So, you can't have an electric airplane?

[mooncliff]

This relates to the liquid fuel argument that we MUST have liquid fuels forever because nothing can take its place. Maybe. The flood of electric cars from at least 65 manufacturers over the next 5 years will be shocking.

...it should be able to fly at 200 mph with a 12,000 foot ceiling, with a range of 450 miles. But like with every X-Plane, the aircraft is just a vehicle for new technology: NASA’s real goal is helping the aviation industry eventually go electric.

http://www.wired.com/2015/03/nasa-st...-wing-science/

[thriftyandboringinohio]

Re: So, you can't have an electric airplane?

Here's your trouble.
This is energy content per unit mass, here in MJ per kg.





Since the source is a light-hearted pop science website, I did check the values for both lithium ion batteries and gasoline to be sure the chart is correct.
Seems to be.

There is a two order-of-magnitude difference between batteries and liquid fuel.
Jet fuel (kerosene)and gasoline are used in aircraft.
It takes a hundred kilograms of lithium ion batteries to deliver the energy of a single kilogram of kerosene.

That's just the fuel (or battery) itself. You need to look at the full vehicle, including the motor and accessories
Electric motors don't compare well to internal combustion engines on a power density basis either, in kW per kg.
An electric aircraft will have super heavy fuel; rather weak motors; and a pile of heavy power system equipment and accessories.

I can easily imagine ultra-light, low speed solar electric aircraft doing a great job as long dwell time platforms for communications and data.
Big, flimsy gossamer things turning slow circles at high altitude for weeks on end, handling signals.

I cannot, though, imagine a practical rugged aircraft running on batteries that has a good useful payload capable of operating in marginal weather.
Notice that for its concept plane NASA mentions good speed, good range, and good altitude, but does not say a single word about useful payload.
I doubt that is an accidental oversight.

[LorenS]

Re: So, you can't have an electric airplane?

I cannot, though, imagine a practical rugged aircraft running on batteries that has a good useful payload capable of operating in marginal weather.
Notice that for its concept plane NASA mentions good speed, good range, and good altitude, but does not say a single word about useful payload.
I doubt that is an accidental oversight.

How about this? http://en.wikipedia.org/wiki/Airship