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Given that presumably Tesla's goal is to take battery costs down by 56% in 3 years from (108 - 140 $/kwh) to (50 - 70$/kwh) and widely held consensus is that 10

Given that presumably Tesla's goal is to take battery costs down by 56% in 3 years from (108 - 140 $/kwh) to (50 - 70$/kwh) and widely held consensus is that 100$/kwh is the price point at which EVs are no brainer on upfront costs with ICE cars, i feel that there is a long way to go. However, i think any successful real world demo starting with niche applications will help. We need all the battery tech to succeed.

DennisP 6y ago
Electric airplanes need significantly better energy density.
- ryder9 6y ago
  hydrogen would probably make more sense in airplanes than batteries tbh airbus is already jumping on it
- choeger 6y ago
  I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary? Right now, we have relatively large, relatively fast, jet planes. Do we need that size and that speed to be commercially viable? Could we also run a larger fleet of smaller, more automated planes or helicopters? If there was no kerosene left by tomorrow morning, would there really be no alternative?
  - djrogers 6y ago
    > I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary? Only if you value overseas travel... It currently takes ~16 hours to fly from SF to Singapore depending on weather. Any longer, and you're going to see a lot of that travel disappear.
    - onion2k 6y ago
      Only if you value overseas travel... It currently takes ~16 hours to fly from SF to Singapore depending on weather. Any longer, and you're going to see a lot of that travel disappear. It takes that long because it's more efficient to do it in a single flight. Taking off and landing are a massive waste of time and fuel. If we only had short range planes people would change their destinations in some cases or they'd plan layovers as part of the trip. I don't think you'd see that many people just stop travelling abroad.
      - tomalpha 6y ago
        Indeed. Though like in the olden days the large number of stopovers might cut down demand somewhat: https://en.wikipedia.org/wiki/Kangaroo_Route#Multiple_stops https://en.wikipedia.org/wiki/Kangaroo_Route#Multiple_stops
      - Animats 6y ago
        In the era when planes had to do that, there was not much trans-oceanic travel. The Pan Am flying boats, the "China Clippers", went from San Francisco to Hawaii to Midway to Wake to Guam to Manila to Macao to Hong Kong. It took a week.[1] [1] https://tripsintohistory.com/wp-content/uploads/2012/10/ClipperSchedule.jpg https://tripsintohistory.com/wp-content/uploads/2012/10/Clip...
      - nopzor 6y ago
        it's not really true that ultra long range direct flights (eg. from sfo to sin) are more efficient. the efficiency gain by not taking off and landing is eaten away by the efficiency loss of having to carry so much fuel (which also comes at the expense of useful load..)
    - dreamcompiler 6y ago
      It's not difficult to imagine in-flight recharging from something like a KC-135 running a big fat generator. If you're recharging capacitors, connect time would probably be a minute or two.
      - 6y ago
  - ReptileMan 6y ago
    I kinda enjoy the ability to get to the other side of the world in 24 hours.
  - baq 6y ago
    the problem with jets is stratospheric water vapor in addition to all the CO2 they emit (quite a lot in itself).
  - pjc50 6y ago
    > If there was no kerosene left by tomorrow morning I suspect the medium term solution would be to make some, either from other hydrocarbons or plant cellulose, or even by the US Navy seawater CO2 to liquid fuel process.
  - kokey 6y ago
    I probably have a skewed perception because I play with small fpv drones, but any weight saving like this usually opens up a whole world of new possibilities we never bothered to imagine before. This will certainly help existing delivery drones and drone taxi projects.
  - ashtonkem 6y ago
    You probably don’t need gasoline density equivalents for short haul flights, but we’re still really far off from where we need to be.
  - Gibbon1 6y ago
    I keep seeing numbers around 500 miles range floated for 8-12 passenger electric aircraft. Fire up google earth and start drawing 500 mile radius circles around metro areas.
  - bfieidhbrjr 6y ago
    > if you can build batteries with the energy density of gasoline Actually significantly worse than that. A plane gets lighter the longer it flies, especially at takeoff when everything is at max thrust. A battery becomes more and more dead weight the longer you fly.
    - bitdotdash 6y ago
      I wonder if this could be solved for with detachable take-off booster. Gets you up in the air, then returns to the airport.
      - ginko 6y ago
        Couldn't you just start with a cable that detaches and is pulled back to the landing strip?
        noodlesoups 6y ago
        Just make sure it detaches properly, you don't wanta a dozen wire to yank you in mid ascend
        mPReDiToR 6y ago
        A "third rail" along the runway and a dodgem/Scalextric type conductor springs to mind.
- 0xffff2 6y ago
  "significantly" sells it short. Electric airliners need a couple orders of magnitude of improvement to even come close to viability.
  - Retric 6y ago
    Jet engines are significantly less efficient than electric engines so it’s lithium ion has 1/20th the useful Specific Energy at takeoff, though that gets worse as the flight progresses and fuel is burned or batteries age. On the other hand for ultra long range flights electric jets can cruise as higher altitudes which makes up for some of that. Also having 1/3 the 15,000 km range of some aircraft is perfectly viable. IMO, Due to cost savings electric aircraft would likely become common at around 4x the current Specific Energy and fully take over at about 10-20x. PS: Energy density is fine for lithium ion, the issue is energy per weight (Specific Energy) not energy per volume (Energy Density).
    - jakehop 6y ago
      An airplane will weigh less, the more jet fuel it uses. A battery powered airplane does not have an obvious way of losing weight in this manner, further limiting range. Talking about 5.000 km is hard: While it won't get you from London to New York without some post-crash landing swimming, the current largest electric plane can fly ~100 miles at around 114mph, with 9 passagers. I see that you take the laws of physics into account, but allow me to state this for the sake of the conversation: In order to replace jet fuel, we must match what we could call it's useful energy density (energy/kg * efficiency). While electric engines are probably more efficient, we're still up to 2 orders of magnitude away – that's requires a 50-100x improvement of energy density, while maintaining the needed high discharge characteristics, developing a sufficiently efficient electric jet engine and taking into account the increased weight. All at a price where people won't need to save up for years, in order to visit their families. While I hope to see a zero emission future in my lifetime (actually a negative-emissions might be needed for at time), I feel like putting batteries into airplanes is a bit too much "Silicon Valley Sophism" – shoving the same solution at each and every problem, rather than figuring out what the core of the problem is. I do love electric cars, but they are not for everyone('s budget). Perhaps the solution is synthetic fuels, combined with carbon capture and a cheap, clean and reliable energy source, such as nuclear power. I know this isn't exactly cheap or readily available either, but it seems like one would bypass a lot of the issues above, by focusing on the source of the problem: Non-neutral use of carbon fuels.
baybal2 6y ago
Wholesale LFP price in China been <$100/kwh for quite a few years, yet...
specialist 6y ago
FWIW, I just learned about "Wright's Law" via Sandy Munro. https://en.wikipedia.org/wiki/Experience_curve_effects https://en.wikipedia.org/wiki/Experience_curve_effects
samatman 6y ago
Electric vehicles are right at the bottom of the curve for "amount of money consumers are willing to spend for more energy per gram/ml". I'd expect this kind of tech to debut in premium phones and laptops, and work its way down.

DennisP 6y ago

Electric airplanes need significantly better energy density.

ryder9 6y ago
hydrogen would probably make more sense in airplanes than batteries tbh airbus is already jumping on it
choeger 6y ago
I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary? Right now, we have relatively large, relatively fast, jet planes. Do we need that size and that speed to be commercially viable? Could we also run a larger fleet of smaller, more automated planes or helicopters? If there was no kerosene left by tomorrow morning, would there really be no alternative?
- djrogers 6y ago
  > I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary? Only if you value overseas travel... It currently takes ~16 hours to fly from SF to Singapore depending on weather. Any longer, and you're going to see a lot of that travel disappear.
  - onion2k 6y ago
    Only if you value overseas travel... It currently takes ~16 hours to fly from SF to Singapore depending on weather. Any longer, and you're going to see a lot of that travel disappear. It takes that long because it's more efficient to do it in a single flight. Taking off and landing are a massive waste of time and fuel. If we only had short range planes people would change their destinations in some cases or they'd plan layovers as part of the trip. I don't think you'd see that many people just stop travelling abroad.
    - tomalpha 6y ago
      Indeed. Though like in the olden days the large number of stopovers might cut down demand somewhat: https://en.wikipedia.org/wiki/Kangaroo_Route#Multiple_stops https://en.wikipedia.org/wiki/Kangaroo_Route#Multiple_stops
    - Animats 6y ago
      In the era when planes had to do that, there was not much trans-oceanic travel. The Pan Am flying boats, the "China Clippers", went from San Francisco to Hawaii to Midway to Wake to Guam to Manila to Macao to Hong Kong. It took a week.[1] [1] https://tripsintohistory.com/wp-content/uploads/2012/10/ClipperSchedule.jpg https://tripsintohistory.com/wp-content/uploads/2012/10/Clip...
    - nopzor 6y ago
      it's not really true that ultra long range direct flights (eg. from sfo to sin) are more efficient. the efficiency gain by not taking off and landing is eaten away by the efficiency loss of having to carry so much fuel (which also comes at the expense of useful load..)
  - dreamcompiler 6y ago
    It's not difficult to imagine in-flight recharging from something like a KC-135 running a big fat generator. If you're recharging capacitors, connect time would probably be a minute or two.
    - 6y ago
- ReptileMan 6y ago
  I kinda enjoy the ability to get to the other side of the world in 24 hours.
- baq 6y ago
  the problem with jets is stratospheric water vapor in addition to all the CO2 they emit (quite a lot in itself).
- pjc50 6y ago
  > If there was no kerosene left by tomorrow morning I suspect the medium term solution would be to make some, either from other hydrocarbons or plant cellulose, or even by the US Navy seawater CO2 to liquid fuel process.
- kokey 6y ago
  I probably have a skewed perception because I play with small fpv drones, but any weight saving like this usually opens up a whole world of new possibilities we never bothered to imagine before. This will certainly help existing delivery drones and drone taxi projects.
- ashtonkem 6y ago
  You probably don’t need gasoline density equivalents for short haul flights, but we’re still really far off from where we need to be.
- Gibbon1 6y ago
  I keep seeing numbers around 500 miles range floated for 8-12 passenger electric aircraft. Fire up google earth and start drawing 500 mile radius circles around metro areas.
- bfieidhbrjr 6y ago
  > if you can build batteries with the energy density of gasoline Actually significantly worse than that. A plane gets lighter the longer it flies, especially at takeoff when everything is at max thrust. A battery becomes more and more dead weight the longer you fly.
  - bitdotdash 6y ago
    I wonder if this could be solved for with detachable take-off booster. Gets you up in the air, then returns to the airport.
    - ginko 6y ago
      Couldn't you just start with a cable that detaches and is pulled back to the landing strip?
      - noodlesoups 6y ago
        Just make sure it detaches properly, you don't wanta a dozen wire to yank you in mid ascend
      - mPReDiToR 6y ago
        A "third rail" along the runway and a dodgem/Scalextric type conductor springs to mind.
0xffff2 6y ago
"significantly" sells it short. Electric airliners need a couple orders of magnitude of improvement to even come close to viability.
- Retric 6y ago
  Jet engines are significantly less efficient than electric engines so it’s lithium ion has 1/20th the useful Specific Energy at takeoff, though that gets worse as the flight progresses and fuel is burned or batteries age. On the other hand for ultra long range flights electric jets can cruise as higher altitudes which makes up for some of that. Also having 1/3 the 15,000 km range of some aircraft is perfectly viable. IMO, Due to cost savings electric aircraft would likely become common at around 4x the current Specific Energy and fully take over at about 10-20x. PS: Energy density is fine for lithium ion, the issue is energy per weight (Specific Energy) not energy per volume (Energy Density).
  - jakehop 6y ago
    An airplane will weigh less, the more jet fuel it uses. A battery powered airplane does not have an obvious way of losing weight in this manner, further limiting range. Talking about 5.000 km is hard: While it won't get you from London to New York without some post-crash landing swimming, the current largest electric plane can fly ~100 miles at around 114mph, with 9 passagers. I see that you take the laws of physics into account, but allow me to state this for the sake of the conversation: In order to replace jet fuel, we must match what we could call it's useful energy density (energy/kg * efficiency). While electric engines are probably more efficient, we're still up to 2 orders of magnitude away – that's requires a 50-100x improvement of energy density, while maintaining the needed high discharge characteristics, developing a sufficiently efficient electric jet engine and taking into account the increased weight. All at a price where people won't need to save up for years, in order to visit their families. While I hope to see a zero emission future in my lifetime (actually a negative-emissions might be needed for at time), I feel like putting batteries into airplanes is a bit too much "Silicon Valley Sophism" – shoving the same solution at each and every problem, rather than figuring out what the core of the problem is. I do love electric cars, but they are not for everyone('s budget). Perhaps the solution is synthetic fuels, combined with carbon capture and a cheap, clean and reliable energy source, such as nuclear power. I know this isn't exactly cheap or readily available either, but it seems like one would bypass a lot of the issues above, by focusing on the source of the problem: Non-neutral use of carbon fuels.

baybal2 6y ago

Wholesale LFP price in China been <$100/kwh for quite a few years, yet...

specialist 6y ago

FWIW, I just learned about "Wright's Law" via Sandy Munro. https://en.wikipedia.org/wiki/Experience_curve_effects https://en.wikipedia.org/wiki/Experience_curve_effects

samatman 6y ago

Electric vehicles are right at the bottom of the curve for "amount of money consumers are willing to spend for more energy per gram/ml". I'd expect this kind of tech to debut in premium phones and laptops, and work its way down.