From Stanford University , the first carbon sequestration project that makes energy. I wonder, will Al Gore say the electricity produced by a carbon solar cell is “dirty energy”? Somewhere, off in the distance, I hear Joe Romm’s head exploding.
Stanford scientists build the first all-carbon solar cell
Stanford University scientists have built the first solar cell made entirely of carbon, a promising alternative to the expensive materials used in photovoltaic devices today.
The results are published in the Oct. 31 online edition of the journal ACS Nano.
“Carbon has the potential to deliver high performance at a low cost,” said study senior author Zhenan Bao, a professor of chemical engineering at Stanford. “To the best of our knowledge, this is the first demonstration of a working solar cell that has all of the components made of carbon. This study builds on previous work done in our lab.”
Unlike rigid silicon solar panels that adorn many rooftops, Stanford’s thin film prototype is made of carbon materials that can be coated from solution. “Perhaps in the future we can look at alternative markets where flexible carbon solar cells are coated on the surface of buildings, on windows or on cars to generate electricity,” Bao said.
The coating technique also has the potential to reduce manufacturing costs, said Stanford graduate student Michael Vosgueritchian, co-lead author of the study with postdoctoral researcher Marc Ramuz.
“Processing silicon-based solar cells requires a lot of steps,” Vosgueritchian explained. “But our entire device can be built using simple coating methods that don’t require expensive tools and machines.”
Carbon nanomaterials
The Bao group’s experimental solar cell consists of a photoactive layer, which absorbs sunlight, sandwiched between two electrodes. In a typical thin film solar cell, the electrodes are made of conductive metals and indium tin oxide (ITO). “Materials like indium are scarce and becoming more expensive as the demand for solar cells, touchscreen panels and other electronic devices grows,” Bao said. “Carbon, on the other hand, is low cost and Earth-abundant.”
For the study, Bao and her colleagues replaced the silver and ITO used in conventional electrodes with graphene – sheets of carbon that are one atom thick –and single-walled carbon nanotubes that are 10,000 times narrower than a human hair. “Carbon nanotubes have extraordinary electrical conductivity and light-absorption properties,” Bao said.
For the active layer, the scientists used material made of carbon nanotubes and “buckyballs” – soccer ball-shaped carbon molecules just one nanometer in diameter. The research team recently filed a patent for the entire device.
“Every component in our solar cell, from top to bottom, is made of carbon materials,” Vosgueritchian said. “Other groups have reported making all-carbon solar cells, but they were referring to just the active layer in the middle, not the electrodes.”
One drawback of the all-carbon prototype is that it primarily absorbs near-infrared wavelengths of light, contributing to a laboratory efficiency of less than 1 percent – much lower than commercially available solar cells. “We clearly have a long way to go on efficiency,” Bao said. “But with better materials and better processing techniques, we expect that the efficiency will go up quite dramatically.”
Improving efficiency
The Stanford team is looking at a variety of ways to improve efficiency. “Roughness can short-circuit the device and make it hard to collect the current,” Bao said. “We have to figure out how to make each layer very smooth by stacking the nanomaterials really well.”
The researchers are also experimenting with carbon nanomaterials that can absorb more light in a broader range of wavelengths, including the visible spectrum.
“Materials made of carbon are very robust,” Bao said. “They remain stable in air temperatures of nearly 1,100 degrees Fahrenheit.”
The ability of carbon solar cells to out-perform conventional devices under extreme conditions could overcome the need for greater efficiency, according to Vosgueritchian. “We believe that all-carbon solar cells could be used in extreme environments, such as at high temperatures or at high physical stress,” he said. “But obviously we want the highest efficiency possible and are working on ways to improve our device.”
“Photovoltaics will definitely be a very important source of power that we will tap into in the future,” Bao said. “We have a lot of available sunlight. We’ve got to figure out some way to use this natural resource that is given to us.”
Other authors of the study are Peng Wei of Stanford and Chenggong Wang and Yongli Gao of the University of Rochester Department of Physics and Astronomy. The research was funded by the Global Climate and Energy Project at Stanford and the Air Force Office for Scientific Research.
This article was written by Mark Shwartz of the Precourt Institute for Energy at Stanford University.
Source: http://news.stanford.edu/news/2012/october/carbon-solar-cell-103112.html
Alan Watt, Climate Denialist Level 7 says:
October 31, 2012 at 10:43 am
I heard carbon nanotubes run several million dollars a pound at present. That will be a bit of a roadblock to commercial-scale deployment.
==================================================================
But haw much of that is the “carbon tax”? 😎
1% efficiency, no sun at night, no efficient or effective storage medium. About 30 years before it is of even maginal use and it can never be used for base load without storage.
nvw… said it first in the 3rd comment.
Science is trying to copy a tree.
Plant a billion trees, wait 100 years, Cut down a billion trees and plant a billion more trees. Burn the trees, while generating electricity. 100% carbon neutral (like I care) and completely renewable.
Arrogant and fund scheming science are trying to copy a tree.
The problem with generating energy during a summery day is that you also need chemical energy storage so that it can be used in winter nights. Producing carbon sun-electrity devices are good for space applications but down here on earth, we have day and nights, and seasons and weather.
Trees do all of that so very well.
Men… will they never learn? Look we made a poor copy of tree! That cost ya 10 billion dollars and a tree works better.
Won’t this count as a carbon offset either way?
wikeroy says: October 31, 2012 at 10:13 am
“Perhaps in the future we can look at alternative markets where flexible carbon solar cells are coated on the surface of buildings, on windows or on cars to generate electricity,” Bao said.
Not to mention roof-tiles….
————————————————————
Or, you could just go buy flexible solar panels or roof tiles now. One source is UniSolar, http://www.uni-solar.com/ but get them soon, because UniSolar is having hard financial times. It seems in the real world, sales depend on market demand and value of the product.
If I read this article right, they intend on using carbon nano tubes for the assembly. Based on the Toxicity studies I’ve seen nano tubes have been shown to be somewhere from toxic to highly toxic.
Are we creating a new problem while solving what may not be a problem?
Even with the many breakthroughs in carbon nano-structures–both producing and aligning–that are being made, this will require lots of work. However, the problem with storage of energy is not insurmountable since even an energy grid which uses all non renewables can benefit from storage technologies. There have been many recent projects working on developing or marketing industrial scale batteries and other energy storage systems. Yes, you do lose energy by converting it, storing it and converting it again but if you are producing it cheaply at one time of day and it can be sold at a much better price at peak hours it could be worth it. Likewise, if you could store it for a more lucrative time of year you could outweigh the loss due to storage. At least, there is yet to be proof that this can’t be done.
The efficiency will need to come up (metamaterials maybe) but they don’t need to be silicon quality if they are dirt cheap.
sunshine hours is so funny.
First he denied the existence of back radiation altogether.
then when he was shown the system used to measure it, it switched to a new form of denial.
In any case back radiation doesnt heat the planet. Its not how the green house effect works.
If you want to know how the effect works.. ask anthony. he believes in it.
Ask Christy, Ask Spenser, ask Monkton.
Sunshine wont.
Ok, great, so if one of these smashes in your backyard it won’t poison you (aside from causing global warming of course *snicker*), but aside from the problem of solar power being incredibly inefficient, does anyone address how toxic the manufacturing process for all these space age carbon materials will be? I know that’s a big problem with our present solar panels. They’re toxic as all heck to manufacture. So, what about these?
Eyal Porat says:
October 31, 2012 at 12:58 pm
Philip Bradley says:
October 31, 2012 at 12:34 pm
I live in a hot place, and I have to say that with the current efficiency of solar panels, the best usage of them is shading the house. This lowers the temperature of the house considerably.
To the best of my knowledge no one has ever measured the net effect of roof top solar panels on the airconditioning requirements of a building. Surprising, given the ‘green’ energy industry claims of ‘saving energy’.
My experience is that the area of the house directly below the solar panels is noticeably warmer/hotter on a sunny day. But my solar panels are attached directly to the roof. If you experience shading then there must be a gap between the panels and the roof.
Solar panels will also provide a useful amount of roof insulation.
Interesting piece of technology. For the moment, I assume the carbon
is in the form of plastics of various kinds. I wonder what the lifetime of
such modules would be once exposed to the sun (UVa and UVb).
In New Zealand, we have some of the harshest sunlight in the world,
it being clean and rich in UVa and UVb. (Closest approach of the planet
to the sun is in early January, which is the height of our summer.)
Plastics left out in the sun have a lifetime of 1.5 – 3 years, becoming
highly embrittled over that time, and subject to breakage under even
slight pressure. Testing in the Arizona desert is inadequate
compared with testing in the Ruapehu desert (centre of the North Island).
So material lifetime may have to be considered as well as increases in
efficiency.
Eyal Porat says:
October 31, 2012 at 10:18 am
I have this nagging question:
If solar panels become EXTREMELY efficient, wouldn’t it be very cold near them?
won’t they trigger an Ice Age due to loss of heat in the atmosphere?
Good point. Earth’s natural solar panels – leaves – do this already, and play an important role in cooling and regulating climate. Thus while CO2 per se will not warm the planet, loss of vegetation cover might.
Photons versus electrons. That is the problem with solar power.
Photons might never be an efficient source of producing electricity (othan the one source we know about …)
Plants have a biological molecule called chlorophyll which turns photons into chemical potential energy which then powers the biological chemical reactions of vegetation.
We are using the chemical potential energy left over from millions of years ago which never got fully converted back into biologic chemical reactions (fossil fuels) to make mechanical potential energy through burning which when used with a magnetic fields creates electricity or directly powers the mechanical energy of a motor.
Do we see how solar energy needs to start using a different philiosophy here. Solar needs to be converted into chemical energy and/or mechanical energy rather than trying to (what might never work) convert it directly into elecricity/electron energy.
——–
Black Carbon solar panels covering everything? I wonder what would happen to the Urban Heat Island in that case.
Yippie, another crap-all efficiency flexible thin film solar cell. Let’s add it to the pile that has been growing for the last 30 years. And as for improving efficiency over time, well, I’ve heard that one before. Modern flexible cells are in the neighborhood of a few percent. I expect this one to do little better.
@ur momisugly DirkH says:
October 31, 2012 at 12:53 pm
Conspiracies and UFOs proliferate when viewed from valleys of the northwestern mountains of the US. I oughta know, I live in a valley in Montana, just a nanosecond by UFO northeast of Lucy. Doubtless there are power sources yet undiscovered and mankind has had a collective sense of UFOs for oinks. But it’s not just about efficient means of producing endless power. It’s also about punishing those (the energy companies) who are the only reason we’re not all freezing to death in the dark. Anyhow, I can’t see Lilliputians building facilities large enough to matter.
Paul Westhaver on October 31, 2012 at 2:00 pm
nvw… said it first in the 3rd comment.
Science is trying to copy a tree.”….
Excellent point. Can someone say what’s the efficiency of a tree (or other plant) of converting photons into biomass?
Interesting.
I can’t access the full paper because it is pay-walled, but a ‘photo-voltaic’ device which operates in the Infra-Red might just be a thermoelectric device, which is not really a Solar Cell.
The real breakthrough would be a solar panel with dark-sucking technology to harvest the energy of the Dark Side for 24 hours per day.
@Allan Watt. Carbon nanotubes are relatively inexpensive today. typical market price depending upon diameter is about $25-$25 per gram. At the top end of the price you will pay approximately $16k per pound. There are some more expensive types depending upon purity but those now have come down to around £200 per gram as opposed to the high of $700.
The University of Malaysia have come up with a process that can turn out 1000 grams of nanotubes a day at a cost to market of between $15-$35 a gram.
I believe your notion of ‘millions of dollars per pound’ is misinformed.
This appears to be an excellent technology on the face of it. There is no harm in sourcing alternative energies to fossil fuels. There will come a point where it becomes necessary so no harm in working on that now if commercially viable methods can be found.
CO2 might be a non-issue for human beings but particulate pollutants are an issue. No harm in reducing those where possible.
@Philip Bradley. What are the air conditioning requirements of a house? The air conditioning requirements of my house are zero. It’s never so warm outside that opening a window won’t cope with and gas fired central-heating takes care of the rest. (53.4800° N)
Roll on global warming I say 😉
Since the DOE motto is not to pick winners, this by definition is worthy of several billion dollars in grants from the taxpayers. Oh and some very connected people involved in the company helps more than anything in this administration. wink wink
Throw in the usual farce of being apple to paint buildings with solar panels and you can double or triple the numbers from the gullible and the guile.
I often wonder what happened to the solar cell that was 100% efficient!
It was a small article in New Scientist over 10 years ago – a guy was playing with a femtosecond laser and tried it on a silicon wafer – which went black. Investigating, he found it was black because all the light was being absorbed and converted to electricity with 100% efficiency. It would also work in reverse where electricity would be converted to light with 100% efficiency. Closer investigation of the silicon showed that as it melted the surface formed tiny mushroom shapes and the speculation was that if the light was not absorbed immediately it would bounce round internally until it was.
I never heard anything about it again. I suppose that it is probable that the power needed to create it far outweighed what the cell could produce in its lifetime, or the military took it over.
Even so, I would have thought that etching silicon wafers could produce a similar surface. Again, it may not be cost effective – not that it is usually a consideration with ‘renewables’!
At the time I really thought it would change the world.
If solar panels were free they would still only have local uses. Collecting diffuse power and routing it to where it is needed is more trouble and cost than it’s worth.
Max Hugoson says:
October 31, 2012 at 11:04 am
Evolution would have to come up with some tricks to deal with breathing. O2 in, SiO2 out. I.e. quartz.
Philip Bradley says:
October 31, 2012 at 3:34 pm
The panels are a few centimeters above the roof tiles (which are made of clay here). Any shade on a roof will do the trick.
BTW, in hot areas the locals tend to build flat roofs. This has a few advantages: they shade the roof with vegetation (vines etc.) and thus have more room, cool place to stay on hot nights and a cooled house.
Here (in Israel) we adopted in many places the stupid habit of building slanted tiled roofs. But with sense kicking in you can see more and more flat roofed houses.