8 ms·

Yep. Also... kerosene gets spent. Pilots can also dump fuel in emergency when it's too heavy to land. Battery powered planes can't dump electricity, so I'd i

by pcurve 4y ago

Yep. Also... kerosene gets spent. Pilots can also dump fuel in emergency when it's too heavy to land. Battery powered planes can't dump electricity, so I'd imagine some trade offs that have to be made.

thriftwy 4y ago
Electric engines may be much more reliable than kerosene engines.
- Toutouxc 4y ago
  This is more about day to day operations than emergencies. For an electric plane, your MTOW (max takeoff weight) is equal to your MLW (max landing weight). An ICE plane can take off with "bonus" fuel that it can't land with for structural reasons, while an electric plane can't.
- pcurve 4y ago
  I would hope so, considering this is what it looks like inside. https://en.wikipedia.org/wiki/Rolls-Royce_Trent_1000#/media/File:Trent_1000_GoodwinHall_VirginiaTech.jpg https://en.wikipedia.org/wiki/Rolls-Royce_Trent_1000#/media/... But. Turbine engine is actually very reliable and doesn't need overhaul for 20,000 flight hours.
  - thriftwy 4y ago
    The problem here is single-engine planes losing engine on takeoff. Would be almost non-issue with electrics.
jansan 4y ago
That is a very good and often overlooked point. So in average on a flight one has to calculate maybe with 60% weight of kerosene, while the battery keeps 100% of its weight during the entire flight.
- tjmc 4y ago
  It gets worse with lithium air batteries that actually gain weight as they discharge because of the formation of solid oxides from the air. Argonne are reporting 1200Wh/kg in the lab though so still worth it.
mcapodici 4y ago
Dumping batteries might be a thing? After all it is an emergency!
- amelius 4y ago
  With parachutes, and you can reuse them. You can also do this on regular flights just to save weight. It's SpaceX style reusability but on a commercial aviation scale.
imiric 4y ago
Electric planes could recharge using solar or wind. As efficiency increases with these technologies, it would mean planes wouldn't require carrying the same watt-for-watt energy as fuel.
- baq 4y ago
  Recharging a small plane with solar power would either take ages or hectares. Pick your poison. Recharging multiple airliners will take a nuclear reactor at the airport.
  - Toutouxc 4y ago
    Why does it have to be poison? Wouldn't having an airport nearby be a blessing for anyone with solar panels on their roof? Just like an industrial zone, it'd be a nonstop load ready to buy from anyone, anytime. (Yes I understand the infrastructure would need to change a lot.)
  - dx034 4y ago
    Recharging would take a lot of energy but it's not unthinkable to have 1-3 GW supplied to an airport (which is what a reactor would likely supply), large metropolitan areas and large industrial factories already get to similar amounts. It's a couple of transmission lines and most large airports are close to population centers anyway. The challenge would be getting the right amount at the right time, like now with quick charging. Like there, you'd probably have buffer storage at the airport so that it consumes electricity when available (e.g. during the day from solar) and dispenses it to aircrafts when needed. Luckily, most airports in the world have nearly all take offs and landings during the day, so there's a big overlap. Dubai would be an example where likely all would come from solar but a lot is needed over night (if we ever get electric long-haul flights). So overall I don't think that this would be the limiting factor. But I guess larger airliners are more likely to run on synthetic fuels than electricity for a long time. And I guess that's fine, we have a lot of areas where cheap and/or dense batteries can help us much more in the short term (grid storage, cars, trucks).
    - 4y ago
anticensor 3y ago
There is no such thing as "too heavy to land". There is such a thing as "too heavy to soft land without breaking the landing gear" though.

by pcurve 4y ago

thriftwy 4y ago

Electric engines may be much more reliable than kerosene engines.

Toutouxc 4y ago
This is more about day to day operations than emergencies. For an electric plane, your MTOW (max takeoff weight) is equal to your MLW (max landing weight). An ICE plane can take off with "bonus" fuel that it can't land with for structural reasons, while an electric plane can't.
pcurve 4y ago
I would hope so, considering this is what it looks like inside. https://en.wikipedia.org/wiki/Rolls-Royce_Trent_1000#/media/File:Trent_1000_GoodwinHall_VirginiaTech.jpg https://en.wikipedia.org/wiki/Rolls-Royce_Trent_1000#/media/... But. Turbine engine is actually very reliable and doesn't need overhaul for 20,000 flight hours.
- thriftwy 4y ago
  The problem here is single-engine planes losing engine on takeoff. Would be almost non-issue with electrics.

jansan 4y ago

That is a very good and often overlooked point. So in average on a flight one has to calculate maybe with 60% weight of kerosene, while the battery keeps 100% of its weight during the entire flight.

tjmc 4y ago
It gets worse with lithium air batteries that actually gain weight as they discharge because of the formation of solid oxides from the air. Argonne are reporting 1200Wh/kg in the lab though so still worth it.

mcapodici 4y ago

Dumping batteries might be a thing? After all it is an emergency!

amelius 4y ago
With parachutes, and you can reuse them. You can also do this on regular flights just to save weight. It's SpaceX style reusability but on a commercial aviation scale.

imiric 4y ago

Electric planes could recharge using solar or wind. As efficiency increases with these technologies, it would mean planes wouldn't require carrying the same watt-for-watt energy as fuel.

baq 4y ago
Recharging a small plane with solar power would either take ages or hectares. Pick your poison. Recharging multiple airliners will take a nuclear reactor at the airport.
- Toutouxc 4y ago
  Why does it have to be poison? Wouldn't having an airport nearby be a blessing for anyone with solar panels on their roof? Just like an industrial zone, it'd be a nonstop load ready to buy from anyone, anytime. (Yes I understand the infrastructure would need to change a lot.)
- dx034 4y ago
  Recharging would take a lot of energy but it's not unthinkable to have 1-3 GW supplied to an airport (which is what a reactor would likely supply), large metropolitan areas and large industrial factories already get to similar amounts. It's a couple of transmission lines and most large airports are close to population centers anyway. The challenge would be getting the right amount at the right time, like now with quick charging. Like there, you'd probably have buffer storage at the airport so that it consumes electricity when available (e.g. during the day from solar) and dispenses it to aircrafts when needed. Luckily, most airports in the world have nearly all take offs and landings during the day, so there's a big overlap. Dubai would be an example where likely all would come from solar but a lot is needed over night (if we ever get electric long-haul flights). So overall I don't think that this would be the limiting factor. But I guess larger airliners are more likely to run on synthetic fuels than electricity for a long time. And I guess that's fine, we have a lot of areas where cheap and/or dense batteries can help us much more in the short term (grid storage, cars, trucks).
  - 4y ago

anticensor 3y ago

There is no such thing as "too heavy to land". There is such a thing as "too heavy to soft land without breaking the landing gear" though.