Live data from Hacker News

Electrifying flight: very different aircraft may end up taking to the sky

economist.com

41–50 of 55 posts

Re: Electrifying flight: very different aircraft may end up taking to the sky

#41
post #35

The real breakthrough in electric aviation will come when it is combined with beamed energy. Rather than storing power onboard the vehicle, you have ground-based stations which power the vehicles with tracking microwave tightbeams. That way, you only need enough onboard battery power to take off, land, and bypass one broken ground station -- maybe 15-20 minutes of total flight time. This would allow electric aircraft…

What about the beams killing birds? Maybe have three beams that don't converge until the plane?

Forget the birds, lets not microwave the atmosphere.

Re: Electrifying flight: very different aircraft may end up taking to the sky

#42
post #2

I would be curious whether electric planes significantly reduce the carbon footprint of flying. My intuition is that you wouldn't be dumping CO2 and H2O (both fairly potent greenhouse gases) directly into the upper atmosphere, so it would be a huge win, but I am neither a climate scientist nor an aerospace engineer, so maybe I'm missing something.

Water is a greenhouse gas?

Re: Electrifying flight: very different aircraft may end up taking to the sky

#43
post #35

The real breakthrough in electric aviation will come when it is combined with beamed energy. Rather than storing power onboard the vehicle, you have ground-based stations which power the vehicles with tracking microwave tightbeams. That way, you only need enough onboard battery power to take off, land, and bypass one broken ground station -- maybe 15-20 minutes of total flight time. This would allow electric aircraft…

So if the beam is cut off, the plane falls out of the sky?

Re: Electrifying flight: very different aircraft may end up taking to the sky

#44
post #35

The real breakthrough in electric aviation will come when it is combined with beamed energy. Rather than storing power onboard the vehicle, you have ground-based stations which power the vehicles with tracking microwave tightbeams. That way, you only need enough onboard battery power to take off, land, and bypass one broken ground station -- maybe 15-20 minutes of total flight time. This would allow electric aircraft…

So if the beam is cut off, the plane falls out of the sky?

Reread the comment, it addresses that issue.

Re: Electrifying flight: very different aircraft may end up taking to the sky

#45
post #41

Earlier quoted context omitted.

What about the beams killing birds? Maybe have three beams that don't converge until the plane?

Forget the birds, lets not microwave the atmosphere.

If you think about it (or run the numbers), you'll realise that our present system of jet engines actually dumps far more heat into the atmosphere than this would.

Re: Electrifying flight: very different aircraft may end up taking to the sky

#46
post #2

I would be curious whether electric planes significantly reduce the carbon footprint of flying. My intuition is that you wouldn't be dumping CO2 and H2O (both fairly potent greenhouse gases) directly into the upper atmosphere, so it would be a huge win, but I am neither a climate scientist nor an aerospace engineer, so maybe I'm missing something.

Water is a greenhouse gas?

Yep: https://www.ncdc.noaa.gov/monitoring-references/faq/greenhou...

Re: Electrifying flight: very different aircraft may end up taking to the sky

#49

The batteries have also another problem not mentioned in the article - you have to carry their weight for the entire duration of the flight, while with regular fuel you burn it up during the flight, making the aircraft lighter and more efficient. Not to mention, that many aircraft can't land with their tanks full - but electric aircraft will have to be able to land with the same weight they took off with.

I don't think that's an issue, especially with the projected use cases. The article says that they're aiming for battery storage of about an hour of flight time, which is plenty for takeoff, final approach, and other situations where you'd want a lot of power in a hurry. Most of the flight, unless it is a very short commuter-type flight where you can conceivably charge with shore power between flights, is going to be running much like a hybrid car, with the jet engine powering a generator working at the best point on its performance/economy curve. So it'll still use fuel, and still get lighter as the trip goes on. Also, those batteries mean you don't need a set of engines that need to handle the power needed at take off, so those can be lighter as well. So I imagine that a 1:1 replacement capacity-wise would probably have at worse the same empty weight, taking into consideration the lighter engines and the smaller fuel tank that would be needed.

Re: Electrifying flight: very different aircraft may end up taking to the sky

#50
post #35

The real breakthrough in electric aviation will come when it is combined with beamed energy. Rather than storing power onboard the vehicle, you have ground-based stations which power the vehicles with tracking microwave tightbeams. That way, you only need enough onboard battery power to take off, land, and bypass one broken ground station -- maybe 15-20 minutes of total flight time. This would allow electric aircraft…

What about the beams killing birds? Maybe have three beams that don't converge until the plane?

With the power you'd need for such a system, three beams would almost certainly mean three times the dead birds.
Post reply on HN