• May 6th 2009 at 4:19PM
  • 43
First things first: electric airplanes are nothing new. The French eplane "Electra" flew in 2007 and the "ElectraFlyer C" wowed the crowds at Oshkosh in 2008. But, these one-offs are not for sale and they're certainly not cheap to put together.

Enter Elon Musk. The man at the head of Tesla Motors is familiar with airborne vehicles thanks to his SpaceX venture and, last week, he mentioned he has an idea for an electric plane. Talking at the Charles River Ventures CEO Summit, Musk said that he's thought about a supersonic electric plane since battery technology has advanced to the point where electric aircraft are possible. Possible, but still a long way off, even for Musk. With the new Tesla Model S and other items on his to do list, Musk did admit that, "I have too much to think about."

[Source: TechCrunch]

I'm reporting this comment as:

Reported comments and users are reviewed by Autoblog staff 24 hours a day, seven days a week to determine whether they violate Community Guideline. Accounts are penalized for Community Guidelines violations and serious or repeated violations can lead to account termination.

    • 1 Second Ago
      • 8 Months Ago
      He's off his rocker. In cars we run into the problem that the battery pack weighs 3x as much and only holds 1/6th the energy, but we can work around that a little bit. In a plane this is an enormous issue. Any electric plane would have a VERY short range.

      Besides, you think range anxiety is an issue on the ground... You may not be able to carry a can of volts, but at least you can pull over and park the car easily if the engine cuts out.
        • 8 Months Ago
        How is that any different than running out of fuel on a flight? In either case, it is very important to make sure the plane is fully prepared for flight, with sufficient fuel or sufficient charge to complete the flight with a margin for safety.

        As for reliability, batteries and electric motors are far more reliable than any aviation piston engine or gas turbine. As long as there was sufficient charge before takeoff, an "e-plane" would be less likely to fail in flight.
      • 6 Years Ago
      What speaks for electric planes : you have large wing area waiting to be covered with thin-film solar cells, and once you are at your cruising altitude, you are above the clouds, meaning predictable power output.
      Free flight during daytime, literally.

      Its happening, as well:
      • 6 Years Ago
      I'm starting to think Musk does not really want to make an electric anything. He wants to make the brand (succeeded already) and then sell it for amount of cash as huge as possible.

      See his biography at Wikipedia. This is exactly how he made money in the past.

      Electric plane is obviously utter nonsense. The amount of energy needed for the plain to work/lift and the sheer mass of batteries makes this pointless at the very start. But it delivers further media attention all around the world. Word "Testa" carves in readers' mind further on.

      Musk started with a cramped useless horribly pricey Lotus electric transplant - a car no one can actually either use or afford. If he really wanted to make electric cars, he'd have kicked off with transforming ordinary daily driver small cars into battery electric vehicles. But this would never spark press coverage avalanche Tesla is experiencing that is necessary to sell the brand for big bucks in the future.

      Then is the Model S. This car is going to compete with Lexus GS/BMW 5er/Audi A6/Mercedes E class/Jaguar XF/Acura TL/Infiniti M/Cadillac STS etc. etc. I'm sorry, but a small startup just CANNOT make a car of this class meeting all the safety, comfort, performance, quality and dependability requirements that are set by huge car making corporations with billions in their reserves and years of hand-on know how just so.

      Then is the aspect of range. What's the point of using 300-mile huge expensive battery when you can cover 90% of driving needs with a 5x smaller and cheaper one with some capacity buffer to avoid full discharge and fit a tiny generator for occasional longer commutes?

      The whole idea of the Model S seems wrong in its roots, designed to be unaffordable and to trigger massive press buzz only, instead of delivering a useful product.

      So the Model S seems to be another brand booster for me, not a real product for people to be happy with all electric propulsion.
        • 8 Months Ago
        jpm says "Be careful, you may end up eating those words."

        Relax, man. Relax. = ))

        This is engineering and business. If that doesn't make for uncertainty I don't know what does. That is, I fully expect to be wrong a certain percentage of the time and you should too.

        And, that's OK. Why?

        Consider this:

        I can be a devoted baseball fan and still really not like A-Rod. It doesn't mean he won't win another MVP because of me.

        I can be a devoted basketball fan and still think the Dallas Mavericks would be more successful if Mark Cuban just learned to not be a distraction. This also doesn't mean that they won't win it all this year or the next.

        And, I can be a fan of electric vehicles and still be critical of Elon Musk. And, again, this doesn't mean that Tesla won't take the world by storm.

        Really, it's OK for people to have their doubts Elon.

        = )
        • 8 Months Ago
        Be careful, you may end up eating those words.
        • 8 Months Ago
        downtoearth: "I'm starting to think Musk does not really want to make an electric anything. He wants to make the brand (succeeded already) and then sell it for amount of cash as huge as possible."

      • 8 Months Ago
      Perhaps a Jet powered by ultracapacitors, with a small battery backup might do the trick, especially for the flights that last less than 2 hours.
      • 8 Months Ago
      Ive read several comments stating batteries this and batteries that...I agree, with today's available technology I have to say the energy storage issue will be a problem..However..I am aware of TONS of promising research into developing batteries and other energy storage solutions that can store orders of energy more than existing technology.

      to all the positive thinkers out there, dont worry about these nay-sayers, these are the same fools that said Tesla could never make an electric car that could be faster, cheaper, and obviously greener than most supercar/exotics....
      • 8 Months Ago
      Supersonic? Does he know how a jet engine works? What's next electric rockets?
        • 8 Months Ago
        I know that, but it's "practical only in outer space". So, how do you get to outer space?
        • 8 Months Ago
        Funny you say that... There ARE "electric rockets."


        • 8 Months Ago
        Of course, to reach low earth orbit from sea-level will require a high thrust chemical rocket. Fueled with, in this case, RP1 (kerosene). However, the payload is the 1,250 kg "Dawn spacecraft" with a total of 425 kg of Xenon propellant for its solar powered Ion engines-with an ISP (Rocket MPG) of 3100 seconds.

        The spacecraft itself will perform a velocity change of over 10 km/s, far more than any other spacecraft has done. Using a chemical fuel such as MMH-NTO (313 ISP) for the same velocity change would require several tons of fuel to accomplish the same thing, boosting the cost of the spacecraft and requiring a larger, much more powerful - and expensive launcher.

        Conclusion: Electric propulsion increases capability, saves lots of RP1 fuel, and money.
      • 8 Months Ago
      Haha. Very funny.

      Electric propellers are reasonable and could make an appearance in motor gliders where start/stop reliability is very important while total range is not. Low RPM torque is also a benefit since ICE's revolve faster at peak power than propellers can handle, so they operate way under capacity and are therefore overweight. But the energy density required to fly high speed aircraft is still waaaay out of reach! The faster the plane, the more that energy difference matters if you were intent on getting very far.
        • 8 Months Ago
        Andy says: "Electric propellers are reasonable and could make an appearance in motor gliders where start/stop reliability is very important while total range is not."

        Check mark box done! = )

        I'm surprised no one has mentioned the Pipistrel Taurus Electro.

        video: http://www.pipistrel.si/news/795

        It's a 2 seat side-by-side self launching sailplane and it's already in production.

        Also food for thought: The price of a new 100HP Rotax 912S (the defacto standard for LSAs) is now north of $20 grand (in part because of exchange rates). U.S. made Continental 0-200s and Lycoming I0-233s are also in that same ballpark price-wise for brand new engines.

        Food for thought: Assuming batteries continue to get better, electric motors and batteries may be able to compete in this market because aircraft engines must be overhauled after a certain period of time (about 1500 hours of flight time give or take a couple hundred hours) and the overhaul can cost 2/3 (or more) the cost of a new engine. So the cost of periodically replacing batteries is more tolerable.
        • 8 Months Ago
        Your tense is wrong -- electric motors have appeared in motorgliders:

        • 8 Months Ago
        Even without a motor, soaring is a form of solar powered flight, so the distinction becomes a bit blurry.
        • 8 Months Ago
        Years ago Eric Raymond flew across the USA in a solar-powered motor glider. He's continued to develop it:

        I don't know why people like him don't get more attention.
      • 8 Months Ago
      One thing at a time Elon...

      The battery and power electronics in the Tesla weigh about 1,000 lbs, and supply about 50kWh of energy. One and a half gallons of avgas weighs about 10 lbs, and supplies... 50kWh of energy.

      Weight's less of a problem for a car since the asphalt keeps it from plummeting to the earth's core. It's a tad more problematic if you're trying to power something like a Cirrus R22 using a 230kW engine.
      • 6 Years Ago
      Elon is great! I think the logical step is to have electric plans as if you look at an Airbus the only moving parts are pretty much just the engines. Batteries are the problem but this is a technical issue which will be overcome without doubt.
        • 8 Months Ago

        Dude, you're such a hater. This is why humans invent things, we have problems and we overcome them. It's people like you who stagnate things and hate on those who move us forward. Instead of saying "can't do this, can't do that" please contribute by maybe giving some advice on what we should overcome. Haters.
        • 8 Months Ago

        Go directly to engineering school. Do not pass go. Do not collect $200.

        Seriously, we all /want/ this kind of thing to work, but the problems won't be solved without pointing out the issues, discussing them, finding more problems, and solving them. And, yes, lives are often at stake during the engineering process, so it's taken /very/ seriously.
        • 8 Months Ago
        The problems with that comment are staggering.

        The number of moving parts on an airplane are vast, to start with.

        Secondly, he said supersonic flight. How would you accelerate air to supersonic speeds with electricity? A prop can't go much past M=.7, and ducted fans would be huge. The weight of the necessary electric motors would be far too high. The problem isn't batteries, it's propulsion.
        • 8 Months Ago

        Of course I understand there are clear [engineering] obstacles to overcome. I was merely referring to his attitude as a problem. That's the first step before you tackle anything.
        • 8 Months Ago
        No, batteries weigh more than av-gas and provide much less energy. You can't wave a magic wand over batteries and say that they will be better than high octane gas... my AP chemistry days are long gone but i'd wager a good deal of money that NO battery can ever have a higher energy density than gas.

        I know the DOD is working on fuel cell UAVs because the fuel cell stack weighs less than gasoline (and you actually need less power to fly a plane than you need to drive a car).
      • 8 Months Ago
      As much as I dislike hydrogen as a fuel for autos, for airplanes it probably makes sense because I don't think batteries will ever be light enough and powerful enough to be a practical power source for flight. There is still that storage and distribution problem.

      Probably bio-diesel is an even better way to go for aircraft. I don't think we can make enough of it to power all of our ground transportation, but we can probably supply enough for aircraft.

      Of course it's a free country and if people want to develop electric planes there's no reason to stop them.
        • 8 Months Ago
        You can turn coal into gas. For planes you need energy density as weight is a factor in a way that it will never be for cars. I have a serious man-crush on Elon over his work at SpaceX but I think he is full of it here. 3x the weight for 1/6th the energy is not efficient and is a recipe for waste. Saying things like this makes me wonder about Tesla.
        • 8 Months Ago
        The problem with using H2 to fuel planes isn't the weight, it's the volume. A liquid H2 tank big enough to fuel a conventional passenger jet would be larger than the fuselage! That would make the plane to large and ungainly to be practical.

        One possible way around that problem would be to use H2 only in a more efficient fuel cell to provide electrical power, then use an electric/biofuel hybrid jet engine where the turbine portion is replaced with a compact electric motor, leading to higher exhaust velocity and greater efficiency. Using biofuels for the main jet fuel and using H2 only for electrical power greatly reduces the volume of liquid that would be needed for each flight.

        Now, if we could only get the price of fuel cells down to a halfway reasonable level...
        • 8 Months Ago
        There's nothing wrong with a series hybrid (fuel-genset and electric drive motor). With that configuration, you could have a quiet, efficient, vibration-free electric motor driving the prop, ~10kWh of battery buffer, and enough potential energy aboard (50 gal/1,200+ effective kWh) for a more than acceptable range.
      • 6 Years Ago
      Battery powered pilot carrying planes have flown, though with the current energy density the range and speed is limited, too limited for commercial use. Improvements in battery technology could improve both range (energy density) and speed (power density).

      However, even current lithium batteries could find use as a power source for electrical devices on commercial planes, replacing fuel guzzling "auxiliary power units".

      With improved energy density, there is the possibility of a commercial "hybrid jet engine", with an electrically driven compressor but no gas turbine, most of the thrust energy would still come from burning fuels but at a much higher efficiency.

      A "hybrid jet engine" powered by biofuels and hydrogen fuel cells might even be possible, as it would greatly reduce the volume of H2 fuel needed. Of course, that assumes that fuel cell pricing comes way down to reasonable levels.
        • 8 Months Ago
        Large transports are where H2 chemical fuel will take over in the future. As new ways of storing and transporting hydrogen are emerging (some very interesting and promising breakthroughs), using H2 will be the only way to go. Carbon based fuels are hopefully going to be phased out.

        As always stated, the combination of electricity and hydrogen is going to be the future.
        • 8 Months Ago
        mebbe he's come up with a way to make ion propulsion rockets real cheap and make it work on earth :3
        yes.. i know they work in space only
        • 8 Months Ago
        Agreed 100%, Chris. I've actually thought of that concept myself a while back. You could eliminate the turbine entirely (and thus a big source of engine drag) and turn the compressor into the rotor of a three-phase motor. Go with a turboprop design (or better, a propfan), and an even higher percent, perhaps even the majority of your power will come from electricity. You've got something that could definitely be a commercial competitor after a decade or two of battery advances.

        As for electric power past the sound barrier, it's not as crazy as it sounds -- not for a practical craft, but potentially as a rich kid toy. The Thunderscreech was supposed to be able to hit Mach 1, and that was 1950s tech (they had trouble with the engines, unfortunately). Counter-rotating supersonic scimitar propellers could probably do the trick. The neat thing from Musk's perspective is that you don't need too much energy -- you need a ton of power. Breaking a record only would require, what, 20-30 minutes or so of flight time? You just need to be able to dump power out like it's going out of style. And modern li-ion batteries can definitely do that, and the motors are quite compact, powerful, and lightweight.

        It'd cost a fortune, of course. But it should be doable. Not as a practical craft, but again, could be the ultimate toy for the green-minded silicon valley types who like to fly. Sell it with a hangar covered in solar panels and you've got customers lined up down the block.
        • 8 Months Ago
        Great minds think alike, meme!

        Of course, electric prop planes would be more efficient than a hybrid jet, but they would also be slower and less powerful. Still, E-Props could find use in many aviation applications where speed isn't essential, such as short hop runs, private planes, survey planes, etc.

        Hybrid jets would be as fast as existing jet planes, but more efficient and quieter, making them an appealing choice for commercial travel.

        Hmm, supersonic transport failed economically due to high operating cost and noise. Perhaps with sufficient refinements and really high performance batteries, a hybrid jet SST might be efficient enough to be successful.
      • 6 Years Ago
    • Load More Comments
    Share This Photo X