Hairy Solar Cells Could Mean Higher Efficiency 203
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."
Anonymous Coward (Score:2, Informative)
Re:Anonymous Coward (Score:5, Informative)
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)
Re:Let me guess... (Score:5, Insightful)
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.
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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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a solar revolution.
So you cannot expect ppl to embrace a technology that
will impact their wallets.
The US is gearing up on Wind, and Solar, but not at the
pace it should.
The afore mentioned oil and gas folks are the likely reason.
We won't run out of natural gas for electricity any time
real soon, but the day is coming.
At the price of a nuclear plant, I'd rather see Solar Thermal
go in out in the middle of desert in the more lifeless sections.
I understand som
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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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to come online as other posters have mentioned.
http://en.wikipedia.org/wiki/SEGS [wikipedia.org]
Total Solar Thermal for just 10% of the Sahara is over
3 times all power used on Earth in 2005 at 40% Efficiency.
So for those who disdain Solar thermal, it could make
all the hydrogen for fuel cells for earth easily.
Setting up the system and managing it will be a Herculean
task thou.
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Not to mention that diversity is good. That way one problem won't take down the entire grid, like grounding all 747s because of a discovered serious problem wouldn't stop all air travel.
Personally, I'd be building nuclear plants while encouraging those who live in more southern areas to install solar water heating systems. Might even save more electric
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Thermal is currently 40% in some units,
and a prototype achieved 60%.
http://en.wikipedia.org/wiki/Solar_thermal#High-temperature_collectors [wikipedia.org]
Excerpt:
As the temperature increases, different forms of conversion become practical. Up to 600ÂC, steam turbines, standard technology, have an efficiency up to 41%. Above this, gas turbines can be more efficient. Higher temperatures are problematic because different materials and techniques are needed. One proposal for very high temperat
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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.
Effort actualy has to be put in (Score:4, Interesting)
I have 2 words for you (Score:2)
2. deserts
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Super heated molten salt is being developed now.
http://en.wikipedia.org/wiki/Molten_salt_battery [wikipedia.org]
http://www.ornl.gov/sci/scale/pubs/SOL-05-1048_1.pdf [ornl.gov]
A hybrid of ORNL plans and the prior link could be the
super solution to night energy storage.
Especially if you could use something like a giant empty salt mine.
http://simple.wikipedia.org/wiki/Salt_mine [wikipedia.org]
Re:Let me guess... (Score:4, Interesting)
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If you're talking about passive solar heating... They're an okay option, but don't provide any cooling (which is needed most when it's sunny out). What's more, as PV panels keep getting more efficient, so too do heat-pumps, which require electricity, not heat (...ignoring inefficient and expensive gas absorption units).
If you're talking about generating electricity via steam or the like, the laws
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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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Wikipedia will tell you how.
Electrolysis of water is the most straight forward method.
http://en.wikipedia.org/wiki/Hydrogen_production#Electrolysis [wikipedia.org]
The pond scum method will most likely be the cheapest at
some point.
http://en.wikipedia.org/wiki/Biological_hydrogen_production_(Algae) [wikipedia.org]
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Sure, it'll be cheaper and more powerful in the future. But they were running a business and the expected savings would pay for the systems in less than two years with an expected lifespan of at least five.
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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.
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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
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Re:Nanowires are nice and everything... (Score:5, Funny)
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Your average silicon PV cell is 12% efficient. That means that for every watt of electricity out, 7 watts goes into heating up the cell, and very little gets reflected back out (since they are black).
A white or light-shaded composition shingle roof would reflect about 30% of the light energy hitting it. While an asphalt shingle generates no electricity, it would absorb 20% less heat than the
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Probably fairly little. You could get the same effect by putting something that's not solar panels (and therefore much cheaper) on your roof, or a larger effect by spending the money you'd spent on solar cells to improve the insulation of your house (provided that there's still potential to do so, i.e. the house isn't wrapped in 12 inches of insulation yet).
You could also try to shade your wind
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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.
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Maybe you mean Carnot [wikipedia.org]? More importantly, if you have a source for this assertion, I'd be very interested in reading it.
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take a look here http://www.ese.iitb.ac.in/aer2006_files/papers/086.pdf [iitb.ac.in]
While local temperatures don't effct the PV Carnot efficiency, the surface temperature of the sun does.
The sun is about 6000K. Locally we are 300K calculate it out and you get a maximum efficiency of about 95% (my mistake...off by 3)
However 80% is a much more realistic end point for consumer grade equipment. Even 50% would bring the cost down to less than ANYTHI
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world and can make power, so spread the power generation
across all 24 time zones and use long haul transmission.
The long haul losses for the US are about 7.2%
http://en.wikipedia.org/wiki/Electric_power_transmission#Losses [wikipedia.org]
So all those Anti-solar idiots out there can stop fondling
their fossil fuel shares, and face the fact that 3% of
the Sahara at 40% efficiency could replace all other forms
of power on earth alone.
Spread it across all 24 time zones
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Germany produces more power from solar than the whole US.
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They may be the world leader, but I'd argue that it's not helping them as much as nuclear power is helping France, which, on average is a electricity exporter.
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might be the trick as the clouds don't effect the tides.
http://en.wikipedia.org/wiki/Tidal_power [wikipedia.org]
You could also put solar power plants in different areas of
the EU and use long haul transmission to carry it to
areas covered by clouds.
Long distance losses are around 7.2% in the US.
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.
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http://en.wikipedia.org/wiki/Electrical_impedance [wikipedia.org]
Look at the impedance for an inductor (which any power line is). It's i * omega * L. L rises with the length of the line. Omega is 2 * pi * f. f for DC is zero (duh!), for AC it's, generally speaking, some positive number. Higher impedance means transmission losses in addition to the purely resistive loss (which does not depend on the frequency).
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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
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Yeah, not much solar power hits the earth:
http://en.wikipedia.org/wiki/Solar_energy#Energy_from_the_Sun [wikipedia.org]
2.5 acres makes 354 Mega Watts
http://en.wikipedia.org/wiki/SEGS [wikipedia.org]
I swear your daddy must work for big oil, or you are just
as smart as a bag of hammers.
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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But the cost of power is based on more than cell efficiency.
For instance, nanocell solar cells are proven and produce power at 0.15 cents a KWH. this is done at about 7 percent efficiency. Coal power typically costs about 0.10 cents a KWH. This is possible because the cells are so cheap and can be placed in "useless" areas like residential siding and roofs. This tech is expected to reach rf percent efficiency at the current price point in 5-10 years.
There is enou
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Of course, clean coal is much more expensive, quite possibly making it more expensive than building nuclear plants. The level of cleaning/scrubbing making coal clean is expensive.
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Coal prices vary but the average has NEVER been below 7 cents a KWH (adjusted to today's dollar) before distribution costs. Those that are that low are typically from non-profit co-op type organizations.
For profit power companies charge anywhere from 8 cents up to 15 depending on market forces (again average).
Finally even is you WERE right and it did cost 4-6 cents before distribution costs, we are ta
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natural gas here in Oklahoma.
Lots of NG electricity for you... (Score:2)
NG generally has cheap construction costs and expensive running costs. But you probably have substantional cheap NG deposits.
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Some were so massive when they came in they caused minor earthquakes.
There are literally dozens if not hundreds of them.
Oklahoma is the 3rd largest Natural Gas producer in the US.
Suprised we use any coal at all.
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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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I live in the center of tornado alley, and my house
is 55 years old, and my friend's house is 70+ years old.
Neither of these houses have been hit by a F0-F5.
Some day that will happen, but I may not be alive to see it.
There are lots of homes around me that are over 50 years
old and none of them have been hit.
A few areas in central Oklahoma seems to be a tornado magnet
Moore and Edmond, some areas almost never get hit,like Norman.
I have no idea why, just a observation of t
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Do you happen to have a source on this? All the times I've figured it, it's around 10X as much.
4X might be with some of the high levels of subsidies and such. Or a large solar thermal installation, which photovoltiacs don't figure into.
Or maybe it's compared to retail electrical prices, and doesn't include support equipment such as the inverter.
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However with nanosolar's thin film cells the price can drop to about 1.5X coal (although space could become an issue).
Currently the payback period for a full off-grid residential solar system is on the order of 7-10 years. (Cited all over the place) This is in line with the roughly 4X for conventional silicon cells.
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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.
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I agree with you, the significant obstacle isn't the efficiency of solar panels. It's the cost of them, more so than the space they take up.
If we could produce solar panels that were half as efficient as current panels for the cost of a ream of
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Add the long term cost of the Iraq war, and the future
war in Iran onto the cost of your petro power.
It is not so cheap anymore.
If the long term projected trillions of dollars went to a
Solar Thermal array like the SEGS system we could
power the earth with 10% of the Sahara Desert
3 times over replacing all forms of power including
oil, coal, nuclear, wind, hydro.
In 2005 total world energy usage was 15 Tera Watts,
the 10% se
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the government (neither state nor federal) does not dare to tax gasoline heavily.
There, fixed that for you.
(And don't start whining about those few cents per gallon. With "heavy", I mean that more than 50% of what you pay at the pump is actually taxes.)
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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"Do they make a spherical version"?