91–100 of 165 posts
I am really quite confident that no serious development of electric passenger aircraft will take place during the coming decade. And it is not a question of feasibility, but rather of priorities. There is so much low hanging fruit to be collected! By the end of the decade, if all goes well, we will be in the middle of replacing petroleum fuelled cars and busses with electric ones, and maybe turning our attention to o…
>Wright Electric said by removing the need for jet fuel, the price of travel could drop dramatically.
Note to self: Bring back Zeppelin travel.
I'm not at the forefront of this field so maybe I missed some great advances in battery technology or airplane efficiency, but how could this possible work when the energy density of a battery (.3-.9 MJ/kg) is 50x less than that of jet fuel (46 MJ/kg)[1]? Or is that simply enough for (very) short haul flights? [1]: https://en.wikipedia.org/wiki/Energy_density
FTA: "The company is relying heavily on innovation in battery technology continuing to improve at its current rate. If not, the firm will not be able to build in enough power to give the plane the range it needs." So, it presumably can't work now but they're putting their money on the idea that it will in the near future.
Currently the shortest LGW-CDG flight is 1h. There is LCY-CDG lasting 1h 20m. For both cities it takes 30 - 60m to get to the airport from central location and you should be there at least 1h before the departure (for a total of 2-3h non-flight time). This makes total travel 3h - 4h30m. For comparison, the fastest train is 2h 25m. I guess you need to travel to and from the train station too, but it's definitely more…
When you take the Eurostar, you have to go through border controls, so you have to been there 30 minutes or 1 hour earlier. (Probably because London is not in the Schengen area)
Currently the shortest LGW-CDG flight is 1h. There is LCY-CDG lasting 1h 20m. For both cities it takes 30 - 60m to get to the airport from central location and you should be there at least 1h before the departure (for a total of 2-3h non-flight time). This makes total travel 3h - 4h30m. For comparison, the fastest train is 2h 25m. I guess you need to travel to and from the train station too, but it's definitely more…
I presume you meant CDG for Paris Charles de Gaulle. CHG is Chaoyang, China ;)
Currently the shortest LGW-CDG flight is 1h. There is LCY-CDG lasting 1h 20m. For both cities it takes 30 - 60m to get to the airport from central location and you should be there at least 1h before the departure (for a total of 2-3h non-flight time). This makes total travel 3h - 4h30m. For comparison, the fastest train is 2h 25m. I guess you need to travel to and from the train station too, but it's definitely more…
What you're saying. The only reason to take a plane vs taking a train for this distance is the price. Usually planes are way cheaper. But the hassle of taking a plane is really making it a tough sell as you say.
Currently the shortest LGW-CDG flight is 1h. There is LCY-CDG lasting 1h 20m. For both cities it takes 30 - 60m to get to the airport from central location and you should be there at least 1h before the departure (for a total of 2-3h non-flight time). This makes total travel 3h - 4h30m. For comparison, the fastest train is 2h 25m. I guess you need to travel to and from the train station too, but it's definitely more…
Earlier quoted context omitted.
Maybe we should think outside of the box. What if, aircraft doesn't need to store all of the required energy on-board? E.g. transmit energy wirelessly through microwave and just have enough fuel for emergencies.
Planes I've been on regularly fly above the clouds, I wonder how much energy could be generated by covering the entire top of the aircraft with solar panels? I don't work in this field so as far as I know it could be a drop in the ocean. Clearly only possible during the day though.
But for the sake of fun - For a Bombardier Q400(that was the only reliable data I could find)[0], the total surface area is ~213 square meters. That's obviously total surface area, so it includes both the top and bottom of the airplane. For simplicity sake, let's say only half is in full view of the sun - so 107 square meters.
Even if we assume magical solar panels that can actually convert 100% of the energy into electricity, and assume that the plane is flying in full daylight, that's only ~100kW.
The aircraft uses two PW100 engines, each producing....3700kW, so the total output of the aircraft is around 7400kW.
So even if the conditions were ideal, we had magical solar panels, and covered every inch of the aircraft, they would produce....less than 1% of power necessary to fly it. To be fair, a normal 2.0L petrol engine produces more power than what those solar panels would produce.
In reality, those panels could maybe power the onboard lights and computers? Just about?
[0]http://www.supersonicinstitute.org/docs/Q400SurfaceAreaRepor...
I am really quite confident that no serious development of electric passenger aircraft will take place during the coming decade. And it is not a question of feasibility, but rather of priorities. There is so much low hanging fruit to be collected! By the end of the decade, if all goes well, we will be in the middle of replacing petroleum fuelled cars and busses with electric ones, and maybe turning our attention to o…
Earlier quoted context omitted.
The equation isn't just energy density; it's also the efficiency of harnessing that energy. Good electric motors are way more efficient than a turbofan.
Electric motors would need to be orders of magnitude more efficient than turbofans (which they aren't). You also need to compare the overall efficiency developed as thrust, not just thermal efficiency. There's also the issue of the mass of batteries not going away during the flight, unlike fuel, which will require maximum landing weight to equal maximum takeoff weight - this will impose a structural penalty versus IC…
One can imagine an electric aircraft relying on powered landing gear (as previously trialled by Airbus/Lufthansa Technik) which would further improve efficiency during taxiing.