Quote:
Originally Posted by Odin
I'm pretty sure that chart is taking the energy of a lithium ion battery its self, not one fully charged with electricity.
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Not sure why you think that. Can you offer any supporting evidence?
per:
Lithium-ion battery - Wikipedia, the free encyclopedia
Volumetric energy density: 250 to 620 W·h/l (900 to 1900 J/cm³)[2]
1000 cm³ = 1L
~2MJ/L energy density for lithium batteries, which is about what was plotted, compared to ~37MJ/L for diesel.
Quote:
Originally Posted by robchalmers
...with electric there would be little differential between take-off and landing weight..
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That is another disadvantage of electric plains, the batteries still weigh a ton when they are depleted, whereas your fuel tanks do not. Dead weight on a plane translates into inefficiencies, you have to create more lift, which doesn't come for free.
Quote:
Originally Posted by robchalmers
...just think of the turn around time if it was a cell exchange at each air port rather than a charge!
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Great, just make sure the airports are spaced 10 miles apart so you can make it to the next one
Quote:
Originally Posted by skyl4rk
electric power has taken over in the remote control airplane hobby
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Indeed, such toys, that have no need for payload that run for maybe 10 minutes (well I usually catch a thermal or two also), do not need to be uber efficient. There are still a lot of fuelies left when the pilot is serious about performance.
As an aside, excellent performance can be had with NO motor too (and extra weights are usually needed), though around here I just bungee launch: