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Not Transparent Aluminum, But Conductive Plastic
michaelmalak writes "Scientists at the US Department of Energy's Brookhaven National Laboratory and Los Alamos National Laboratory have fabricated transparent, thin films capable of absorbing light and generating electric charge over a relatively large area. The material, described in the journal Chemistry of Materials (subscription required), could be used to develop transparent solar panels or even windows that absorb solar energy to generate electricity. The material consists of a semiconducting polymer doped with carbon-rich fullerenes."
Sounds like this would be great for skyscapers, where you have huge windows all the way up and direct sunlight for long periods of the day.
to a manufacturer in China..
I assume they'd act like tinted windows since they'd be absorbing some of the light.
car windows which gradually charge the battery perhaps?
Now when we run out of indium-tin oxide(or the chinese just stop selling it to us), we can still make LCDs, OLEDs, and EL wire.
This is the kind of implementation that actually makes sense. You don't need dedicated hardware or real estate to set it up. Granted northern exposure probably would work but put this stuff all over southern exposure windows in a whole city and tie it all onto the grid. It's akin to not using food crops for biofuels. Algae and switch grass make more sense.
Now the big key is getting the cost per kilowatt down where it's competitive with traditional power generation. And of course you really need a large scale storage system. I remember a Popular Science article about giant underground flywheels.
the question is, transparent to what, really. If it's opaque to everything _except_ human-visible light, that's still a pile of the spectrum and of energy.
-- Who is the bigger fool? The fool or the fool who follows him? --
It's transparent because the film has a hexagonal structure - extremely thin (and therefore transparent) at the center of the hexagon, thick (and therefore opaque) at the edges of the hexagons. The electricity is generated at the edges, as that is where the light is absorbed and that's where all the electrons are ready to be knocked off their molecules. It's not blocking certain wavelengths and allowing others through (well obviously to some degree it is, but not in the visible spectrum). It's blocking light in certain parts and allowing light through in others.
It's basically going to tint the windows, how much will be determined by how densely the hexagons are packed - more hexagons means more electricity but also a darker tint.
Security is mostly a superstition... Avoiding danger is no safer in the long run than outright exposure. - Helen Keller
Some links that have more information, without having to give money to the Chemistry of Materials:
http://news.discovery.com/tech/material-could-collect-sunlight-from-roof-and-windows.html
http://www.lanl.gov/news/releases/scientists_produce_transparent_light-harvesting_material.html
Oh, and one more thing:
Buckminster Fuller strikes again! AHAHAHAHAHAhahahahahaha... hah.
--
I want my Dymaxion
This work is licensed under a Creative Commons Attribution 3.0 Unported License.
It's transparent because the film has a hexagonal structure - extremely thin (and therefore transparent) at the center of the hexagon, thick (and therefore opaque) at the edges of the hexagons.
Actually it's a little bit more interesting than that. In addition to being thinner at the center, the light-absorbing polymer is not well-ordered (amorphous) in the center region, which leads to it being worse at absorbing light. At the edges of the hexagons, the polymer orders better, which allows it to absorb light more efficiently. This makes the structure more intelligent, in principle: if the honeycomb structure acts as one half of the conduction pathway (necessary for a photo-voltaic), then it makes sense to have the material close to it do the light-absorbing, and have the material further away (center of hexagons) which cannot participate in light harvesting, just be transparent. So this in principle allows one to design more efficient semi-transparent solar cells.
Peeling back the layers of hype a bit, however, these kinds of solar cells are horribly inefficient. The best materials we currently have to make plastic solar-cells ("organic photo-voltaics") have pretty poor efficiency. Making a solar cell that's semi-transparent just makes the efficiency (per unit area) even worse. But, this is fairly fundamental research: by demonstrating that they can tune the light-absorbing capabilities of the polymer based on its ordering (and control ordering by using the honeycomb patterning and preparation parameters), this provides useful information about how to make higher-performance plastic solar-cells. So this research may actually end up being more important for conventional solar cells ('opaque') than it is for window-coating solar-cells or whatever.
P.S.: The materials used in the paper have an absorption maximum at 503 nm (green), so they probably create a purplish tint. The absorption spectrum can be tuned to change the tint, however this will impact the solar collection efficiency.
Disclaimer: Some of the co-authors are colleagues of mine. However I wasn't involved in this work in any way.
What's really going on in solar is that big US companies with real manufacturing expertise are moving in.
This is where the action is. Solar is a heavy-manufacturing business, and it's the companies with experience in running big factories that are now taking over.
your efficiency per square foot may be crap, but your square footage can be huge. That's assuming, of course, this stuff ends up being cheap. The manufacturing process should be ultra cheap, but I don't know about producing the solution. It should be a lot cheaper than traditional panels, but will it be cheap enough to make it worth it? That's the question.
That's exactly right. The promise of organic photo-voltaics is that they will be so much cheaper to produce that the lower efficiency won't matter. But one of the harsh realities is that a photo-voltaic setup has certain fixed base costs (think of how much it costs to physically install each 1 m^2 panel, and tie it into a house's electricity system). Thus, according to industry partners, there is actually an efficiently level below which a solar material is not worth using even if it were completely free to produce. So, for organic solar cells to become commercially viable, they need to improve efficiency, even while reducing costs. Of course we're now reaching levels where it is indeed viable to use organic photo-voltaics, see for example Konarka's flexible solar panel that is built into a bag, so that it charges your cellphone; but there is a threshold of efficiency necessary to offset fixed installation costs.
How can a transparent thing absorb a large fraction of the energy? This sounds like an oxymoron.
Some drink at the fountain of knowledge. Others just gargle.
That may be true, but I know for a fact that a lot of entrenched industry on the old money energy side hates the idea of solar and has gone way out of their way to make it not happen, because it threatens their business model. Solar can break the perpetual check to them, because eventually it can be paid off. You can NEVER pay off your local utility monopoly, and that's the way they like it. And speaking of hybrids, read up on large NiMH batteries and chevron, an oil company and how they bought up the patents, etc and then sat on it, refused to license it, making manufacturers start from scratch an building large ones, helping delay electric vehicles. Toyota had to develop their own, when it already existed!
Any way, back to solar. I've been into it for decades now, and back in the old days we had to do "guerrilla solar" (and also wind chargers, which are sorta hard to hide) because damn if you could get a "permit" to install it. Local electric company guys would get to the building inspectors (read:bribes) and no matter what, they wouldn't "permit" it, so we had to do it stealthily. This was on purpose, conspiracy, market manipulation stuff. You can google "guerrilla solar" for some stories about how much of a rip it was. Home Power mag has a lot of it in their old back issues.
I have NO doubt it still goes on with amazing solar breakthroughs, the patents get bought, then poofed away, stuff like that.