I was wondering what happens to solar panels are mounted on high altitudes, such as top of a mountain? What I can see are benefits:
- cooler air (panel output higher)
- thinner air (sun radiation stronger)
- very rarely (never?) cloud coverage

The drawbacks are long power feed line back to "ground", but wouldn't the above benefits outweight this?

sending power over any distances would eat up all of the benefits you've mentioned many many times over. unless your home is on that mountain top, forget it.

It depends on the run, AND the voltage you are running. If your panels are in series, up to 550V, you will have very little loss for a couple hundred feet, because you are only pushing 7 amps or so.
Alternatively, you can park your battery shed & inverters at the top, and run 240VAC down to the house. (but you still have to water the batteries)
Just how far is "Long" ?

There's discussion of power line losses and links to (NEC & etc) external information in this fishbowl forum - please do a little searching and you'll find it.

I did not see it there, can you share the link ?

I just went to this solar guppy page:
http://www.solar-guppy.com/forum/search ... b8d5bf56c9

and typed in "wiring size" in the search text box, specifying find this term, and POOF - I got half a dozen links to half a dozen different sub-forums.

Total time: 47 seconds.

My take is the poster was thinking miles of wire ... as others have said, what ever gains you had get lost in the wire losses, not to mention the copper would be more than the solar panels

Also, very few if any mountains are above the weather ... storm clouds here in florida go as high as 40K feet in the summer ... Everest is "only" 29K high

Do we need to go that high? When I was in Hawaii few years ago the Mauna Kea mountain is about 12000 something feet high and at the top you could see the clouds below... (At least that day... not sure if that is normal...)

Still I did not get an answer to the question how much better the panels perform at high altitude (=thin air)? It is know fact that big telescopes (like I saw at top of Mauna Kea) are located high to reduce the effect of atmosphere... thus the sun radiation should be stronger too there... How much? That was my question. If it is like 50% higher then you could assume the panel output may be almost 50% higher! This is significant increase and may offset the copper cost? Or, if your house is located somewhere in the mountain slope the run would not be all the way to the bottom.

More than a couple of hundred feet, and you are loosing it in the wire.
Perhaps a pole mounted tracker will be a better return/boost in your power.

What area are you in/looking to do this ? Maybe someone nearby can offer advice


Link to an Excel Spread Sheet, with wire/voltage loss calc.
http://www.wind-sun.com/smf/index.php?topic=1477.0
first post
http://www.uwgb.edu/nevermab/voltage_dr ... lator_.xls

I wasn't really going to build a system at the mountain... this was just a question out of curiosity.

By looking at this wikipedia link:

http://en.wikipedia.org/wiki/Solar_radiation

The sun radiation in outer space is 1366W/m2, which means about 36% increase to the STD (1KW/m2) conditions. In addition majority of the increased radiation is from short wavelenghts (UV), which conventional solar panels may not be able to utilize?

But just a wild guess at 12000 feet the atmosphere is still ~70% thick and the radiation increase is only like 10% higher than at sea level. In other words the gains are marginal and not worth the increased complexity and cost to build such system...