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Solar Power-Cell Breakthrough
An anonymous reader writes "Researchers from the Nanomaterials Research Centre at Massey University in New Zealand have developed synthetic dyes that can be used to generate electricity at one tenth of the cost of current silicon-based solar panels. These photosynthesis-like compounds work in low-light conditions and can be cheaply incorporated into window-panes and building materials, thereby turning them into generators of electricity."
This is a very interesting collision of physical and organic chemistry. Discoveries like this are why I (and I'm sure many others) find myself (themselves) becoming a() bigger and bigger advocate(s) of solar power every day. There is so much power streaming out of the sun. really, every single power source on the planet (save perhaps nuclear) derives from a solar process. Our beloved/lamented fossil fuels wouldn't exist without the creatures that created those fossils -- creatures who ate plants, ate something that ate plants or were actually plants themselves: plants use the sun.
;)
:)
Even hydroelectric power owes its existence to the sun. Perhaps in very ancient times evaporation didn't require a star close by due to the young, heated surface of the planet. But today's surface temperatures just won't cut it without our friendly star.
Wind power...well, I'm not really saying anything new here. Everyone feel free to cringe at the thought of the inefficiency of grain ethanol!
Basically, if you are an advocate of nuclear power as clean power, well then you should probably turn your fandom towards the biggest nuclear power plant in the solar system...of course, I've personally got no problem with some breeder and a couple dozen pebble-bed reactors - just saying
So what if we are just consuming its leftovers, with a giant picnic like that we ants can be assured of a bountiful feast of crumbs
Which brings me to my point which I had forgotten.
These researchers have taken a hint from nature's own, good-old photosynthesis. So to me, it seems as though we have cut the hydrocarbon out of the solar-food-chain. Rather than waiting a couple million years for plants to convert sunlight into food for themselves and other creatures, die off and then turn into black, sweet, sweet crude; we simply cut out the middle-men/middle-dinosaurs and make direct use of the sun's bounty.
Solar-power is the most elegant power source yet discovered. Now to harness it cleanly.
My Computer Music Tutorial Videos
Photosynthesis isn't a compound; it's a process.
here are the coral links. site is slashdotted right now so I dont know when it'l get cached.
t ml / Press_Releases/04-04-07.html
http://www.stuff.co.nz.nyud.net:8080/4017784a13.h
http://masseynews.massey.ac.nz.nyud.net:8080/2007
09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
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First, Ti in any form is not particulary common, and good ores with an economically valuable Ti percentage are hard to come by (though NZ and AU are were most of it is found). Our current known reserves of good Ti ore are projected to run out by mid-century, but I always buy these projections with a bit of skepticism.
That being said, the amount of Ti used in such a panel is trivial, because the layer's thicknesses are measured in nanometers and microns. Your golf clubs have as much Ti as a football field of such panels. Refining of TiO2 to Ti metal is expensive and energy intensive, and I presume it is necessary in order to make these panels, even though the panels actually use TiO2. The process is probably Ti02 ore -> Ti -> TiCl4 -> TiO2 nanostructures. This is because the TiO2 in the panels needs to be extremely pure, and TiCl4, being a gas, can be distilled. It is then mixed with water under controlled conditions to release HCl and produce the nano-particles/structures necessary for the panels.
This article seems mostly hype to me. TiO2 nanostructures along with various dies are heavily researched around the world, with thousands of published articles. Since the article has no data, I presume all that happened was that these guys beat the previous efficiency record by a whee bit. The problem with these types of cells is that the efficiency still sucks...around 5% vs 20% for a standard silicon-based cell, and 40% for top of the line multi-junction cells (which are enormously expensive and are currently used for things like satellites or the Mars rovers). In a typical silicon cell, the silicon is about half the cost of the final package (not including the inverters, installation and all that jazz, however). Therefore, even if these TiO2 and dies cost ten times less, that won't even reduce the cost by 50%...and then you need several times the acreage to collect the energy you need.
For now, and for at least another decade in the future, silicon is king. Unfortunately, it is very expensive and there is a serious demand crunch right now, driving prices even higher (though many silicon manufacturers are heavily ramping production to solve this).
Weird article. Lessee.
>Dr Campbell said that unlike silicone-based solar cells, the dye- based cells are still able to operate in low-light conditions
I'm unfamiliar with these silicone-based solar cells: are those the ones you tape on Pam Anderson's breasts?
Titanium/titanium dioxide? All the dyes they talk about are organic: porphyrins are heterocyclic aromatics that complex a metal ion in their centers. Not titanium dioxide, the compound: a metallic ion all by itself. Probably iron or magnesium. Ditto hemoglobin.
With those complaints aside, one of the neat things about using naturally produced chromophores is that, well, they're naturally produced, so we could get them in enormous quantities. Similarly, they can be tuned, so you could have ones that absorb different wavelengths of light, with high efficiency, stacked, to extract more energy out of the sunlight than a single-bandgap cell like most photovoltaics.
But essentially they're trying to replicate the behavior of plants, and rather than messing about with dyes in solution, it seems way more productive (although, clearly, harder) to try and get plant cells to do this for us: harness the ion gradients in their chloroplasts, parasitize their electric potential. Most of the machinery is already there. We just need to get the voltage potential outside the cell.
Nostalgia's not what it used to be.
Hmmm...according to his published papers this news brief is all wrong. these things get 0.14% conversion efficiency in nearly full sun. Bah.
Some drink at the fountain of knowledge. Others just gargle.
An earlier poster made an passing reference to Gratzel cells. From the Wikipedia article this does indeed appear to be what TFAs are talking about: dye-sensitized solar cells. The Ti is not part of the porphyrin dye, but is actually as the oxide, TiO2. A photon stimulates an electron to transfer from the dye molecule to the conduction band of the TiO2. (Iodine is also involved as part of the cycle, at least as described above.)
The wiki mentions a Swiss 7% efficient experimental cell (using some exotic dye) that's highly resistant to temperature degradation. Theoretical efficiency can go to 33%. TFA doesn't mention their efficiency, although their "most efficient" claim would indicate higher than 7%, anyway. Question is -- as earlier poster mentions -- how robust they are.
-- Alastair
Moderating my parent comment Overrated before it has even been up-moderated is an abuse of the moderation system. It is abundantly clear that the moderation was used in this case because someone did not agree with me, and knew that any other negative moderation would be denied in metamoderation.
The individual who did this is an enemy of slashdot, and is actively working to make the system not work - not that it needs much help, since the issues with the "Funny" and "Overrated" modes are a design problem.
The Overrated moderation provides an end-run around the system, and should be abolished.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Great stuff, hardly news though, it just seems like the same thing as some Swiss lab has been working on for years.i cleID=0002C2E1-17B2-1508-97B283414B7F0000
Publications: http://isic2.epfl.ch/page58678.html
Some press coverage: http://www.sciam.com/article.cfm?chanID=sa025&art
Products?: http://www.solarisnano.com/solarenergy.php
These guys already have that technology and are about to start production. http://www.nanosolar.com/
There is something wrong with their system. I have an off grid house with a mere 6x75 watt panels and 4x6volt deep cycle batteries, and we could run a microwave off the inverter for a short while if we had to. Such a system today would cost lsubstantially less than $10K. My neighbor has 3.5KW of panels, runs a software development business out of his house, and has one of those electric/oil heaters to burn off excess electricity on really sunny days. They only run their generator on cloudy winter days.
We have plenty of space. Are you using your roof for anything important? (Maybe you live in an apartment, so putting them on the roof never occurred to you...?) Even with today's solar panels at ~20% efficiency, people can and do power their entire homes with solar using just their roof space - although, it depends largely on how much power you use, obviously.
Even if you could only power 1/10th of your home, it would be worthwhile if it were cheaper than grid power - and that's not even considering the environmental benefits.
Space efficiency isn't really the issue with solar power. The important factor is cost.
Your number is averaged over both day and night over a year and works for southern Canada, here is a map: http://upload.wikimedia.org/wikipedia/en/7/78/Inso lation.png. As you can see from the map, much of what
is going on is that the Earth is round so that surface is tilted with respect to the average direction to the
Sun. Solar panels are tilted back towards the Sun so this compensates though there is still a larger airmass
and so a larger likelihood of having a cloud in the way. A number closer to 300 w/m^2 is a better estimate
because of the tilt. In a month of 30 days you get 32 kWh from a sqaure meter of 15% efficient silicon
solar panel. So, you want about 31 square meters of panels to handle a 1000 kWh monthly power usage. That's
about 5.5 meters on a side. You can get that much for the same that you are currently paying for grid power
at http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html and fix your rate for up to
25 years, so yes, it probably is worth it.
STA, "sustainable technologies australia" have been working on the Gretzel cell photovoltaic cells for 15+ years.
its nothing new, but its not a developed or reliable technology, it still has a LONG way to go.
and the energy equation verses lifespan for manufacture does not work at present, also the reliability is not great.
to get good performance from these calls, also required using some chemicals that are know carcenogen and have been banned in many (most) research organizations.
so far, silicon, is way ahead of this technology, but also silicon cell have had a HUGE amount more R&D funds ploughed into it
these cell try to emulate what a leaf on a tree does, its acutally better simply to grow a plant and turn it into fuel.
nature is better in this respect that our attempts at creating the same technology by using the "gretzel cell" active die photovoltic system.
Finally keep in mind,,
"SOLAR IS NUCLEAR"..
"Here's the problem with that: even if we started cutting back our CO2 output (disregarding all of the other pollution we put out that's causing us problems now) by 1% cumulative per year it would still be a long time before we stopped putting out more CO2 than the system can ordinarily handle."
Considering that nobody knows what "ordinary" is, it's kinda hyperbolic of you to put this forth.
Also there's the fact that its quite possible that the CO2 levels are actually an effect of global warming and not vice versa. You know, the planet warms up, the oceans (think BIG CO2 sink) release more CO2.
Oh wait. I can't talk about that! Taboo! Must silence me because I don't scream doom about global warming! I must be a global warming denier.
Sorry to say, I'm not. I believe global warming is happening. I just don't believe the radical view that humans are the primary cause.
"Even if we stopped emitting CO2 today, aside from that which is absolutely necessary, there would still be too much CO2 for quite some time to come."
Especially since it's still being released by sources outside of our control.
"but coral reefs have been hurting badly and the acidification of the ocean due to CO2 gas exchange is implicated."
Please tell me you have some cockeyed plan for cooling the oceans to slow down the CO2 release from the gradual warming.
God I need a laugh.
"CO2 is also toxic and even small increments in the percentage of the atmosphere it makes up causes health problems including dizziness, nausea, and general malaise."
Small increments? The concentrations you're talking about are so far in excess of where even catastrophic CO2 scenarios place levels that we'd need several HUNDRED years of ever increasing CO2 output (and sustained, spiked warming trending) to reach that level.
"The point is that we really needed this technology decades ago, and we're already late on getting started using it. "
Just like we "needed" asbestos for a flame retardant. Just like we "needed" lead in gas and paint. Just like we needed thalidomide as a sleep aid for pregnant women.
Or do you mean "like we needed 45 nanometer IC technology back in the 50's"?
You can't rush materials technology. Developing useful technologies takes lots of time, money, and effort. Trying to force a "breakthrough" just winds up sending you down dead ends. In some cases, "dead" is more than just a euphemistic turn of phrase.
"I cannot disagree strongly enough."
But strength of conviction doesn't equal strength of argument.
"If we could actually follow the so-called radical agenda, which I like to call the rational agenda"
Radicals always do...
You said it yourself. Completely turning off consumption of fossil fuels and other pollutants isn't going to fix this problem now. Or even in the near future. Or even in most people's lifetimes.
BUT, going cold-turkey on it right now would have one major effect. It'd destroy civilization as we know it. There are NO viable replacements IN PLACE RIGHT NOW.
Yeah, it's every anti-capitalist, anti-corporate, anti-industrialist's dream. But for just about everyone else who's taken at least two seconds to look at it OBJECTIVELY, the very idea SUCKS. And there's no government in the world, no matter HOW crazy, that'd go for it. And since it'd take government intervention to stop the private sector...
"since we all live in the atmosphere and we will all suffer if it becomes less hospitable to human life"
IF.
Howsabout this?
""Since we all live in the atmosphere and we will suffer if an asteroid crashes into the planet.""
"But without them asking for a certain level of change, we would be unlikely to have even the positive change we are currently implementing."
Don't have a very high opinion of your fellow man do you?
Chas - The one, the only.
THANK GOD!!!