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| Thread ID: 150670 | 2022-05-13 00:46:00 | Electric aircraft in the near future? I don't think so. | Roscoe (6288) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1486209 | 2022-05-13 00:46:00 | I knew that you would find the following interesting - taken from "How The World Really Works" A scientist's guide to our past, present and future, by Vaclav Smil. How soon will we fly intercontinentally on a wide-bodied jet powered by batteries? News headlines assure us that the future of flight is electric - touchingly ignoring the huge gap between the energy density of kerosene burned by turbofans and today's best lithium-ion (Li-ion) batteries that would be aboard these hypothetically electric planes. Turbofan engines powering jetliners burn fuel whose energy density is 46 megajoules per kilogram (that's nearly 12,000 watt-hours per kilogram), converting chemical to thermal and kinetic energy - while today's best Li-ion batteries supply less than 300 Wh/kg, more than a 40 fold difference. Admittedly, electric motors are roughly twice as efficient energy converters as gas turbines and hence the effective energy gap is "only" about 20 fold. But during the past 30 years the maximum energy of batteries has roughly tripled and even if it were to triple that again densities would still be well below 3,000 Wh/kg in 2050 - falling far short of taking a wide-bodied plane from New York to Tokyo or from Paris to Singapore, something we have been doing for decades with kerosene-fueled Boeings and Airbuses. |
Roscoe (6288) | ||
| 1486210 | 2022-05-13 04:47:00 | Yes, they seem to be concentrating on short trip planes. For obvious reasons..... Imagine a flat battery on a large plane while over the ocean and miles to go.... |
piroska (17583) | ||
| 1486211 | 2022-05-13 06:17:00 | And the good news is all these Electric Cars and Trains and Planes will be powered by Electricity produced by Coal. :lol: | B.M. (505) | ||
| 1486212 | 2022-05-13 06:45:00 | even short flights with mid size is out of the question. there is small aircraft, ie 5 people, that can do really short distance. but thats about it. one thing is aircraft safety means they must have enough fuel on board to go to alternate airport or return. that drastically reduces your range. then theres the all important what happens in a crash or a forced landing. its all BS talk to make ev cars look better than they are. |
tweak'e (69) | ||
| 1486213 | 2022-05-13 08:09:00 | Being electric, they would need a very long lead? Ken :) |
kenj (9738) | ||
| 1486214 | 2022-05-13 08:27:00 | Being electric, they would need a very long lead? Ken :) No, they're fueled by a Whim. |
B.M. (505) | ||
| 1486215 | 2022-05-13 08:45:00 | Shouldn't really be a problem, think about it, theres Hybrids in cars where the engine actually charges the battery, the neighbours have two electric, one a Leaf they have to charge nightly, the hybrid never gets charged as its engine can charge when its moving, so shouldn't be that hard to have a Airplane generate the forward motion and the few hundred km of wind into a generator that recharges the batteries. | wainuitech (129) | ||
| 1486216 | 2022-05-13 09:22:00 | Aah, perpetual motion? Have you cracked it? :) Ken |
kenj (9738) | ||
| 1486217 | 2022-05-13 09:43:00 | Shouldn't really be a problem, think about it, theres Hybrids in cars where the engine actually charges the battery, the neighbours have two electric, one a Leaf they have to charge nightly, the hybrid never gets charged as its engine can charge when its moving, so shouldn't be that hard to have a Airplane generate the forward motion and the few hundred km of wind into a generator that recharges the batteries. :crying: :crying: |
B.M. (505) | ||
| 1486218 | 2022-05-13 10:31:00 | Aah, perpetual motion? Have you cracked it? :) Ken Exactly, some bright engineer can design something, they have a similar but smaller device now on all planes called a Ram Air Turbine, that if the plane loses all engine power it drops down into the airflow and generates power the RAT will power vital systems (flight controls, linked hydraulics and also flight-critical instrumentation So shouldn't be that hard to design a wind powered charger. ( prob not to good for a helicopter if its hovering ) :D If the battery is self charging in theory it could stay up indefinitely. |
wainuitech (129) | ||
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