They may actually get PVs to useful effencies yet!
Solar power researchers at Princeton University have discovered that by mimicking the surface of leaves, they can create solar cells that are better at capturing sunlight for a 47 percent efficiency boost. In the kind of discovery that’s obvious after the fact, the researchers have “roughed up” the surface of their cells, in …
They may actually get PVs to useful effencies yet!
I find the PVs quite efficient ... I run Slackware ;-)
Except they never say the efficiency of the cells being used to start with. A 47% improvement may sound dandy, but if it's a 47% improvement over 8% efficiency, then the cells are only about 12% efficient and well behind the curve. Overall numbers please.
"They may actually get PVs to useful effencies yet!"
They already are.
You mean corrugating a surface within the same perimeter increases effective surface area? The trapping of incident light is incidental (sorry) but useful.
We need a professor to tell us this Physics 101 detail?
So if you take matchboxed size solor cell with the surface area of a tenis court, how much light does it capture? Hint: It's not a tenis court's worth.
Go back to class this instant. I'll be sending a letter home to your parents.
* Advanced students may convert the units used in this example to microwales, but I fear that would've gone soooo far over the OP's head that it would've been lost :)
Given that the previous half century of trying to improve solar cell efficiency appears to have missed this particular design trick, I'd say "Yes. We have objective evidence that we *did* in fact need a professor to tell us this.".
And no, since the article suggests the effect depends rather less on simply increasing surface area and rather more on increasing the proportion of the surface that presents the best angle of incidence to incoming light. This isn't rocket science, but it isn't Physics 101 either.
Whatever the new procedures they may have brought to the process, the one thing they did NOT invent was the idea that roughening the surface could improve solar capture.
To the extent that this article may have given you that wrong impression, this article (and perhaps its sources) are in error.
I have only an observers interest in Solar Cell technology, but even I know that surface roughening techniques were being demonstrated and characterised 30 years ago.
At the time, it wasn't the idea that was innovative, it was the technical process. I imagine that continues to be the case.
If you "crinkle" the aluminum foil lining a solar cooker (aluminium to you Brits), instead of using it flat as it comes off the roll, you can actually get a nice crunchy cookie (biscuit to you Brits) or properly cooked biscuit (scone to you Brits).
Side note: What ever happened to the TransAtlantic English Translation tool that Sarah Bee proposed several years ago?
You guys describe scones as biscuits ??? That's just messed up. We left you with a perfectly good language and you just had to go tinkering.
Language mutates. Get used to it.
Good food is tasty, regardless of the name-tag or country of origin.
Dumpling, potsticker, ravioli, gujiya, samosa, wonton, mandu, pierogi, tortellini, modak, pelmeni, agnolotto, bao, momo, nikuman ... almost all cultures have the same basic food. If we stopped looking for differences and started looking for similarities, the world would be a much more peaceful place.
You seem to have omitted damper from your list.
There are many variants, but my favourite uses six cans of beer - one for the damper and the other five for you. The taste improves as you increase the number of cans...
"Damper"? That's an un-leavened flat-bread ... which most cultures also have a long tradition of producing. Johnny cakes, hoe bread, etc ... I was discussing stuffed, thinly rolled sheets of flour, salt, eggs, (and maybe a drop of water) wrapped around whatever is tasty & locally available.
Beer (also available in most countries) is always good ... and the ingredients are the same as bread and most pastas ;-)
"you can actually get a nice crunchy cookie (biscuit to you Brits) or properly cooked biscuit (scone to you Brits)."
Oi, since when has a scone been a biscuit?
It's a little cake.
The mind boggles.
It's a variation on the name of a basic food that most of humanity survives on. Live with it. Or don't. Your loss, not mine.
No, the mind boggles at "ho bred"
That's "hoe bread", twit.
A hoe is an ancient agricultural implement. Bread is a staple. Hoe bread is a grain-based product originally baked on the blade of a hoe.
Not certain why folks have issues with this. Probably lack of proper education.
It sounds to me like the leaves just implement a crude form of anti-reflective coating? So what's wrong with using a standard vapour deposited AR coating as used on optics, glasses (decent monitors), etc. ?
Most AR coatings are wavelength- and angle-sensitive. They perform differently when different wavelengths of light strike or when they strike at different angles. Usually what happens is that the resultant output of light alters. I believe the scientists are trying to reduce reflection without unduly altering the wavelength of light that comes out (since collectors are more sensitive to certain wavelengths). They may also give a leg up against AR coatings since most coatings aren't close to 100% effective.
Should we trust anything written in "Photonics" when they say :
... leaves' surface structures are “designed to bend and control ....
Surely that should be HAVE EVOLVED TO...
Nah, sleep easy.
There is a lot of 'created' that even on the telly the quotation marks can be heard - it's a bit lazy, being used as shorthand but it's fairly common.
( they do it to wind up thier fellow Evolutionists)
Efficiancy might be better in the lab, but stick one on your roof and the rough one quickly becomes gunged up with dust and sticky stuff, which simply slides off the smooth one. Efficiency gets compromised. There, you didn't need a professor for that one ...
I would have thought that covering the cell in a thin coat of transparent material that is smooth should sort that out.
Rough collection surface behind a smooth transparent glass/plastic for practical applications then? Question is can someone turn this research into a practical design without trading off too much efficiency.
"covering the cell in a thin coat of transparent material"
I'm not certain, but I think that would cancel out at least some of the effects. From what I understand, the "roughenning" improves efficiency at least in part because it stops as much light being reflected due to it arriving at the wrong angle. If you add a layer of transparent meterial over the top, that light will be reflected still.
I have not read enough about this to know 100% if I am right, but it makes sense to me from this article. If I'm wrong, I'm happy for someone to let me know :)
But considering how quickly smooth surfaces get roughed up and "hazy" after exposure to the elements (and thus takes on dust and sticky stuff ANYWAY), I would think the rough stuff has a leg up since roughening it MORE probably will have less of an effect while the drawback of attracting dirt isn't as big an issue as first seen.
Would a dewdrop shape that could collect light entering at most angles and reflect it towards a central capturing mechanism work the same way? I'm interested enough to throw it out there, but too lazy to think it through. Typical.
Prof' Green was doing sculptured surfaces on Solar Cells to capture more light YEARS ago at UNSW - http://www.greensolargroup.com/index.php?url=/default/page/118