Solar Cells And Electric Motors

Plenty have tried, but the fact of the matter is that a wing large enough to produce enough power, is too heavy to fly with that power. Just about. I think if you spend megabucks its possible to produce a fragile nightmare that may ghost along at head height at midday in the atacama sesert...

I think the current produced by solar cell is a very tiny fraction of the current required to run a motor.

Here's probably the ultimate of what you're looking for.

Helios! Developed for NASA. It holds the altitude record for non-rocket powered flight. Beating out the SR-71 by several thousand feet.

It uses a system of solar cells and rechargeable power cells. The solar cells, some 65,000 of them, do the recharging during the day and the power cells take up the load at night.

One goal for this vehicle is to function as a poor mans satellite. Circling over a city at 60,000 feet for up to six months at a time. A replacement comes up to take over services and the original lands to be refitted for whatever mission is next. Could do wonders for the cell phone industry.

Several prototypes of various sizes have been built. The smallest I've seen had around a 15-20 foot wing. It flew on the solar cells and if I recall correctly, used Astro motors.

So in spite of what D.H. may think, the wing is not too heavy nor fragile for the job. And though not cheap, it doesn't require mega bucks or NASA couldn't sponsor it.

Chuck

Ceti @comcast.net wrote in news: snipped-for-privacy@4ax.com:

Yes it's been done, take a look at the following webpage, next to the last airplane at the bottom:

- HPT

The full scale item (100+ foot span) had a mid air structural failure during testing. IIRC, they were testing in the Hawaiian islands (great test site, eh?) and got into more turbulence than they anticpated. If memory serves, this happened within the past year.

KB

That's the claim.

Searching the Internet, the only reference to "Sol Mite" is on that page.

Notice the wing covering reflects some light. That's not good for solar cells.

I am trying to find a solar cell which sources 1/10 the power required and weighs less than the total plane weight of 144 grams.

Does anybody know what (available) solar cell might be used in that? I guess not.

Yes, but it i slightly beyind the reach of the avearge modeller,

Asshole.

And a mega buck is only a million bucks. Why that's scarcely 550,000 uk pounds, in todays money at todays exchange rate.

As I said.

I think silicon cells - he most efficicent - are heavy.

There are som new phosphors coming along - rare earth ligands - that look promising, burt iff yu dio the watts per square meter calculations, you wll find that even at 100%, its a very low power model indeeed you will have.

The physics off fligt mean that what you need up with must be large, and very slow. And very light. Not surprsingly, ecen with themost odernmaterials, rthats very fragile.

As I said.

The one did crash but, the project continues none the less. A new one is being built.

The one that crashed did have structural failure. It had been overstressed on a previous flight! As in taken beyond the design limits. Then it was over stressed again on the final flight. Show me a type that won't crash when this sort of thing happens!

And the true D.H. shines through! Go sober up you twit!

As you said: "a wing large enough to produce enough power, is too heavy to fly with that power"

As I said: Sober up you drunken slob!

Thanks for the information. It was what I had found out for the most part. The solar cells are too heavy to do the job that I am looking for. Still the same I appreciate all your help.

| Plenty have tried, but the fact of the matter is that a wing large | enough to produce enough power, is too heavy to fly with that power. | Just about. I think if you spend megabucks its possible to produce a | fragile nightmare that may ghost along at head height at midday in the | atacama sesert...

As others have said, it has been done.

Helios is the extreme example, but others have done it too.

Ultimately what you have is a powered glider (because they're efficient) with lots of solar cells. They generally fly poorly, having very little power, but they do fly.

{ German, no idea what it says }

I could have sworn I saw a page on a solar powered plane in the back of a R/C magazine within the last year too. I recall that he'd started with a coreless motor, then went to an Astroflight 010 when the original motor kept burning out ...

In any event, it's not cheap, and it generally turns out to be incredibly fragile.

Why did you have to respond like that? Megabucks is a term like Megasale, not intended to be finite. But being a Brit, you probably can't understand the concept.

The aircraft was a design concept and proved that it could be done with CURRENT technology. While it may be beyond the average modeler, it is certainly not beyond SOME modelers!

replacement

I remember seeing the "Solar UHU" in a Hobby Lobby catalog a few years back. This was a version of the popular UHU glider powered by NiCds, with the solar cells on the wing giving it a bit of extra duration. It was in the catalog only one year, and I haven't seen it since. A totally solar-powered plane is going to have to be like an indoor model, extremely light, very fragile, and with very minimal payload capacities. However, if you wanna try it, do your homework, crunch the numbers and try!

Morris

Extreme silliness.

And lots of weight.

Apparently that was given up a long time ago. All of the links are dead.

I would like to find out what cell is used in order to determine how much weight for the power. Then some knowledgeable people could opine on the potential reality. There are allusions to various cells, but no one ever states a name or part number.

That appears to have the cell, but there is no weight given.

I would think something that great would be filmed. The photo gallery doesn't have any pictures of the thing in flight.

Extraordinary claims require extraordinary proof.

newssvr12.news.prodigy.com!newsdbm05.news.prodigy.com!newscon03.news.prodigy.com!newsmst01a.news.prodigy.com!prodigy.com!newscon06.news.prodigy.com!prodigy.net!border1.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!cyclone.austin.rr.com!fe2.texas.rr.com.POSTED!not-for-mail

Certainly beyond D.H. It was nice of him however to acknowledge his betters!

| >As others have said, it has been done. | >Helios is the extreme example, | | Extreme silliness.

eh? | >but others have done it too. | >Ultimately what you have is a powered glider (because they're | >efficient) with lots of solar cells. They generally fly poorly, | >having very little power, | | And lots of weight.

Weight and power go hand in hand. Low power is OK if you have low weight. And high weight is often OK if you have lots of power.

I doubt the planes are that heavy.

| >but they do fly. | >

| | Apparently that was given up a long time ago. All of the links are | dead.

Ok ... not my site.

| I would think something that great would be filmed. The photo | gallery doesn't have any pictures of the thing in flight. | | Extraordinary claims require extraordinary proof.

There's nothing extraordinary about this. It's tricky, but not rocket science. (And even rocket science usually isn't rocket science.)

I found the magazine I was talking about. June 2004 `Fly RC', Issue

1. Page 162. The plane is `Solarus', builder is Jonas Romblad.

Wingspan is 2.3 m. Weight is 480 grams. Power is provided by 16

10x10 cm silicon solar cells. Nominal output is 3A at 0.5V each. Motor is an Astroflight 010 with a 8.5:1 gear box.

Apparantly it maintains altitude with only 10 watts of power -- pretty impressive.

And yes, there is a picture of the plane in flight. With solar cells.

It wouldn't be kosher of me to scan the article for you, but you could probably buy it at

Or you can just read this --

http://64.233.161.104/search?q=cache:i5uYLOTgpy0J:

(Had to go to google cache for it ...)

In any event, Fly RC is a pretty good general R/C magazine.

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There you go again ...