Self-Assembling Photovoltaic Cells 103
dhj writes "MIT scientists have developed a self-assembling photovoltaic cell in a petri dish. Phospholipids (think cell membranes) form disks which act as the structural support for light responsive molecules. Carbon nanotubes help to align the disks and conduct electricity generated by the system with 40% efficiency. The assembly process is reversible using surfactants to break up the phospholipids. When filters are used to remove the surfactants the system reassembles with no loss of efficiency even over multiple assembly/disassembly cycles. The results were published September 5th in Nature Chemistry."
Like this story from before? (Score:5, Informative)
Re:Like this story from before? (Score:5, Funny)
Re: (Score:3, Informative)
It seems to have added extraneous apostrophes in the process. Check your code. It's means "it is".
Re:Like this story from before? (Score:4, Funny)
The exce'ss apostrophe's are their on porpoise. They have been found to attract troll's more affectively.
Re: (Score:2)
Yes. The story was disassembled into it's component letters and then reassembled to harvest more Slashdot trolls. Recycling at it's most efficient.
Did you mean self-assembled?
Re:Like this story from before? (Score:5, Funny)
Naturally the only logical conclusion for the dupe is that MIT News hired some Slashdot editors.
Re:Like this story from before? (Score:5, Funny)
To be fair, the article on MIT's site is dated "September 7, 2010." Naturally the only logical conclusion for the dupe is that MIT News hired some Slashdot editors.
That's not possible. The grammar of MIT's articles is far too good. It doesn't contain spelling errors that a basic spellchecker would have fixed. It doesn't have links to stories that are behind a paywall when freely accessible ones are also available. It doesn't needlessly link to someone's blog when articles a bit closer to the primary source are readily available. If it has the occasional blatant factual error that the slightest and most basic fact-checking would have corrected, this remains to be demonstrated.
To reiterate, there's no possibility that MIT News has hired some Slashdot editors. They probably list "ability and willingness to run a quick automated spellchecker" and "familiarity with English grammar" as requirements for their editors. They have little incentive to engage in the other practices I listed.
Incidentally, it's not an instance of a "grammar nazi" when you expect paid professionals who call themselves "editors" to either correctly and consistently use basic spelling and grammar or, failing that, call themselves something other than "editors." Maybe "reposters" would be a good title. The standard and the expectations are higher for "editors" who draw a wage. It's not the same situation as the Slashdot users who post for leisure and are nit-picked over issues of grammar.
Re: (Score:3, Funny)
If this is what's going to happen from now on, then I'lll start recycling my posts:
"Slashdot has become so big that the left hand doesn't know what the right hand is doing, and neither hand actually READS Slashdot..."
(originally posted on Friday September 10, @04:20AM)
Re: (Score:3, Funny)
Re: (Score:2)
Has NOBODY seen Stargate SG-1? This is how the replicators started, dammit!
Re: (Score:2)
AND self assembling does not necessarily mean self manufacturing or self replicating.
Now, if they were some how able to splice these photo voltaic cells into a plant or algae so you could grown a film of solar panels, now that would be cool.
Re:Like this story from before? (Score:5, Funny)
Go ahead, mock Slashdot!!! Do you have any idea just how much it costs to bring a story from 09/19/2010 through a wormhole to 09/07/2010??? You should be getting down on your knees and thanking your robotic overlords that Slashdot spares no expense (not even space and time) to get you the latest news!
Re:Like this story from before? (Score:5, Funny)
Dude...you need to get out more.
Re:Like this story from before? (Score:5, Insightful)
Dude...you need to get out more.
Don't bother... I've been there. Way overrated IMO.
Re: (Score:2)
Dude...you need to get out more.
Don't bother... I've been there. Way overrated IMO.
uh... no argument here, but how do I get back in?
Oh joy. *Another* photovoltaic breakthrough (Score:3, Insightful)
To be tossed in the same boxes as "may lead to a cure for obesity" or "may lead to breakthrough in cancer treatment."
Wake me when I can buy it at Wal-Mart, and if there's a penny stock or investment opportunity, I'm not interested.
Re: (Score:2)
---
Solar Power [feeddistiller.com] Feed @ Feed Distiller [feeddistiller.com]
Re: (Score:1)
Re: (Score:3, Insightful)
I prefer climate change, instead of global warming. Climate change doesn't add to the confusion. But it was "colder in winter this year", etc.
Re: (Score:2)
Of course the overriding theme of "Global Warming" is that extra CO2 is causing extra warming. If you make the theme "Climate Change", and then point out that this winter was colder than last winter, some people might start asking awkward questions like "what the fuck is making it colder ?".
Perhaps CO2 also flies south for the winter ?
Re: (Score:2)
For goodness sake, we can't have honesty for the fear of awkward questions now? Are you over there welcoming our new anti-sex-ed overlords?
Solar power has the same problem right now as Linux. Stop snickering in the back, I'm serious and I'm going somewhere with this. People keep trying to convince others to use Linux because of the problems with Windows. There are flaws in that, though. For one, there are improvements to Windows from time to time. A big one was going from Vista to 7 so quickly, with its bet
Re: (Score:3, Funny)
Ditto.
Anyone can make any sort of wild "forward looking statement". I may have designed a zero emissions perpetual motion power generator. If I can get enough hits to my site, and persuade enough investors, I'll make a fortune!
Come visit my site [givemeyourmoney.scam] today! We'll all be rich!
I'm still waiting for flying cars [google.com], obediant robots to clean the house [google.com], distant places to live or visit, green energy, world peace, and [google.com] a few other things [google.com]. World of tomorrow my ass. When I w
Re: (Score:1)
Anyone can make any sort of wild "forward looking statement". I may have designed a zero emissions perpetual motion power generator. If I can get enough hits to my site, and persuade enough investors, I'll make a fortune!
It's been done [steorn.com]. But I get the sense they're more desperate than filthy rich.
Ya. I have gray hair... The cake is a lie!
I love that you have gray hair and said, "The cake is a lie!" In fact, I'd say this shows we've already entered a brave new world even if flying cars haven't really panned out. Fact is, it's 2000 and things are different. Even in my lifetime (no gray hair yet) computers and communication have become completely pervasive in every aspect of our lives. Things will be different in 2100 in ways you can't imagine—and won't rea
Re: (Score:2)
We do have obedient house cleaning robots. The roomba vacuums for us and there are robots to clean the eaves, wash floors/windows and clean pools. The jetsons was 2062, so we still have some time before you can complain about the quality of those products anyways. I'm not sure what you are complaining about here...
Re: (Score:1)
Another recycled story? (Score:4, Funny)
Re:Another recycled story? (Score:5, Funny)
OiouooeeeoeaioIaieioeoeaaieueeioaeoe ktsrjbtrcclthcnvrstnllstrtwththfrstcmmntfrmthlstrtclbtrccldntnwcmmnt yy ,'.'():
aeeIaiiuale CllmwhncnpcktptLws '.
Would it kill you to organize your recycling? You don't even have to alphabetize it, just separate the vowels and consonants from the garbage, to make our lives easier. And we don't recycle y's, either, you can just throw those away.
Re: (Score:2)
And we don't recycle y's, either, you can just throw those away.
I'd hang on to them, they're collectable as hell to those that collect them. You never know when you'll run into a phiosopher or some y's guys, and then you can pick up a few bucks.
Re: (Score:2)
In Soviet Russia, self-assembling photovoltaic cells develop you.
Yeah Yeah. Now how do I get out of this cell?
Over simplification (Score:1)
40%! (Score:5, Informative)
One of the problems with solar that no one seems to talk about is the system is limited by the size of the southern facing roof on a house. In the case of desert power generation, a large amount of land is required. If solar cells can make the leap from 12% efficiency to 40%, this will change everything. Your roof installation will be able to produce a much more meaningful amount of power especially in the context of trying to run air conditioning during day light hours. More importantly, the same applies for many malls, warehouses, factories, etc. At 12% efficiency, the roof of a mall is simply too small to generate enough power to be off the grid during the day. The amount of land required per MegaWatt will drop considerably. At 40% efficiency solar starts to become a much more viable option.
Re: (Score:3, Informative)
Re: (Score:3, Insightful)
That's true, but plants turn carbon from the air into a solid. If my solar panels could manufacture carbon fiber bicycles, I'd be really happy.
$20?! awww, I wanted a peanut! (Score:2)
Re:40%! (Score:5, Informative)
Actually photosynthesis tops out at 25% efficiency.
11% using the sun's spectrum.
It all depends on where you want to measure the efficiency.
Re: (Score:2)
Actually photosynthesis tops out at 25% efficiency. 11% using the sun's spectrum.
It all depends on where you want to measure the efficiency.
Can you provide a link for that 25% figure? If my 1% figure is too simplistic or just plain wrong I'd like to know about it - it was years ago I read it.
Re: (Score:2)
Oh sorry I forgot to include it.
http://en.wikipedia.org/wiki/Photosynthetic_efficiency [wikipedia.org]
That article goes in to quite a bit of detail.
Re:40%! (Score:5, Informative)
Nobody needs to go "off the grid" for solar to become viable. It all comes down to $ per kw/h. Even if solar can only meet 10-20% of your needs, if you can recoup your investment in a reasonable timeframe, solar is viable.
If you live in Phoenix and have a $200 a month light bill, a hypothetical $2,500 solar array that saves you just $40 a month but which lasts for 20 years looks like a pretty good deal - it'll pay for itself 3 times over. Unlike, say, a $2,500 3D television. And of course there's the network effect - if everybody installs one of the things, demand for electricity declines by 10-20% - as does the price - meaning you could all be saving a lot more than just $40 a month. That'll also spill over into the cost you pay for locally-produced goods and services.
Re: (Score:3, Interesting)
I wonder though if it's possible for energy costs to go down. It might be like bandwidth, where once the ISP has invested in the architecture to support a certain throughput it doesn't really cost them much to run it at full capacity and they don't save any money by turning things off and letting fiber go dark.
Hydroelectric and nuclear power aren't ever going to be turned down, and
Re: (Score:3, Insightful)
Hydroelectric and nuclear power aren't ever going to be turned down,
Not entirely true, as someone has already noted. Hydro especially can be turned "up and down" as demand dictates. We burn very little oil for electricity - it's too expensive for that. We do burn a lot of coal though, and if solar were capable of supplying just 10-20% of our energy needs, it would certainly put a dent in the cost of coal-generated power.
Re: (Score:3, Insightful)
Who cares? Use solar where it's economical. Use something else in Lansing.
Re: (Score:1, Offtopic)
I disagree. Let's assume I can sell you a very very cheap solar cell that runs at 2% efficiency. The price is so low that the $ per kw/h is very low. However, this is not a viable option. In this case, you will quickly recoup your investment, but you aren't producing much power. Do you plan to make your roof 5 to 10 times as large?
$ per kw/h is important, but it is not the only important metric.
I do agree that there is no absolute need to be off the grid. However, it seems to me that a logical goal for
Re: (Score:2)
I disagree. Let's assume I can sell you a very very cheap solar cell that runs at 2% efficiency.
We already have that. It's called biofuel.
Re: (Score:3, Insightful)
Let's assume I can sell you a very very cheap solar cell that runs at 2% efficiency. In this case, you will quickly recoup your investment, but you aren't producing much power. Do you plan to make your roof 5 to 10 times as large?
No, but if they're cheap enough at just 2% efficiency to pay for themselves quickly, it might make sense to cover the sides of buildings with them, as well as parking garages, covered parking spaces, the sides of freeways, etc. So in aggregate you could end up generating just as m
Re: (Score:2)
I disagree. Let's assume I can sell you a very very cheap solar cell that runs at 2% efficiency. The price is so low that the $ per kw/h is very low. However, this is not a viable option. In this case, you will quickly recoup your investment, but you aren't producing much power. Do you plan to make your roof 5 to 10 times as large?
$ per kw/h is important, but it is not the only important metric.
I do agree that there is no absolute need to be off the grid. However, it seems to me that a logical goal for the technology should be: a typical house should be able to cover its southern facing roof with solar panels and produce enough power to run lights, refrigerator, and A/C on a summer day at noon.
I'd say a more realistic goal is to be saving money.
Let's take another look at that 2% grid - if that solar power is cheaper than buying from the grid (after taking the infrastructure into account), then why wouldn't you use it? It's cheaper than the grid.
Re: (Score:1)
Re: (Score:2)
Amen:
3DTV with no broadcast programming yet: $2000-3000
Watching your wall-eyed toddler walk into plainly visible obstacles [slashdot.org]: Priceless.
Re: (Score:1)
Re: (Score:1, Insightful)
Negative. You're assuming that if power use decreases by 10-20%, the cost of power will decrease. It will not. The power company will charge more for less.
Also, $200/mo light bill?! Maybe for AC in Phoenix... but that's a lot of lights. :)
Re: (Score:3, Informative)
Negative. You're assuming that if power use decreases by 10-20%, the cost of power will decrease. It will not. The power company will charge more for less.
That's not true. The cost of power in many places in the US (and elsewhere, I'd imagine) varies during the course of the day depending on demand. So when demand is low power is cheap, but when demand is high (in the sunbelt, on hot sunny days), the price of power skyrockets, sometimes to ten times or more what it costs when demand is low.
Solar cells hav
Re: (Score:2)
Re: (Score:2)
Actually, check out Net Zero Energy Home [netzeroenergyhome.ca] (our local building's site is here [riverdalenetzero.ca]). The idea was to balance out over the course of the year - you'd be drawing power during the winter, but supplying during the summer (when we get those nice sixteen hour days).
The cost of building was coming down nicely as well - if/when I build a home, I'll be seriously looking at one done this way.
Re: (Score:3, Insightful)
Speaking from experience, when demand for a utility goes down 10-20%, the utility company will try to raise rates 10-20% based on the fact that they have had a drop in revenue, but still have the same costs.
Re: (Score:2)
Speaking from experience, when demand for a utility goes down 10-20%, the utility company will try to raise rates 10-20% based on the fact that they have had a drop in revenue, but still have the same costs.
That's what I've seen in Central Virginia, as usage dropped. Which makes solar (or whatever) 10-20% more competitive. Of course, these are requests by the utility to raise rates, since the utilities here remain regulated.
This effect is not limited to electricity, either. Same thing happened with our water utility -- all that effort to get people to conserve water really paid off! If you reduced your usage, your bill stayed about the same. If you didn't reduce, then you got to pay more.
Re: (Score:2)
Thank you. I did state they'd "try to raise rates". But I hadn't thought through all the implications. But in my case, solar isn't a good match for my circumstances, since I live way north. And until I am sure it's financially and physically viable for me to do so, I won't be doing that. Think of the problems involved with hail during the summer and heavy snow with little daylight during the winters, But I do appreciate your comment since it got me thinking about alternatives again :)
Re:40%! (Score:4, Informative)
---
Solar Power [feeddistiller.com] Feed @ Feed Distiller [feeddistiller.com]
Re:40%! (Score:5, Informative)
At 1 kW/m^2 (100 percent), you get 5.5 m^2, which means 2.3 meters (7.7 feet) on a side.
At 40 percent, you get 13.7 m^2 = 3.7 meters (12 feet) on a side.
At 20 percent you get 27.6 m^2 = 5.5 meters (17.23 feet) on a side.
At 10 percent you get 55.2 m^2 = 7.4 (24.3 feet) meters on a side.
Re: (Score:2)
Re: (Score:3, Interesting)
"At 20 percent you get 27.6 m^2 = 5.5 meters (17.23 feet) on a side.
At 10 percent you get 55.2 m^2 = 7.4 (24.3 feet) meters on a side."
Ok, who owns/rents/whatever a house that's less than 25 feet per side in this day and age?
Re: (Score:2)
Not really. (Score:2)
Re: (Score:2)
> The same setup up north would be multiples of that size
We use 1150 kWh per kWp in Toronto. The Bay Area gets about 25% more. So "multiples" in that case is a little less than "2".
Here's some numbers to consider. The local power company pays 80 cents per kWh for rooftop solar (yes, you read that right). At that price, a system normally pays off in 10 years or less. That means if all you want to do is break even, it would be at about 40 cents a kWh.
Now that's a lot more than you pay now (in most places).
Re: (Score:2)
Re:40%! (Score:4, Informative)
Actually, you hit on something that must be adjusted for solar to work. Modern structures are rarely insulated enough. That insulation can be natural (semi-subterranean homes), or artificial (like XPS, EPS, and fiberglass). On a few occasions, I've had opportunities to look inside residential walls. Rarely are the walls insulated well. They're insulated well enough to pass inspection, and meet the bare minimum of the building codes. For example, I was replacing the wall around a tub/shower. On the outside wall, there was only about 3/4" encapsulated fiberglass behind the concrete block wall. I guess that was enough to pass inspection at the time. The person who owns the house noted that in the summer, the A/C couldn't keep up. All you had to do was touch any of the interior walls. You could feel the outside heat on the exterior facing walls (from inside) and even the interior walls (not facing outside). The heat from the attic was heating the interior walls too.
As long as it is acceptable to build houses as cheaply as possible, we will continue using more power than is required. So yes, solar can be way too expensive to supply even the power to just cool the house.
There are some very interesting projects that people have done for alternative methods of cooling homes. While you may be able to hack something together from your local big-box hardware store, you'll never see a full kit nor instructions on doing it there. The building codes in your are may expressly forbid some. I know plenty of people who live in planned communities, where they are not allowed by deed restrictions, to put up solar panels, windmills, or even change the construction of their roof (a white roof reflects more solar energy than a black shingle roof).
Re: (Score:2)
There are some very interesting projects that people have done for alternative methods of cooling homes.
Do you have any good links on this regard? I'm quite interested in this. I've been looking at (though not building yet) distillation refrigerators using solar heat as fuel.
Re: (Score:3, Informative)
Do you have any good links on this regard? I'm quite interested in this. I've been looking at (though not building yet) distillation refrigerators using solar heat as fuel.
I'm not sure if this is exactly what you're looking for, but I've done a lot of research on building a passive house in a climate with extreme temperature variations and the following links made good starting points:
http://en.wikipedia.org/wiki/Passive_solar_building_design [wikipedia.org]
http://en.wikipedia.org/wiki/Superinsulation [wikipedia.org]
http://en.wikipedia.org/wiki/Ground-coupled_heat_exchanger [wikipedia.org]
GreenBuildingTalk forums [greenbuildingtalk.com]
Other options include designing the overhang of your house to be long enough to block most of the sun du
Re: (Score:2)
Re: (Score:3, Informative)
Re: (Score:2)
Re: (Score:1)
Do you have any good links on this regard? I'm quite interested in this. I've been looking at (though not building yet) distillation refrigerators using solar heat as fuel.
This is a good start [builditsolar.com]. Earth tubing is easy to understand, easy to explain to luddites and is a fairly easy addon to an existing structure. And before anyone points it out I like the word easy.
Re: (Score:2)
The thing I am interested in about ground source heat pumps is that I have read that temperatures in the ground go down to 55 F at 4 feet and hold relatively constant. Below that, they get hotter. What I am interested in is how this relates to the metal gadolinium (and some other compounds). Gadolinium is magnetic at below 65 F, and non-magnetic above. If you have a gadolinium (or gadolinium plated) wheel immersed in a 70 F bath of water, and cooled by a 55 F air/water source, part of the
Re: (Score:1, Interesting)
As long as it is acceptable to build houses as cheaply as possible, we will continue using more power than is required. So yes, solar can be way too expensive to supply even the power to just cool the house.
The sad thing is that building poorly insulated houses does not, by any mean, means that the house is built "as cheaply as possible". In fact, once you account for the projected energy spending, anyone will easily understand that cheapening out on the thermal aspects of any house ends up constituting an extra source of maintenance expenses. Any competent civil engineer who is employed designing the thermal behavior of any project is forced to design details such as the insulation as a function of the ene
Re: (Score:3, Informative)
Where are you getting this 12% efficiency factor from? That may be a decent figure for thin-film solar cells, but single-crystal silicon solar cells (the highest manufacturable efficiency) are well past 20% right now. And I don't believe the article at all when it says 40% power efficiency. Even the most advanced multijunction cells barely eek past 40% efficiency (and I think that's only due to the light being highly concentrated - >100x).
What they probably meant is that the quantum efficiency is 40%, es
Re: (Score:1)
Re: (Score:2)
> but single-crystal silicon solar cells (the highest manufacturable efficiency) are well past 20% right now
Commercial cells available in quantity are lower, about 15 to 17%.
That's only the cell itself. If you consider the losses due to resistance on the front surface, reflection off the wiring on the front face, wiring losses, and the area of the panel that is not covered by cells (look at an image of any mono-Si panel) you'll get PANEL efficiency around 14% for just about every panel in the world.
Maury
Re:40%! (Score:5, Informative)
40% is just the efficiency of the individual molecules in converting photons to electric charge. The overall efficiency of the device must be abysmal. The real breakthrough here lies in the fact that these guys can disassemble and reassemble the component light harvesting molecules of the device. This is important since photovoltaic devices using organic molecules are prone to degradation during irradiation by sunlight (see: http://en.wikipedia.org/wiki/Polymer_solar_cell [wikipedia.org]).
Re: (Score:2)
Re: (Score:2)
> If solar cells can make the leap from 12% efficiency to 40%
Umm, you need to read the statement again. The statement is that the _wiring_ is 40% efficient. The silver wires used on the panels on my roof is about 90%.
*yawn*
> run air conditioning during day light hours
False dichotomy. Every watt you generate on your roof is 55% of a watt that doesn't come from coal. That is a worth doing.
Going "off grid" for a mall is pointless. The grid is excellent for delivering power 24/7. Forget about replacing th
Wrong approach (Score:2)
Not For Sale Yet (Score:2)
Title pretty much says it all. I'm not interested in "cheap" and "easy" and "free" energy or anything else if it's not going to ever make it to market. As it is, despite several years of "breakthroughs" in solar power, if you went out today to get solar installed for your home, you would be using 1980s era technology at thousands of dollars per KW.
Wake me up when I can actually buy any of this.