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Hairy Solar Cells Could Mean Higher Efficiency
Posted by
ScuttleMonkey
on Mon May 19, 2008 04:40 PM
from the warm-fuzzy dept.
from the warm-fuzzy dept.
kitzilla writes "Two research groups working independently have come up with what they say are cheap processes for growing nanowires to be used with solar cells. The 'hairy' cells provide a direct path for electrons collected at the panel face to reach an electrode, something which has the potential to dramatically improve system efficiency."
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Science: Nanowires of Unlimited Length 111 comments
StCredZero writes with word of a research team from the University of Illinois who have developed a way to manufacture nanowires of any length from various materials. Not, unfortunately, carbon nanotubes, or we would be looking for news on space elevators soon. The process is analogous to drawing with a fountain pen — as liquid is drawn from a reservoir, a solvent (water or an organic) evaporates and the solute precipitates onto a substrate. The researchers have demonstrated a way to spin and wind a nanowire onto a spool; they have produced a coil of microfiber 850 nm in diameter and 40 cm long. Here's the abstract from the journal Advanced Materials.
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Anonymous Coward (Score:2, Informative)
Re:Anonymous Coward (Score:5, Informative)
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Let me guess... (Score:5, Funny)
If every solar cell advance that was announced actually led to improvements of solar cells you could actually buy, then they would be 99.9999999% efficient and cost less than crackers.
But I'm not bitter, nooooooo.
Re:Let me guess... (Score:4, Informative)
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Re:Let me guess... (Score:5, Insightful)
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Re:Let me guess... (Score:4, Interesting)
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Re:Let me guess... (Score:4, Insightful)
I don't see its proved anything of the sort to be honest. Unless the poster who made the original suggestion is in a position to bring this product to market himself, and was willing to make what I assume would be a large investment to do so without the benefit of any patent protection, then no one has lost anything. On the flip side the patent holder may be able to find an investor willing to back development of the technology; it would be considerably harder to do so if the investor knew that if the product was a success, they'd have to very quickly face competitors selling identical products who didn't have to make as large an initial investment.
Disclaimer: I know crap all about solar power or the validity or utility of this particular patent; I'm just trying to make a distinction between the development of software and that of physical inventions.
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Re:Let me guess... (Score:4, Informative)
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Wow, are u clueless or what (Score:4, Informative)
In addition, it is fairly easy to store the heat in salts and generate during the night. Spain, Arizona, New Mexico, Northern Africa, etc. are all headed in GW size of solar thermal. Spain expects to sell power back to its northern neighbors at a tidy profits. Arizona has a 1/4 GW install going in. In addition, another group is close to building a 1/2-3/4 GW in NM or southern CO (possible to take advantage of 3 different power companies and 5 states incentives).
All in all, the only joke is a fool like you.
Parent
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in systems large enough to generate megawatts of electricity there are solutions to this problem, but systems meant to be installed on top of a residential roof are notoriously bad for needing to be repaired every season, for some unlucky souls...
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Planned installations chasing incentives are a far cry from power plants installed to meet grid needs.
24h power (storage and retrieval of energy) is unnecessary system complexity when you are not looking to replace the current grid, and at their current level of deployment (nil, pretty much) this is not a concern. You might want to co-fire with natural gas to avoid thermal cycling of your plant like they do at Kramer Junction in CA, but that's beside the point.
Furthermor
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36% in concentrator cells, but they'll be stuck in the lab for quite a while, and will probably be infeasible for large installations.
Thermal is currently 40% in some units, and a prototype achieved 60%.
That's the efficiency of the turbine itself. The plant will have some additional losses (not all of the sunlight hitting the area of the plant will actually be collected, etc).
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Re:Let me guess... (Score:4, Insightful)
Generally solar is good as long as the sky is clear. Imagine what would happen to a 100% solar economy hit by a month of thick clouds. I don't think relying on something as random as the weather for your main energy supply is a good idea. It's OK e.g. when you want to power farm machines, because if there's no power you can wait, but powering cities with it doesn't seem wise. I also think that green activists should stop pretending they can do without nuclear power (at least those of them that do), because right now they can't, and telling everybody not to invest in nuclear and wait until we come up with adequate energy storage technology is making the global warming worse by preventing substantial CO2 emission reductions.
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Effort actualy has to be put in (Score:4, Interesting)
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Re:Let me guess... (Score:4, Interesting)
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</Homer Simpson>
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Re:Let me guess... (Score:5, Interesting)
I just invested in a PV system for my house (in sunny SoCal). As a computer geek, I asked our guy if it was stupid to invest, since there always seem to be efficiency breakthroughs on the horizon.
He reminded me that efficiency generally meant "smaller" and perhaps "cheaper". But since my roof was plenty adequate for what I needed, "smaller" wasn't really an issue. Cheaper will ALWAYS be the case, as it always has been.
Don't get frozen by the thought that solar power isn't worth investing in today. It totally is.
Adman
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Re:Let me guess... (Score:4, Funny)
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Sheeit Negro, that's all you had to say! (Score:2, Interesting)
Know what would rawk? A 5 year moritorium on new PV cell research so we could get some actual PV cell production going.
Lab advancements != commercially viable (Score:5, Insightful)
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Give this technology another 20-30 years, maybe even less, and the advancement of production will drop the price.
Nanowires are nice and everything... (Score:2, Informative)
Re:Nanowires are nice and everything... (Score:4, Interesting)
I also always wondered why people don't advertise how much cooler CFL bulbs are than incandescent bulbs. I replaced 480W of lighting in a bathroom with 72W (replaced 60W clear bulbs with 9W vanity CFLs) and not only is it brighter and the light softer (and thus makes ladies feel prettier when doing whatever it is they do for hours in bathrooms) but it's a lot cooler. And they will pay for themselves in roughly 13 months.
And similar swaps make a really significant difference when sitting under the 5-bulb light that is just above the dining table. A friend of mine used to unscrew some of the bulbs when she did homework.
So basically now I save electricity while saving electricity.
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Now we just need affordable dimmable CFLs for that dining table fixture, and low-wattage CFLs wi
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Also, in Texas, your average living room is larger than Italy, but tha
Re:Nanowires are nice and everything... (Score:5, Funny)
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Dramatic efficiency improvements unlikely. (Score:5, Informative)
Add in to this that a large part of the cost of solar is the energy needed to produce the cells, which means that if you get that energy from a more expensive power source, the price of the cells will increase. I.e, if one started to replace relatively cheap generation capacity with more expensive solar cells, then the cost of energy, and hence the cost of the cells, would increase.
It would therefore appear to me that for solar to have a chance to become competitive what is needed is focus on lowering the cost of producing the cells, because the gains from improving their efficiency cannot offset their presently large price, and it appears unlikely that pushing for higher and higher efficiencies will be possible without making the cells more expensive.
Re:Dramatic efficiency improvements unlikely. (Score:5, Informative)
Therefore getting to the 80-90% range would result in a 5-18X improvment.
Since solar is currently 4X, that means it will drop to
Now remember that hydro is essentially 100% tapped. Wind has a much more limited range and is already approaching the likley maximum efficiency. Nuclear is great but will take some time to spin up. Oil/natural gas prices are climbing rapidly and coal is becoming more expensive to mine and or clean.
Solar PV provides a great load matching power source that will help reduce an individuals demand on the system even if it doesn't complely remove the need for other power sources as well.
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While I am not a "tree-hugger" I am a "tree-shacker-hander"
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Re:Dramatic efficiency improvements unlikely. (Score:4, Informative)
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The downside is that we are unlikley to improve much because of Karnat restrictions.
PV has a Karnat limit of about 98 percent. Therefore while at the moment thermal is better for large power plants, PV will eventually pass thermal. We are already pretty close efficiency wise to storing electricity cost effectivly.
Thermal is great for now.
Re:Dramatic efficiency improvements unlikely. (Score:5, Interesting)
Just to be contrary: at least in theory, solar COULD supply base-load. All you need to do is integrate the Earth's power grids. Then you'd have a more or less constant amount of current available throughout the grid.
Of course, this isn't practical - even ignoring the political implications, transmission losses would create serious problems. Getting away from AC current and using DC for all grid transmission could fix part of that problem, but that's not likely to happen any time soon.
And yes, you're certainly right about nuclear. Realistically, it's our best option at this point in time. That's one thing that France got right.
Parent
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There are, of course, disadvantages as well. In particular, HVDC doesn't really work well for a grid, only for point to point links. So if you want to move power from one AC grid to another then HVDC makes sense (8GW link under the English Channel for example - note that England and France use the same frequency but different phase - and the angle (presumably) isn't constant - so you'd probably have to use a DC link although that could
Re:Dramatic efficiency improvements unlikely. (Score:4, Informative)
I said 4X WIND POWER costs. Not current power costs. Britain's Royal Academy of Engineering estimates the cost of wind power at roughly 3 times that of nuclear, so even if you achieve 90% efficiency that would put you at roughly twice the cost of nuclear generation ( assuming 15% efficiency for present cells ). Now, to give an idea of how hard 90% efficiency would be to reach, the Sun's average surface temperature is 5778K , meaning a solar cell at 300K could at best reach 95% efficiency without violating the laws of thermodynamics.
That is, ignoring ANY other problems you are closing in on the theoretical limits allowed by the laws of physics if you are to get such efficiencies, and you have to do this without increasing the costs of your cells. Any dust on the cells and you can forget it. Protective glass coating is a no-no since it would absorb in the UV range. Heck, simply finding a material that is reasonably transparent at all the relevant wavelengths could be tricky. Add in to this that you cannot use any expensive/toxic/rare elements, that the cells should have to last for a long time, that they should survive a wide range of temperatures and be able to handle a reasonable level of abuse, and it becomes far from certain that it is even possible to reach 80% efficiency, let alone to do so in the foreseeable future.
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wind is nowhere near tapped.... i think the Department of energy once found in a study that wind power plants could provide up to 40% of the energy needs of the US, overall, the problem though, i
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At SOME point the bullet has to bitten as far as cost goes somewhere. Oil and coal aren't going to stick around for ever.
Fraud alert ... (Score:5, Funny)
Wow, ANOTHER solar cell breakthrough (Score:5, Insightful)
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Re:Not first (Score:5, Funny)
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