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Battery supply problems faced by electric air taxis
- mogadsheu 7y agoIt’s pretty clear that battery technology and cost efficiency is going to have to advance substantially before it can have a meaningful impact on air transport. Blimps might be a slight exception.
- sliken 7y agoOr just use hydrogen, it's a much denser energy storage medium, and airflight is less cost sensitive than ground transportation.
- tonyedgecombe 7y agoOr not bother with air taxis, civilisation won't collapse because some rich arsehole can't get across New York in five minutes.
- ClumsyPilot 7y agoSure, but on another hand we should encourage the rich asshole to spend his money so it could be useful to the rest of the economy.
- hasfhashdahsd 7y agoBut does it? Just because it got a battery, it doesn't mean it actually solves the issue "getting around without taking forever and wasting resources" well. In the long run, it would be better to reduce commutes. And that's something we can do with some policies, on paper. No need to invent human slingshots or anything.
- Scoundreller 7y agoUniversal basic income and massive carbon taxes to pay for it! It’s about time we tax actual destruction, not a minimum wage earner’s Netflix subscription.
- himinlomax 7y agoBest way to do it I've ever seen is the automated transactions tax, whereby you replace most taxes with a small percentage taken on every financial transaction (plus a larger one when converting to/from cash to account for the black economy). It's progressive because poor people will only pay twice (once on their salary/benefits, once when buying stuff), whereas rich people will pay several times when moving money around.
- Scoundreller 7y agoWhy tax the income side when you could just tax the consumption side?
- pjmorris 7y agoTaxing consumption is regressive; Bill Gates can't eat that many more hamburgers than the average person.
- Scoundreller 7y agoWrite everyone a cheque. Taxing income is quite regressive too: it’s how people with nothing can survive.
- himinlomax 7y agoTaxing income at a few % as this scheme intends is not regressive.
- himinlomax 7y agoFor simplicity's sake. All transactions are taxed equally, no way to evade it by making false or borderline claims about the nature of exchange, and no resource have to be wasted on optimizing or litigating them.
- pjc50 7y agoIf climate casualties become serious, people might start questioning whether allowing people to be rich and be assholes and not contribute to solving the problem is sustainable...
- choeger 7y agoIt also won't collapse because some rich arsehole won't be able to post comments on Hackernews from their smartphone.
- jnsaff2 7y agoHydrogen is denser by weight, but by volume the story is completely different. The tanks need to be large.
- wffurr 7y agoWhat if most of the aircraft was hydrogen tank or bag? Then it could use the hydrogen for some of its lift! We can call it an "airship". Or compress the hydrogen, but then you have 700 PSI handling issues and the tanks have to be very strong.
- AllegedAlec 7y ago> We can call it an "airship". Yeah, let's make a huge one and call it the Hindenburg! That sounds like a foolproof plan.
- WorldMaker 7y agoToo bad that there hasn't been decades of materials science improvements, including and in particular to handling flammable materials, between some highly propagandized disaster and today.~ (Almost every modern cruise ship is bigger than the Titanic, imagine if people acted like the Titanic was the last word on how big a cruise ship could get.)
- JumpCrisscross 7y ago> just use hydrogen At that point, why not package the hydrogen on a carbon chain...oh wait. A lot of these schemes compare poorly against synthetic jet fuel manufactured from atmospheric carbon.
- Hypx 7y agoLikely the issue is cost. We can make liquid H2 pretty cheaply these days. We don't know if synfuel can get close to that price.
- jacobwilliamroy 7y agoI remember Sid Smith saying that we have enough lithium in known reserves to replace every car on earth one time. https://www.youtube.com/watch?v=5WPB2u8EzL8&t=35m29s https://www.youtube.com/watch?v=5WPB2u8EzL8&t=35m29s
- jacobush 7y agoYesterday I learned that Sodium batteries might become a contender to Lithium batteries. And they are safer.
- marcosdumay 7y agoSodium is very clearly a contender for stationary batteries. It may even be competitive for surface mobile applications like cars... But there is just no way it can compete on air transport.
- myself248 7y agoI keep being intrigued by vanadium redox flow batteries, and I've seen some in the real world in stationary applications. And the prospect of instant charging by spit-swapping in a mobile application is pretty wild. How scarce is vanadium, though?
- selectodude 7y agoIt’s like 2 percent by mass of spent iron slag.
- detritus 7y agoNow now, no need to be rude. /
- marcosdumay 7y agoVanadium has an horrible weigh/charge ratio. That's why it's used in stationary applications. Sodium redox flow batteries are all the hype nowadays, because sodium is much cheaper, sulfur for the oxydizer is also very cheap, weight/charge is very high, and volume/charge (important for stationary applications) is also much higher. But I think it's stuck in a patent minefield.
- deleted 7y ago[deleted]
- syllable_studio 7y agoIn the chart from the article I see that capacitors are shown as having high specific power. Would it not work to use a hybrid approach of capacitors for takeoff and then Li-ion for most of the flight? I know it would make the system more complicated and therefore more expensive up front, but I wonder if it's an option or if it's out of the question for one reason or another. I've read that supercapacitors are being used for busses and other applications. https://en.wikipedia.org/wiki/Supercapacitor https://en.wikipedia.org/wiki/Supercapacitor
- fw_double_e 7y agoCapacitors are great for high load requirements but not great as an energy storage device. i.e. if you wanted to draw several hundred amps for a second or two with relatively low heat waste, an ultra-capacitor arrangement would be the way to go, but for energy storage, a battery wins hands down. There's huge research going into expanding the capacity of capacitors. Check out this video about capacitors: https://www.youtube.com/watch?v=EoWMF3VkI6U https://www.youtube.com/watch?v=EoWMF3VkI6U
- code4tee 7y agoThe Achilles heel of electric aviation is that batteries don’t shed weight as they discharge. A fundamental aspect of Aerospace engineering is that rockets/planes shed a lot of weight during flight by by burning fuel. Many big jets take off at weights far too heavy to land and long ranges are only possible because of all the weight shed in flight. Until that issue can be addressed with electric aviation, electric planes will be a concept limited to very short range flying. Rockets solve this problem by dumping the dead weight overboard but not sure a bunch of dead airplane batteries parachuting back to earth is a viable approach.
- repiret 7y agoDon’t conflate rockets and airplanes. Most of the energy an airplane uses is to overcome parasitic drag – to overcome the air resistance caused by moving forward through the air mass. While some of the energy is used to keep the plane in the air, that is not dominant. Yes, planes have a higher maximum takeoff weight then maximum landing weight, but that has to do with the design of the landing gear, in some hypothetical world where jet fuel did not shed weight, planes would only have slightly worse range. The real problem with electric aviation is that batteries have terrible weight to energy ratios compared to fossil fuels.
- bgarrettglaser 7y agoPS -- author here, happy to discuss.