Can I build a perpetuum mobile with solar cells???

[Gene Stonerly]

I'd like to build a helicopter that will always fly around while
taking photos of the world. During the day, its solar cells
will load its batteries, during the night it will run from
battery power.

The pictures will be sent to my computer and I'm going to
sell them.

It will be the perfect voyeur-helicopter.

Is it possible to create such a perpetuum mobile???

 

[Roger Hamlett]

On Fri, 1 Feb 2008 00:49:30 -0800 (PST), Gene Stonerly
<stolen_energy@yahoo.com> wrote:

I'd like to build a helicopter that will always fly around while
taking photos of the world. During the day, its solar cells
will load its batteries, during the night it will run from
battery power.

The pictures will be sent to my computer and I'm going to
sell them.

It will be the perfect voyeur-helicopter.

Is it possible to create such a perpetuum mobile???
No.

The problem is that the available cross sectional area of the
helicopter will be too small to gather enough power for any but short
flights. You might well be able to make such a device with a few
minutes flight duration, from several hour's charging, but not one
that is going to stay in the air for very long.

Best Wishes

 

[CptDondo]

On Fri, 01 Feb 2008 21:33:32 +0000, Roger Hamlett wrote:

On Fri, 1 Feb 2008 00:49:30 -0800 (PST), Gene Stonerly
stolen_energy@yahoo.com> wrote:

I'd like to build a helicopter that will always fly around while taking
photos of the world. During the day, its solar cells will load its
batteries, during the night it will run from battery power.

The pictures will be sent to my computer and I'm going to sell them.

It will be the perfect voyeur-helicopter.

Is it possible to create such a perpetuum mobile???
No.
The problem is that the available cross sectional area of the helicopter
will be too small to gather enough power for any but short flights. You
might well be able to make such a device with a few minutes flight
duration, from several hour's charging, but not one that is going to
stay in the air for very long.

Best Wishes

Didn't NASA try something like this? And didn't the full-scale model
break up in bad weather?

 

[Cornelius J Rat]

"Roger Hamlett" <rogerspamignored@ttelmah.demon.co.uk> wrote in message
news:vq37q3hbu8fc79bjoueclq7qd9dikt89eq@4ax.com...

On Fri, 1 Feb 2008 00:49:30 -0800 (PST), Gene Stonerly
stolen_energy@yahoo.com> wrote:

I'd like to build a helicopter that will always fly around while
taking photos of the world. During the day, its solar cells
will load its batteries, during the night it will run from
battery power.

The pictures will be sent to my computer and I'm going to
sell them.

It will be the perfect voyeur-helicopter.

Is it possible to create such a perpetuum mobile???
No.
The problem is that the available cross sectional area of the
helicopter will be too small to gather enough power for any but short
flights. You might well be able to make such a device with a few
minutes flight duration, from several hour's charging, but not one
that is going to stay in the air for very long.

Best Wishes

An aeroplane (not a helicopter) has been built that is capable of storing
enough solar energy to fly through the night. You do need advanced fuel cell
technology and very high efficiency PV cells.

http://www.solarimpulse.com/en/challenge/index.php?idContent=18&idIndex=7
"In 2005, Alan Cocconi, founder of AC Propulsion, succeeded in flying an
unmanned airplane with a 5-meter wingspan for 48 hours non-stop, propelled
entirely by solar energy. This was the first time an airplane of this type
was able to fly through a whole night, thanks to the energy collected by,
and stored in, the solar batteries mounted on the plane."

Solar Impulse plans to fly a manned solar aircraft around the world in
around 2011.

 

[Cornelius J Rat]

"CptDondo" wrote

Didn't NASA try something like this?

Yes, Pathfinder and Helios, both built by AeroVironment, Inc.

The Pathfinder was OK -
http://www.nasa.gov/centers/dryden/news/FactSheets/FS-034-DFRC.html

And didn't the full-scale model break up in bad weather?

The Helios "experienced control difficulties while on a checkout flight on
June 26, 2003, and the aircraft suffered some structural failures and was
subsequently destroyed when it fell into the Pacific Ocean .....An
investigation to determine the cause(s) of the control problems that led to
the loss of the craft is still in progress as of this writing." It was using
a special experimental fuel cell designed to allow to continue flying by
night and was intended to fly at up to 100,000 feet.

http://www.nasa.gov/centers/dryden/history/pastprojects/Erast/helios.html

Nothing similar shows on the Current Research list. AVInc
(http://www.avinc.com/) will sell you an Umanned Aircaft System (UAS or RPV)
but they don't say anything about work on solar aircraft.