

Solar-powered plane makes 26-hour flight - transmit101
http://news.bbc.co.uk/1/hi/world/europe/10550430.stm

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vollmond
This is exciting news, scientifically. I'm curious what practical applications
there are. I can think of a few, but I'm sure it's not exhaustive

• Cheap, quick-to-setup communications relay (mobile cell tower with its own
satellite uplink to reduce costs of on-the-ground devices?)

• Non-military surveillance (I assume it would be easy prey for anti-aircraft
weaponry, but would probably be quite useful for constant surveying of
disaster sites, for example)

• Small datacenter that is easy to keep out of any nation's jurisdiction (a
few large hard drives and another satellite uplink, and just keep it circling
over the Atlantic)

• Long-term airborne advertising (is it powerful enough to tow an old-school
banner?)

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ars
> I'm curious what practical applications there are

None. It's totally pointless actually.

Very cool, but pointless.

All those solar cells and batteries cost more than just fueling it with
regular fuel, and leaving the solar cells on the ground to power other things.

> Cheap, quick-to-setup communications relay > Small datacenter > Long-term
> airborne

Not cheap at all, and a blimp (zeppelin) would do a much better job for all of
those.

(The batteries alone cost more than $20,000, and the solar cells probably in
the $100,000 range, and the carbon fiber around $50,000 for the raw materials.
I would estimate half a million each if mass produced.)

It might possibly be interesting for continuous surveillance, if you have no
ground station where you can land. (But it flies so slow (43 mph) that it
would take a very very long time to get anywhere.)

For regular constant surveying it's cheaper to have two planes and use them in
relays.

I'm all for reducing hydrocarbon usage, but lets reduce it for fixed
installations, and save the hydrocarbons for the mobile ones (planes, cars).

If you look at the specs <http://en.wikipedia.org/wiki/HB-SIA> it can just
barely fly, it's not even strong enough to hold two people.

~~~
gaius
LOL! I suppose you would say the Wright Brothers were wasting their time,
"it's not even strong enough to hold two people" indeed!

All exciting new technologies start out too feeble for practical use, just
like human babies...

~~~
ars
Not exactly.

They said:

"Once improved battery efficiency makes it possible to reduce the weight, a
two-seater is envisaged to make a non-stop circumnavigation."

Uh hu. We've been waiting for improved battery technology for decades. This is
cool, but utterly impractical. Solar power plus batteries simply are not
physically capable of doing a better job.

They are going for high profile, but low impact projects.

High profile - what's cooler than a perpetual plane? But low impact - if they
actually wanted to help reduce hydrocarbon usage this is not good way to do
it.

I totally see the coolness. But my response was about the practicality.

~~~
gaius
But battery technology _is_ improving and that should be easy to prove: these
weren't lead-acid batteries after all.

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nike
Bertrand Piccard, who is leading this project, comes from a family of
explorers (e.g. he was also the first to travel non-stop around the world in a
hot-air balloon). He also gave a pretty interesting TED talk (starting with
ballooning as a metaphor for life, then moving on the solar airplane project):

[http://www.ted.com/talks/bertrand_piccard_s_solar_powered_ad...](http://www.ted.com/talks/bertrand_piccard_s_solar_powered_adventure.html)

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ww520
Why don't they make a solar-powered airship? That's more practical. Airship
requires less energy to stay up and navigate, and has greater surface area to
receive sun light.

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hugh3
Airships are already capable of staying in the air for days at a time. But
they're so expensive to operate that they're no good for most of the possible
applications of this thing.

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ww520
Curious, why are they expensive to operate?

How about building a hybrid of airship and plane? Make it more maneuverable
than airship with the extra power from solar energy and staying up longer than
a plane. It's possible for a robotic hybrid airship to stay up for months and
years. Rest floating to suck up solar power when it runs low on energy, then
move on when the power is charged up. If it caught up in a gulf stream, just
let it ride out the stream to go around the Globe.

It would be interesting to see these Solar Birds floating in the sky. (Ha, I
even got the name for them. Someone grabs some funding quick to get it going.)

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borism
First, not very easy to put a lot of usable solar panels onto airship, but it
requires WAY more energy than a glider to maneuver due to ENORMOUS size. Sure,
solar airship may have it's applications too.

Second, it's not very exciting to fly around the world in airship if you
already did it in a balloon.

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GrandMasterBirt
I have to say, I am not impressed with the article... "Perpetual Flight?" I
say yes you can probably fly this airplane forever until a motor breaks or
something BUT there is a big difference between a single pilot airplane that
takes a team of people to ensure it does not have the wings scratched and a
commercial airliner that runs on solar. While the airliner is awesome if we
can pull it off, I would not be surprised if we were 20-50 years away from
that.

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vollmond
I'm not sure why "Perpetual Flight" would have anything to do with airliners -
typically you would prefer to land those fairly often. This would never need
to land, signifying to me that it would be useful as an automated drone of
some sort, possibly a cheaper alternative to a geosynchronous satellite.

~~~
gaius
You would never need to refuel. You could set down anywhere there was a
runway. That massively lowers the barriers to entry of "being an airport".

