Originally Posted by msbbarratt
(Post 10285995)
A lot of these downsides go away or become irrelevant if you consider the electricity to be free (solar, wind, etc). One way or another we seem to be heading kinda in that direction, but it's a long way from free still.
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Originally Posted by krismiler
(Post 10286296)
Possibly some energy could be returned to the batteries by windmilling propellors on the descent in the same way electric vehicles can recharge their batteries by using the motor as a brake.
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Originally Posted by Chris Scott
(Post 10286268)
Yes. Unless they employed very clever technology, the props on the electric one would be nearly as noisy.
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Originally Posted by DaveReidUK
(Post 10286291)
One way around that would be a quick-change battery module so that they don't have to be recharged in situ.
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Originally Posted by Gargleblaster
(Post 10286302)
Regarding this type, this is one of the funniest posts I've read in here: https://www.pprune.org/tech-log/4363...ml#post6118466
I'll never forget that flight. It was spectacular. |
I wonder if this could be for the isles of Scilly route?
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Originally Posted by rog747
(Post 10286465)
I wonder if this could be for the isles of Scilly route?
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Originally Posted by DaveReidUK
(Post 10286469)
See first post: Orkney islands could get first electric plane service
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Originally Posted by krismiler
(Post 10286296)
Possibly some energy could be returned to the batteries by windmilling propellors on the descent in the same way electric vehicles can recharge their batteries by using the motor as a brake.
Electric cars can recharge to around 80% very quickly, it's the last few percent which takes time to trickle in. A car driver that approaches a red traffic light at 50 mph and then brakes to stop the car is wasting the kinetic energy that is in the car - he should have started coasting early enough to come to a stop right at the traffic light without any braking. Because this method is impractical in normal traffic, hey, an electric car can use the motor as a generator to convert the kinetic energy back to stored electric power in the battery. An airplane that descends from cruise level to landing does use the coast technique already, the engines are already just idling, it cannot be done more efficiently. If you want to “brake” by using the propellor to drive the e-motor as a generator, your aircraft will have more drag, thus descend more steeply than the idle glide path. You will have to expend (=waste) energy either before starting descent, by staying level longer, or by flying level at the bottom of the descent. There is no such thing as a free lunch! |
Originally Posted by WHBM
(Post 10286335)
There was such an experimental road vehicle some years ago, an electric (normal) bus which towed a trailer with the batteries in it, which was swapped every couple of hours for another when the vehicle passed the charging base. Like most other such initiatives, it seems not to have worked out.
If that's really true, this is going to be close to the peak performance theoretically achievable with lithium ion chemistries. It still won't be as good as petrol in energy per kg or volume, but the nicer characteristics will make them far more useable. No need to swap out the battery, just fill it like you would any other fuel tank. |
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Originally Posted by stalling attitude
(Post 10286568)
I think the Orkneys are quite close together. Could just use a long mains extension lead from Kirkwall instead of mucking about recharging batteries
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Originally Posted by msbbarratt
(Post 10285995)
A lot of these downsides go away or become irrelevant if you consider the electricity to be free (solar, wind, etc). One way or another we seem to be heading kinda in that direction, but it's a long way from free still.
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They were talking about 5 minutes charge times for cars |
why not use a boat?
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Originally Posted by WHBM
(Post 10286686)
Oil is just there under the ground, it is as "free" as solar or wind. People have managed to take "ownership" of it and charge for it, but that is an artificial concept, Costs for capital plant and operating costs for extracting, processing and distributing to point of use apply to all forms.
Best of luck to the Electric Islander PR stunt crew. Remember, anything is possible if you throw enough cash at it...... |
The propeller tips of an Islander sit only a few inches from the ears of the pilot and front seat passenger, where as most light twins are low wing and the few feet of difference in engine position has a huge effect on interior noise levels. Can anyone comment on the noise of the turbine version ? |
I wonder what the flight planning is for fuel Lands End to St Mary's?
We know the weather can be and/or go dodgy at both ends - If they cannot get in at St Mary's do they plan for returning to Land Ends, plus a hold then diversion fuel to say NQY if Lands End goes out? Probably would stretch an electric BN islander - but a most interesting concept |
Originally Posted by lbhsbz
(Post 10286695)
why not use a boat?
I've done Kirkwall to Westray by boat, for example, a commercial service, weaving in and out of tiny little rocky islands - it takes about 90 minutes, and I'm guessing (I'm no sailor) that regularly there are surface conditions that make that very ill advised. The total distance is about 20nm! So even in an Islander, under 10 minutes - and whilst clearly some conditions, such as heavy fog would be as problematic as for a ship, many other conditions would be fine for the aeroplane but not the boat. The air ferry around those two groups of islands is most definitely essential to maintaining a decent quality of life for the people who live there. G |
One way around that would be a quick-change battery module so that they don't have to be recharged in situ. |
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