Ask Slashdot: What Stands In the Way of a Truly Solar-Powered Airliner?

centre21 writes "I've been reading about solar-powered aircraft all over the Internet, as well as solar power in general. But I'm wondering: is it more than just solar cell efficiency that's preventing the creation of a solar-powered airliner? Conspiracy views aside (which may be valid), it seems to me that if I were running an airline the size of United or American, eliminating the need for jet fuel as a cost would be highly appealing. So, I'm asking: what stands in the way of creating true solar-powered airliners?"

Comments

Let's go retro...

[Flounder]

I always thought that heavy-lifting solar-powered airships would make excellent replacements for long-haul trucks.

Re:Let's go retro...

[gman003]

Let's bring some numbers into this.

According to this page, I can get a cargo container from Shanghai to San Francisco in 18-30 days. That's a distance of roughly 10,000km,

The Hindenburg could reach air speeds of 135km/h. While modern airships could doubtless reach higher speeds, we're also running off solar power here. So let's just run with that 135km/h figure. That gives us about three days to cross the same distance.

For further comparison, a Boeing 747 can make the trip in roughly 11 hours.

So we're beating the container ship by a factor of 6-10, but the jet is beating us by a factor of 6. So we just have to have a price halfway between the two. Unfortunately, that's hard to figure out, because the container ship charges by volume, while the aircraft rates I can find charge by weight. Ultimately, though, it's a moot point, as any figure I can come up with for the costs of running a solar-powered airship will cite work by a certain Dr. M. Y. Ass.

But hey, it might be a good niche to fit into. Faster and safer* than a container ship, but slower than a jet. Someone might be able to find a good use for that.

* Assuming, of course, no Sky Pirates are encountered. Then all bets are off.

Re:Size.

[K. S. Kyosuke]

You use the energy to synthesize liquid hydrocarbons with high energy density, then you pour them into the airplane...and you have a solar-powered airplane! Come to think of it, all airplanes are solar-powered these days, only the sunlight is of a vintage brand.

Re:The math doesn't work

[faedle]

Technically, the "MPG" per passenger mile is lowest on an airplane. A fully loaded Boeing 747-400 gets the equivalent of 91 miles per gallon.

Short Answer

[CanHasDIY]

what stands in the way of creating true solar-powered airliners?

Nothing.

Oh, you meant airplanes? Yea, sorry, can't help you there.

Re:Solar powered jet engine

[Anonymous Coward]

Something like a hydrogen plant on the ground that produces liquified hydrogen which is then used for fuel.

The on-the-ground solar power collection mechanism that's currently most workable is algae. We've already had 747s fly on fuel produced from algae and algae are much more efficient than solar panels at harvesting energy from the sun. From what I've read, the only reason algae-based fuel isn't used commercially today is cost.

Re:Uh, surface area?

[dublin]

Please get into the habit of using metric. Pretty please? we look like the scientific laughing stock.

Sorry, the Metric system is not magic pixie dust imparting scienceyness.

I'd argue that the *real* work of making technology work is done more in US than Metric units: Both the Aerospace industry (which *is* on-topic here) and the Energy industry (especially Oil & Gas, upstream and downstream) use predominantly US units worldwide (with the exception of those weirdos at Airbus...)

Metric is not better, or really, even particularly easier, unless you're just incompetently innumerate to start with.

Oh, and by the way, I work in solar and used to work in commercial aircraft manufacturing, and the suggestion of horse-drawn airplanes in a thread above makes more sense than solar-powered airplanes. The very idea shows a stunning ignorance of basic physics.

P.S.: I do contract product design and development work and refuse to work with shops (even overseas) that can or will not design/produce geometry or parts in US units. This one filter weeds out 90%+ of the unqualified low-quality vendors, so it's quite useful.

P.P.S.: The *correct* length unit is the "Dublin", which is between a yard and a meter, so that the acceleration due to gravity is an even 10 Dublins/s^2, making life ever so much easier for physics and engineering students the world over. ;-) (Yeah, it's "Earthist" - I call home planet prerogative - get over it...)