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Pliable Solar Cells on a Roll

michael posted about 10 years ago | from the you'll-be-covered-in-the-stuff dept.

Technology 241

klevin writes "New Scientist is running a story on someone else who's developed thin, flexible, photovoltaic cells: 'The thin and bendy solar panels can be stuck to fabrics, sheets or backpacks and promise a go-anywhere electricity supply.' Whatever happened to those sheets of solar cells that some university here in the US developed several years back? As I remember, the concept was that they could be draped across roof-tops and whatnot. Never heard anything after that." We had post about solar building clothing last year.

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Slashdot is evil! (0)

Anonymous Coward | about 10 years ago | (#11128655)

Google it! NFJ

Wonder... (1)

ShieldW0lf (601553) | about 10 years ago | (#11128787)

How durable is it? If it got ripped, would it work anymore?

Could you grab a roll and keep it round the house, then just cut strips off and make things with it?

And 1 euro per watt... WTF? How many cubic meters of fabric in a watt exactly?

Re:Wonder... (1, Funny)

Anonymous Coward | about 10 years ago | (#11129028)

And 1 euro per watt... WTF? How many cubic meters of fabric in a watt exactly?
Depends if they're metric watts or english ones.

Hmmm. (2, Insightful)

krymsin01 (700838) | about 10 years ago | (#11128657)

Would be good to use as a solar sail, I bet.

Not really (2, Interesting)

Nomihn0 (739701) | about 10 years ago | (#11128690)

If I understand solar sails correctly, this is not how they work. Instead, they utilize the combined force of billions of subatomic particles radiated by stars hitting a parachute shaped foil to tow a capsule. This is why they are made to be exceptionally lightweight and large in their surface area.

Re:Not really (0)

Anonymous Coward | about 10 years ago | (#11128700)

Forgive my grammar, it's late.

Re:Not really (2, Informative)

krymsin01 (700838) | about 10 years ago | (#11128705)

Yes, you are correct in that, but if you made the sail out of a large, lightweight, flexible solar panel, you'd be generating electricity and momentum.

Weight is the key... (3, Informative)

The Kiloman (640270) | about 10 years ago | (#11128836)

Usually people imagine solar sails as being made of a very VERY thin film,on the order of a few micrometers thick... the point being that there's very little additional mass created by the sails themselves since you need so much surface area to create any appreciable force. Also, the less mass that's used for the sails, the more mass that's available for payload (or just plain not there, which means greater acceleration).

Here's a few links (thanks Google and the obligatory Wikipedia):
A geocities-looking site with some usefull info [solarsails.info]
Planetary Society has some more info [planetary.org]
Wikipedia entry [wikipedia.org]

Re:Not really (-1, Flamebait)

MoralHazard (447833) | about 10 years ago | (#11128711)

The OP never said this would make a solar sail WORK, dummy. And as the OP's response to your JP (jackass posting) would indicate, you're about the only person who didn't understand that.

Good try, though--you almost managed to sound intelligent. Keep it up, you'll do it eventually!

Re:Not really (2, Insightful)

WalksOnDirt (704461) | about 10 years ago | (#11128771)

But unless they can make it much thinner, this WOULDN'T make a good solar sail.

At "a little thicker than photographic film", it is probably too heavy to be a good solar sail material.

(Yeah, I know you never said it would, but you do seem to be defending that position.)

Re:Not really (2, Informative)

Anonymous Coward | about 10 years ago | (#11128747)

Oddly enough, not so much the force but the momentum. And not subatomic particals so much as light. Stars appearently make a lot of light. And that's why solar sails, as opposed to cells, are reflective. The radiation pressure equation would probably provide more insight into this should you wish to investigate further.

Re:Not really (0)

Anonymous Coward | about 10 years ago | (#11128880)

Does that mean that if the solar sail was made of PVCs it would slow down?

Seriously, If a solar sail were made of that material, it could generate quite some wattage, in addition to its task as a sail. I think that's what he meant.

Re:Hmmm. (1)

FuturePastNow (836765) | about 10 years ago | (#11128732)

As I'm sure others will point out, this would not make a good solar sail. But that doesn't mean it would not be useful for space applications- picture a very long, flexible solar power-cell rolled up around a spacecraft for launch, then unrolled and made rigid in space (piezoelectricity?). I imagine it could have a lot more surface area than the solar cells currently used.

Re:Hmmm. (1)

JPriest (547211) | about 10 years ago | (#11128813)

What is new about pliable solar sells? What about this jacket [tomshardware.com] for instance?

Re:Hmmm. (2, Informative)

The_Dougster (308194) | about 10 years ago | (#11129003)

Piezoelecticity is a force to voltage type thing and while pretty nifty, is unrelated to photovoltaic cells.

For the laymen out there, I'll explain this in technical terms. If you have a roughly cylindrical quartz crystal, and if you squeeze it, the crystal lattices "snap" into an alternative arrangement which free's up some electrons and essentially produces a static charge. When you remove the stress, the crystal lattice snaps back into its rest state and wants its electrons back.

Conversely, by applying an alternating current to a quartz crystal, you can make it physically stretch and shrink.

Because a quartz crystal is somewhat like a spring, a given shape/mass/volume of it will possess a resonant vibrational frequency. If you apply a signal to the crystal at or near the resonant frequency, the crystal's vibrational magnitude will increase, just like the famous Tacoma Narrows bridge "Galloping Girdy".

Piezoelectricity is a weird and wonderfull direct mechanical to electrical conversion phenomenon and it is typically used in electronics to convert a sloppy signal into a more precise one, or by utilizing higher harmonic modes, to multiply a lower frequency into a higher one.

Re:Hmmm. (1)

The_Dougster (308194) | about 10 years ago | (#11129023)

Oops, I missed the point, you proposed to apply a voltage to unroll the material. Personally I would think more along the lines of those pop out punching glove xxxxB type things with a small worm drive to extend and retract it.

Well a little piezoelectric tutorial can't hurt anyways :-)

Re:Hmmm. (1)

TummyX (84871) | about 10 years ago | (#11128935)

um, no it wouldn't. i can't believe you got modded up insightful.

solar sails need to be incredibly light and (as a consequence) thin.

solar sales work on light pressure not by converting light to electricity to drive an engine.

Re:Hmmm. (1)

krymsin01 (700838) | about 10 years ago | (#11128973)

I am fully aware that solar sails need to be incredibly light and thin. What I was trying to say, and apparently failed horribly at, is that perhaps it would be cool if (after a lot more development) could make a solar cell light, thin, and flexabile enough to make a solar sail out of.

Re:Hmmm. (3, Interesting)

The_Dougster (308194) | about 10 years ago | (#11129072)

Solar sail? Try relativity rocket.

Just use the solar cells to power up a linear accelerator and shoot nuclei out the back at near the speed of light. If you can get 0.999c from a nucleus you get a tremendous thrust for one little atom. Remember, F mA when you approach the speed of light. Relativity rockets (super ion engines) are probably the best means of propulsion where electric power is plentiful but mass is dear. I'm sorry, but that tiny momentum of a photon is so small it is pathetic. Granted you get 2x boost for reflection vs 1x boost for adsorbtion, but 2 x 0 still equals 0. The only way to practically get around in space is to shoot nuclei out the back of a rocket engine at the speed of light.

But what will the Terrorist implications be? (-1, Troll)

ravenspear (756059) | about 10 years ago | (#11128662)

With this kind of ultra portable power source, wouldn't it be easier to operate more destructive equipment in the field?

I mean to me this sounds almost as dangerous as amateur rockets. Thank goodness the ATF already banned those.

Re:But what will the Terrorist implications be? (0)

Anonymous Coward | about 10 years ago | (#11128694)

I sincerly hope you are joking... cause there is no solar panel that can compare to the power of a lithium ion battery in the common cell phone...

as for amature rockets... whats wrong with those? you can do way more damage with a car that a small carboard tube with a little black gunpowerder in it.

Re:But what will the Terrorist implications be? (1)

Bastard of Subhumani (827601) | about 10 years ago | (#11129047)

as for amature rockets... whats wrong with those?
The fact that an armature [wikipedia.org] belongs in an electric motor, perhaps?

Re:But what will the Terrorist implications be? (0)

Anonymous Coward | about 10 years ago | (#11128696)

Godwin's law for Slashdot:

The longer a Slashdot story stays on the front page, the more the probability of someone mentioning terrorists or banning by the US government approaches one.

Re:But what will the Terrorist implications be? (1)

krymsin01 (700838) | about 10 years ago | (#11128779)

That should be Donald's Law, I think.

Re:But what will the Terrorist implications be? (2, Insightful)

HillBilly (120575) | about 10 years ago | (#11128709)

Get over the terrorist thing. Stop letting them win with your paranoid thoughts.

Re:But what will the Terrorist implications be? (0)

Anonymous Coward | about 10 years ago | (#11128956)

please don't feed the trolls. Thank you!

Re:But what will the Terrorist implications be? (1)

Scrameustache (459504) | about 10 years ago | (#11128719)

Right, we should suspend ALL technological devellopments and scientific research, lest the boogyman, I mean, terrorist use it. Also, let's scrap all the tech we have and go live in caves.

You first, of course.

Re:But what will the Terrorist implications be? (1)

isometrick (817436) | about 10 years ago | (#11128804)

One word (hyphenated to ease your reading speed): J-O-K-E.

Good day to you.

Re:But what will the Terrorist implications be? (0)

Anonymous Coward | about 10 years ago | (#11128759)

You're obviously in your early stages of becoming a troll. Not bad, but not entirely convincing. Keep working on it, i see potential here.

Re:But what will the Terrorist implications be? (0)

Anonymous Coward | about 10 years ago | (#11128762)

Who cares? The ATF and the FBI and the CIA and the friggin NSA have no authority in EUROPE, you saddite. If GW Bush trespassed in my house, I would be fully within my rights to have him arrested, prosecuted, and thrown in prison. Hail the old world!

Re:But what will the Terrorist implications be? (1)

Zen Punk (785385) | about 10 years ago | (#11128884)

Could I inquire as to what a "saddite" is?

Re:But what will the Terrorist implications be? (1)

dteichman2 (841599) | about 10 years ago | (#11128791)

There won't be any terrorist impications. At least not beyond today. To get a decent amount of power, you need a large surface area. Seems like that'd be a little visible to me, given that solar cells are highly reflective. If terrorists are out in direct sunlight with enough room to lay out a mat of these and not be spotted, are they in position to attack a field of wheat.

Re:But what will the Terrorist implications be? (2, Insightful)

LordEd (840443) | about 10 years ago | (#11128839)

It didn't say it was ultra-powerful, it says it was thin and cheap in trade for efficiency (and possibly usefulness)

A truly inventive person can use anything to any purpose. Don't fear the technology, fear the people using it. If we abandoned all technology used by terrorists, we'd be living in caves and the government would be licensing the use of fire, wheels, and hammers.

-- guns don't kill people, kids playing video games kill people

Re:But what will the Terrorist implications be? (2, Funny)

berkut7 (761778) | about 10 years ago | (#11129025)

Oh no! Ossama got an AA battery!

Re:But what will the Terrorist implications be? (1)

Hognoxious (631665) | about 10 years ago | (#11129056)

Ossama got an AA battery!
Is that AA battery as in a smallish cylinder giving 1.5 volts, or AA battery as in a platoon of ZSU-23-4s?

Didn't RTFA, but... (1)

Dorsai65 (804760) | about 10 years ago | (#11128664)

I wonder how the efficiency of these panels compares to the more conventional ones. I can't help but think that there's probably a difference; but if it isn't too bad, they could prove to be pretty useful.

Re:Didn't RTFA, but... (1)

aheath (628369) | about 10 years ago | (#11128683)

QTFA:

"Kroesen's team has made its solar cells bendy simply by making them thin. But this has involved a trade-off. While the best solar cells are now working at efficiencies above 20%, the H-AS cells are only about 7% efficient. The researchers think efficiency is worth sacrificing for a cell that is going to be more generally useful, though they still hope eventually to reach 10% efficiency."

Re:Didn't RTFA, but... (1)

Dorsai65 (804760) | about 10 years ago | (#11128729)

mmmmmmmm - I think not. You can get a similar convenience by using smaller rigid cells on a foldable surface, and still have the higher efficiency. Oh, well.

Re:Didn't RTFA, but... (0)

Anonymous Coward | about 10 years ago | (#11128689)

OMFG paragraph three sentence three is WAY too deep into the story for this person to venture...

Re:Didn't RTFA, but... (1)

luvirini (753157) | about 10 years ago | (#11128710)

Allready the quite low efficiency of traditional solar cells makes their use in many applications too cumbersome, so the fact that these are flexible is not likely to help with the lower efficiency as the surface area will start to get very big.

Re:Didn't RTFA, but... (1)

Dorsai65 (804760) | about 10 years ago | (#11128743)

True. If it was a difference of even 10%, it might be worthwhile; but between 20+% and SEVEN? Nah.

Re:Didn't RTFA, but... (1, Insightful)

Anonymous Coward | about 10 years ago | (#11128876)

Actually, the artical states that they are MUCH cheaper to produce than the traditional glass based panels. Since they can produce it continuosly in sheets, it's a much cheaper process, about 1 euro/watt And that definately will help. Lower cost per watt is a good thing.

At that price you can produce a kilowatt/hour for around 1000 euro (or about $1330). It will make the idea of a household producing it's own energy and not relying on a public power grid much more realistic.

The flexible part will help enable a number of other applications.

Imagine Camping with a tent made out of the stuff. Charge a battery all day, and run your lights and small applainces at night.

Imagine a sailboat with a sail made out of it. It could power a rather nice navigation system I think.

Imagine the applications of something that is essentially a fabric producing electricity. Your clothing could power your cellphone, MP3 player, PDA, etc.

Also remember that it's a technology in it's infancy. it should get more efficient as the process is improved upon. The implications are far reaching and rather astounding if you ask me.

Re:Didn't RTFA, but... (0)

Anonymous Coward | about 10 years ago | (#11129005)

More than this it could also be very good for emergency uses. For example emergency life rafts could have their upper surfaces made of this material and it could be used to extend battery life for the emergency beacon. (In any case the emergency beacon is going to be most useful at night when rescuers can see people, so it would be very useful if it turned out that the battery for the beacon was totally dead anyway).

Another example might be providing power for some systems in areas affected by an earthquake. Disaster relief organisations turn up, find a conveninent patch of land, and unroll a huge area, and the place has power for some essential services. When the disaster is over, simply roll it back up, put in on the back of a low loader and drive it to the next disaster.

In other situations, though, I'd want to know how long it takes before the energy required during manufacture, transport to market, etc., is recouped to know whether it would be worth suggesting this as a way to provide cheap additional energy to top up fossil fuel sources.

Re:Didn't RTFA, but... (1)

Spruitje (15331) | about 10 years ago | (#11128721)


I wonder how the efficiency of these panels compares to the more conventional ones. I can't help but think that there's probably a difference; but if it isn't too bad, they could prove to be pretty useful.


At the moment it's around 7% which is a little bit lower than conventional solar cells which have an efficiency of around 20%.
But they are working to get it to 10%.
Second, they can produce it for 1 a watt.
Which means that it's 8 to 10 times cheaper than conventional solar cells.

Are there other applications besides clothing? (2, Insightful)

aheath (628369) | about 10 years ago | (#11128669)

I wonder if there are other applications that make more sense than clothing that can charge a cell phone.

I think this type of material could be very useful to provide electricity in places that do not have access to a reliable electrical grid.

How many watts are needed to run a a phone, a refrigerator, a radio or a computer?

Re:Are there other applications besides clothing? (1)

ThisNukes4u (752508) | about 10 years ago | (#11128685)

Quite a bit more than I would think can be powered by embedded solar cells. It is hard enough for a regular solar cell to power anything with somewhat demanding electricity usage. Besides the fact that solar energy is not exactly the 100% uptime 24h solution.

Re:Are there other applications besides clothing? (1)

dougmc (70836) | about 10 years ago | (#11128712)

I think this type of material could be very useful to provide electricity in places that do not have access to a reliable electrical grid.
Solar cells are already used in lots of applications that don't have access to an electrical grid, reliable or not. Pliable solar cells might be useful in more applications, but the ones we have now are used quite a bit.

What applications, you might ask? `35 mph school zone' lights (it's easier to add solar cells than to run wires.) Remote creek monitoring stations. Satellites in orbit. There's lots lots more.

As for providing 110v power to remote locations, this is done too. It generally requires quite a bank of solar cells, and lots of batteries (the sun isn't up 24/7) to provide the power used just by a single household, but some people do it.

How many watts are needed to run a a phone, a refrigerator, a radio or a computer?
This is easily measurable. For a fridge, it's a lot, but you can read the average right on the yellow label on the front when you buy it. For a phone, what kind of phone? A cell phone probably averages much less than one watt (assuming the time spent actually talking on it is minimal.) For a computer, it depends on the type of computer. A PC often uses 100-200 watts of power (not counting the monitor), but some computers use a lot less.

cell phone (1, Informative)

Anonymous Coward | about 10 years ago | (#11128753)

Cell phones, and battery powered devices in general are pretty easy to figure out.

If your phone has a 780mAh LIon battery (it does, roughly), then the battery contains 0.78*3.7 (3.7 is the nominal voltage) or 2.8Wh of power. then you figure out how long the battery lasts.

In the case of a phone, just turned on, doing nothing, it probably lasts at least 56 hours. 2.8Wh/56 = 0.05W. The phone is using 50mW of power on average. When you are talking, you probably get about 5.6 hours of talk time. So it's using 0.5W (500mW) on average.

All this is pretty easy to do with battery-powered devices. If you have a wall-powered device you need something to measure the power usage, like a Kill-A-Watt.

Re:Are there other applications besides clothing? (1)

pyat (303115) | about 10 years ago | (#11128966)

Well, my laptop power supply is rated at 65W.
It takes about as long to charge the battery (while still using the computer) as to exhaust the battery so i'd imagine the power consumption of the laptop itself is about half this.

Regarding the mobile phone. My charger has a rating of less than 7W, and i usually need to charge it for about 2.5 hours every 3 days. This is very manageable with solar cells (you have 72 hours to accumulate 21 watt-hours of energy).

Solar clothes (1)

Rii (777315) | about 10 years ago | (#11128672)

So... what color is it?

I can see it now (2, Funny)

SuburbaniteFury (776695) | about 10 years ago | (#11128678)

The new Apple fashion: instead of black shadow people in their iPod advertisements, everyone is now covered with solar panels. (This might actually help the batter life, though, so it's not a total loss.)

Solar Area 51. (0)

Anonymous Coward | about 10 years ago | (#11128679)

"Whatever happened to those sheets of solar cells that some university here in the US developed several years back? As I remember, the concept was that they could be draped across roof-tops and whatnot. Never heard anything after that.""

I believe the aliens complained about it, making it difficult for their craft to land.

nothing says nerd like.... (0, Offtopic)

nilbog (732352) | about 10 years ago | (#11128684)

'The thin and bendy solar panels can be stuck to fabrics, sheets or backpacks and promise a go-anywhere electricity supply.'

...and an instant replacement for the classic "kick me" sign.

Re:nothing says nerd like.... (1)

Tablizer (95088) | about 10 years ago | (#11128720)

...and an instant replacement for the classic "kick me" sign.

Neon self-charging Kick-Me signs? Those are for the rich kids. Not sure if it counts as a status symbol to have one on, though. Is it better to be jammed into a gold-lined garbage can as freshman than a tin one?

Re:nothing says nerd like.... (1)

nilbog (732352) | about 10 years ago | (#11129054)

how is this off topic?

If you put a million monkeys with slashdot mod privledges in front of a million computers....

Re:nothing says nerd like.... (1)

Moderatbastard (808662) | about 10 years ago | (#11129073)

Jokes are always offtopic, especially if you're too stupid to get them. There was a memo or something.

WARNING (3, Interesting)

Dash'n'SlashDot (841636) | about 10 years ago | (#11128688)

God, solar panelling on the clothes. try to imagine the warning labels they would put on thee things: WARNING! DO NOT USE WHILE BATHING OR WHILE HAVING SEX. ... Don't laugh. You heard it here first. Expect it on your self-heating winter coats next year.

Obviously.... (0)

Anonymous Coward | about 10 years ago | (#11128754)

anyone who wears solar-cell clothing doesn't have to worry about either of those activities. I hear that they'll be sold exclusively under the "Members Only" lable.

Re:WARNING (0)

Anonymous Coward | about 10 years ago | (#11128790)

Just lieve the warning signs off and let the evolution handle it.

Re:WARNING (1)

Icarus1919 (802533) | about 10 years ago | (#11128999)

Normally winter occurs because there's less sunlight than usual. I don't think they're going to be producing your imagined self heated clothing through solar panels any time soon.

Re:WARNING (1)

TummyX (84871) | about 10 years ago | (#11129120)


WARNING! DO NOT USE WHILE BATHING OR WHILE HAVING SEX


I think that warning is pretty redundant for most people around here...

Iowa Thin Film Technologies (2, Informative)

Anonymous Coward | about 10 years ago | (#11128697)

The poster might have been thinking about Iowa Thin Film Techologies [iowathinfilm.com] ...

Flat vs. Flexible Info (4, Informative)

sahrss (565657) | about 10 years ago | (#11128703)

To address some of Klevin's confusion, since I've been following solar panel advancements:

Thin, flexible cells have been around for a while. One reason they haven't caught on heavily is because they're nowhere near as 'powerful' (efficient at conversion) as hard panels. Did a quick search (don't take this data *too* seriously, but it represents what's normal); compare panels from these two pages:
Flexible [solar-electric.com]
Solid [solar-electric.com]

Specifically, compare "Unisolar 32 watt flexible solar panel" from the first link to "Shell ST40 thin film CIS 40 watt solar panel" on the second. The flexible panel is 940 sq. inches and 32 watts, while the solid panel 663 sq. inches and 40 watts. Big difference in watt per area.

I ended up choosing a big solid one to fit in the rear dash of my car; flexible would have been easier to deal with, but it won't fold, and produces less power. (I use the panel in my car to power my laptop/cell phone combo while camping and stuff, it's very cool and gets a lot of questions from random interested people!)

Here's another chart to compare the two: Product Page [selectsolar.co.uk]
Tried to find an efficiency rating chart comparing the two types, but no luck. The numbers are out there somewhere...

Re:Flat vs. Flexible Info (1)

$uperjay (263648) | about 10 years ago | (#11129002)

Solar on the rear dash is a very smart idea. I don't know why most cars don't have this attached by default and coupled to rechargable batteries.

sweet! (2, Funny)

Cannedbread (841645) | about 10 years ago | (#11128704)

i live in oregon and i really cant wait to get a solor powered raincoat. oh wait

Re:sweet! (1)

BladeMelbourne (518866) | about 10 years ago | (#11128746)

I live in Antarctica and cant wait to try one of those solar powered raincoats on June 22nd.

Cheap solar panels (2, Insightful)

Squalish (542159) | about 10 years ago | (#11128708)

Screw clothing to charge cellphones, etc. I can't think of a more petty use.

The major impact of this tech has nothing to do with its portability/flexibility. The article estimates that the price for a final process fab will be about 1 euro per watt, compared to a highly competitive market which has so far only produced 5.6 euro per watt glass panels.

Simply put, this would make photovoltaics as an energy source an order of magnitude more competitive, if the process is scalable.

Re:Cheap solar panels (2, Interesting)

Squalish (542159) | about 10 years ago | (#11128718)

Okay, was reading the wrong data, that was peak price, the lowest prices one can find are around E2.66 per watt for crystalline + E3.15 for thin film.

Still, 1 euro per watt would make a HUGE difference in the viability of solar.

An order of magnitude? (0)

Anonymous Coward | about 10 years ago | (#11128964)

You must be converting the Euro into the forthcoming American Lira.

Bendy (1)

Tablizer (95088) | about 10 years ago | (#11128713)

The thin and bendy solar panels can be stuck to fabrics, sheets or

"Bendy"? Seems English is becoming as flexible and bendy as solar panels. Gotta do some practicizing myself.

Re:Bendy (1)

m3j00 (606453) | about 10 years ago | (#11128730)

bendy [m-w.com] .

Re:Bendy (1)

A nonymous Coward (7548) | about 10 years ago | (#11128780)

Dubya? Is that you?

Re:Bendy (1)

dread_pirate_smoochy (841658) | about 10 years ago | (#11128979)

Dang! You must be an expert in Wordyology !!!!

Solar Cells on a Roll (3, Funny)

fireboy1919 (257783) | about 10 years ago | (#11128751)

I don't care what anyone says.

Now matter how pliable or environmentally friendly, solar cells are not good on a roll. They taste absolutely nothing like butter, and quite frankly, I find them barely palatable.

Don't the editors try this these things themselves? This is as bad as that "http://slashdot.org/article.pl?sid=02/10/28/18522 41&tid=126" story. Trust me, those things taste absolutely nothing like fruit-rollups.

Re:Solar Cells on a Roll (1)

AmberBlackCat (829689) | about 10 years ago | (#11128873)

Maybe there's something wrong with your roll...

people are missing the point (1)

rubee (826908) | about 10 years ago | (#11128764)

although its a nice novelty to have a solar-backpack, the real good news is that this trend will eventually bring down solar panel prices and make them avaliable to a wider audience. the biggest obstacle today to a solar panel on every roof is cost and installation, for they are already highly efficient (they can capture something like 30% of all energy to that hits a certain surface).

Re:people are missing the point (1)

PabloJones (456560) | about 10 years ago | (#11128845)

Actually, the biggest obstacle is making them efficient in the first place. A solid panel made of crystalline cells can only get between 11% and 14% efficiency (thin film PVs gets even less), when optimally tilted towards the sun. This is because only certain wavelengths are allowed to be converted into energy at the moment. Scientists are still working on a molecule or bunches of molecules (I'm not entirely sure how it all works) that will be able to utilize more of the spectrum. Until then, we are stuck with relatively expensive panels, which are also not terribly eco-friendly to manufacture.

Re:people are missing the point (1)

The_Dougster (308194) | about 10 years ago | (#11128931)

Your post made me remember something that I was wondering about a while back but never found an answer.

Since Infra-Red radiation is part of the electromagnetic spectrum and very near the wavelengths of visible light, can it be focused using an optical lens just as one can focus light rays?

I had an idea about placing a fresnel lens in front of a large low-availability IR radiating source and focusing it to make a hotspot. A small area with an extremely high temperature is much more thermodynamically usefull than a large area with a relatively low temperature.

You might use this, for instance, to focus process heat onto a catalyst to improve chemical reaction rates.

Re:people are missing the point (1)

Hognoxious (631665) | about 10 years ago | (#11129100)

Since Infra-Red radiation is part of the electromagnetic spectrum and very near the wavelengths of visible light, can it be focused using an optical lens just as one can focus light rays?
Yes, you can buy IR film[1]. I think the refractive index of the glass is slightly different, so you have to focus differently - you see a red dot or mark on some SLR lenses for this purpose.

[1] Film was a kind of light sensitive medium, usually shaped like a strip or tape used in cameras in the old days.

What if.... (1)

dteichman2 (841599) | about 10 years ago | (#11128766)

Could you use one of these as the roof for a shade structure (it's portable). Then you could use the power for say... a fan. Nice day at the beach.

Is $US52 per square metre about right? (4, Informative)

thorpie (656838) | about 10 years ago | (#11128769)

They quote 7% efficiency, 1 euro per watt.
Full sun is 1000 watts/sq metre, so with 7% efficiency we get 70 watts/square metre, so it has a cost of 70 euros/sq metre or, at 1.33 euros to the dollar, about $US52.60/sq metre.
Cover a 10 * 4 metre area of roof for $2,100 and get enough energy, in the middle of summer, to boil your 2 kw electic kettle all day.
At 12c per kwH for electricity, @ 2.8 kw * 6 hours/day * 365 days/year gives a cost saving of $735 pa, or a repayment of the $2,100 capital in 3 years

Are these numbers OK?

At this price will it be practical to disconnect from the grid sometime soon?

Re:Is $US52 per square metre about right? (1)

matt21811 (830841) | about 10 years ago | (#11128902)

Finnally someone who gets it.

The whole aspect of attaching this product to clothing or backpacks is just a gimmic to attract press attention.

The real story here is that the cost per what is falling. Only one order of magnitude in efficiency (in $ per watt) to go before we stop burning coal for electricity. I look foreward to a time when countries that whose only natural resourse is large amounts of scourching hot desert and they are considered energy rich.

Re:Is $US52 per square metre about right? (2, Informative)

DustyShadow (691635) | about 10 years ago | (#11128937)

I think you 1.33 US dollars to 1 euro.

thank you, my error, cost around $US93 /sqm (2, Insightful)

thorpie (656838) | about 10 years ago | (#11128977)

Thank you, so a cost of $93 sqm making close to $4,000 to cover 40sqm, or a repayment time of 6 years. Not so good, They won't get you to disconnect from the grid

Re:Is $US52 per square metre about right? (1)

Hognoxious (631665) | about 10 years ago | (#11129107)

Are these numbers OK?
No, you forgot to discount the capital over time and to allow for depreciation.

Is this different... (1)

anethema (99553) | about 10 years ago | (#11128806)

Without even glancing at the article (this IS /.) I'm curious how this is different than the rollable flexible solar cells that have been on the market forever.

I can buy them at canadian tire, thats how common they are. Product # 11-1575-0 for example. (might neet to enter a postal code, v1p1c7 works.)

Maybe they are more efficient or something? These seem about the same as a rigid solar panel for the size. More expensive though obviously.

FINE, I just looked at the article..seems the only advantage is they are expected to be dirt cheap. I've heard that before. I'm still waiting to wallpaper my house in transparent OLED film :)

Re:Is this different... (1)

LordOfYourPants (145342) | about 10 years ago | (#11128938)

FINE, I just looked at the article..seems the only advantage is they are expected to be dirt cheap. I've heard that before. I'm still waiting to wallpaper my house in transparent OLED film :)

I've got my north wall wallpapered with an OLED screen broadcasting a white image and my south wall wallpapered with solar panels to catch it all.

I hereby claim prior art for all the future perpetual motion/infinite energy machine creators who attempt to patent my brilliant idea.

United Solar Ovonics (1)

egotripper (202546) | about 10 years ago | (#11128835)

Energy Conversion Devices created the thin-film amorphous photovoltaics used in their flexible solar panels, and created United Solar Ovonics to commercialize it. ECD Ovonics (the current name, I guess) is at www.ovonic.com. A quote from one of the documents on their site says, "ECD Ovonics and United Solar Ovonic hold the basic patents covering the continuous roll-to-roll manufacturing of thin-film amorphous silicon alloy multi-junction solar cells and related products. More information is available at www.uni-solar.com."

Spheral Solar Power in Canadian Tire... (1)

Mr. Flibble (12943) | about 10 years ago | (#11128851)

As I remember, the concept was that they could be draped across roof-tops and whatnot. Never heard anything after that.
http://www.atsautomation.com/solar_technologies/de fault.asp [atsautomation.com]

SSP as mentioned on Slashdots pior story for having solar "denim" has small flexible solar panels avaliable now in Canadian Tire. Not that this helps those of you not in Canada... But you can buy them now.

What about Iowa Thin Film Technologies? (1)

jjeffers (127519) | about 10 years ago | (#11128852)

Right down the road from me is Iowa Thin Film Technologies [iowathinfilm.com] who have been making these sort of things for a number of years. Disclaimer: I wasn't able to access TFA so I could be way off base. -Jim KB0THN

Re:What about Iowa Thin Film Technologies? (0)

Anonymous Coward | about 10 years ago | (#11129014)

What about the Australian National University - 70 microns thick, dual layer - see
http://www.originenergy.com.au/environment/fi les/f actsheet_sliver.pdf.

Highways (1)

under_clocker (827643) | about 10 years ago | (#11128872)

The key to solar energy lies in our highways...
we need to research that as a viable source of electrical, and thermal energy.
IF we can build effecient nano- machines and embed them into the pavement we may achieve a new form of effecient enegry...
MIght require road side banks of capcitive storage cells...

Price per watt is what matters (1)

The_Dougster (308194) | about 10 years ago | (#11128891)

Any reasonably useful photovoltaic system is going to need about 1kW output under typical conditions. So with this material, for around $1000 you can generate maybe 50 cents worth of electicity each day. Obviously you aren't going to get rich by selling power back to the grid with a scheme like this but 1kW of totally free power would be kind of nice to have.

I always thought that a cool thing to do would be to use the excess electricity from PV cells to crack water and make Hydrogen gas rather than goofing around with expensive batteries.

Probably one of the cheapest ways to store Hydrogen "on site" is the old upside down reservoir immersed under water. In this case you would just make some electrodes under the reservoir, maybe concentric stainless steel rings? And set up the cell array for 1.5 volts, which IIRC is close to the optimum voltage for water cracking. Hook it up and collect your "Brown's Gas" during the summer, and burn it during the winter.

I just love PV Cells, they really spark my imagination. I even have a little 5V/1A PV array to play with. Too bad where I live if it isn't raining then its probably snowing.

Re:Price per watt is what matters (2, Interesting)

humbads (240455) | about 10 years ago | (#11129013)

Yes, you will get rich. If a $1000 investment yields $0.50 per day worth of electricity on average, then that results in $182.50 per year in revenue. Assuming no maintenance, land, installation, or other overhead costs, you are earning 18.25% yearly on your investment. It would be like printing money!

Re:Price per watt is what matters (1)

Verio Fryar (811080) | about 10 years ago | (#11129115)

That would be true if you do not take into account the amortization of the inversion. How long these panels last?

Re:Price per watt is what matters (1)

The_Dougster (308194) | about 10 years ago | (#11129152)

Yeah, now that you mention it, I believe that it used to cost around $5000 for a 1kW PV array. This is a 5X price drop in capital equipment costs. If you set up shop like in New Mexico, you might make more like 90 cents per day's worth of power also because of the increased solar mean day index, and desert land in NM is probably super cheap.

Hooking up to the grid is both tricky and lossy. You must feed in a synchronous AC signal which is in phase with the grid. Typically you would use a DC->AC motor/generator set and you absolutely have to match the phase with the grid or else you have serious sparks flying. Fortunately, there are a lot of commercial solutions already out there which can do this.

Nice insight humbads, you set up some financing and I'll engineer it up. Deal?

Solar power head wear (1)

j14ast (258285) | about 10 years ago | (#11128900)

Now I'll finaly have a excuse to wear my big black cowboy hat. If anyone asks Im powering my prescott based p4 laptop 8P

Wearable Solar Panels Are Already Available (-1)

rpiquepa (644694) | about 10 years ago | (#11129004)

Besides the New Scientist, other newspapers commented about these pliable solar cells which will come to the market in about three years. Check for example this article [scotsman.com] in the Scotsman or read my blog for more details, references and pictures [primidi.com] . But please also note that a company based in Switzerland, Flexcell [flexcell.ch] , is already selling flexible, custom-designed solar cells and modules.

Electricity is only a small part of the game (2, Interesting)

dr.Flake (601029) | about 10 years ago | (#11129007)

What amazes me is that all this investment time and "energy" is spent on cells that produce electricity.

Whereas the collection of Heat is as simple as it can get, but rarely used.
Though most mediteranian countries use solar heat for heating their domestic water, but that is about it.

What i have in mind is the use of solar heat, collected during summer, to warm domestic homes during winter. (Thats where real amounts of energy (read CO2) are needed !)
Water is an exellent storage container for heat and is dirt cheap.

The only problem is where to store all the warm water. Probably the easiest solution would be to pump up ground water, heat it, and pump it back. (The ground is actually an exellent therman insulator!)
Use the 1kW of solar energy from a couple of M2 of these cells to make water run through 100 m2 of cheap solar heat collectors.

Now we are SAVING evergy.

Home Power Magazine (0)

Anonymous Coward | about 10 years ago | (#11129074)

Here's a GREAT resource when it comes to "hands on" (i.e. Real World experience) solar installations.

Home Power Magazine [homepower.com]

I've been a reader since issue #15 or so.

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