3 ms·

The A380 and 747 are both remarkable aircraft, but I love my direct flights to all major cities within 1000 miles, and many beyond that. Electric airliners are

by bdamm 8y ago

The A380 and 747 are both remarkable aircraft, but I love my direct flights to all major cities within 1000 miles, and many beyond that. Electric airliners are likely to bring this ratio into even more profound focus, offering direct flights to thousands of smaller cities you didn't know you wanted to go to, until it takes 30 minutes to fly instead of 3 hours to drive. And with so many airports linking up mass transit, the air travel network is almost an extension of public transit. If you're like me and fly with TSA-Pre, showing up at the airport 10 minutes ahead of gate call can become a regular and reliable thing. Good times ahead! For those of you in the Bay Area, this is like having a cheap ticket to fly to South Lake Tahoe, or commuting from Santa Rosa to San Jose. Operators like Surf Air might become commonplace. And the A380 and 747 had to die as airliners came to realize this is the future.

0xffff2 8y ago
>Electric airliners are likely to bring this ratio into even more profound focus, offering direct flights to thousands of smaller cities you didn't know you wanted to go to (All) electric airliners are unlikely to exist commercially without a fundamental breakthrough in energy storage technology. Even hybrid-electric systems are only barely viable as a research area right now, and they are decades away from commercial production. I'm a researcher in this field, and I wish I could say otherwise, but the rosy picture you paint is unlikely to be reality at least within the next 3-4 decades.
- radicalbyte 8y ago
  Are artificial fuels (i.e. hydrogen or something we can make from hydrogen) going to be viable for flying within a reasonable timeframe? Whilst I expect that short-haul flights will be replaced by high-speed trains we're still going to need planes for intercontinental travel. EasyJet are hoping to have electric planes covering the London-Amsterdam route in 2030: https://www.express.co.uk/travel/articles/1039041/flights-easyjet-electric-plane-london-amsterdam-2030 https://www.express.co.uk/travel/articles/1039041/flights-ea....
  - ars 8y ago
    > Are artificial fuels (i.e. hydrogen or something we can make from hydrogen) There is no difference between a synthesized fuel and one pumped from the group - it's the same molecules. What matters is your energy source to make the synthesized fuel. In any case hydrogen is a particularly bad fuel for airplanes. The best fuel is actually the one we already use.
    - radicalbyte 8y ago
      By artificial fuels I mean ones created by us using renewable energy. If we can create something similar to current fuels from a renewable source then that would be fantastic.
  - 0xffff2 8y ago
    I believe that hydrogen is being looked at a bit, but it presents some significant safety concerns since it needs to be compressed pretty substantially to get good energy densities. It's my general impression that the safety concerns outweigh the usefulness for the time being. Right now, my organization is focused on a number of hybrid electrical approaches with the main goal being to minimize losses by using the descent phase to charge batteries that are then used to assist in climb on the next flight. I haven't heard about the EasyJet proposal before. I'm looking for more info, but I can't find enough to form an intelligent opinion yet. Interestingly enough, it seems to be a YC backed company that's developing the vehicle.
  - bdamm 8y ago
    High speed trains are unlikely to replace short hop air transport in America. The fact is that rights of way don't exist, and land acquisition is enormously expensive. Freight dominates the railways.
- FabHK 8y ago
  Yes. I think a lot of people envisage performance improvements like in semiconductors, doubling every 2 years or so. In reality, battery tech seems to be improving at maybe 5% or so annually, doubling every 15 years, or so (please correct me if I’m wrong, I don’t work in the field). Given the specific energy of kerosene vs batteries, at least two doublings seem necessary for things to get commercially viable. So, 3+ decades seems reasonable, lamentably.
  - 0xffff2 8y ago
    Kerosene also benefits from the fact that it is consumed over the course of the flight, so that an airplane gets lighter and therefore less fuel-intensive as it flies. The weight of enough batteries for a fully electric narrow-body airliner is punishing when you consider that you have to carry that weight around all the time instead of it steadily decreasing from takeoff onward. I haven't run the numbers, but off the cuff I'd estimate that you need at least one more doubling of energy density to account for the higher average weight of the aircraft in flight. Now you have to hope you can maintain sustained consistent improvements for half a century just to get into the realm where battery energy densities start to make sense for a fully electric airliner with the same capabilities as our fully hydrocarbon based airliners of today. And of course it's not anywhere near as simple as swapping the engines on existing air frames, so if you want to have your electric airplane the day that the batteries exist, you need to make a pretty sizeable bet today by investing in the groundwork for all of the other systems.

by bdamm 8y ago

0xffff2 8y ago

>Electric airliners are likely to bring this ratio into even more profound focus, offering direct flights to thousands of smaller cities you didn't know you wanted to go to (All) electric airliners are unlikely to exist commercially without a fundamental breakthrough in energy storage technology. Even hybrid-electric systems are only barely viable as a research area right now, and they are decades away from commercial production. I'm a researcher in this field, and I wish I could say otherwise, but the rosy picture you paint is unlikely to be reality at least within the next 3-4 decades.

radicalbyte 8y ago
Are artificial fuels (i.e. hydrogen or something we can make from hydrogen) going to be viable for flying within a reasonable timeframe? Whilst I expect that short-haul flights will be replaced by high-speed trains we're still going to need planes for intercontinental travel. EasyJet are hoping to have electric planes covering the London-Amsterdam route in 2030: https://www.express.co.uk/travel/articles/1039041/flights-easyjet-electric-plane-london-amsterdam-2030 https://www.express.co.uk/travel/articles/1039041/flights-ea....
- ars 8y ago
  > Are artificial fuels (i.e. hydrogen or something we can make from hydrogen) There is no difference between a synthesized fuel and one pumped from the group - it's the same molecules. What matters is your energy source to make the synthesized fuel. In any case hydrogen is a particularly bad fuel for airplanes. The best fuel is actually the one we already use.
  - radicalbyte 8y ago
    By artificial fuels I mean ones created by us using renewable energy. If we can create something similar to current fuels from a renewable source then that would be fantastic.
- 0xffff2 8y ago
  I believe that hydrogen is being looked at a bit, but it presents some significant safety concerns since it needs to be compressed pretty substantially to get good energy densities. It's my general impression that the safety concerns outweigh the usefulness for the time being. Right now, my organization is focused on a number of hybrid electrical approaches with the main goal being to minimize losses by using the descent phase to charge batteries that are then used to assist in climb on the next flight. I haven't heard about the EasyJet proposal before. I'm looking for more info, but I can't find enough to form an intelligent opinion yet. Interestingly enough, it seems to be a YC backed company that's developing the vehicle.
- bdamm 8y ago
  High speed trains are unlikely to replace short hop air transport in America. The fact is that rights of way don't exist, and land acquisition is enormously expensive. Freight dominates the railways.
FabHK 8y ago
Yes. I think a lot of people envisage performance improvements like in semiconductors, doubling every 2 years or so. In reality, battery tech seems to be improving at maybe 5% or so annually, doubling every 15 years, or so (please correct me if I’m wrong, I don’t work in the field). Given the specific energy of kerosene vs batteries, at least two doublings seem necessary for things to get commercially viable. So, 3+ decades seems reasonable, lamentably.
- 0xffff2 8y ago
  Kerosene also benefits from the fact that it is consumed over the course of the flight, so that an airplane gets lighter and therefore less fuel-intensive as it flies. The weight of enough batteries for a fully electric narrow-body airliner is punishing when you consider that you have to carry that weight around all the time instead of it steadily decreasing from takeoff onward. I haven't run the numbers, but off the cuff I'd estimate that you need at least one more doubling of energy density to account for the higher average weight of the aircraft in flight. Now you have to hope you can maintain sustained consistent improvements for half a century just to get into the realm where battery energy densities start to make sense for a fully electric airliner with the same capabilities as our fully hydrocarbon based airliners of today. And of course it's not anywhere near as simple as swapping the engines on existing air frames, so if you want to have your electric airplane the day that the batteries exist, you need to make a pretty sizeable bet today by investing in the groundwork for all of the other systems.