everyone else in the thread is using-Internal Combustion Engine?

Felix

Sorry. I thought in context that it wouldn’t be confusing. Also, I put and S on the end to make it more obvious that the E meant “engines”.

peyelut

Unlike “real” Airplanes, batteries DO NOT GET LIGHTER as they discharge.

Felix

True. But neither do FF aircraft refuel in flight without mating with tankers.

Neither do engines or passengers.

No big deal. Takeoff is where you need the plane the lightest.

Cybersmythe

peyelut, I”ve actually thought about the whole batteries don’t get lighter thing, and all in all, that has to go in the “pro” side of the pros and cons of electric airplanes because it means that you can always take off with full “fuel” and don’t have to make the kind of payload-vs-fuel decisions that can have disastrous consequences.

MarkW

They laughed at the Wright brothers, therefore electric airplanes will succeed.
Ok, it that’s the line you want to defend.

Frederic

“They laughed at the Wright brothers, therefore electric airplanes will succeed.”
—————
My thoughts exactly. Who the hell needs the laws of physics, the arduous knowledge about engines, energy density, power/weight ratios, performance comparison, economics, technology history, past failure… when Felix’ out-of-the-hat argument is enough to predict the future.

Felix

Not out of the hat. Out of chemistry, physics and economics.

I wonder if commenters here subscribe, for instance, to Spectrum, the journal of the IEEEE, where battery improvement issue are cussed and discussed in practically every issue.

I also wonder why there is so much resistance (!) to the idea of light, powerful batteries. Could it possibly be ideological, since the physics and chemistry show that power densities comparable to fossil fuels are possible. The design challenges are not insuperable.

Phaedrus

No one laughed at the Wright Brothers and there were many more inventors out there about to “take off”. Aircraft still need to be as light as possible so the walking cargo can get on-board with some hope of takeoff.

The next step for aviation will be synthetic fuels (already trailed).

This idea of batteries for everything is asinine.

Felix

No one says batteries for everything.

People most certainly scoffed at the Wrights personally and at heavier than air flight in general.

When Langley failed, the consensus and conventional wisdom was that it was impossible, as no less a personage than Lord Kelvin intoned.

Yes, others were working on heavier than air flight, but all at the fringes and without establishment support. A Brazilian, for crying out loud.

The Ohio bicycle shop boys were most certainly laughed at.

Bryan A

Felix
It’s the principle. They laughed at the Wright Brothers.
(Snip)
Airworthiness and load capacity may have to await improved batteries. But functional hybrids are flying already.

Ah yes, functional hybrids. And why are hybrids soooo functional? They still depend on the good old trustworthy high density energy found in Fossil Fuels

Cybersmythe

The reason they laughed at the Wright Brothers is because nobody understood anything about flight. The Wrights had no benefit of any real theory (except for propellers, where they had the theory that they themselves devised) and so it was anybody’s guess as to how an airplane might work, or even if one was possible.

It’s been more than 100 years since then, and the theory behind all this airplane performance stuff was been pretty well worked out sixty or seventy years ago and now it’s taught to undergraduates.

Clyde Spencer

“Pure electric will require improvements in battery tech.”
That is an understatement if I ever heard one! Not unlike saying pigs will need some modifications to fly.

Felix

As noted, Al-air batteries would work now, but have problems which are being ironed out.

The Siemens pure electric aircraft engine from 2014 works with Li-ion batteries, but, at only 81 horse, lacks the power for passenger planes, even with more than one of them.

MarkW

Once again, we are relying on somebody to fix existing problems.
Some problems can be fixed, some can’t.

drednicolson

Like the fundamental problem that you need to expend more energy filling the storage medium than you will get back from emptying it. Just the second law of thermodynamics in action. Every time energy changes form you pay a tax in waste heat on the total available. And moving your energy to an offshort account in the Canary Islands won’t evade it. 🙂

No big deal. Turnround efficiencies of around 80% or better battery wise.

Heavy ground based power stations are more efficient burners of fuel than aircraft are.

Overall its not a lot different.

And of course you can recharge from hydroelectric or nuclear power.

Felix

The problems with batteries can and will be fixed.

markopanama

Hey, in a strong wind, even turkeys can fly. Governments are providing lots of strong wind to lots of turkeys.

drednicolson

Wild turkeys are perfectly capable of flying under their own power. They spend most of their time on the ground because that’s where the food is. They roost in the trees at night. 🙂

Hivemind

Actually they can’t. Even in a strong wind they drop like a stone.

Felix

Not like that at all.

There will be battery improvements. Pigs are unlikely ever to fly on their own.

Ve2

Not forgetting the 20 man backup crew that repeatedly flew backwards and forwards between the many stops and Europe travelling of course by conventional planes.

Bryan A

Oslo to Bergen in 3-1/2 hours and a month in Bergen for repairs

Felix

Nope. Maybe a little time to recharge if the day has been cloudy and the flight was below the cloud deck.

John from the EU

Another electric aircraft success… A horse and carriage would have been faster.

Felix

Commercial aircraft won’t be like the concept demonstrator SI 2. I’d have thought this obvious, but apparently not.

ATheoK

2040… Right.

That gives them enough time to invent a better battery that’s been promised for fifty years… Maybe.

And that original solar plane, had so much room that the pilot could relax, stretch, visit the loo… Not!

Not to overlook, what happens if the plane meets a severe storm,
or birds decide to perch along the wings.

http://www.sciencebuzz.org/sites/default/files/images/solarimpulse.jpg

Bryan A

ATheoK
Perhaps that 50 year promise is after cold fusion is finally developed to recharge the batteries

Felix

Recharge isn’t really a problem. Can be done in flight with 3rd generation PV cell films, weighing about as much as paint.

Until you look at the fundamental physics of it. What you get from a solar panel is watts per square meter, what you need to keep an aircraft in the air is watts per pound.

Put that lot together and you end up with a wing loading so low that the plane is fragile and very very slow.

Solar aircraft are a gimmick. They have no serious potential for load carrying. Even for ‘staying up indefinitely’ a helium blimp is better.

Felix

Batteries have made huge strides in the past 50 years. Dunno how you missed this technological revolution, which so many people hold in their hands every day.

Why move from a wonderfully efficient power unit (becoming more efficient) where the fan produces 80% of the thrust (20% from the core turbine exhaust) and replace it with turbines with generators, heavy batteries, high current power electronics and a heavy motors and propellers. Sounds like a boondoggle for grant money. Power density of the fuel is the secret to successful flight.

Felix

If a turbofan engines continue to offer better performance and lower cost, with comparable safety, then by all means stick with them.

That may well be the case for the rest of this century. Or not.

But hybrid and maybe even eventually pure electric could become competitive with turboprops for regional commercial aviation.

Electric motor in a ducted fan is far more efficient than a turbofan

Thats not the problem. The only real problem is battery energy density.

But that is a total show stopper.

Power density of the fuel is the secret to successful flight.

No. energy density is the secret

Walter Sobchak

From the linked article: ““The energy density for batteries isn’t high enough to even get a couple of people off the ground, let alone 30 or 40,” says aviation analyst Richard Aboulafia. ”

And that is not going to improve sufficiently. In any battery the amount of energy is directly proportional to the mass of the electrodes. You can improve energy density by scanting the material in parts such as the cell walls. But unless you change the electrodes you quickly run into the limits imposed by their composition. And their composition is controlled by the principles of electrochemistry. Those principles have been well known for a very long time. There are very few changes yet to be rung on those bells.

“The energy density for batteries isn’t high enough to even get a couple of people off the ground, let alone 30 or 40,” says aviation analyst Richard Aboulafia.

That is the correct answer but a totally wrong reason. You can build an electric plane that can get a hundred people off the ground, do one circuit and land with flat batteries….

John from the EU

And more dead weight too. Plus the aircraft does not loose weight during flight too. This aircraft has 60 kg battery per person. No room for baggage either.

beng135

Remember the old wind-up watches that took advantage of movement/shaking to wind-up? That’s what we need — a plane like that. Runs on a wound-spring and bumps of turbulence will wind it up. As long as it finds turbulent spots, it’ll keep going & going….

Felix

Piezoelectric nanochrystals do that.

But electric produces a whole lot less shaking going on than FF engines.

Sam C Cogar

Felix – June 24, 2018 8:03 pm

….. since the physics and chemistry show that power densities comparable to fossil fuels are possible. .

Shur nuff, …… Felix, …. not only possible, but actually, factually far, far greater power densities than fossil fuels.

Felix, all you have to do is design a functional nuclear generator small enough to be installed in airplanes and then your “electric motor(s) driven airplanes” can fly round the world ….. non-stop.

So, get with the program, ……. Felix, we know you can do it.

MarkW

I’ve been listening to people proclaim that the age of battery whatever is just about upon us for over 50 years.
Please come back to me when they have one of these things that can compete straight up with a 30 year old Piper Cub.

Felix

There are hybrids today with way over 65 or even 150 hp, and pure electric with more than the former. Not sure about attachment to a Cub, however.

This is from three years ago:

https://www.flyingmag.com/aircraft/siemens-unveils-260-kw-electric-aircraft-motor

“Weighing in at a little over 100 pounds, the new motor delivers a continuous output of 260 kilowatts (the gasoline-piston engine equivalent of about 350 hp), compared with just 60 kw (81 hp) for an electric engine tested in flight by Siemens, Airbus and Diamond Aircraft last year.”

MarkW

A better solution is to just power the plane directly with the turbine. The electric motor only buys you conversion losses.

Felix

There is a number of reasons for adding electric to the power mix, to include quieter operation, less vibration, greater fuel efficiency and power distribution, among other reasons.

http://www.machinedesign.com/batteriespower-supplies/future-electric-hybrid-aviation

The research might be chiefly motivated by CACA concerns, but it’s a promising technology in any case, IMO. NASA’s rear propulsor design is interesting.

Dunno about the Airbus project.

ATheoK

So promising, that they’ve been promising it for generations.
And your 2949 time frame adds another generation.

Felix

Battery power density has indeed improved over the generations.

Further improvements are perhaps more likely to come from incremental gains rather than a breakthrough technology, but that can’t be ruled out either. The history of science and technology is replete with those.

Improvements have come recently on a variety of fronts. We now have cheap and plentiful replacements for Li, which provide the same energy density at much lower cost.

We have improvements to Li-ion and Li-S batteries greatly increasing their output, charging rate and lifetime. We have rechargeable Al-air batteries.

Just such gradual improvements over 22 more years could go a long way toward making electric vehicles competitive.

A late, great buddy of mine was a BP VP who’d have been president were he not an American. Way back in the ’70s, he said that future generations would curse us for burning such rich chemicals as petroleum, which take so long to make.

EVs can reduce real pollution by concentrating it at point sources. CACA skeptics don’t need to be down on EVs. If they’re economically competitive, they’re better than gas and diesel powered vehicles for other reasons. Same goes for natural gas-powered cars and trucks, so common in other parts of the world, but effectively banned in the US.

IMO people who dismiss battery improvements out of hand haven’t kept up with what’s going on in research.

Ragnaar

They are not banned. People should want your product and pay for it.

Power density is not the issue. Energy density is.

It is possible to calculate the maximum amount of energy contained in a chemical bond. And thereby the amount of energy that can be released by making or breaking it.

This leads directly to an upper absolute limit of how much energy a particular battery chemistry could ever store.

As an engineer I am SICK TO DEATH of people with no knowledge of fundamental physics claiming that ‘development will make things better ’till they are good enough’

Solar panels, batteries and windmills CANNOT EVER do the job that people expect at sane prices or at high positive EROEI. This is not an opinion, its engineering FACT.

Only ONE battery technology I am aware of is capable of taking a jumbo ducted fan across the Atlantic – Lithium air batteries.

And no one knows how to tame them sufficiently to be even safe to use, let alone commercially viable.

The rest is hand waving airy fairy nonsense from people indulging in magic thinking.

Science in engineering is not about learning what we can do, it’s about learning what we cannot do. Not now, not ever.

Felix

Leo,

The Norwegians are considering short haul, dozen-passenger regional flights, not trans-Atlantic with hundreds of people.

Actually, Li-air might not be the limit. Lithium offers high power density, but presents other problems. Silicon gets you comparable power much more safely and cheaply.

Engineering problems remain, but they aren’t insuperable.

Felix

Battery technology has constantly improved for generations, at the rate of five percent per year. Tesla people say seven to eight.

MarkW

Batteries have improved. Therefore batteries will continue to improve.

Felix

Every reason to think so, and no reason not to think so. There has been continual progress in fossil-fueled aviation and other technologies. We are indeed still using some airframes from the 1950s in military aircraft, but new production Chinooks use composites instead of aluminum.

True, we’re stuck with the periodic table, unless nuclear power could harnessed. But chemical batteries could be revolutionized by sold state electrolytes and other improvements. Li and S are light elements. The problems with that reaction and with those involving oxygen from the air in a liquid electrolyte, largely due to contaminants, could be overcome with polymers.

Solid state batteries might be available in the next decade.

More absolute retard thinking from another…person

Development of technology is an asymptotic curve towards the theoretical maximum.

There is always a theoretical maximum.

It cannot be reached, let alone exceeded.

Airliners today are little better than they were in the 1960s

They don’t fly any faster, are not much bigger, and although they use a bit less fuel and are quieter, and have a bit more range, its not a dramatic difference.

We could still be using 707s quite happily if thats all we had.
The physics of flight are pretty well understood. It tales a certain amount of energy to fly a plane – essentially you have to feed in as much energy as the plane would lose it of was in a glide and losing altitude. I cant be bothered to do the sums again, but from memory is about 3 watts per pound for a one in 20 glide slope.

To get the plane to altitude takes more power. Again from rusty memory its about 100 watts per pound for an 800 feet per minute rate of climb.

Those numbers are probably wrong, but they are in the ball park.

These are not numbers that can be magically improved.

We can tweak the glide slope a little. One in 25 perhaps. Thats what all those little wing tip plates are about. A little less fuel in cruise. We can make the engines a bit more efficient. Thats why turbofans replaces turbojets – at speeds up to around 600mph they are better converters of fuel to thrust.

But we still dont have a single viable supersonic passenger plane in the air.

In fact we ditched both the ones we had.

People werent prepared to pay the premium.

The greatest fallacy summed up in one sentence.

Are you being sarcastic? I hope so. If not you have epitomized the ‘green idiot’ perspective completely.

Hivemind

Perhaps if we did away with the heavy batteries. Just plug it straight into the mains.

Leo Smith

Even if batteries achieved 100% efficiency as against what the chemistry is theoretically capable of, it is not enough.

ONLY LITHIUM AIR can do the trick for aircraft, and thats a technology that doesn’t work yet.

Felix

It’s not the only system, but versions of it work now.

Wesley Hull

Where did you did you find that 30 year old Piper Cub?

dmacleo

cubcrafters rebuilds and up-engines older cubs as well as produce brand new ones based off older models,
only thing I can think of actual cubs were (iirc) stopped production in mid to late 1940’s

Felix

Fifteen thousand Super Cubs were built from 1949–83, then again from 1988–94. Mine is from the second production period, so isn’t quite 30 years old yet.

don k

If Norway is serious about electric flight by 2040, I think they might do better to think in terms of blimps/zeppelins etc. While the Hindenburg and many other early attempts came to an unfortunate end, the Graf Zeppelin did travel around the world and made dozens of trans-Atlantic crossings without much grief. A modern version with battery powered electric motors might be able to achieve reasonable speed and efficiency. I’m not sure I’d want to ride out a North Atlantic Winter storm in a big basket tied to a bag of gas. But other people might think that was an adventure.

Felix

Maybe filled with helium rather than hydrogen.

What’s old is new again:

http://www.navair.navy.mil/index.cfm?fuseaction=home.NAVAIRNewsStory&id=4810

ATheoK
Cybersmythe

The problem with lighter-than-air is that they can’t carry very much, mostly because they rely on buoyancy to stay aloft, and the effectiveness of buoyancy relies very much on the density of the medium you’re flying through. Air just isn’t very dense. Lighter-than-air gives some advantages for stuff that has to hover, but airliners don’t hover.

Here’s what I mean, the Hindenburg was three times the diameter and almost four times the length of the A380. However, the A380 carries almost 900 people and their baggage and the Hindenburg carried fewer than 150.

Felix

More slowly. Which wasn’t a big deal if you enjoyed the luxury hotel ambiance and weren’t in a hurry on a biz trip.

jorgekafkazar

That’s a pretty outrageous realm you have going there. A magic kingdom, in fact.

Komrade Kuma

No Felix its outside the realm of reality.

Aircraft need to carry a payload otherwise whats the point. Aircraft weight is critical and comprises empty craft mass plus crew, fuel load mass and payload mass. Hydrocarbon fuels stash energy away at 30-40 Megajoules per kG whereas the best bateries are achieving about 1 MJ/kG. Allowing for engine efficiency batteries will weigh 10 to 20 times as much as hydrocarbon fluid. So long viable payload, so long range, so long rationale.

Not even rocket science, sport.

Felix

Of course they need to carry a payload, and hybrids are already capable of doing so.

Likewise the pure electrics being developed by NASA. Just not dozens of passengers. Yet.

The problems with Li-S and Al-air batteries aren’t insuperable.

Felix

My realm is reality. How can you be so sure better batteries aren’t possible over the next 22 years? There have been big improvements just in the past year.

Substitutes for Li with better performance and cost are coming:

https://news.utexas.edu/2017/02/28/goodenough-introduces-new-battery-technology

Not rocket science, alright. Just chemistry and physics.

Komrade Kuma

Its to do with the energy density of the chemical bonds in the hydrocarbons vs those in the battery. The hydrocarbon thing has had multiple solutions in operations for hundereds of millions of years. Bit of catching up to do there Felix.

In any case putting CO2 in the atmosphere just makes the (hydrocarbon manuacturing) plants grow so ultra lightweight, renewable HC fuels seems way more prospective for aircraft to me. Carbon and its natural friends) hydrogen, oxygen etc) evolved a whole series of quite amazing technologies without help. Just what did Silicon, lithium and aluminium manage? Sweet FA is the answer to that until some OCD humans came along.

Get back to me when NASA launches a rocket and a reasonable payload into orbit uisng ‘electrics’.

Felix

Komrade,

Apparently you’re unaware of the powerful affinity which Al and O have for each other.

Leo Smith

aluminum weighs a lot more than carbon and hydrogen.

QED

Felix

Depends upon the amounts involved.

Komrade Kuma

Actually I am very much aware of it. They react instantaneously to form a very stable oxide. Very useful in some situations, corrosion protection etc. When they really get together they burn buildings down and if you add aluminium powder to mining explosives for extra ‘brissance’ ( speed of explosion) they really get cracking. Perfect solution for an aircraft, eh? NOT. Aircraft safety might have something to say about their suitability.

Leo Smith

What he said.
#

Leo Smith

we can be sure by understanding the basic electrochemistry of batteries.

a 100% perfect battery still isn’t good enough.

Zack aa

Passengers provide crowdsourced Samsung power.

Felix

Awesome!

Harness all that power!

You will believe a man can fly!

Leo Smith

The problems with Li-S and Al-air batteries are insuperable.

Sorry.

You can only store so much energy in a chemical compound. Even if you achieve that 100% its not enough.

Felix

I’m not qualified to comment on Li-S, but the jury is still out on Al-air, assuming its economic recycling issues can be sorted out.

Felix

I’m also not qualified to comment on zinc-air and potassium-ion. So I value Leo’s experience with model airplane batteries.

Much as with fusion, Li-air is an engineering problem, not an issue of elementary physics. Where there’s a will, and dollars, there’s a way.

However, of the four proposed avenues toward commercial Li-air batteries, this might be the most promising:

http://pubs.rsc.org/en/Content/ArticleLanding/2015/EE/C5EE01215E#!divAbstract

Felix

Actually Li-S is indeed superable, thanks to solid electrolyte tech, about which I read this AM. From June 11 in the IEEEE journal:

https://spectrum.ieee.org/energywise/energy/the-smarter-grid/the-joy-of-batteries

Ragnaar

Range is limited by fuel. Batteries weigh so much per unit of range. A lot more than fossil fuels. The article is about a good design with good batteries, and it has little payload or range. Value is range and payload.

noaaprogrammer

Just think of all the leg room one or two passengers will have!

Cybersmythe

Yes, in fact you can build a gasoline/electric or diesel/electric or gas-turbine/electric airplane with existing technology that could be a regional passenger airliner with 20 seats or so and quite a nice range, but why would you do such a thing? What do you hope to gain from a hybrid airplane?

Do you perhaps think that because a gasoline/electric hybrid car can be more efficient than a straight gasoline powered car a hybrid airplane would be more efficient? If so, then, well, that means that you don’t have a clue about why a the hybrid car is more efficient and about the essential differences between airplanes and cars.

The most important thing to understand is that a hybrid system is more complicated than a non-hybrid system. That complexity provides more places for inefficiencies to creep in. What that implies is if you’re looking to make the system as a whole more efficient, there must be a big “win” somewhere. An internal combustion engine works best when it’s operating near its maximum power and near it’s minimum RPM, and a an IC engine with higher power will generally burn more fuel than a smaller one, so for efficiency’s sake you want to put the smallest engine in your car that you can. So, what sizes the car’s engine? It’s not the power required during driving, it’s the torque required to accelerate.

Now, IC engines have horrible torque at low speeds. To account for this, we’ve adopted multispeed transmissions, which give the engine the necessary mechanical advantage to accelerate from a standing start and still have the ability to drive at high speeds. Something else you could do, however, is have a second engine that you only use when you need to accelerate. If you’re going to do that, then why not use something with better torque characteristics like, say, an electric motor. If you do that, then you can put a small battery in the vehicle and only use the gasoline engine to charge it. You could then only operate a very small gasoline engine only when needed and always operate it at or near ideal conditions for maximum efficiency. That is the big “win” for gasoline/electric hybrid cars, and why they’re significantly more efficient than pure gasoline powered cars, especially in city driving where you stop at a stoplight every 500 feet or so.

So, what’s the big win for a gasoline/electric hybrid airplane? I can’t think of one. The important characteristic of an airplane engine isn’t torque, it’s power. The excess power sets the rate of climb, and your desired rate of climb determines which engine you need to use for a given airplane. (The excess power required to climb at a given rate is the weight of the airplane times the rate at which it goes up.)

Of course, some light airplane owner/pilots are interested in minimizing their fuel burn. (Renters don’t care because airplanes are most often rented “wet.”) The mechanism that they use to minimize fuel burn is: slow down, and operate the airplane with the throttle wide open and the variable-pitch propeller at the minimum speed for the intake manifold pressure. (An application of the old RAF “Reduce the revs and boost the boost” saying.) The power is then set by operating the mixture “lean of peak,” something that requires special instrumentation.

I’d be interested to see if you have any information comparing the efficiencies of a light airplane operating lean of peak with that of a gasoline-electric hybrid airplane, either proposed or flying. I suspect that the difference would be minimal and might not be toward the hybrid.

Felix

There is a number of reasons for going hybrid or electric for short haul, without reference to “climate change”. Norway, like the Pacific NW of the US, where there is also a lot of interest in electric aviation, is blessed with cheap hydro power.

People accustomed to electric aviation such as RC and drone operators also look with favor on it. It may or may not have its place in the mix in 2040, but IMO to dismiss it out of hand smacks of Luddite anti-technologism.

Cybersmythe

Dude, I’ve been an engineer for thirty years, and my family’s been doing it for a hundred. I CREATE the sort of change that you keep saying is going to happen. If I’m skeptical about it, it’s not because I’m a follower of Ned Ludd. (And I had an electric model airplane in the 1970’s, just so you know. As I recall, it had NiCad’s. Man, that takes me back.)

Anyway, I’m not dismissing anything out of hand. You talked with enthusiasm about some hybrid airplane as if that was a viable solution for some purpose and I’m asking where the efficiency gains for a something/electric hybrid aircraft are supposed to lie, and you say “there’s a lot of interest in electric airplanes because of cheap hydro power.” Well, maybe, but that doesn’t say anything about hybrid anything.

As that other fellow says, the problem with electric airplanes is that batteries suck, and they suck for some pretty fundamental reasons. It’s not clear that anyone can overcome the suckage. Other things could use a battery that works substantially better than current batteries, so battery development is already going about as fast as it can. So, we’ll see. Until then, electric airplanes are a waste of time and energy.

Felix

I’ve linked too many articles on the advantages of hybrids to repeat them here. By “interest” I mean that Boeing, Siemens and other large companies see profit in the technology. They aren’t subsidy farmers like Musk.

Instead of dismissing electric hybrid aviation out of hand, based upon your century of engineering expertise, how about actually reading up on what’s going on?

StephenP

Regarding the ease, or lack of it, of getting into it, I was reminded of the Sinclair C5 electric car.

Steve Oak

Both Boeing and Airbus have development programs for electric aircraft. Initially small and later much larger.

https://www.investors.com/news/boeing/

Henning Nielsen

Norway must be the greatest place on earth for climate hypocrisy. One of the richest persons here, owner of a big hotel chain, misses few opportunities to embrace the climate change gospel. However, when going to a conference in Sweden, he uses his private jet. Not so surprising maybe, but more so when his employee who is in charge of “sustainability” arrives a little later in HIS private jet. Neither person is very eager to comment on this internal climate policy.

Andrew Cooke

“Difficulty in scaling up” is a feature and not a bug. In the Malthusian world only the rich elite actually should have access to services like air travel. Making air travel exceptionally expensive and impossible to scale up meets this important need.

Yes, I am saying this tongue in cheek in a mocking tone. However, like all good jokes, it unfortunately has a basis in reality

Lank

I’m not sure that EV aircraft should be ‘mocked’. Already there is a commercial service in western USA using 12 seater passenger, twin engine, hybrid aircraft. As batteries develop to have higher energy density, and I’m sure this will be the case, these hybrid aircraft will have longer range and more carrying capacity.
The acceleration, small size, considerably fewer moving parts and reduced fuel storage requirements and usage of electric motor hybrids have considerable benefit over most conventional aircraft.
I believe commercial development of EV aircraft and hybrids will progress in leaps and bounds as battery technology evolves. Why not?

RicDre

” …these hybrid aircraft will have longer range and more carrying capacity.
The acceleration, small size, considerably fewer moving parts…”

I would think a hybrid (Jet engine & Electric or ICE and Electric) aircraft would have more moving parts than a Jet or ICE by itself.

Michael Keal

Because there’s no need for them!

Of course if someone can develop a battery that stores more energy per kilogramme than jet fuel or petrol and that wasn’t too expensive this idea would, for economic reasons, probably succeed.
Until then this is stupidity signalling masquerading as virtue signalling.

You know, like shutting down fully functional coal-fired power stations and replacing them with whirligigs in order to ‘save the planet’ from that evil chemical carbon dioxide.

Lank

Michael, this is new technology. I don’t think anyone is suggesting that they replace current aircraft, at least until huge improvements to energy storage are made. However, there is clearly a role in short haul flights and the technology is improving. Why all the negativity?

jorgekafkazar

Because this is a really, really stupid idea. Anyone who would take a short haul flight in one of these needs his / her head examined.

Felix

With you on the whirligigs. Haven’t looked at the economics of hybrids, but where cheap hydropower is available, it might pencil out.

Or it might just be driven by subsidies and grants rather than any compelling economics, akin to the EV car craze. Hard to say Boeing’s motivation is.

ATheoK

At this point in the thread you are just thread bombing.

Felix

How so?

I’m providing information on recent developments in battery and aviation engine technology.

jorgekafkazar

Where in the commercial flight catalog is that EV service listed?

Leo Smith

How can batteries develop higher energy density than the laws of physics allow?
In the 1800s steam engines were perhaps 7% efficient. By 1930 steam turbines were up to 37% give or take, They are still 37% give or take.

LIpoly batteries are around 37% of as good as they can theoretically be. There is not much left to come.

And there is no better technology except lithium air. And that has huge issues that need to be solved, and even that only just gets you into kerosene energy density.

Felix

That’s the case today. But tomorrow we may, indeed probably will, have liquid Li or other elemental batteries and superior materials, possibly superconducting.

It’s not just the underlying chemistry, but the design of the whole system, that matters.

Just this year, we discovered that we don’t need expensive, rare lithium for “lithium” batteries. There is more in the world than we have dreamt of in our philosophy, physics, chemistry and engineering.

John from the EU

Felix: I am very sorry for you. The Laws of Physics will not change. Not tomorrow, not ever. Period.
Get your head out of the clouds. Please.

Noam Sayen

Do you mean this:

“Zunum Aero reveals details of its 12-seat hybrid-electric passenger aircraft that it hopes to be operational by 2022.”

https://www.forbes.com/sites/michaelgoldstein/2018/05/22/hybrid-electric-passenger-jet-gets-100-plane-launch-order-from-jetsuite/#77d1ba7f5c08

Last time I checked my calendar, this is 2018.

Wesley Hull

Could you please provide a reference or link to said commercial service. I did a search and found nothing.

ResourceGuy

2040 is the new 2030 prediction. It’s inflationary.

Well at least the West Side Hiway is for U-cars only in 2028. Unless Hansen comes up with a new date, as doommongers always do. Their heir, if dead themselves.

PS Prolly they’ll raise the street to be able to say the prediction would have been filled.

Bryan A

Ah Yes, the solar powered electric plane that took (16 months) over a year to (fly 22,000 miles) circumnavigate the earth at a daily averaged rate of 2 miles per hour

Felix

Still, at daylight cruise speed of 56 mph, it could reach Bergen from Oslo about twice as fast (3.4 hours) as driving. Or in around one third the time during heavy traffic. But it carries only its two pilots.

Non Nomen

Please take into account the time required to recharge the batteries. That also requires at least two stopovers on the way. Recalculation needed…

Bryan A

And the turn around time for their often needed repairs

Felix

That applies to demonstration project IS 2, not to future a/c. Electric engines will require less repair. Airframe tech is also on the march, thanks to “space age” composite materials.

Felix

Non,

A hop that short wouldn’t require any landings en route.

The plane flew from Japan to Hawaii, albeit slowly, since they had to operate at night as well as day.

Non Nomen

Oslo to Bergen: 480km or 300 miles.
oops…just realized you must have meant the Solar _Impulse.
Sorry…

Felix

On an air line, it’s 189 miles.

https://www.distance.to/Bergen/Oslo

Straightening out the route is what makes even a slow plane competitive.

But with advancing tech, both speed and load capacity could increase.

Felix

Yeah. I did. The toy in the post, obviously couldn’t make it.

John from the EU

No, it carried 1 pilot.
https://en.wikipedia.org/wiki/Solar_Impulse
It was a nice experiment costing a lot of money showing that the technology used did not belong in aviation.

NorwegianSceptic

Not much ‘daylight’ in Norway in winter (about half of the year), and Bergen is also one of the rainiest Places in the country……

RicDre

In 1986, Burt Rutan’s Voyager aircraft flew non-stop around the world in nine days. It also had two pilots and was powered by two small Fossil-Fueled motors. Solar Impulse didn’t quite make up it to that standard.

RicDre

Darn, I didn’t press the Edit button quickly enough…I meant to say “Solar Impulse didn’t quite make it up to that standard.”

Felix

Except the plan isn’t for ’round the world flight, but local and regional passenger travel. The potential is there now with hybrids and pure electric might be possible in future, if it’s economically feasible and technologically possible.

RicDre

“Except the plan isn’t for ’round the world flight”

True, but I wasn’t comparing Voyager to the aircraft in this article, I was comparing it to the aircraft you mentioned, Solar Impulse

Felix

And I was pointing out that Solar Impulse 2 could fly all around Norway today, WX permitting. It just couldn’t carry passengers.

But technology marches on. An Al/air battery-powered place could probably carry passengers today, but recycling the Al takes power.

The Columbia River dams’ first major use was smelting aluminum, which is a very energy-intensive process. Now they power server farms.

RicDre

And I was pointing out that Solar Impulse wasn’t designed to fly all around Norway, it was designed to fly around the world, and compared to Voyager, it did that very badly.

On the other hand, I agree with you that technology marches on and one day we may have non fossil-fuel powered aircraft. If we do, it’ll be interesting to see what technology makes it possible.

Phaedrus

Trains?

noaaprogrammer

Yeah, batteries will soon take over nuclear-powered submarine technology; and shortly thereafter NASA plans to send astronauts to Mars using electric rockets!

Felix

Batteries are important in nuke boats, too. Just not as critical as in diesel-electric.

Felix

First aerial circumnavigation of the globe with gas-powered planes took 175 days:

http://pioneersofflight.si.edu/content/first-flight-around-world

Johann Wundersamer

comment image&imgrefurl=https%3A%2F%2Fitsafunnyoldworld.wordpress.com%2F2013%2F08%2F09%2Firish-asterix-soc%2F&docid=GD1fZvUKhLc35M&tbnid=-gqy3PP7uJICvM%3A&vet=1&w=543&h=720&source=sh%2Fx%2Fim

Bruce Cobb

Cool toy. Not much practical use though.

jamie

I want one….;)

Bryan A

might be cheaper to do this with a tesla

mwhite
Ellen

To be fair, they stated the limitations and uses quite clearly: this one is really only useful for flight training, and VERY short hops. They weren’t predicting trans-oceanic flights. It’s nice to see an electric vehicle company with a sense of proportion.

Felix

Even local passenger service in Norway will be fraught with difficulties. Any such aircraft will necessarily be lightweight. The WX in Norway will mean it won’t be able to fly on many days in winter, spring and fall.

Useful electric aircraft must await advances in battery technology. Even flying during daylight hours only, powered by solar cells, probably won’t be able to supply enough energy.

John Hardy

Agreed. There are other weather-related issues. I imagine all-weather operation in Norway requires effective airframe anti-icing. In modern transport aircraft this is typically done with ducted hot air from the engines.

Clyde Spencer

And, flying in Winter will require diverting battery power to the passenger cabin to keep people from freezing. And then, there is the issue of degradation of battery performance when the batteries are cold. Summertime toy!

MarkW

Spring and fall toy. Summer heat is bad for batteries as well.

Felix

Solid state batteries would also be less susceptible to heat, among their many other advantages, such as lighter weight, lower cost, longer life, double the power density (or more) of Li-ion and less flammable.

https://www.wired.co.uk/article/what-is-solid-state-battery-toyota-dyson

Felix

Felix: You really are a card. You believe every bit of marketing bollox you read don’t yo?

Assuming you are actually capable of it, why dont you get a degree in engineering and make all this wonderful stuff happen?

Alan Tomalty

What about turbulence. Airplanes that light would be uncontrollable through bad turbulence.

John Harmsworth

Even on the ground! They would be a regular sight blowing past your window on breezy days. They would have to put a return deposit on them.

John from the EU

I fly those type of aircraft and they can handle more than you think. But it depends on pilot skills.

NorwegianSceptic

Luckily Norways coastline is known for its tranquil weather conditions… (/sarc)

Felix

John and Alan,

The B-25 had rubber bulge deicing. but also anti-icing features. For most of the year in Norway, depending upon altitude, icing would indeed be a problem. On short hops, the risk might be manageable with ground deicing.

As others have noted, so light and aircraft would surely be at grave risk from turbulence. A heavier plane would need more powerful engines. Hard to achieve with present technology. Solar Impulse’s loaded weight was 3500 pounds. SI2’s four engines each produced 17.4 hp, powered by Li-ion batteries. Its wingspan was wider than a 747 and it flew slowly. See link above.

Obviously, a long way to go.

drednicolson

In Lindbergh-era aviation, you de-iced by deliberately stalling and free-falling through the warmer low-altitude air, hoping you get enough off to recover before crashing.

Non Nomen

Do it with passengers on board. Either they are freaks and love it, or you are dead right after landing/crashing.

MarkW

Rubber boots means a major weight penalty, not to mention the weight and power consumption of the pump needed to inflate them.

Your 1 hour of flight time just took a major hit.

Felix

I know that rubber is heavy. Endurance of Solar Impulse 2 is 36 hours.

I’m not imagining the toy in the post as a passenger plane.

Phaedrus

SI was effectively a low powered glider. It use weather systems to get around the globe. And thats part of why it took so long!

Michael S. Kelly, LS, BSA, Ret.

There is a physical limit to what can be accomplished with batteries, and we are bumping up against it. Batteries store energy in the form of chemical potential, the same as fossil fuels. But fossil fuels use oxygen from the atmosphere as the oxidizing reactant. Batteries have to carry both fuel and oxidizer. A simple way to see the effect is to imagine that airplanes powered by fossil fuel were required to carry the air needed to burn it. A gasoline engine has an air/fuel ratio of about 15 by weight. A Cessna 172 carries 336 pounds of avgas, so it would have to carry 5,040 pounds of air. That’s probably a non-starter, since the plane’s gross weight is 2,450 pounds.

What is really needed is great advances in fuel cell technology. The Apollo fuel cells could put out 135 kW-hr, and weighed a mere 250 pounds each. Compare that to a Tesla battery. The 85 kW-hr battery weighs 1,200 pounds.

What’s more extraordinary about the comparison is the the Apollo fuel cells carried their own fuel and oxidizer – namely, liquid hydrogen and oxygen. A hydrogen fuel cell operating on atmospheric oxygen would have a considerably better specific energy.

I’m not sure why this is so hard to grasp, but I’m sure someone will have a comment…

Felix

Not true of aluminum-air batteries.

RPT

You are quite right, we will soon have al-air batteries. Possibly before we have fusion, which has been just around the corner for a few generations.

Felix

IMO definitely air batteries before fusion.

But fusion is getting closer, too. Fusion was just 30 years away in 1958, but now it’s probably more like 20 years. Improvement!

If we keep on the same path, the problem of fusion is with materials science, ie engineering, figuring out what must go on the inside of the containment vessel.

Leo Smith

lithium air is the only technology that might do the job. Al air still too heavy

Its interesting that a lithium air battery will land far heavier than it took off having combined all that air…into oxide.

Its interesting that this post has brought out all the ‘throw enough of someone else’s money at it and we can create technology that breaks the laws of physics’ brigade.

I usually associate that with renewable energy enthusiasts.

Felix

I’m a “renewables” opponent, despite living in a region infested with its offending installations, and with kith and kin profiting therefrom.

However, the history of science and technology is replete with instances of breaking what were thought to be impossible barriers.

In any case, the proven tech of hybrid aeroengines shows promise.

Cybersmythe

Actually, it’s useless for flight training, as anyone who has ever considered the economics of flight training could tell you. If you intend your flight school to survive, you don’t fly an airplane for an hour and then leave it on the ground for an hour, you fly for about 50 minutes and leave it on the ground for 10.

“Thank goodness, well-meaning energy ignorance has a short lease.”

Anonymous Heins

Video by COLDFUSION? Anyway this electric airplane looks like a great sport-toy. Any aircraft this light will end up in the cheap seats if a cross-wind gust hits it when landing, and the parachute won’t save you.

vboring

Lithium-ion might not hack it.

Aluminum air batteries have a theoretical energy density in the same neighborhood as jet fuel.

Felix

Nor do the problems with Al/air batteries seem insurmountable.

Dunno about the power requirements for flying v. ground vehicles, though. Light planes, maybe. Even a domestic passenger liner or commuter aircraft however, can’t say.

The two P&W turboprop engines on a Bombardier commuter airliner range from 2150 to 5071 shp. The original 100-series carries up to 39 passengers. The stretched Q400 holds up to 78 passengers. Its 2016 upgrade can handle 90.

By comparison, the latest models of Honda CRV sport a 160 hp engine.

Non Nomen

Under Norwegian wx-conditions a heating of the cabin to prevent fogging and to keep the passengers in a reasonable mood is mandatory. Another problem is the de-icing of the leading edge of wings and tail unit. That requires a lot of energy which can’t be drawn from the battery. So you’ll either sit in a heated plane on the ground, unable to take off because of rapidly waning electic power, or you’ll soon be running into trouble because of severe icing conditions when airborne. Maybe a fine aeroplane in best dry and warm conditions like Australia, but not suitable for latitudes of 60°N and higher.

Felix

Especially where mountainous.

The winds might help provide lift going one way or the other. If they don’t flip you over.

MarkW

Be tough to power your way out of a downdraft.

Felix

Not with a hybrid engine.

https://www.wired.com/2017/04/hybrid-jet-finally-make-electric-flight-reality/

Duplicating link from above.

MarkW

Save the weight of the generator and electric motor and just power the plane directly from the turbine.

Jim Gorman

Exactly. If you need a 100 kw ICE to charge a 100 kw battery/electric motor, why even have the battery/electric motor? Conversely, if you have sufficient battery/electric motor for the flight time, why have an ICE? None of this makes any engineering sense!

don k

“Under Norwegian wx-conditions a heating of the cabin to prevent fogging and to keep the passengers in a reasonable mood is mandatory. ”

These are the descendants of Vikings. Surely if you promise them rape and plunder at the end of the journey, they can put up with a bit of discomfort.

Schitzree

Al-air batteries aren’t rechargeable. Do you mean Al-ion batteries?

https://en.m.wikipedia.org/wiki/Aluminium-ion_battery

Felix

Perhaps you consider this design and other allegedly rechargeable Al-air batteries to be Al-ion:

http://www.greencarcongress.com/2015/01/20150109-fuji.html

Walter Sobchak

Essentially you are burning aluminum, which is fine. The combustion product is Aluminum Oxide. The problem is that Aluminum Oxide is a refractory. It takes a metric $#;+ ton of energy to turn aluminum oxide back into aluminum. You can’t make a rechargeable aluminum-air battery.

The aluminum air battery doesn’t produce any CO2. The same cannot be said of the power plants that run the aluminum smelters.

Felix

True that normally you can’t recharge, but have to replace the old Al element and recycle it. But rechargeable Al batteries have been developed:

http://www.greencarcongress.com/2015/01/20150109-fuji.html

Also right about the energy intensiveness of recycling the Al. But Norway does have lots of cheap, plentiful hydropower. Of course energy used in recovering Al can’t be used to offset fossil fuel power.

Nuclear power and hydro power used to run smelters

Unfortunately, unlike jet fuel, the products of reaction are not gases that can be safely released into the air. They have to be carried.

Leo Smith

No, they don’t.

No, they do not have a theoretical energy density in the same neighborhood as jet fuel.

Only Li-air does.

Wayne Townsend

If “petrol fuel planes” demand fuel mixing “on the fly” and this plane does not give any experience regarding that, it is even of limited use in flight training, unless you expect to train only people who purchase $100,000 electric planes.

Non Nomen

The Norwegians are world champions in buying Teslas, highly subsidized and/or tax exempt. The batteries of a Tesla have a weight of 500kg approximately, that’s almost the weight of that flying machine, so what is the battery capacity of that flimsy apparatus? In unfavourable flying conditions, pretty common in Norway all year long, esp. if de-icing is required, the batteries won’t last long. Fasten your seat belts, gentlemen, it’s going to be a ride you’ll never forget.

joe - the non climate scientist

it’s going to be a ride you’ll never forget.

more like a ride you will quickly forget – along with winning the darwin award

Clyde Spencer

Is that because they are a wealthy country — wealth from North Sea crude oil?

Gordon Jeffrey Giles

They are going to use Unicorns to help taxi the planes and then provide mid-air refueling of the Ultra-lite Lithiums with Santa’s Reindeer pulling the Green Battery Charger Sled. It’s all in the report man….can’t you read!

Phillip Bratby

Things haven’t changed much over the years. I remember model airplanes powered by elastic bands. Maybe they should consider scaling them up as they don’t need massive batteries.

Felix

See the video in my first comment, above the picture of the circumnavigating solar-powered plane.

Clyde Spencer

Ladies and Gentlemen, we’re holding right now and are next in line for takeoff. We will be given permission as soon as they finish winding the rubber bands. While we are waiting, we will be serving beverages followed by a pre-flight meal, and followed up with more beverages. Please enjoy your wait.

Latitude

great!…self igniting planes

Major Meteor

I like how they required what looks like a diesel generator to charge it up again. I think it’s a cool toy. Rich people will love it.

Latitude

This is what they were using…and they had to rent it

https://www.kennards.com.au/generator-20-kva-trailer-mountable.html

comment image

Non Nomen

AUD 18.000 minimum, I guess.

John Hardy

As many folk will know I’m a fan of electric road vehicles: but electric transport aircraft are just silly at the present state of technology. 400 tons of 747 London to LA at 500 m.p.h, 7 miles up? This is an application for which the incredible energy density of hydrocarbon fuels is the only possible solution now and for the immediate future.

As an aside, part of my enthusiasm for EVs was that I felt we were burning our grandchildren’s aviation fuel. It felt to me that using petroleum to propel cars was like burning the furniture because one was to lazy to go out to the wood shed. We have a choice with cars. We don’t with aircraft.

And for the avoidance of doubt, nuts to CO2 emissions. Never an issue of concern to me

Felix

To be fair, they envision domestic passenger service. Basically commuter a/c. But still, the power required isn’t possible with present battery technology.

John Hardy

Felix – you are quite right. On the other hand Oslo to Narvik is still 1000 km and they probably use 737s. High Gross max take off weight of a 737-800 is about 79,000 kg. The Theoretical energy required to lift 79000 kg to a height of 10000 metres and accelerate it to 800 km hr is about 2500 kw-hr (if I have done my maths correctly). That’s about 25 model S batteries at 540 kgs each or 13,000 kgs. And that’s just to get established in cruise, and ignores aerodynamic drag.

Felix

I suppose that Oslo to Narvik wouldn’t be direct. Surface transport in Norway is generally slow, so air travel doesn’t need to be speedy to compete. Electric makes sense for a nation with so much hydropower, should battery powered aviation prove possible.

The eco-Norse timetable is optimistic, but IMO isn’t outside the realm of possibility, given improved battery tech, which could be a long time coming.

John Hardy

I think there are currently 8 direct flights a day

MarkW

Using electric planes?

Felix

Solar Impulse 2 obviously could easily fly from Oslo to Narvik under clement conditions, but dunno if an all-electric passenger plane could by 2040.

Leo Smith

To be fair the battery technology is just about there for a one hour or less flight.

The sums are the same no matter what the size of plane, and I have coaxed 45 minutes out of electric model planes OK. No payload of course, and the Reynolds numbers make full size planes a bit better on lift to drag, which is the crucial issue in how many watts per pound you need for level flight.

(guess why a 747 looks and handles like a giant sailplane: it all about lift to drag…)

Felix

You can also get a bit of benefit from design differences from electric v. gas or kerosene power. NASA is working on this.

Unfortunately we need a bit more than a ‘bit of benefit’

We need a breakthrough in energy storage or power produ8ction frankly.

Actually the highest energy density of anything is in a tank of deuterium or a pellet of plutonium.

Atomic engines could make a plane that never needed refueling at all.

If only we could think of a way to make an atomic engine safely and light enough.

+42

MarkW

Aviation fuel can be made from many things. It doesn’t have to be pumped from the ground.
It’s better to use fossil fuels to get rich, and let our kids use that wealth to invent solutions to problems that won’t be cropping up for hundreds of years anyway.

Leo Smith

Lithium air has the same theoretical energy density as kerosene. Its the ONLY battery technology that does. Forget Al-air. Its nowhere near that good.

A 747 powered by lithium air/electric ducted fans is possible, if a functional Li-air battery could be constructed.

That is a huge ‘if’.

It may happen one day but I am not expecting it in my lifetime.

Felix

How old are you?

Sorry!

But really interested.

67 years

fxk

747 lithium air and ducted fans? Tip speed on propellers is probably the most limiting factor limiting fast flight. Ducted fans will also be limited in how fast they can turn. Are you envisioning ducted fans producing thrust, like a just, or screwing through the air like a “normal” prop. Granted, fan shrouds do improve performance, but at the expense of additional weight.

A turbofan engine IS a ducted fan. Driven by a turbojet.

Tom Halla

If they can produce something with the performance of a DC-2?

Stephen Richards

Remember. One of these Norwegian nutjobs is an EU commissioner. Someone with absolute power across the EU.

RPT

Who?

Norway is not an EU member.

Felix

Dunno whom he had in mind, but Norway is a member of the EEA:

http://ec.europa.eu/trade/policy/countries-and-regions/countries/norway/

rocketscientist

As if propulsion were the only thing that required power during flight.
Avionics … things like radios, radar, altimeters, GPS…..all require power. Electricity is made usually by shaft power drawn off the engine to a generator or powered by and APU.
You used to have to go to Popular Mechanics to see write-ups for such naïve concepts.

Ignorance to the core. Far too many problems to be practical in under 50 years. Heck it might take that long to even develop enabling technologies.

Leo Smith

the avionics consume a fraction of the total power. Straw man.

Joel Snider

Funny that all these high-minded greenies insist upon the perks that go with an advanced western fossil-fuel-powered society, even as they do their best to sabotage it at every turn.
Ignorance and elitism – it’s a horse race.

steve case

The video I saw talked about flight schools using electric aircraft. Yes they would be great for much of the instruction, but learning how to manage a conventional engine is important because that’s what you will fly as a pilot if you ever want to actually go somewhere besides take off and land at the same airport.

joelobryan

Flight schools would need to use extra batteries. A flight training school commonly could fly 3 training sorties in the morning and 3 in the afternoon, and then one after dark. & flights in a day per aircraft. Can’t do that without extra batteries to swap out.

In the video about the flight in WA, where they found the generator wasn’t up to the recharge task, I can not believe they didn’t try out the generator-charger combination before driving out to the bush to recharge the plane.

Leo Smith

I used to charge my Lipoly batteries in an hour for model planes. Flown gently that would keep them in the air for 45 minutes or so, so only two batteries and one charger needed to fly nearly all the time.

Ian W

Well Uber has a sub-division ‘Uber Elevate’ and they are planning a passenger service with electrically powered VTOL aircraft starting in 2 years time. The demand for Unicorns may exceed supply.

https://www.uber.com/info/elevate/

commieBob

Even with free fuel, electric powered aircraft might not be viable. Surprisingly, electric motors can be competitive with the kind of turbines used in jet aircraft in terms of power to weight ratio.

Where electric power falls down is batteries and/or fuel cells. The very best fuel cell provides about one horsepower per pound. That’s about six times heavier than the electric motor it would power. link

Surprisingly, smaller, slower, aircraft don’t use fuel more efficiently. A decent airliner gets a hundred miles per gallon per passenger. link

In terms of resource use and pollution, it seems to me that jet airliners operating with fossil fuels, are actually better than any possible electric alternatives.

Leo Smith

horse power per pound i not the issue. You can flatten a lipoly battery in a minute and a half and get huge ‘horsepower.

https://www.youtube.com/watch?v=YuMCIad06LM

It’s watt hours per pound that gives you commercial flight

commieBob

You need both. You can have infinite watt hours per pound and still not be able to get off the ground if you don’t have sufficient horse power per pound.

Oh yes, but my point is that watts per lb are more than adequate on LIpoly batteries already. Its not a real world problem with available technology.

rovingbroker

Anthony Watts wrote, “Medication aside, I don’t think these people understand the concept and difficulty of scaling up such technology.”

I think they do.

Boeing Co.-backed startup Zunum Aero plans to deliver its first hybrid-electric plane in 2022 to JetSuite Inc., setting the stage for a new era in regional flying.

JetSuite, a small charter airline with plans to expand a commercial operation nationally, eventually will receive as many as 100 aircraft that seat up to 12 passengers each, Zunum co-founder Matt Knapp said in a statement Monday. JetBlue Airways Corp. has invested in Zunum and JetSuite. The charter operator is also backed by Qatar Airways.

https://www.bloomberg.com/news/articles/2018-05-21/boeing-backed-startup-targets-2022-debut-for-electric-plane

Zunum is designing the propulsion architecture so that higher-performing batteries, electronics and motors can be plugged in over time. This way, the company intends to expand range from 700 nm in the early 2020s to 1,000 nm by 2030.

http://aviationweek.com/aircraft-design/zunum-s-software-style-approach-developing-electric-propulsion

We’ll see.

Non Nomen

We’ll see.

Exactly. When they do as Tesla, another startup with considerable teething problems, did and still does, they are going south.

Walter Sobchak

No we won’t.

Felix

Hybrid prop engine tech has already been demonstrated:

https://www.flyingmag.com/hybrid-electric-aircraft-motor-powers-up

This option is probably the only way that the Green Norwegians can make their deadline.

MarkW

The advantage of hybrid electric is matching engine speed and torque to conditions.
Not a big problem with propellers.

Felix

Yup. Developing hybrid jets is obviously more challenging.

RicDre

A hybrid Turboprop Jet engine might one day be possible or perhaps a hybrid Turbofan Jet engine since the air from the front fan bypasses the jet engine.

Felix

They are being worked upon as I type.

RicDre

I’d be very interested to see how they are approaching the technology, do you have a link to an article I could look at?

Felix

One program:

https://www.zdnet.com/article/boeing-jetblue-invest-in-electric-aircraft-maker-zunum-aero/

Copying some of my previous comments:

There are hybrids today with way over 65 or even 150 hp, and pure electric with more than the former. Not sure about attachment to a Cub, however.

This is from three years ago:

https://www.flyingmag.com/aircraft/siemens-unveils-260-kw-electric-aircraft-motor

“Weighing in at a little over 100 pounds, the new motor delivers a continuous output of 260 kilowatts (the gasoline-piston engine equivalent of about 350 hp), compared with just 60 kw (81 hp) for an electric engine tested in flight by Siemens, Airbus and Diamond Aircraft last year.”

Another:

After setting an electric aircraft record last year, the Siemens electric plane became the first electric glider tug:

https://www.siemens.com/press/en/feature/2015/corporate/2015-03-electromotor.php

This year it suffered a crash.

Siemens’ serial hybrid flew this year in Hungary.

Since 2013, Chip Yates’ electric Rutan Long-EZ has set records and outperformed, at less cost, gas-powered light planes such as Cessnas under FAI supervision.

This technology is more mature than might be imagined, but not ready for multiple passengers yet.

The Norwegians are far from alone:

https://en.wikipedia.org/wiki/Electric_aircraft#Developments

Among the projects listed in that link is this:

http://atwonline.com/airframes/easyjet-joins-electric-aircraft-project

UK (budget carrier) LCC easyJet has formed a partnership with US-based Wright Electric, which aims to develop an 180-seat electric aircraft for commercial aviation use within 10 years. EasyJet said it has been working with Wright Electric “over the course of 2017,” providing “an airline operator’s perspective” on the project in areas ranging from maintenance to revenue management.”

https://www.theguardian.com/business/2017/sep/27/easyjet-electric-planes-wright-electric-flights

Please overlook the source. It’s just quoting the companies.

Who knows whether such an ambitious time table can be met.

A pure electric plane from three years ago in Slovenia, relying heavily on Siemens technology:

https://www.youtube.com/watch?v=WiADDbeFanU

And one in Oz, from five months ago:

RicDre

Thank you for providing the links.

Felix

You’re welcome. You can find others in this long comments section.

Electric ducted fans are already a reality in model aircraft. Unfortunately at model speeds they are woefully inefficient and so flight times are short.

MarkW

It’s not just challenging, it’s a waste of effort.

Felix

Boeing, Siemens and a number of other companies beg to differ.

HAS

Hybrids have a lot going for them. Allows the turbine to run at a constant optimised speed, distributed motors, superconducting motor/generators to compensate for weight.

Current target has them entering service for regional aircraft in early 2030s. Both Airbus and Boeing are developing.

And then of course there are drones.

Felix

Drones would be OK for cargo. Pilotless passenger planes might be a hard sell, even if the aircrew were only along for the ride.

I’d be willing to risk a ride in a drone, however, for short hops, if it had a good glide capability and backup manual controls for emergency landings.

MarkW

In modern jets, the crew is pretty much along for the ride. From takeoff to landing, the crew just monitors.

simple-touriste

And sometimes, the crew is there just to pull the stick in a situation with a high AoA (*): high attitude, negative climb rate and crashes the plane.

(*) yes there is no AoA indicator in either Airbus or Boeing cockpits, I knew there is some debate about whether it would be useful

MarkW

Super conducting motor/generators??????????

Have you factored in the weight of a tank of liquid helium?

HAS

high temperature superconductors use mechanical cryocoolers with very low power requirements. Also we are just cooling a very small volume, unlike MRIs where the magnets need to be big enough to wrap around a body. All quite doable.

MarkW

Low power is relative. Most of the ones I’m familiar with draw more power than this airplane motor does. Then theirs still the extra weight to deal with.

HAS

Try “High power density superconducting rotating machines—development status and technology roadmap” Haran et al 2017 iopscience.iop.org/article/10.1088/1361-6668/aa833e/pdf to get you started. Add to that completely sealed cryostats with coils that are excited inductively to reduce load. Remember power is required at ~50K not 4K.

MarkW

I didn’t say they weren’t possible, just not practical for this application.

HAS

Yes you did, but that view was based on your knowledge of low temperature superconductor technology. When it was pointed out that you had the technology wrong you just refer back to your original mistake. Can’t help you anymore, sorry.

MarkW

You haven’t provided anything beyond vague assertions.
Pretty typical.

RicDre

“Super conducting motor/generators??????????”

I was wondering about the same thing. I thought maybe someone had invented room-temperature super-conductors and I missed the announcement.

David Hoopman

Decades ago I concluded that the stupidest thing you could possibly do is jump into your car and drive it until you run out of gas. Now I can move something even more stupid to the top of my list.

John Harmsworth

Why settle for electric? Catapult launched gliders or ballistic passenger capsules wouldn’t require any carried energy at all!
Or just catapult people directly.

Non Nomen

Oars and rows and paddles for the passengers and a competent drummer, and off they go.

MarkW

They tried that to get free range immigrants over the border.
They are still working on mastering the landing.

Jim Masterson

The landing is easy. The hard part is walking away from the landing.

Jim

jorgekafkazar

Catapults are noisy:

John Harmsworth

I know we’re supposed to be polite but do we have to be patient and tolerant much longer with these Green idiots? I’m going to explode pretty soon!

Bruce Cobb

Laughing at them works wonders – very therapeutic, and they hate it. Win-win!

drednicolson

Snoopy’s doghouse looks like a safer plane ride than that.

Toto

ATTN: Elon Musk. The Norwegians are really good at drilling tunnels.

dmacleo

bet an aircraft like this can drill one faster…..

MarkW

At 300kg, it wouldn’t dig a very deep tunnel.

Gary Pearse

Lets not forget that this kind of dismissal followed the Wright brothers’ <100m flight. The small plane depicted is a fair start. Who knows,maybe they can be recharged continously in flight, microwaves? Maybe they could refuel passively using powerlines' magnetic fields… My point is you should write your article to define the limitations and what possible technologies might be tried. At some point we will have to fly someway without petroleum fuels. Hopefully we dont consider converting half of American agriculture to corn fuel to make things worse.

Non Nomen

Power lines brought more a/c down than recharged them. Microwaves are a safe method to heat up the passengers until they explode.

Gary Pearse

Its hard to make a difficult point

Clyde Spencer

“At some point we will have to fly someway without petroleum fuels.”
Why? As someone pointed out above, av’ gas can be made from things other than crude oil.

M___ S___

People seem not to be able to do the barest research—to check on energy density. The only way we’ll see electric aircraft is if they are using fuel cells that convert fossil fuels to electricity first, and then they use the electricity to drive electric motors—propellers only.

Keep in mind that these politicians are no better than 99% of our own politicians—incompetent people making decisions and creating edits for all of us.

John Mason

Looking at the Wikipedia article on Energy Density it’s about a 40 to 1 ish advantage in power per weight of current aircraft to an electric one.

Perhaps by 2040 there will be some break thru, but without that, electric aviation is just not going to feasible or competitive.

In a ground vehicle the weight of the batteries can be handled to a certain degree that we have some vehicle applications that work (light duty commuting or long distance if the vehicle can switch to gas like the Chevy volt or Honda clarity).

For me, when I’m on a long road trip looking for 900 miles in a day even the long distance electric car solutions aren’t tenable. Quick replaceable battery packs like people exchange propane tanks was one approach, but the car makers have nothing remotely standardized with their batteries. So we are left with the charging stations.

In that state, electric cars are still not competitive and when the whole life cycle of the electric vehicle including the fossil energy require to mine and make and later dispose of the battery, I doubt there is any CO2 savings at all. It’s all virtue signalling.

Order of magnitude * 4 for aviation.

John Hardy

John Mason: 900 miles a day is an edge case, but if you insist: https://www.theverge.com/2018/1/2/16842816/tesla-model-3-la-new-york-record-cannonball-run. Tesla Mosel 3 2800 miles LA to NYC in 50 hours

Ah. The Mosel 3.
Run entirely on German white wine.

Bit of a waste, in my opinion.

Auto

Sheri

There is a complete lack of reality in these people’s lives. They live in a dreamworld and for some reason, rational people keep electing them. Or we live in the dreamworld and the people who elect them are rational……

Marcus

An electrical battery fire at 10,000 ft would really light up their “dreamworld” !!

drednicolson

For maximum poetic impact, the plane ought to be named Icarus.

richard verney

It’s a toy. An expensive plaything for the wealthy.

When I lived in Norway, there were lots of small sea planes at the bottom of people’s garden who lived on the islands in the Fjord. Great for hopping to see the neighbours for a BBQ, but presently nothing more serious than that.

Steve Lohr

The film reminds me of this old clip of demonstrated steam powered aircraft shortly before they became commercially viable: https://www.youtube.com/watch?v=_yowX1_1sEg (sarc)

dodgy geezer

It’s a big model aircraft….

shrnfr

Of course, thorium reactors were being developed to do exactly this. Perhaps it is time to go back and dust off the blueprints. We do not need so much plutonium these days. We have enough bombs. http://www.businessinsider.com/aircraft-nuclear-propulsion-molten-salt-reactor-2016-12

Gamecock

As often happens with these theatrical technology presentations, the actual achievement is NOT in what is promoted.

The great achievement here is the plane itself, not the electric drive train. That thing might fly with a 5hp Briggs & Stratton.

Felix

Not that different from a light sport aircraft.

Three types of Light Sport Aircraft. In the foreground, an E-LSA Antares USA Ranger weight-shift control trike. In the background, an S-LSA Evektor SportStar and an L-LSA Zlin Aviation Savage Cub:

comment image?download

Their owners hate it when you call them “ultralights”.

MarkW

With the exception of the kite in the foreground, everyone of those air craft carry way more in passengers and cargo and can all fly a lot longer than 1 hour at a time.

For that matter, the kite in the foreground has the same passenger and cargo passenger capacity as the plane in the video. It probably has a similar speed and range as well.

Felix

Yup on the kite.

MarkW

I’m guessing it costs around an order of magnitude less as well.

Felix

Yes, but without much promise of future development.

Ve2

They hate it more when you call them a crumpled heap of duralium.

Mike M.

A solar powered horse could pull back a giant rubber band to launch a sling shot airplane. With a good sized draft horse ( 5 ton pull) you could probably go a couple miles on a nice day if the wings don’t fall off. (Maybe even up there long enough to wake up after the initial G’s?)

Pierre

Now let me get this straight. We are going to carry big high density high amperage batteries on a passenger plane! I won’t fly on one.

GoatGuy

So…

Its like there is an alternate reality universe in which the Green Goblins live, and refuse to acknowledge physics, whether packaged as aerodynamics, payload fraction or energy intensity.

So…

The problem of batteries is as a technology for powering aircraft all comes down to kWh/kg. Not volume (they’re not fluffy down pillows, nor anchors of pig iron), not output power (completely sufficient when scaled with kWh). The very, very best battery options availabe today, and even tnose envisioned for the next 10 years (being the time-to-market for today’s various announcements and hints-for-future-tech), just don’t exceed 0.5 kWh/kg.

FUEL CELLS — where the “battery guts” is separated from the ion-generating “fuels” which are stored in some variation of tanks, are the eletric equivalent of internal combustion engines. Fuel + oxygen (ICE) → engine → heat + mechanical power → transmissions to convert torques. For the fuel-cell it is something like electronegative ion A + electropositive B → fuel cell → heat + electrical power → motors … giving mechanical power.

Thing is, CONVENTIONAL BATTERIES have “fuel” (A+B) contained in usally-but-not-always smallish cells, hooked massively in parallel into banks, those in series into large batteries. And they weigh a LOT. The remarkably well-and-thoughtfully engineered-for-safety-and-heaps-of-power-production TESLA Model S (85) battery weighs in at 1,200+ lbs (550 kg), stores 85 kWh of useful power, and has all interlocks, per-cell fusing, anti-flammability and other protections built in. OUT THE DOOR spec is 85 kWh ÷ 550 kg → 0.156 kWh/kg.

So…

As I said above, the most aggressive claims for near-future all-in, all-packaged tech for any weight sensitive use is something like 0.50 kWh/kg, or about 3.2× better performance than a Tesla energy anchor. At the very least, when working with airframes and aloft-mass-budgets, you can substitute stainless steel frames, cells, banks, hardware with titanium. No problem. Well, except for catching fire. You could even lighten it further with carbon-fiber composite materials, where utile.

But that’s about it.
_______

Looking at the flight profile though of just about any commercial aircraft, what becomes immediately obvious is that if “100% power” is needed for some part(s) of the flight, it is clear that 35% to 50% is needed during most of the rest of the flight. The CRUISE portion.

This — at least to anyone who was born after 1950 — immediately suggests the optimizing crux solution. HYBRID architecture. Storing hugely mass-efficient liquid fuel aboard at just under 4 kWh/kg (without needing to also store the oxygen!) is quite a win for providing most of the energy required for the nominal flight. A much smaller and lighter weight set of batteries could then be required JUST to service that “100% parts” of the flight. Hybrid. Battery storing a bunch of extra power for a bunch of extra thrust (becoming extra lift) to climb to altitude. To get to full cruise speed.
But then the “next part of the sanity-check” comes into play.

Because you see, there are these pernickety beings called PASSENGERS that don’t want to use air travel that goes at the Speed of Smell™. They are accustomed to air travel times from under an hour to well under ⅓ of a day … for most points of domestic travel. And — not for Norway, tho’ perhaps — but the United States, ⅓ of a day, 8 hours at 450 knots nominal speed is a whole lot of miles. Seattle to Tampa. San Diego to Boston. Honolulu to San Francisco. New York to Milan. London to Chicago. Reykjavik to Los Angeles “over the pole”‘.

And those require 400 to 500 knot, 10,000 meter (35,000 ft) flight.

Even the shortest hops that we regularly use as domestic travelers — within nominally commercial air traffic corridors — by propeller planes are still “turbofan” designs, with 250–300 knot airspeed expectations. Can’t tell you the number of last-minute el-cheapo LAX → SFO flights I took on mid-sized Saab prop planes over the years. Seating for 25 to 85, LAX → SFO in under 2 hours (regular jets do it in about 60 minutes), but nowhere near a taxing trip. Noisy and comfy. As the booby prize, the single attendant just handed out free everything. Beer, wine, nuts, crackers. Consolation for being late-out-the-gate (always!!!), slow and noisy, and much easier than making dumb penny-change for the fliers.
Still… it was fine.

I think I and the other 25 to 85 passengers (these flights were ALWAYS totally full) were satisfied with “the deal”. Fast enough, endurable enough.

Question is, what was the power required to accomplish this? The Saab 340 weighed about 12,000 kg at takeoff, powered by a pair of GE 1,300 kW (1,750 HP) turbofans; Cruise 250 knots, ceiling 25,000 ft, range 900+ nautical miles, 34 passengers, 2 pilots, 1 attendant. 3,220 liters of JP–1 jet fuel at takeoff. 3,000 kg worth. Cruise at 40% full power at 25,000 ft, at 250 knots. You do the math.

40% of (2 × 1,300 kW) → 1,000 kW nominal during cruise.
80% of (900 knot ÷ 250 kt/h) = 2.9 to 3.0 hr aloft
3.0 h × 1,000 kW = 3,000 kWh.

IF that were battery, even at 0.5 kWh/kg, that’d be 6,000 kg of battery. At something closer to 0.30 kWh/kg (figuring Tesla tech, in light-weight packaging and only modestly improved internal cell chemistry), you’re talking 10,000 kg. In battery. For JUST the cruise part.

Compare that back to the 3,000 kg of jet fuel. Jet fuel kind of wins. Because the mass of a jet engine to convert it from liquid fuel to rotary power is absolutely no more than the same power permanent super-magnet type 500 kW (ea) output motors and electronics. Not with FAA tolerances, safety and overkill.

_______

This is why I think its generically “nuts” to consider all-electric domestic flight. Either its going to have to be slower (with the public upsold as to why), or its going to have to be hybrid. There’s no alternative.

UNLESS we get awfully lucky and serendipitously discover some unimagined-so-far battery chemistry which takes us cleanl over 1.5 kWh/kg. 40% of jet fuel. At that point, it’d work.

Just saying…
GoatGuy

GoatGuy

Also: that 3,000 kg of jet fuel, converted to kWh of motive power directly is about 3.5 kWh/kg so that is roughly 10,000 kWh of jet-engine produced energy. For the WHOLE trip at longest range … 900 nautical miles.

Even if “400 nautical miles” is chosen as the acceptable puddle-hopper range, you’re still looking at over 5,000 kWh of motive power required for the plane. Maybe more. At 0.35 kWh/kg, 5,000 kWh becomes 14,500 kg. Clearly this weighs MORE than the entire fueled-up and ready-to-take-off Saab 340 with 30 passengers (12,000 kg at TKO of which 3,000 kg is fuel).

Building a plane around a 15,000 kg battery is going to take another 10,000 kg of airframe, motors, seats, electronics, cubby space, and so forth. With a takeoff weight of close to 30,000 kg, and a complete inability to shed ‘fuel mass’ during flight(!!), I doubt very much that a 5,000 kWh plane is going to do better than 150 knots, and give only 200 nautical miles of range.

All that for all-electric flight?
Need WAY better batteries.

GoatGuy

drednicolson

Apparently, with aluminum-air and lithium-air batts, you would gain mass during flight, as the metals oxidize during discharge.

Felix

Yes. Slightly.

GoatGuy

4 Al + 3 O₂ → 2 Al₂O₃
4 × 27 + 3 × 2 × 16 = 204 whereas (4 × 27 aluminum = 108).

The take-up doubles the mass of the original reacting aluminum. Not “slightly”.

And the rather dissapointingly practical problem is that aluminum hydroxide naturally bonds with H₂O to for gelatinous alumina “hydrated hydroxides”. Which take up much higher volume than either the aluminum or the anhydrous oxide.

Since H₂O is also bound with the (Al₂O₃) production takes mass … it is consumed by the electrochemical cell and must be resupplied externally. But for aircraft, this is yet another dead weight burden. That and either making enough room in each cell to take the overburden of hydrous aluminum oxide volume-wise, or coming up with an active electrolyte-and-plate scrubbing technology that elutes the sloughed off gel, captures it, and one presumes… that without too much weight penalty or reliability-and-cost add-on, recovers the alumunium oxide and separates the bound water, again for use back in the cells.

Just saying, tho’ really attractive, the aluminum-metal + air battery is very likely not to suddenly become the predominant tech, cheap and also light-weight.

GoatGuy

GoatGuy: First of all a rousing cheer from me for making the real points so clearly BUT with one exception.

I doubt very much that a 5,000 kWh plane is going to do better than 150 knots, and give only 200 nautical miles of range.

I suspect this is where your understanding of aerodynamics falls short. So did mine until I started thinking about it during my electric model plane heyday 15 years ago…

The power to sustain (cruise) flight is a function of the planes weight and lift to drag ratios ONLY.

If you want a faster plane, chop off its wings. You will reduce drag, and lift in pretty much equal proportions.

A light plane can take off at 50mph and maybe have a top speed of 150mph. A jet airliner takes off at 180mph and has a top speed of 550 mph.

In all cases for efficient use of fuel there is about a 3:1 ratio between stalling speed and top speed. Jet liner are designed to fly at high altitude where they can – due to less atmosphere being there – fly faster for the same drag. However it takes a long time and a lot of energy to get there, so thats only viable for long haul.

What a given amount of energy storage gets you is either maximum altitude or maximum DURATION.

SPEED is not actually in the equation except insofar as if you try and break the sound barrier, your lift to drag ratios become appalling, and energy use climbs dramatically.

Thats is why commercial planes fly a little under the speed of sound. They actually consume fuel at similar rates per lb of aircraft as a light plane doing 100mph, but speed means more passengers per year. And thats means more profit out of the airframe. Whose costs of capital is in terms of percent interest per year. (In fact that, and the reduced downtime for engine maintenance is what drove the almost overnight switch to jet passenger planes in the 1960s. It is also the reason that jet engines are in pods under the wings. Easier to service/swap out = less downtime)

So at subsonic flight speeds, what a given amount of fuel buys you is altitude and duration, or both. Speed can be anything you want, and as range is a function of speed, so too can be the range. Up to a practical limit of say 500mph.

Currently I’d say a BEA (battery electric aircraft, not British European Airways) could do an hour in the air. Giving it a practical range of say 400 miles at a top speed of around 400mph.

Beats a WWII Spitfire anyway 🙂

The trade off for high flight speed is of course a high take off and landing speed. Even with massive increase in wing area and huge flaps a modern airliner can’t really fly at less than 130mph. Hence 4 mile runways instead of a cricket pitch to fly from…

(You wont see a better example of a dead stick landing on a sixpence than this: Ernst Udet in the 1930s – https://www.youtube.com/watch?v=1VdXVowLKQ0 – a large wing area biplane using massive sidslip to act as airbrakes . kills the planes speed and dumps it for a 50 meter rollout – if that. If he had had wheel brakes… )

(Actually I forgot the adapted STOL cCubs that delight in this sort of thing https://www.youtube.com/watch?v=bPSElw8qEsI )

Anyway my point is that you wont ever see that kind of landing from a jet airliner,. although you might from a Hawker Harrier..

So thats my lengthy objection to one phrase. Electric model planes already do way better than 150 knots.

And I would guess personally that 400 miles range is on. Otherwise I agree with you totally.

How much payload? Not a lot.

Big Bubba

There is possibly one application for electric that no-one has mentioned: assisted take off for gliders.
The norm is a tow plane for getting in the air, and if you don’t fancy a tow there are gliders with pop up (and retractable once airborne) petrol motors. Electric might be a good exchange for them?

Felix

After setting an electric aircraft record last year, the Siemens electric plane became the first electric glider tug:

https://www.siemens.com/press/en/feature/2015/corporate/2015-03-electromotor.php

This year it suffered a crash.

Siemens’ serial hybrid flew this year in Hungary.

Since 2013, Chip Yates’ electric Rutan Long-EZ has set records and outperformed, at less cost, gas-powered light planes such as Cessnas under FAI supervision.

This technology is more mature than might be imagined, but not ready for multiple passengers yet.

The Norwegians are far from alone:

https://en.wikipedia.org/wiki/Electric_aircraft#Developments

Among the projects listed in that link is this:

http://atwonline.com/airframes/easyjet-joins-electric-aircraft-project

UK (budget carrier) LCC easyJet has formed a partnership with US-based Wright Electric, which aims to develop an 180-seat electric aircraft for commercial aviation use within 10 years. EasyJet said it has been working with Wright Electric “over the course of 2017,” providing “an airline operator’s perspective” on the project in areas ranging from maintenance to revenue management.”

https://www.theguardian.com/business/2017/sep/27/easyjet-electric-planes-wright-electric-flights

Please overlook the source. It’s just quoting the companies.

Who knows whether such an ambitious time table can be met.

Already exist.

Don’t know what all the fuss is about, an electric aeroplane can fly quite well using electricity. All that is needed is some technology that will allow efficient handling of the extension cords between the airports. 🙂

Cheers

Roger
🙂

Non Nomen

The a/c are hooking on the overhead power lines. Norway has many of them. Some are really, really dangerous. They catch a/c in flight and bring them down.

drednicolson

And the lower the craft’s flight ceiling, the more likely it is to take a high-voltage clothesline.

John the Econ

Actually, I’m excited about this technology. If the cost of an hour of general aviation flight could get down below $20/hr from the >$100 it largely is today, I’d jump back in. Mind you, with the current state of this technology, I wouldn’t consider cross-country flights, or even venturing far past the landing pattern. After all, I can’t remember how many times have I picked up a supposedly intelligent battery powered device that proclaimed that it was ready to go with a multi-hour charge only to have it die on me less than 30 minutes later. But just to be able to bounce around a traffic pattern and practice touch & go’s inexpensively at my local airport would be great.

As for scaling this up to anything that would be commercially viable to replace contemporary airliners, it won’t happen, at least for a very long time and until some other radical breakthroughs are achieved on many levels. For one thing, these hyper efficient and lightweight planes are barely capable of 100 mph, versus 250 to 350 for turbo-prop commuters and over 500 for jets. In other words, considering the slow speed and frequent stops for recharging required for a cross country trip of any significant distance and the associated costs of keeping passengers for long periods of time, you’d get there faster and cheaper by just driving.

Yirgach

The second video from the top indicates a low cost per hour because they assumed the cost of the electricity was 0.
Anyway, that’s the way I read it.

John the Econ

The cost of electricity is a fraction of the equivalent amount of energy in gasoline. Also consider that the aviation gasoline that most general aviation aircraft use costs much more than the automotive variety, usually $5 to $7 dollars per gallon in the US at the moment. But that is not the only advantage. What an electric plane does is turn the economics of general aviation on its head. Not only is the “fuel” much cheaper, but so is the maintenance. Most general aviation engines only have a 2000 to 3000 hour life before they must be overhauled or replaced. Those overhauls and replacements typically cost $20,000 and up. Of course, the anticipated cost of that, along with required maintenance is factored into the hourly cost of operating one of these planes. Electric motors with few moving parts should theoretically last indefinitely.

Yirgach

Thanks for the reply. Besides the costs of fuel and maintenance the other greater cost, which is the elephant lurking in the room, is safety. Until there multiple miracles in battery design – storage, density, safety yet alone overall systems integration and performance, there will be no safe advantage. I’ve flown enough to know what can happen during a flight and also at the most dangerous times, which is landing and takeoff (I’m not a pilot, just a thankfully alive passenger).
Experienced an aborted landing at OHare where we were 100 ft off the ground, a real roller coaster ride. Then multiple lightening strikes over the years, not to mention windshear and altitude drops similar to the Vomit Comet. Protection against these “speed bumps” requires a lot more energy, frame strength and resiliency than is currently available for this technology.

I will concede that in 50-100 years that MAY be over come, I just do NOT want to be an early pioneer.
Note to self – steer clear of air taxis in Norway.

Felix

Surely safety design concerns and challenges exist, but being surrounded by up to 50,000 gallons of kerosene is also a hazard in case of a crash.

drednicolson

Fuel can be jettisoned in an emergency to reduce weight and fire risk, while retaining enough to keep control of the plane.

5000 kg batteries aren’t so easy to dump. And just imagine one of those impacting in somebody’s backyard.

Gamecock

Turn around time another killer. Commuter jets can be refueled in minutes.

I remember when a Hawaiian Airlines 737 lost its roof. They said it had made 90,000 flights (!).

Felix

PV cell-coated aircraft refuel themselves in flight. With IR spectrum cells, they can even do so at night.

And advances in battery technology will grant electric a/c longer range.

O purlease!

The A380 is the world’s largest airliner. … Wing Area, 845,0 m²…typical full sunshine insolation at midday at the equator 1kw/sq m

So 845kw. times 20% solar panel/drive train efficiency

It takes around 4 watts per pound to keep an airbus in cruise, or roughly 10 watts per kg, so at best we can fly an airbus weighing 845000 x 0.2 x 0. 1 kg …= 16.9 metric tonnes off a solar panel at midday on the equator.

An Airbus a 380 is 360 metric tonnes empty.. take off weight is around 560 tonnes.

PLEASE go away Felix and learn to Do Basic Sums as well as how to roll a spliff.

Felix

As I keep repeating, no one is talking about jumbo jets.

Flight Level

Some facts. Solar impulse, wing load 15kg/m2. Airbuses and other fifi’s fly in the realm of 150kg/m2 of wing load. Anyone with appropriate education realizes at this point that the flight envelope of Solar Impulse is very similar to a kite. That’s why it lands after sundown to avoid even the slightest thermal.

To this day some V’s have been kept top secret for that contraption. An educated guess places Vne in the 2 digit numbers. An otherwise common gust can disassemble Solar Impulse, reason it has never been flown in any but uber-friendly weather.

As the chart’s room saying goes, climate does not kill. weather does.

Salon aviation for armchair green would be pilots. Fueled by ignorance optimism turns generally ugly and Solar Impulse was excellent at demonstrating it without casualties. Game over.

A go-round in a battery operated A/C can become harrowing, even more so since take off and landing weights are identical unless depleted batteries are jettisoned in mid-air.

One amongst the (too) many reasons why no self-respecting PIC should accept to expose pax to green fantasies.

How many times do we have to scream it out ? Planes are not fork-lifts ! They don’t need batteries as stabilizing ballast deadweight to prevent capsizing while carrying loads.

Felix

Solar Impulse repeatedly flew at night, albeit slowly. It took days of continuous flight to cross from Japan to Hawaii.

But for the distances traveled by regional airlines, it could reach higher speeds during the day. Its cruise speed under photon capture was 56 statute mph, but was capable of higher velocity. It needed the heavy batteries to fly at night.

A daytime only, all-electric plane would actually make sense even with today’s tech.

Flight Level

Oh my my… Felix, your intervention is a brilliant example of why aviation requires that much training of which you exhibit evidence of none.

Reality is that airmanship and airworthiness are very closely related to maths. Let’s give it a go in a rather simplified way, would we ?

So if you equate the power required for a fixed wings level flight at constant airspeed to the power you could gather from the available surface considered as covered with photovoltaic cells, you’ll discover that, funny enough, the surface cancels out on both sides of the equation.

Leaving you with a cruise speed depending solely on the A/C aerodynamic and weight characteristics.

That’s in a bright light with that much of total energy falling per unit of surface.

Scaling up becomes nonsenical. Size simply cancels out on both sides of the equation.

Harrowing shear terror for someone who knows that airspeed and altitude are the most precious commodities for safe flying.

A solar powered aircraft has an absolute upper cruise speed llimit, educated guess, in the lower 3 figures for the most optimal airframes.

Things get ugly at altitude where winds of 250 knots are not that uncommon. Rendering boundary transitions a delicate exercice even for airframes whose Vne is in the upper realm of 4 figure numbers.

Turbulences, airholes and other things nice do exist, trust me on that. How bad can they be ? Figure the cabin crew service cart leaving a serious imprint of it’s shape on the upper cabin lining.

That’s why requlations require at least one pilot to be permanently buckled at all times. And much more.

The good thing with tolar A/C is that they cancel the paper trail a PIC is supposed to endure after a close encounter with a weather system on steroids, hail and presumably lighting strike.

Yep lightening. One of the best way to ruin your concentration on that crosswords while en-route. That’s quite a sound and light-show, paperwork and probably a dime of chipped paint for a liner. A no-event.

However your milleage might seriously vary on a fully composite electrically powered airframe covered by interconnected PV cells.

We take icing very seriously. A totally no-jokes topic. Jets are blessed as they have more than enough power to spare for heating their critical and control surfaces while turboprops carry anti-ice boots and a serious payload of optimism.

Anti-icing is a costly commodity since most of time it’s just a deadweight with stringent maintenance schedules. Until the moment when the “shields up” call becomes a life saving necessity. Happens also in summer BTW 😉

Airframe icing is a cummulative hazard. It depends on where you’ve been, what’s the weather sandwich you’re in and the noise-abatment craziness du jour, just to quote a few.

Not all landings are finalized. Some have to be aborted for various reasons, weather inclusive. Just another day at the office unless engine power becomes scarce. Then it quickly becomes the last day at the office. Inclusive for the souls who paid for their supposedly safe trip.

In other words a very ugly situation for a solar powered aircraft without significant reliable power reserve and flight characteristics a kite could be proud of. Tilt, game over, crosswinds win.

Well Felix, I could spend my evening writing down reasons why, despite the quest for profits, solar A/C are not a suitable transportation means.

Educating you is out of my roster.

Now it’s your turn to document yourself on the topic. And let those who pride themselves in the safety of their PAX and the souls under do what they’re supposed to do.

I’ll call it quits, it’s been a bumpy day despite the seemingly perfect sun-tan and barbecue inciting weather all over a few clouds down…..

Felix

You’re missing the point that SI 2 is only a concept demonstrator. It should be obvious that a commercial aircraft would be more substantial.

The issue is power, and advancing battery and PV tech promise to provide it. With more power, airframes can be sturdier (also thanks to materials science) and an excess of reserve power can be made available.

No Felix, the issue is that you cant do maths, dont understand physics and have about as much engineering comprehension as the average amoeba.

Menicholas

Simple question of energy density.

jmorpuss

“Wireless high power transmission using microwaves is well proven. Experiments in the tens of kilowatts have been performed at Goldstone in California in 1975[73][74][75] and more recently (1997) at Grand Bassin on Reunion Island.[76] These methods achieve distances on the order of a kilometer.”
https://en.wikipedia.org/wiki/Wireless_power_transfer

tty

Most aircraft tend to operate over distances larger than one kilometer. And wireless power transmission, while possible, is insanely wasteful, and highly dangerous for any living thing caught by the beam.

Hivemind

This is actually a very practical proposal for Norway. Their people can drive half an hour North, South, East or West and be out of the country, where they can catch a normal aircraft to get to where they want to go.

The idea is really nothing but virtue signalling.

Felix

The fact that other airlines are aiming to get electric and hybrid short haul aircraft in service even sooner doesn’t mean that it’s not virtue signalling. But it could also be driven by fuel cost savings, low noise levels, maintenance or other operational considerations.

https://www.wired.com/2017/04/hybrid-jet-finally-make-electric-flight-reality/

It’s possible that Safran S.A., Boeing, Airbus, Raytheon, etc are virtue signalling or subsidy farming, but I don’t think so. Could be that they’re anticipating technilogical advances.

The next generation of batteries Obviously will need to deliver a lots of power at the same time as being smaller, safer and lighter than lithium-ion ones.

Scientists have made progress. For instance, MIT’s Dr. Qichao Hu has invented a polymer ionic liquid that allows batteries to hold double the energy of current lithium-ion models. Making batteries lighter will increase the energy savings and flying range of airplanes. Who can say what advances will occur in the next ten to 20 years?

http://www.solidenergysystems.com/

In the meantime, hybrid aero engines hold promise of savings.

Have you ever looked at a map of Norway in your life? From Oslo to Tromsö is over 700 miles as the plane flies, or over 1000 miles of road.

And that’s not even the greatest distance in Norway.

The country is over 1000 miles long!

Felix

As I said, there is no commercial air route in Norway of 870 statute miles. Alta is 770 miles by air from Oslo (twice a day, WX permitting) and Tromso 713.

Don’t have to look at a map. I’ve been there.

tty

Oslo-Longyearbyen is about 1250 miles. Been there too.

Felix

IMO the electric commercial service probably wouldn’t go to Svalbard.

You’ve been in some cold places.