Saturday, June 24, 2017

All-Electric Small Airplane

From today's emails, I find that a company called Eviation announced an all-electric powered small plane at this year's Paris Air Show.  The company showed a prototype of the aircraft, rated for a 600 mile range.  I don't know if they're doing it here, but pilots ordinarily like to have about 1/4 to 1/3 of their fuel available for contingencies and I assume 600 does not include contingencies. 
Omer Bar-Yohay, CEO of Eviation Aircraft, made the announcement:
“At a time when we are more connected than ever, our mobility options must adapt to reflect this new, efficient future. Whether it is a zero emissions, low-cost trip from Silicon Valley to San Diego, or Seoul to Beijing, our all-electric aircraft represents a chance for people to move with the speed and impact our global economy now demands.”
I have to point out that "zero emissions" only applies only to the exact moment when the airplane is running and completely ignores how it got to that point.  Before I go into that, though, I think it's reasonable to ask, "what's the big deal?" 
I'm not aware of electric planes on the market because I haven't cared to look.  Solar electric airplanes go back decades.  I don't think the technology is exotic or that this is some sort of technological tour de force.  Anybody who has ever seen a Radio Controlled model of a flying Snoopy on his doghouse, or some of other crazy things seen at RC shows will realize that the golden rule of aviation is that anything can fly if the lift to weight ratio is greater than one.  Stick on a big enough engine or make a big enough wing area and you're done.  Making an electric airplane means enough engine or wing to overcome the horrible inefficiency of the propulsion system compared to gasoline.  As I pointed out weeks ago, "While battery makers desperately try to figure out how to reach a specific energy of 450 Wh/kg (Watt-hours per kilogram), gasoline already offers 12,000 Wh/kg."  I don't think it's a stretch to say they'd get at least twice the range if they used Av gas instead of batteries.  Perhaps three or four times the range. 

Earlier this week, several outlets reported a study from the Swedish Environmental Research Insitute that the "carbon footprint" of producing the batteries for an electric car was equivalent to driving for 8 years.  This ignored recharging the batteries for the life of the car, which is obviously coming from an electric power generating plant somewhere, so more than likely generating CO2 itself.  I'm sure you've seen electric cars referred to as coal powered.
The report shows that the battery manufacturing leads to high emissions. For every kilowatt hour of storage capacity in the battery generated emissions of 150 to 200 kilos of carbon dioxide already in the factory. The researchers did not study individual brand batteries, how these were produced, or the electricity mix they use.
The study looked at two models of electric cars, a Nissan Leaf and the Tesla Model S, containing batteries of about 30 kWh and 100 kWh.
Even before buying the car, emissions occurred corresponding to approximately 5.3 tons and 17.5 tons of Carbon Dioxide. The numbers can be difficult to relate to. As a comparison, a trip for one person round trip from Stockholm to New York by air causes the release of more than 600 kilograms of carbon dioxide, according to the UN organization ICAO calculation.
Unless I miss my conversion (or misunderstand their units) the 17.5 tons of CO2 to manufacture the Tesla's batteries is equal to about 26 round trips flights from Stockholm to New York.  The 5.3 tons for the Leaf corresponds to 8 trips.  The electric airplane will not be immune to this sort of reality.

The way I look at it, wanting to buy an electric vehicle (airborne or road) is virtue signalling.  Wanting to sell an electric vehicle is more like the old quote, "there's a another one born every minute."  You want to spend money to feel good?  We'll be more than happy to take your money!


  1. All I can think of is that the weight stays the same during the whole flight, whereas with a conventional plane it gets lighter as the fuel is used. So more efficient as the flight goes on.

  2. Where I have seen electric motors and battery packs work well is in sailplanes. It simplifies a motor installation and as it is used intermittently, it is practical. My biggest problem with electric vehicles, from the standpoint of practicality, is that neither the energy department or that ever so brilliant Warren Buffet have never seen fit to electrify tracked freight lines. Why run diesel electric when you could run straight electric especially if it was planned in conjunction with small thorium reactors. That would seem to be the low hanging fruit but I suspect the only corporatist interest lies in where the cheap or maybe even "free" money lays. indyjonesouthere

  3. I understand the drive to make new and different stuff - "Hey, look what we can do" - much of which has little or no practical value (sailing ships in bottles, etc.) other than demonstrating determination, rare abilities, and often, more money than sense; better mousetrap, beaten path, and so on. Electric passenger aircraft fall into that category (it's also possible that whatever they've accomplished may turn out to be useful for a limited application in extremely quiet military/civilian drones, or maybe that's where they got this idea in the first place).

    But....I would have to very seriously question the intelligence and wisdom of anyone who might buy an electric airplane and try to use it for its intended purpose.

    That said, I'll still bet they'll sell some. As long as none are over my house when the little red light announcing "5% battery left" comes on, and no one I know is stupid enough to leave the ground in one, I don't really care.

    By the way, I have this bridge in New York I'm thinking of selling, and I'll discount for cash....


  4. This analysis is fine as far as it goes. However, it ignores the carbon footprint of the Energy required to charge the batteries. It also ignores the carbon footprint of disposing old batteries and how long those battery packs last in the real world.

  5. You're overlooking the obvious:
    whatever the initial buy-in, in terms of carbon or bucks, you're free from the future vagaries of gasoline pricing or availability.

    (E.g. you build a solar-recharged electric car in 1972. When OPEC goes crazy the next year, you care not a whit.)

    A car (or a/c) that uses solar recharging drives for zero dollars going forward, until the battery fails.

    So whatever I paid up-front for a solar roof on my garage, and a Leaf or Tesla, whatever OPEC - or the free market, or the .Gov - does after that point means jack to me, for a decade or more.

    If I use battery-stored solar in the regions below the snow belt, for LED lighting, a TV, microwave, laptop, and refrigeration, the grid can melt down, and energy isn't a problem for me. Ditto most natural disasters that don't burn, scour or level my house to the ground.

    That's the reason to do this, and it's not nothing. Notwithstanding the initial buy-in costs, carbon cost/benefit, and any "green" cost/savings.

    A lifeboat doesn't substitute for a functional yacht, but it's a great alternative to a life jacket, or nothing.

    And a commuter airline in the Sunbelt, using solar, will laugh at the next hike in jet fuel prices. Solar doesn't have to approach the energy capacity of a gallon of hydrocarbon fuel to make sense; if hydrocarbon fuel becomes unobtanium, solar-electric ability is pure gold.

    1. One of the things I tell friends and family - and I'm pretty sure I've written here - is that there are situations where putting in a solar powered house makes sense. The easiest example is if you decide to put in a house far off grid. I've read stories (so it must be true) of people putting in small communities far from the nearest power poles and the utility charges so much to hook them up to the grid that they live off solar cells and batteries.

      In simple terms, if everything else about your house costs you $200,000 and hooking up to the grid costs $500,000, you can do solar cheaper.

      Basically everyone is betting that someone else will pay to get the long cable run so they can hook up to the grid. Once that first line is run, it's much cheaper to connect.

      A societal disruption that can keep hydrocarbons unavailable for long periods is also known as a SHTF or TEOTWAKI event. I think everyone reading here considers that.

  6. "If I use battery-stored solar in the regions below the snow belt, for LED lighting, a TV, microwave, laptop, and refrigeration, the grid can melt down, and energy isn't a problem for me..."

    Uh, well, as long as your high-tech electrical system doesn't need parts, or a hail storm doesn't destroy your solar panels.

    Electronc components fail, or degrade, eventually, requiring repair or replacement. When the grid collpases and whomever survives is living in caves, where will your replacement integrated circuits that keep your charge controller operating come from?

    1. One of the most common questions I've gotten over the years since I wrote my series on EMP is whether or not solar panels are affected. I still don't have an authoritative answer, but I think the answer is that solar panels will be fine - if you are not grid tied. Pickup from EMP appears to be an area phenomenon, and they're small enough to not pick up large amounts of the energy. I'm a bit less optimistic about the controllers and fairly certain that if you're grid tied, the surge on the power grid will destroy your controllers. In a pinch, you could connect cells to batteries, though. Yeah, it's inefficient, but it's better than nothing. Better still would be to stick some extra backup controllers in an ammo can.

      Even here, far from the snow belt, solar power has "hidden costs" that most people don't consider. Birds crap on your solar panels. Dirt blows in. Leaves fall. They're not maintenance free. Likewise, storage batteries need care. Plus, despite our "Sunshine State" moniker, we're not as good for solar power as the southwestern states because of clouds. Like pretty much everywhere in the country, we also have periods where the sun doesn't stay out more than an hour or two a day. Nobody charges a battery bank in that amount of time.

    2. Nosmo,

      "until a hailstorm..."
      I'm in SoCal.
      I've read about those, but have yet to see one hereabouts in half a century that damaged anything more than a weather report. Maybe two little ones around here, lifetime. YMMV, depending on where you are.

      And I get that electronic parts fail.
      So spares. TANSTAAFL

      Now, tell me how and where to buy a spare oil well and refinery on the average salary.

      And maybe just don't assume that because solar electric doesn't make sense for you, wherever there is, it doesn't make sense for anyone, anywhere.
      It's a big country, and a bigger world.

      And perhaps, look up what the profit margin is on small airlines, and look up what commuter airlines spend on fuel.
      I'll wait.

      I didn't say the idea is flawless, I said it has merits.

      My second car will probably be electric, or a hybrid. Not for tree-hugging tofu-slurping green planet nonsense, but because for 75% of my drives, I'd enjoy telling Big Oil (ours, or Arabistan's) to suck it.
      And I'll be looking into juicing it using solar.
      $4K/year, minimum, not spent on gasoline would go a long way around here.

  7. Well, glad you don't have hailstorms; we had a good one about 6 weeks ago. We're in the mountains, and the elevation, plus being on the downslope, helps dampen them a little - we got 2" of pea-size hail in the yard, but 10-15 miles away where it's lower and flatter they saw golf ball to baseball size hail. Right during rush hour. If you think that's hard on a roof you should see what it does to a Lexus. One of my fellow inmates at the gym is wrestling with his insurance company and the company that covered his roof with grid-tied solar panels. As he put it, the solar panels did an excellent job of protecting his shingles. Now all he needs is a full set of panels that work again.

    SiG pointed out the hazards of EMP, and while it may not damage the panels themselves, all the fiddly bits that make the solar-produced juice usable may not fare so well.

    There's certainly substantial value in being independent of mass-consumed energy sources, and solar is a prime way of accomplishing that, assuming sufficient spares and repair capabilities can be accumulated.

    Regardless of where one lives, after the apocalypse it'll be handy to have a Prius whose batteries get recharged by the sun, but being the only non-government moving vehicle may attract more attention than desired.

    Oh, and good luck with those earthquakes, hope they miss your neighborhood.