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:

447 thoughts on “Pipe dream: Norway wants electric airplanes to provide passenger service

  1. 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.

    • 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

    • 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

      • 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.

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

          • “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.

          • 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

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

      • 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.

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

    • 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.

      • 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.

          • 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)

          • 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.

          • 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?

          • 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

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

          • 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.

          • 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.

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

          • 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:


          • 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.

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

          • 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?

          • 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, 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.

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

          • “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.

          • 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.

          • 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.

          • 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.

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

          • 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.

          • “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.

          • 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.

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

          • 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.

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

          • 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. 🙂

          • Not like that at all.

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

          • 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.

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

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

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

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

          • 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.

          • 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.

          • 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.

          • 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….

          • 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.

          • 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….

          • Piezoelectric nanochrystals do that.

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

          • 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.

        • 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.

          • 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:


            “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.”

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

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

          • 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.

          • 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.

          • 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.

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

          • 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.

          • 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.

          • 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

          • 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.

        • 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.

        • 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.

          • 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.

          • 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’.

          • Komrade,

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

          • 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.

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

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

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


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

          • 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.

          • 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.

        • 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.

          • 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.

          • 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.

          • 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?

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

    • 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.

  2. “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

    • 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?

      • ” …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.

      • 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.

        • 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?

          • 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.

        • 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.

      • 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.

        • 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.

          • 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.

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

    • 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.

    • 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

      • 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.

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

          • 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.

        • 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.

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

      • 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.

        • 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.”

          • 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.

          • “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

          • 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.

          • 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.

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

  3. 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.

    • 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.

      • 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.

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

        • 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.

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

      • 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.

        • 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.

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

        • 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.

          • 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.

        • 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!

      • 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…

          • 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.

          • 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.

          • 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.

          • 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.

    • 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.

  4. 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.

  5. Lithium-ion might not hack it.

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

    • 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.

      • 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.

        • Especially where mountainous.

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

        • “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.

    • 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.

      • 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:


        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.

  6. 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.

    • 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.

      • 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

  7. 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!

  8. 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.

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

    • 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.

  9. 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.

  10. 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

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

      • 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.

        • 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.

      • 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…)

        • 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.

    • 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.

    • 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.

      • 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.

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

  12. 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.

  13. 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.

  14. 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.

    • 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.

      • 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.

  15. 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.

      • 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.

  16. 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.


    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.


    We’ll see.

    • We’ll see.

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

    • 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.

      • 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.

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

          • 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

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

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

        • 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.

          • 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.

          • 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.

          • 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.

        • “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.

  17. 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.

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

  19. 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!

  20. 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.

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

    • “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.

  21. 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.

  22. 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.

  23. 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……

  24. 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.

  25. 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.

  26. 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?)

  27. 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.

  28. 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.


    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.


    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…

    • 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.


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

          • 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: 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.

  29. 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?

  30. 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. 🙂



    • 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.

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

  31. 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.

    • 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.

      • 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.

        • 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.

          • 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.

          • 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.

        • 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 (!).

          • 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.

  32. 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.

    • 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.

      • 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…..

        • 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.

  33. “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.”

    • 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.

  34. 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.

    • 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.


      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?


      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!

      • 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.

  35. Maybe it would be more feasible without a pilot, just autopilot ?
    Imagine the weight saving without cockpit etc.
    The electric engine with just one moving part compared to hundreds is very nice.

    • IMO even over the next two decades, passengers are still going to want a pilot/attendant on board, even though most airliners now are essentially already operating on autopilot for at least most of the trip.

      The weight savings in personnel however pales in comparison with that which could be saved by battery energy density gains.

      People underestimate the improvements in batteries over the past few decades, ie from lead-acid to Ni-cad to Li ion, etc.

      Tesla estimates advances in cost and power per unit weight of 7-8% per year. I’ll go with a more conservative 5% per year. That means a tripling in energy density in 20 years, without a breakthrough, just in incremental improvements.

      • If autopilot makes the ticket cheaper then people may accept it.
        They are also experimenting with removing the passenger windows to save weight and increase strength.
        Electric planes are so much quieter too – imagine the advantage of not having a curfew.

      • “Felix

        IMO even over the next two decades, passengers are still going to want a pilot/attendant on board, even though most airliners now are essentially already operating on autopilot for at least most of the trip.”

        In 2000, Air New Zealand introduced a new in-flight cockpit safety policy called “The Pitbull”. It was a pitbull terrier dog to keep the pilots away from the controls.

        • A lot of passengers have died from pilot error.

          But a pit viper would be more energy efficient.

      • People overestimate the improvements in batteries over the past few decades, ie from lead-acid to Ni-cad to Li ion, etc.

        You Felix being chief among them.

    • Speaking of weight savings, 3rd generation thin film PV cells might not weigh more than paint.

  36. I did the sums. Lithium polymer is just about capable of an hours flight time with a reasonable load.

    If Norway is small enough to be serviced by one hour flights, then its possible.

    Not very economical, but possible.

    • Depends upon speeds. At 190 statute mph, Oslo to Bergen is about an hour. At 620 mph, Oslo to Narvik is around an hour.

      But battery technology should be at least a third better than now by 2040, without major breakthroughs.

      So the target is not a pie in the sky pipe dream, but not outside the realm of possibility.

      The issue is whether a fleet of all electric passenger planes will make economic sense then. In a hydropower-rich country, maybe.

      Hybrid electric will probably already make sense in the 2020s.

  37. I suppose a battery to get you up to 3k AGL and then excellent soaring conditions. Ok, how many here hold a glider pilots license, raises hand,…. Hmmm oh well.

  38. Rich mans summer toy. With commercial aircraft it’s not only the energy required to power the engines that thrust the plane through the air. You need power to drive all the flight surfaces, landing gear, cabin pressure etc etc…simply not possible with batteries at a commercial scale.

    What about nuclear power?

      • Well, my comment was a bit toungue-in-cheek, even though the US did develop an engine and it did fly in the 50’s or 60’s, Russia faked it, these were some of the concerns raised. Carrying the reactor that is shielded and it being crash/leak proof. Wasn’t going to happen then on a commercial scale, just like battery powered flight now for different reasons.

  39. Real world right now applications for aircraft electric power are:
    Self launching sailplanes. There are a couple in production right now – the Lange Antares, the Pipstrel Taurus Electro and the Electro Silent and there is a system called FES which can be fitted to may sailplanes as a get you back home or to an airport.
    Soon, perhaps some flight training will be carried out in electric aircraft like the one in the video.
    Also soon for an aerobatic aircraft designed to operate not too far from the airport with a mission endurance of 30 to 45 minutes. getting it cross country to aerobatic contests will need to be done sailplane style on a trailer towed behind a car.
    Glider towplane is possible also with spare battery packs but likely expensive.
    Depends whether you want to share an airframe with a large incendiary bomb.
    The REAL near future application is in VTOL flight which requires no magic tech.
    The single largest problem with VTOL has been to deal with engine failure in VTOL and transition to/from wingborne flight modes. Solutions have been ejection seat (military only), autorotation (helicopters but they are horrible complex, expensive, maintenance hogs) and twin engines with expensive shafts and gearboxes (V-22 Osprey).
    Distributed electric power for VTOL solves this problem. Use a conventional turbine or piston engine for cruise to get decent range and speed and at least 8 electric motors which only need two blade fixed pitch props (low maintenance). Battery power (only the safer LiFePO4 batteries required) only required for a couple of minutes after takeoff, and for emergencies such as engine failure. Simply glide to within a couple of hundred feet of the ground and start the electrics and go into VTOL mode to land in any area at least the size of the aircraft. Encounter bad weather? Just land and wait it out. High wing loading and tiny wings for comfortable ride and high speed cruise as you are never going to takeoff and land in conventional airplane mode. Landing gear needs to be much lighter and less strong for same reason. No unobtainium or “then magic happens” required.
    See evtol.news for the 50 or so electric VTOL projects going on. These folks, for the main, are trying for pure electric which I think isn’t yet possible. I’d like a two seat VTOL homebuilt with 1000km range and 300km/hr cruise. Think of what private aviation could be if it didn’t need airports.

  40. Light aircraft are a strange mix of the advanced and the ancient. You may for example find a ‘glass cockpit’ instrument panel coupled with an engine that requires you to adjust the mixture manually, like a 1920’s car.

    The engines are very prone to temperature shock damage, which means you have to be careful over too rapid warming or cooling. That, and they run with a rich mixture, spewing pollution. Car engines overcame these issues decades ago.

    They have an obsession with dual magneto ignition just in case of an electrical fault, yet use obsolete carburettor fuel metering which is prone to blockages, icing and flooding, and can equally well knock the engine out suddenly.

    It wouldn’t be hard to improve on this. Battery power is not very practical though. One option might be a fuel cell and electric motor. Or, just a more modern IC engine. Rotax have taken steps in this direction but the aviation industry seems reluctant to accept anything that looks vaguely modern at the sharp end.

    • The aviation business is conservative, I should know having 40 years experience of it.

      The reason is simple: “don’t fix it if it ain’t broke”. Aerospace equipment must have extreme reliability. ‘This is well-nigh impossible to achieve with new technology. For example the aerospace industry is always the last to abandon old processors and operating systems. They have had the bugs straightened out and are sufficient, so there is no reason to change.

  41. I think electric aircraft are a very niche market for the foreseeable future.

    The trainer idea is sound, particularly if the next step is a jet (don’t waste time learning about piston engines, that you will not be using next).

    An unmanned aircraft something like Solar Impulse with very long endurance has attractions doing satellite type jobs such as radio relay and surveillance.

    Maybe they will eventually become useful as transports, but it is difficult to see the point.

  42. Did you notice they stated there is no fuel cost?
    These will be great in any location that has mostly consistent, clear weather with no electrical storms, etc.

    • Yes. It’s one thing to be able to get off the ground for a short flight under ideal conditions, and quite another to have sufficient reserve for safety margins. You can see people flying motorized ‘hang-gliders’ every day, and the accident rates are unacceptable. People are only now becoming aware of the dangers of high energy-density batteries. It is quite likely they have already reached their limit.

      And it is still only short, low speed, flight. The jet engine displaced propellers for good reason in long distance flight.

      • And, of course, you have to go low level because a climb takes a helluvalot of precious energy. Have a look at the rugged and mountainous terrain of Norway, with fjords everywhere, such type of a/c must follow terrain through the valleys. Wind conditions and directions are unpredictable, and with a lack of power capacity you’ll either pancake your flying flea or have to ask the coast guard to pick you out of the cold water – Norwegian waters are cold, even in mid summer.

  43. A great analysis on electric aircraft was done at Bjorne’s Corner by an actual aircraft engineer who is considered an opinion maker in the industry at https://leehamnews.com/?s=+electric+aircraft&submit=Go He walks through the design of the craft, tradeoffs, and economics. A good read, well commented by experts and worth the effort if one is interested. Felix might want to read it. There are performance and redundancy requirements set by law that are not addressed by most true believers.

    • In a 13-part series, he devotes only a bit of Part One to batteries, then goes straight to hybrids.

      Battery tech is where it’s at.

      I’m not a true believer in electric aviation. I just don’t think regional commercial prop planes by 2040 is a pipe dream.

    • Maybe not a 747, but battery technology could support regional aviation by 2040.

      Please read what VC guru Bill Joy said this month about solid (plastic or polymer) electrolyte Li-S battery development and its aviation potential:


      Recent advances in PV cell tech also open up more of the spectrum to capture, to include UV and IR light. Which of course means that an electric plane could still generate power at night.

      Polymer batteries, piezoelectric nanocrystals and other cutting edge research will be commercialized in this half century.

      IMO people would benefit from studying more and scoffing less. Scams like Solyndra have given electric tech a bad name, as has its association with CACA spewers and subsidy farmers.

      • VC guru Bill Joy said, ” What I have is electricity, which can turn an electric motor. That’s more like a turboprop. So, someone smarter than me might have a way to do an equivalent of a 747 that’s electric. I don’t know how to do that. But I think regional jets and commuter jets and drones will be radically improved by it.”

        Well I don’t know how to do that too but I know WHY I don’t know how to do that. Because the energy density of his Li-S battery is 500 wh/kg. Take a small airliner, the Saab 340, with 34 passengers. Its two turboprop engines produce 1300 kW each. Cruising speed 290 mph. Flying 3 hours, it travels 570 miles and consumes 7800 kWh energy. So the battery will weigh 15,600 kg. That’s almost twice the weight of the airplane (8140 kg) just the battery. He doesn’t meed someone smarter than him. He needs a magician to change the laws of physics.


        • Those aren’t the Li-S batteries of the company in which he has invested $65 million US.

          The technologies he’s backing promise a three to ten-fold increase in energy density.

          Nor would the first electric regional passenger planes fly routes of 870 miles. Nor does the battery energy density tell the whole story, with engine weight savings, PV cells, piezoelectric nanochrystals and airframe advances factored in. Etc.

          • Li2S8 = 270 g/mol
            ave. voltage = 2.1 V
            S8 => Li2S3 discharging, 5 electrons transfer = 10.5 eV = 4.7 e-22 wh x 6 e23 molecules/mol = 280 wh / 0.27 kg = 1037 wh/kg
            That’s the best they can do. A factor of 2 improvement. Unless they can change laws of chemistry

            The Li-S battery would still weigh 7,800 kg. The turboprop engine weighs only 198 kg.

  44. I really don’t see the point of an electric vehicle that requires fossil fuels to charge it. It all cool and what not, but if the Alarmist want to knock a dent in CO2 emissions, they need to be focusing on new forms of energy …. preferably new forms capable of competing with fossil fuels or nuclear without completely covering the earth with bird killing windmills or surface covering solar panels or mirrors.

    Aside from efficiency of end product, which I cant see this as being an increase in efficiency, all this electric toy does is move emissions from the vehicle to a power plant.

    • Norway is hydroelectric. And there is always nuclear.

      An all nuclear/electric society is actually very feasible, apart from transport.

      Ships can be nuclear. Trains can be electric. But portable power (cars/boats/planes) is still a hydrocarbon fuel UNLESS lithium air batteries can be made to work OR we come up with a technology no one has even thought of yet, because (and this is addressed to YOU Felix) we can calculate how good any technology we HAVE thought of CAN be THEORETICALLY and if its not good enough THEORETICALLY its sure as heck ain’t gonna be good enough in practice.

      And you guessed it, windmills solar panels aluminum air batteries lithium polymer batteries super capacitors all can’t even do the job theoretically.

      And hoping that throwing money at them, will, is simply childish delusion.

      Some technologies are close – like windmills solar panels and lithium polymer, close enough so that by using the surplus energy we have in cheap fossil fuel they can appear to actually be viable…

      But on their own they are not.

  45. Even using it as a trainer bothers me since the response to throttle changes is so different between electric and IC motors. Just switching from an electric to an IC powered aircraft can get you killed.

  46. I am surprised that they did not mandate these planes carry a windmill at the back to charge the battery. So much wind energy is wasted when the plane is flying.

    • Or with props.

      But PV cells on the wings will also recharge the batteries and run the engines directly.

      • The efficiency of PV cells isn’t really thrilling. They also add some weight, plus extra wiring and charge controllers.

        • Third generation PV cells will improve efficiency.

          Plus, we can now access the whole spectrum from UV to IR.

          • You still Cant Do Sums, can you, Felix.

            Ignorance must be bliss: You read stuff and you Believe, and the world is a hopeful rosy place of fantastic dreams .

            I was like that when I was 7. But unlike you, I wanted to make those dreams come true.

            At 7 I built my first and only perpetual motion machine out of Meccano.

            It simply locked up solid and wouldn’t turn.

            10 years later with A level physics and maths, I understood why.

            14 years later with a Cambridge degree in engineering, I knew nearly all there was to know about the theory of machines. And electricity and electronics.

            And realized that outside of some unknowable breakthrough, most of what I dreamt of as a child was impossible.

            I mentor students these days., One Russian kid came and said ‘why cannot we have vertical take off jet planes?

            I said ‘we can, but it takes huge power’ he said ‘but a helicopter does not’ and then I tried to explain the difference between power and thrust, energy and momentum. This guy is a Cambridge student FFS and he doesn’t appear to understand this…

            You are a dreamer and a believer Felix.

            I am on old tired engineer, who has been building stuff, most of which eventually worked, or was proven not to be able to ever work, all his life.

            And that is the key phrase, ‘been proven not to work’.

            I can prove that solar panels wind,mills and electric planes wont work. Not without some as yet undreamed of technology. Not commercially. Of course they all work as examples of what can be done, but that is not the same as being viable economically.

            Because that is the second lesson an engineer learns – lots of stuff works, but is still useless.

            ‘An engineer is someone who can build for five bob what any damned fool can build for a quid’

            .Why subsidise technology that barely works when we already have stuff that works better and is cheaper? There is no good reaosn except to employ more people.

            Why not just give them the money instead of employing them?

            It’s actually CHEAPER. We are paying people to rush around, go to work and consume vast amounts of energy to build stuff that doesn’t work, instead of paying them to stay at home and have a nice relaxed life.

            What is the point?

            Its all head games, its all about making stupid people feel good about themselves ‘saving the planet’ ‘social justice’ etc etc.

            Well Felix, I hope you feel good about yourself, you roll up another fat one, and bliss out, sunshine, but please., leave the job of running the world you so casually take for granted, to people like me, who actually understand how technology works.

          • If we ever succeed at starting a stable, controlled fusion reaction, we could produce beryllium as a byproduct. With an aluminum-sheathed beryllium airframe and no shortage of energy for charging batts, we could take a second look at fully electric commercial aircraft. If.

    • If you put a wind turbine in airplane, it will produce drag, the opposite of thrust generated by a propeller. Efficiencies: electric generator = 95%, battery = 90%, electric motor = 95%, propeller = 85%
      Overall efficiency = 0.95 x 0.9 x 0.95 x 0.85 = 0.69
      So if the turbine makes 1 lb drag, the propeller makes 0.69 lb thrust. Net 0.31 lb drag. That’s why nobody puts wind turbine in airplane. It only slows it down and wastes energy

  47. Well…Take an ATR 42, an otherwise considered as awfully underpowered 48 seater common on (very) low cost regional routes, sports a total power in the range of 4’000 HP for the less gifted engine versions.

    Very few pilots genuinely like to fly it. Thin extremely prone to icing wings and marginal power reserve are amongst the features that build it’s fuel economy and widow making potential reputation.

    Now, how could an electric powered airframe with similar MTOW compete in the process, even with this reference of what most consider minimal for airworthiness power figures ?

    Hey folks, try to be serious already. At turboprop altitudes the ambient temperature is in the -25 Celsius and downwards.

    Jet fuel does not mind being that and even more cold. Nor do the turbines BTW. Their efficiency even increases with cold intake air.

    The temperature management of the batteries will be a very demanding science fiction project.

    Passenger flights above 8’000 feet require cabin pressurization with corresponding air renewal. Quite energy demanding indeed. Reason why you’re not allowed to smoke anymore on planes due to intensive cabin air recycling, but that’s another story. Good thing, cockpit air is not recycled so…

    The main reason for planes to fly high is the benefit from thinner air and consequent drag reduction. Which would be actually welcome for airframes with marginal battery energy storage capabilities.

    Now throw the pressurization constraints and voila, you have yourself a more realistic picture of why climate militant NGO’s are not the most appropriate aviation schools.

    Nope, planes are not forklifts, they do not use their on-board batteries as ballast weight for increased stability while carrying loads.

    • Flying above the cloud deck means more photon “fuel”.

      Solid state batteries will be less susceptible to cold.

      In case you subscribe to Aviation Leak, this article from April reports on progress of Siemens’ electric aircraft program, on both hybrid and pure electric engines.

        • Felix, congratulations, is that all you could afford to understand from or my post and google around for answers ?

          Commercial aviation is a very serious trade.

          My scope is not to prevent you from flying solo whatever pleases you over unpopulated areas and far enough from our airspaces. Even more, please do so, you’ll learn quite a lot in the process.

          However we have a far greater respect for human life and can not afford to impose armchair fantasies on people who trusted us the most by stepping on our board.

          Even with a supposed efficiency of 100% of future magic PV cells, solar A/C’s will have the flying envelope of a kite.

          Because their performances do not depend on the airframe surface area. Yep. Do the maths, see for yourself, it cancels out on both sides of the constant speed level flight energy balance equation for PV powered planes.

          On the other hand, a quick estimation of 747 flying a New York to Paris route requires a pure mechanical energy equivalent to 5’000 tons of TESLA automotive battery packs. And even more if real world efficiencies are introduced in the estimation…

          Add a quite few more for regulatory reserves. In other words, good luck to stuff all this in the 747 and lift up (or even move) with more than a 15 times MTOW overload factor.

          Aircraft propulsion can be assimilated to what happens in a vacuum cleaner. Quickly moving air, an awful lot of it.

          Reason why a mains powered unit will outperform big time even the best cordless portable self contained battery operated vac of similar weight.

          Planes are not trains, last time I called it for the day, there was not even a single pantograph item on the checklist. But promised, I’ll check on Monday, just in case I’ve been careless enough to miss it.

          Consequently your best bet could be to lobby for electrified air corridors and pilots desperate enough to fly in them. Good luck on both counts.

          • No one is yet proposing an electric 747, although work is progressing on electric and hybrid jet engines.

            Your airframe design issues apply only to a pure PV cell a/c, which is not in the offing for passenger service. A commercial a/c would not be a kite. It would include batteries with sufficient power to propel a heavier airframe. PV cells could be integrated into a conventional design, although the propulsor option constitutes something of a departure from traditional design.

            The engineers working on electric aircraft design and power pack development have at least as much concern for passenger safety as do you. My middle name is honor of an ex-Navy United pilot. I number at least a dozen ex-military commercial pilots among my friends and even a few civilians.

            I don’t own an electric sport plane, but might buy one in future. I do fly over largely unpopulated areas, and any workable design is liable to be akin to a glider. If not in fact a glider with an electric engine for TO.

            My Googling around led me to discover that even older style glass Li batteries are good down to -20 degrees C. Si-air batteries however have the advantages of greater safety and lower cost than Li, with nearly the same high energy density, theoretically comparable to gasoline.

          • Well Felix, let me disclose to you and all other greenwashed armchair pilots that weight induces drag. The infamous lift induced drag. Quite a spectacular one indeed as it decreases with speed.

            However for this to happen, the A/C should be able to reach sufficient airspeed and overcome the parasitic drag which drastically increases with speed.

            Consequently, all the industry is oriented towards weight reduction, amongst other.

            Except greenwashed armchair pilots, those who pretend that the comparatively excessive weight of batteries is somehow beneficial to a viable and reliable aviation.

            Purposely ignoring all inherent realities and physics of flight.

            Which is a form of terrorism, intellectual terrorism.

            The future will sort out the physics as it has never failed to do in the past.

            Hopefully without claiming too many innocent lives.

            Till then and even after, we’ll fly you around safely. Including to climate conferences and other similar junkets.

          • You’re attacking a strawman. I didn’t say that greater weight was an aerodynamic plus, just that electric planes won’t be kites.

            Battery tech actually promises less weight on TO than full fuel tanks. The drawback is that you won’t get lighter with time.

            I’m not greenwashed. I’m a hard core CACA skeptic. But that doesn’t mean that we shouldn’t pursue better battery technology. When and where its physically and economically competitive, it will be preferable to burning such a rich mix of compounds as petroleum, with which so much else can be done.

            Trans-Pacific flight in stratospheric jumbo jets is likely to remain JP-fueled for the foreseeable future. But that need not apply to short-haul passenger traffic. Not because of emissions but economics.

          • Yes Felix, why dont you buzz off and pursue better battery technology, and when you have found it, make yourself a billionaire on the back of it.

            Until then, you remind me of this song.,

    • Again another straw man. (I agree about the awfulness of an ATR 42, having been stuck for 6 hours with one that they dare not fly due to lack of airport deicing equipment)

      Batteries need cooling. It is trivial to insulate them against cold, and use their internally generated heat to keep them warm, or open up slots on the insulation to cool them if they overheat. Its no more difficult than e.g. controlling an air cooled piston engine.
      Cabin pressurization is again a trivial matter of an electric air pump.
      Other straw men include lack of weight loss in flight , insufficient power, and lack of speed.

      In reality theere is only one thing between now and battery electric passenger aircraft.

      Battery energy density.

      Leonardo da Vinci sketched out designs of planes. We could have had powered flight in the 1600s. IF we had had a high power to weight motor of some kind. But we had to wait till metallurgy produced lightweight strong steels and alloys, till steam had shown how to build engines, and until petroleum gave us the fuel, and internal combustion showed us how to use that fuel and the air it needed to burn as the working fluid in an engine, instead of carrying water to make steam.

      All that, just to have an engine that could fly a plane.

      In the same way all we are lacking in electric off-grid transport is a suitable battery. About 10 times better in energy density and still safe to handle than what we have now.

      That’s all.

      Problem is, no battery is even theoretically capable of 10 times current performance, except lithium air. And thats almost impossible to make a safe practical battery out of.

      Like windmills and solar panels, transport batteries are so tantalizingly close to actually being viable, except that the physics shows they are all not and never will be. They have to be supported on the backs of other technologies…and subsidized.

  48. The car shown in the video. Is a Tesla. Tesla is the only company to be investigating WiFi power. Perhaps WiFi is the way to go?
    Another thing, how does an aircraft power consumption breakdown during a trip? Does take off require greater power consumption than flying? If so ground charging is vastly uneconomic. Perhaps charging from airships might become feasible?
    Just thoughts, you know, just thoughts.

    • Naturally power settings at cruise are lower than during TO. It’s common for instance for naval patrol P-3s to feather one of their four engines once at altitude.

    • Very easy to calculate. If you Can Do Sums. Unlike Felix…

      Take an aircraft with a glide angle of one in 20. (thats the same as lift to drag ratio really and is about Airbus 380 standard) flying at 450 mph…

      That is very nearly exactly 200 meters per second, so without power it’s losing altitude at a rate of 10 meters per second in a glide.

      In order to counteract that it needs a power input of about 98 – say 100 watts per kilogram, to stay in cruise.

      Add another 100W/kg and it will climb at 20 meters per second.

      An airbus will climb at around 1000 fpm. Or 5 meters per second. So for climb out it needs another 25 watts per kg.

      Takeoff probably even more again.

      So let’s say to operate an aircraft with an effective cruise speed of 450 mph needs a power to weight ratio of 150 watts per kg to climb and 100 watts per kg to cruise. And that’s a state of the art airframe.

      An airbus weighs in at 500 metric tonnes fully loaded so it needs 500,000 x 150W = 75MW takeoff/climb power and 50MW to stay in level flight.

      Now to cross the Atlantic – 3500 miles from London to New York more or less, at 450mph takes 7.77 hours. Let’s round that up to 8.

      So the battery needs to be around 400 MWh

      Obviously the power taken to get up to cruise is power you can subtract from getting down again. So I have used cruise power.

      I have totally IGNORED drive train efficiency. battery to shaft will be good 90% or better – but shaft to thrust will be worse. Probably no better than 60%.

      Lets say 50% overall.

      So in reality we need an 800MWh battery.

      How much would such a battery weigh?


      Is a typical battery without casing or protection and is 3000Ah at 3.7V – and weighs in at 48g, so thats 230watt hours per kg

      So a li-Poly battery bank to get us 800 MWh is about 3500 metric tonnes. Oh dear that’s seven times the weight of the aircraft!

      It is simply impossible.

      Let’s look at how much energy density we WOULD need to do the job.

      There’s 200 tonnes of fuel and passengers in an Airbus 380 and 800 passengers. Let’s say with luggage they are 100kg each so thats , so lets assume a payload of around 80 metric tonnes.

      Leaving 120 tonnes of fuel – well it can carry 80, 000 gallons or 300 cubic meters or around 240 metric tonnes.

      So how much duration would standard batteries of this weight get us? We can cram in about 55MWh so just about half an hour’s flight.

      What energy density would we need to achieve to get across the Atlantic? Well we need 800MWh in 240 tonnes give or take And that’s still only half the range of a kerosene powered jet.

      800Mwh and 240 tonnes is 800kwh and 240 kg so 3300 watt hours per kg.

      As I said a reasonable off the shelf Li Poly is around 230 watt hours per kg.

      What wiki has to say about lithium batteries is this:

      Each gram of lithium represents Faraday’s constant/6.941 or 13,901 coulombs. At 3 V, this gives 41.7 kJ per gram of lithium, or 11.6 kWh per kg. This is a bit more than the heat of combustion of gasoline, but does not consider the other materials that go into a lithium battery and that make lithium batteries many times heavier per unit of energy.

      So in theory lithium has the requisite energy density, but in practice it does not.

      Because lithium alone is not a battery.

      Lithium air is described in Wiki as follows:

      Pairing lithium and ambient oxygen can theoretically lead to electrochemical cells with the highest possible specific energy. Indeed, the theoretical specific energy of a non-aqueous Li-air battery, in the charged state with Li2O2 product and excluding the oxygen mass, is ~40.1 MJ/kg. This is comparable to the theoretical specific energy of gasoline, ~46.8 MJ/kg.

      Pairing lithium and ambient oxygen can theoretically lead to electrochemical cells with the highest possible specific energy. Indeed, the theoretical specific energy of a non-aqueous Li-air battery, in the charged state with Li2O2 product and excluding the oxygen mass, is ~40.1 MJ/kg. This is comparable to the theoretical specific energy of gasoline, ~46.8 MJ/kg. In practice, Li-air batteries with a specific energy of ~6.12 MJ/kg at the cell level have been demonstrated. This is about 5 times greater than that of a commercial lithium-ion battery

      6.12MJ/kg is about 1700 watt hours per kg. Still less than half what we need to get us across the Atlantic.

      And that in a nutshell is the Big Sums that tell us where the electric Airbus is at.

      Forget solar panels hybrids and the like, the sums on those don’t make sense either. Cruise power is less, bit not markedly less, than takeoff and climb power, so hybrid is not worth doing. The solar energy falling in the wing is at best (full tropical midday sun) 850Kw with probably only 200KW actual electrical output when we need 50MW to stay aloft.

      What wee need is a battery at least 12 times better than state of the art lithium polymer, which is the best energy density in common usage to get half the range of the airbus 380, though we can get to New York from London. To match fuel we probably need around 20 times better battery – 5000 watts per kg.

      the theoretical energy density of lithium air is 11,000 watts per kg. But so far all we have achieved is 1,700 wh/kg ..but that’s the closest. Double that to 3,400 watt per kg and we are able to get across the Atlantic with passengers at 450mph.

      Thats how near and yet how far we are away from viable commercial electrical flight.

      Current production technology gets us a couple of hundred miles range max. Best battery ever made maybe 1500 miles range, and it’s a lab scale battery.

      We have to match 30% of what lithium air is theoretically capable of to get transatlantic flight and about 70% of what its theoretically capable of to match the range of modern airliners.

      So far we have achieved 15% in the lab…only.

      Now there is something else that is worth saying. These figures are independent of speed. In essence the energy needed to get a given wight of plane a given distance is simply a function of the glide angle – the lift to drag ratio. Commercially it pays to do that as fast as possible to get more paying passenger miles per year, and as fast as possible means 40,000 feet and Mach 0.85 because that is where the best speed and lift to drag rations can be found.

      The final thing I want to add to this, for the Felixes of this world, is to show how it only takes an hour – thats how long this post has taken, – to cut through all the cockwomble and flapdoodle of – say – Electric flight, down to the crucial bare essentials of the numbers and the technology. I accept I am in a particularly privileged position to do this in this case, because I have a class degree in engineering that includes all forms of it – fluid dynamics. structures and materials, theory of heat engines and electricity and machines, plus 5 years spent pushing electric model planes to the limit and doing the theoretical calculations on them, so this is not new ground for me, but the point remains. In an hour I can say with a high degree of assurance where the technology is at, where it could be at and where it most certainly never will be at.

      Because I know physics , chemistry, engineering and maths. And can Do Sums.

      Starting from the basics of lift to drag ratios (glide angles) its possible to easily calculate how many watt hours per kilogram we need to get across the Atlantic in any plane. In the end NOTHING ELSE MATTERS.

      Experience of electric models shows that drive train efficiencies are around 50%. For an geared propellor at 50mph sort of speeds. Thats the inverse of the Betz equations for wind turbines that give a theoretical 67% max efficiency for a wind turbine. Ducted fans are far less efficient at model plane speeds, but theory suggests they could do better than Betz limits at the right airspeed. so 50%-60% is in the ballpark at 450mph +-.

      Then we can go to the basic electro chemistry and get figures for best theoretical energy density of lithium, which is the best battery material there is.

      And that makes it look all possible, except we have the practical matter of constructing a real life battery.

      And we have a simple dichotomy. In theory a lithium battery COULD fly a ‘leccy plane as well or better than fuel but in practice…it cannot.

      Its like looking at the energy density of plutonium – 80,620,000 MJ/kg or around 22394444444 watt hours per kg and saying that essentially a kg of plutonium would fly an airbus one and a half million miles….except that we need a safe way to turn that energy into thrust that doesn’t weigh hundreds of tonnes and leave a radioactive wake…

      The problem is that any practical lithium battery involves another electrode and some sort of electrolyte, and these mean weight.

      And that means we are unable to achieve the theoretical energy densities of lithium alone.

      All the above, means that when I say ‘the whole problem resolves to one of energy density and nothing else matters’ that is not an ‘opinion’. That is what the physics and maths says. Backed up by experience.

      And when I say ‘although in theory a lithium air battery might be able to get an Airbus across the Atlantic, in practice its a considerable way off at the moment’ again that is not ‘opinion’ but facts derived from basic electro chemistry, and the practical state of battery technology.

      Someone ought to be paying me to stop people investing in stuff that will never work…

      It occurs to me that the above is worth a post of its own, if Anthony feels likewise..

      • I think You forgot to factor in one thing. Lithium-air batteries work on the reaction Li + O2 -> LiO2. That means that one ton of lithium at take-off will change to seven tons of lithium dioxide during the flight.

        But we can look on the bright side. There wouldn’t be any new MH370 mysteries. Seismographs could easily pinpoint where an aircraft with several tons of lithium metal onboard went into the sea.

      • Worse, Li-air battery has carbon cathode. At best, it produces 500 A/kg of C at 1.8 V
        Power = 500 (1.8) = 900 W/kg
        Small turboprop engine can generate 1300 kW. To match that power, you need
        1300,000/900 = 1,444 kg of carbon
        That’s just the cathode of the Li-air battery. The turboprop engine weighs only 198 kg

  49. It’s just another way of getting funding for climate-related schemes. The founder of Norwegian Air Shuttle, Mr. Kjos, recommended that the money for research of e-planes should be given to UNICEF. He said this may happen some 50 years from now, but that it is the job of airplane builders, not a government, to develop this technology.

  50. This is absolutely no problem. All we need, is to make smaller humans. This can be achieved by forcibly and drastically reducing the intake of nutritients, thereby also reducing the climate-destroying agricultural footprint of humanity. Footprints in general will of course also become smaller.

  51. To get some perspective. Electrical planes have about the same performance today that conventional aircraft had in 1908, five years after Kitty Hawk.
    From that point it took about 15 years to small-scale, short-haul commercial operations and 30 years to the first small-scale trans-oceanic operations. Non-stop operations across the Atlantic took 40 years.

    And this was with accelerated technical developments during two world wars to help. And it could all be done by incremental improvements of technology, while long-haul electrical aircraft will require some new, and at present quite unknown, storage technology.

    Long-haul electrical aircraft before 2050 is extremely unlikely, and most likely will never happen at all.

    • In a few hours we’ll throw matches in and spool props up in excess of 8’000 horse power to safely carry 4 dozens of souls from A to B.

      Even so with, ok, a somehow comfortable power reserve, we’ll spend time to consider the weather and decide on the safest procedures to cope with it’s inherent stochastic variability and provide for safe fuel (think energy) reserves.

      Then fill the numbers, add some on our appreciation and check the reading of the fueler meters.

      Just a very abbreviated description on how seriously we feed our powerplants.

      Because should it be, we all depend on whatever happens when we push forwards the levers. At any moment, without much warning, all those behind, cabin crew and finally ourselves depend on available power, lots of it, for as long as it takes.

      Reliable power is cardinal for airspeed and altitude, there’s no tow truck that we can call in mid-air, go-round’s, alternates, weather sandwiches.

      That’s how much the overly simplistic energy to weight ratio matters in the trade.

      Today, roughly speaking, jet fuel offers 15 times more energy reserve per weight when compared to the best and most optimistic battery promises in lab conditions.

      Which sets electric battery powered aviation on pair with diesel locomotives at best.

      Ever wonder why locs do not commonly fly ? Or why electric trains trains have pantographs ?

      In aviation, “range anxiety” spells “death and destruction”. Good luck with that.

      • It makes for good innocent fun to apply the ICAO fuel reserve requirements for General Aviation to an aircraft with a 1 hour endurance and about 85 mph cruise.

        1) VFR: to destination + 30 minutes
        2) VFR at night: to destination + 45 minutes
        3) IFR: to destination, then to designated alternate + 45 minutes

        In case 1) you have a practical range of about 40 miles (30 minutes) in 2) about 20 miles (15 minutes) and in case 3) 10 miles (7,5 minutes, if designating take-off site as alternate).

    • Long-haul isn’t the issue.

      For 2040, we’re talking Bombardier Dash 8, tops, not Boeing 737 (granted a bit of overlap), let alone 747.

      Given the periodic table, the max power density of the best battery conceivable today just about equals gasoline. But the whole system power pack has to be weighed, not just the “fuel”.

      Whether via incremental improvements, or a big breakthrough, batteries are going to improve over the next 22 years.

      If widespread adoption of electric a/c even occurs, it’s liable to proceed from its present RC, quadcopter drones and two seat toys to four seat light plane to very short hop small transports to regional commuter liners with a dozen to two dozen to three dozen to four dozen passengers. Those steps could occur in the ’20s and ’30s, but it all comes down to battery development. And maybe the speed with which third generation PV cells advance.

      As noted, thin film 3rd gen might not weigh more than paint. Just a WAG on my part. But I’m a technological optimist.

      • Felix, and the shaft horse power of DASH-8 300 is ? And even then, it’s a sad to fly bird in icing conditions. Think, Norway, north, wet sludgy snow, a bit of quick sun, clear ice…

        This morning, quite some south of 49, bumby enough to cancel coffee pouring, at 8’000 feet shields-up for the descent, just saying, would you think icing in june ? Very satisfactory to know that we carry enough of what it takes to make the call and get out to better skies if needed.

        And you dream that a cap in right mind will let PAX board an electric flying coffin ? What’s up, recharging stations on clouds ? Hey, grow up kids…

        How many people do you greens want to kill, each and every way ? Is that a mandatory save-the-earth strategy ?

  52. no backup . and if batteries go to fire mode?
    might train a pilot but then a normal planes going to be vastly different to handle.
    i wouldnt get in one

    • It might work if you go directly on to a jet, and never fly an IC-powered aircraft. But nowadays it is becoming normal to use a jet trainer from the start.

  53. This probably makes more sense for Norway than most countries. It’s very mountainous. This can make air travel highly advantageous for even quite short journeys, providing there are airstrips. It also means they have plenty of cheap hydro power.

    • Norway ? That’s quite north as the name says. Mountains rugged terrain, downdrafts, uncharted power lines, quite a specific set of quickly evolving weather systems, limited battery endurance. Ok, I’m out of there.

      • Powerlines are well charted. Icing and diversions due to changeable weather are much worse problems.
        There are some very short segments with few passengers up in the Lofoten archipelago, e. g. Bodö-Röst, Bodö-Svolvär and Bodö-Leknes, all three about 100 kilometers (65 miles). These might conceivably be practicable for electrical aircraft by 2040. Unfortunately the area has rather difficult weather conditions.

        • Glad powerlines are charted and fjord buzzing got probably safer. Yet…

          Such short legs in energy strapped and probably unpressurized birds would route into and not above the weather. That is into this kind of all option packs included northern style weather system.

          Good thing, they can save weight on weather radars, weather detours being quite no-no with only that much of electrons to drive the props.

          White knuckles…

          However this electric aviation scam is actually quite easy to debunk. Surprisingly they seem to let choppers out of the equation. I don’t talk of drones on steroids and the inherent autorotation problems in case of engine failure.

          I mean real choppers, the kind that can safely fly with even modest 4-bangers.

          The green aviation gurus stay safely away from the rotary wings topic. Maybe they finally have an instinctive perception on how much energy choppers need…

          So them do-gooders continue their efforts to persuade us that motorized gliders or multi-engine kites as the future of mankind.

  54. The ambition is to have pure electric aircraft on some very short flights (20-40 min) where there are very few passenger (5-7) per flight. We have a couple of those in this country. The dream part of it is to have this available in 5-7 years.

    For the 2040-ambition they are really talking about hybrids, although when in the mass media they say ‘eletric’ about everything.

    The case for hybrids is to reduce the main power plant by using the batteries for power application, i.e. take-off and climbs. With current state-of-the-art batteries it will give a total weight penalty, but reduce emissions per flight as long as it uses plug-in hydropower for battery charging.

    Norway has no domestic production of aircraft. I believe the global market for hydropower plug-in hybrid aircraft is rather small.

    And while there are a lot of promising battery chemistries out there, history has shown that they are large on promise and small on delivery. In the lab you get fantastic properties, but by the time they come in industrial size applications with the packaging and auxiliary systems needed for safety and reliable operation they tend to be where they are today: 250 Wh/kg for energy, and power at the cost of storage and life cycle.

    BTW, I work with electric and hybrid systems for maritime applications. They have made tremendous progress in the last 5-6 years, but we are at the top of the asymtote now.You still have to choose between going for power or energy – can’t have both with batteries.

  55. I have a private pilot’s license and have a few comments. 1 – most initial training consists of two passengers. How does that impact performance? Not clear from the video. 2 – what is the transition like to the next larger aircraft, as that would most likely not be electric? 3 – I didn’t hear a cost and couldn’t find one on their website. Most of the current crop of Cessnas are 30 yrs old at least and are well paid for.

    As usual they hype is well ahead of the fact.

  56. The plane in the video is light enough to be wheeled around by one man.

    If someone wanted to build an electric plane capable of carrying 10 passengers, how much more battery weight would it need? Could it fly into a headwind and not be blown backward? How much range would it have?

    Another question nobody seems to ask–why bother building an all-electric plane anyway? The energy used to charge the battery of the electric plane probably came from a fossil-fuel fired power plant with a stack some 100 to 200 feet above the ground. A commercial jet burning kerosene has most of its emissions 30,000 feet or so above the ground. Using an electric plane is actually moving the emissions closer to the ground.

  57. Yes… we have developed two different electric airplanes…. one can taxi and fly to the end of the runway… and the other has enough capacity to fly 150 miles, but it takes a bulldozer to pull it out of the hanger.

Comments are closed.