MIT Envisions DIY Solar Cells Made From Grass Clippings 126
Zothecula writes "Research scientist Andreas Mershin has a dream to bring inexpensive solar power to the masses, especially those in developing countries. After years of research, he and his team at MIT's Center for Bits and Atoms, along with University of Tennessee biochemist Barry Bruce, have worked out a process that extracts functional photosynthetic molecules from common yard and agricultural waste. If all goes well, in a few years it should be possible to gather up a pile of grass clippings, mix it with a blend of cheap chemicals, paint it on your roof and begin producing electricity. Talk about redefining green power plants!"
Adds new import to the phrase "keep off the grass" (Score:5, Interesting)
Of course, at 0.01% efficiency, you won't be able to tell the difference. Unless, of course, you're into that "other" grass, in which case it's "Oh so kool man! Now I don't have to mow the roof AND get enough power to run a watch one day a year."
Re:Adds new import to the phrase "keep off the gra (Score:5, Insightful)
Of course, at 0.01% efficiency, you won't be able to tell the difference. Unless, of course, you're into that "other" grass, in which case it's "Oh so kool man! Now I don't have to mow the roof AND get enough power to run a watch one day a year."
OK miss negative Nancy. It's 0.1% and it's still experimental. I think it's awesome that they can do that.
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1) reduce electrical demands
Yeah, good luck with that.
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Actually, it's very easy if a government wants to; they just need to tax it heavily.
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See how long you stay in office after you tax energy usage to the point where the average American starts to take notice. And how do you plan on taxing the rest of the developing world when they don't follow suit? Once they realize they like having life with reliable electricity and all the conveniences and comforts of modern living, my guess is you will have a hard time getting them to reduce their energy demands. It's only a matter of time.
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You wouldn't just tax energy usage, you'd cut something similar, like sales taxes, in exchange for the tax increase, and then explain to the public that it's really an opportunity to lower their taxes if they use energy more efficiently (i.e. find and replace inefficient appliances, and shift as much usage as possible into off-peak hours). It would still get stiff resistance from anyone in the energy supply chain, but that's pretty standard for public politics.
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I'm not saying they should do that, I'm saying they can.
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I would just say more land. It's amazing what huge tracts of land can do.
Re:Adds new import to the phrase "keep off the gra (Score:5, Informative)
"Photosynthesis in plants only operates at a couple percent efficiency in the first place."
WRONG!!! Try 9% under regular sunlight, and ~15% under LED lighting.
Oh, did I neglect to mention photobiology/optoelectronic R&D is my job?
Re:Adds new import to the phrase "keep off the gra (Score:4, Funny)
Yes, you did. Then you realize this process the article describes is about as sensible as manufacturing vitamin D by extracting it from Humans standing in sunlight (regular or otherwise).
I'll take your figures for the efficiency since your the expert, but - The article quotes "electrical power density of 81uW/cm2". If they doubled the efficiency it still wouldn't be worth it.
Did I neglect to mention I can do math?
Re:Adds new import to the phrase "keep off the gra (Score:5, Informative)
WRONG!!! Try 9% under regular sunlight, and ~15% under LED lighting.
The GP is correct for the typical case of real plants: http://en.wikipedia.org/wiki/Photosynthetic_efficiency [wikipedia.org]
The typical case is pretty low efficiency, the best case (sugarcane) is lower than your 9% number.
Oh, and did I neglect to mention your .sig is obnoxious? I'm guessing you're an undergrad with a bottle-washing role.
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"Oh, and did I neglect to mention your .sig is obnoxious? I'm guessing you're an undergrad with a bottle-washing role."
Research director, actually. Good job assuming when you're clueless.
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I'm sorry if it offends you. See, I only think of the HUMAN condition, not gender-specific nonsense. Therefore, I am immune to the power that words seem to have, free of the influence which your mind succumbs to.
You don't get very far in life holding onto such silly nonsense.
Die a couple of times like I have, maybe your brain will turn on some other section that will enable you to think outside of all of that.
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That's all nice and good, but the fact that you feel the need to make some sort of statement with such a gender-offensive signature says you are lying to yourself.
Sort of like how the most vociferous gay-bashers are the most in-the-closet gays, and the most "family-values fundie preachers" are t
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>My face when you don't understand a homophonic joke.
Go back to Code Pink, where the rest of the easily-offended and thin-skinned female humans go.
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FYI, the "lead a horiculture" quip was invented by a woman. [wikiquote.org]
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My face when you don't understand a homophonic joke.
Nice!
For the easily wooshed feminists : that's an n and "horti" sounds like "horse to".
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How do you make a hormone? Kick her in the stomach!
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BTW, the Feminists don't have a point. XD
http://en.wikiquote.org/wiki/Dorothy_Parker [wikiquote.org]
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You might get significantly higher efficiency off of a monochromatic light source at 700nm, but then were talking about something to capture energy from the Sun, so that bit of data is irrelevant. Your average plant is going to convert 9% or so of its captured light into chemical storage, but then nearly half of that gets reused in its own metabolic processes.
Now that 5%-9% value is the important one to be concerned about when you're going to reprocess that biomass directly into energy. In this case, they
Re:Adds new import to the phrase "keep off the gra (Score:4, Informative)
Ignoring the fact that there's no such thing as "regular sunlight" due to variances in season/geography: LED lights can come in any of an enormous variety of spectra, be combined, or not even be a single wavelength at all and be an ultraviolet light with an LED UV emitter (white LEDs). What meaningless numbers and broad statements...
Translations since you want to be an obnoxious dick.
"Regular Sunlight" - The spectrum of light emitted by the sun which makes it though to the surface under normal atmospheric conditions consisting of a distribution of all wavelengths within the visible spectrum along with limited radiation outside this range which have near negligible effect on photosynthesis.
"LED lighting" - Controlled, artificial lighting used in laboratories which have been designed to produce a desired light spectrum. This is used to produce the ideal lighting conditions with the highest achievable efficiency (most likely a combination of red and violet LEDs).
"Efficiency" - The ratio of energy put into a system to the ratio of energy put out
Re:Adds new import to the phrase "keep off the gra (Score:4, Informative)
They figure with $30-40 million in government grants they may be able to double that.
hopeless? (Score:2)
the lifespan of well treated chlorphyll bearing protein is about 30 minutes. the chlorphyl molecule resides in an equistly (qunatum) tuned environment to achieve it's meager effieiciency in cells. I strongly doubt anything recovered form grass shavings will be of lasting use.
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If you have no electricity to start with, even a little is a huge improvement. This is not meant for industrialized places.
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(81 microwatts) per (square centimeter) = 0.0752514624 watts per (square foot)
75 watts from 1000 square feet of collecting area? I think there are better uses for the zinc and tin making the substrate.
So, in a few years? (Score:5, Funny)
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Indeed. O place this in the 10 year or 25 year class.
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Actually, it needs to be a chart of how long it is until the "awesome technological breakthrough!" in question is never heard about again. It ranges from 1 to 6 months.
I still remember arguing with supposed geeks online years ago about a claim some company was making about delivering 2 Gbps internet to every home in a neighborhood over existing power lines. Yes, 2Gig individually to each home. Some piffle about power lines having infinite bandwidth because they are not inside a shield like a regular cable o
Or you could electrocute yourself in the process (Score:5, Informative)
in a few years it should be possible to gather up a pile of grass clippings, mix it with a blend of cheap chemicals, paint it on your roof and begin producing electricity.
Just because it's "green" doesn't mean it's safe to let just any yahoo install an electric generator on his hut. Methinks it might be wise to let the village electrician do the installing.
Re:Or you could electrocute yourself in the proces (Score:5, Interesting)
Re:Or you could electrocute yourself in the proces (Score:5, Funny)
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Just because it's "green" doesn't mean it's safe to let just any yahoo install an electric generator on his hut. Methinks it might be wise to let the village electrician do the installing.
And just to be safe he should wait till it goes dark. Oh wait a minute ...
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Not that it'll produce enough current to be dangerous.
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Just because it's "green" doesn't mean it's safe to let just any yahoo install an electric generator on his hut. Methinks it might be wise to let the village electrician do the installing.
Waiting for the Electrician, or someone like him?
Do you call the electrician when you have to replace the batteries in your flashlight?
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That's okay. Any yahoo can install an OS, but I've yet to meet a yahoo that doesn't consider him/herself a geek who will try.
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Just because it's "green" doesn't mean it's safe to let just any yahoo install an electric generator on his hut. Methinks it might be wise to let the village electrician do the installing.
Nice thinking.... this is how you create jobs, and dig villages out of poverty. Now everyone who wants this solar electricity mat is forbidden from doing it themselves, so they'll have to hire a member of the union of village electricians, who will have to be trained by someone with the proper certifications, givi
Concentrated right? (Score:2)
If all goes well, in a few years it should be possible to gather up a pile of grass clippings, mix it with a blend of cheap chemicals, paint it on your roof and begin producing electricity.
I assume the method concentrates these photosynthetic molecules. If so you're going to need several roof-areas-worth of grass clippings. And then you have the old problem of taking arable land and forcing food prices up. If this produces much with the grass clippings from an average suburban house then I'm amazed - and will it last through the winter?
Re:Concentrated right? (Score:5, Interesting)
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Definitely better for the environment at these efficiency numbers. Better to burn methane than to let it escape.
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Compost heap big enough could generate enough heat to run a Stirling Engine.
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Re:Concentrated right? (Score:4, Interesting)
and will it last through the winter?
If its made out of grass clippings, then by April or May at worst I'll have enough to make another cell-roof.
One weird issue is if its pitifully 0.1% efficient, it might be more productive overall to simple TDP the collected grass clippings into gasoline and dump it into a generator. Or ferment into ethanol. Just simply burn as biomass?
I think a solar powered electric self growing fence would be pretty cool, at least until it shorts out and starts itself on fire. Which brings up the other idea of a self growing survival tool, a mushroom grown in pitch blackness which when placed in sunlight eventually bursts into flame using self generated photosynthetic electricity.
Efficency (Score:5, Interesting)
From the fine article they're getting 0.1% efficiency right now. In other words, about a thousandth. Conveniently, you get about a KW of light per sq meter. So, you get about one watt per square meter. So I could get about 40 watts at noon off my roof, well, other than that tree being in the way which shades me from the summer sun. That is somewhat more than the naysayers claim (barely enough to run a watch, etc) but is not enough to be useful.
Its unlikely they'll exceed the best plants which have had hundreds of millions of years to optimize their design... so figure 5% or so would be quite an achievement. So in Star Trek miracle land, a KW or two is quite possible off a typical roof. Of course in Star Trek miracle land, you'd have 47% efficient cells thus generating about 40 KW. I donno what I'd do with 40 KW laying around, I guess air condition my entire open air backyard, replace my beer fridge with a supermarket open display case so I don't have to waste time opening the door?
The crack about painting it on is laughable. conductive acid rain and bird poop will short it out. You're still going to need glass/plastic/etc and the cost of that will probably make high efficiency silicon more economical.
Re:Efficency (Score:5, Informative)
Of course in Star Trek miracle land, you'd have 47% efficient cells thus generating about 40 KW. I donno what I'd do with 40 KW laying around
Sell it back into the power grid for use in high density apartment buildings, and higher density manufacturing industry.
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Yeah those aluminum smelting plants and server farms need all the clean-sourced electricity they can get.
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Re:Efficency (Score:5, Informative)
That is somewhat more than the naysayers claim (barely enough to run a watch, etc) but is not enough to be useful.
Sorry, but you're off by several orders of magnitude. A wrist watch consumes microwatts of power - around 1 micro watt (Slashdot seems to strip the micro symbol). Thus 40 watts is enough to power 4 million wristwatches.
Seiko makes a watch with an IC powered by only 25 nano watts of power!
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(Slashdot seems to strip the micro symbol).
Indeed, along with most other useful non-latin letters.
Try u, as in um and ug. It looks close enough. Alternatively there's the one that's popular in the medical industry - I assume it's because label printers don't do it - mcg.
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You're saying the same thing he is saying...that the naysayers are exagerating when they say a roof of this material can only run a watch.
Re: Star Trek Miracle Land (Score:2)
So in Star Trek miracle land, a KW or two is quite possible off a typical roof. Of course in Star Trek miracle land, you'd have 47% efficient cells thus generating about 40 KW.
We are very close to Star Trek miracle land, then, since the highest efficiency to date is 43.5%:
http://upload.wikimedia.org/wikipedia/commons/d/d0/PVeff(rev111103).jpg [wikimedia.org]
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Yeah that was my point. The point is that is a "research" graph not a "I can buy it at home depot or at least over the internet from a website" graph. The best research I've seen to this point is 47% so that would be a "realistic" goal for biological systems to reach. In fact they have to reach at least that, or people will probably install silicon systems instead to get more power and more reliable power (lower maint, etc).
Right now, literally off the shelf over the internet, "commodity grade" COTS pane
QWK (once a week) (Score:2)
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Well, you could have a grass roof. Then you'd be right both ways.
Oh Boy! (Score:1)
2.5million hectares per GW (annual average) (Score:4, Interesting)
If you blanket all of Germany with cells of this type, you'll get 13.6 GW on average, assuming perfect and unlimited storage - Germany needs 70GW of electricity. And of course, you'd have to blanket *all* of the country, so you'd have to say goodbye to forests, mountains, lakes, rivers, fields
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It is only a matter of improving efficiency. If this material is so cheap, it can be used as a paint to reduce electricity requirements by 5%. Maybe with further tweaks that can turn into 10 or 15%. No-one said this has to be the only method in use. It's just a cheap one that uses abundant materials. A proof of principle, if nothing else.
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No, it's not. It's a matter of how much the efficiency can be improved. In no way will this ever become a realistic electrical source. By its very nature it cannot produce enough.
"If this material is so cheap, it can be used as a paint to reduce electricity requirements by 5%."
No, that presumes you can stack paint. You can't. It's the area that counts, not how much paint you have.
As figured out by someone elsewhere on this topic, an entire house r
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If they get it to 1% efficiency, they'll have 136GW in Germany.
So only half of the country will need to be covered in rotting grass.
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Oh, please... (Score:5, Informative)
Yes, it takes grass clippings. Also "zinc oxide nanowires interspersed with titanium dioxide sponges".
Claiming that this is a solar cell made from grass clippings is like the Rubik's cube solver built from Lego (one component of which was a computer; the computer's not built from Lego). If you want a car analogy, it's like claiming your car is made from glass (since it has glass in the windows).
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I thought exactly that when I RTFA.
I don't know if zinc oxide nanowires and titanium dioxide sponges can be manufactured for pennies per square metre (which is what will be required to use this technology in developing countries) - but I suspect that along with improving the output efficiency of the solar cells, there is a lot of work to do to improve the cost efficiency as well.
It all comes down to marketing hype.
myke
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If you want a car analogy, it's like claiming your car is made from glass (since it has glass in the windows)
Sure, but this kind of bullshit is routine in what passes for the "science and technology" press.
We have "quantum teleportation" in which nothing more ontologically robust than the quantum state is "teleported".
We have "downloading 3D objects" in which nothing but a perfectly ordinary binary file is downloaded.
We have "controlling a with just your mind" in which "your mind" apparently includes a few hundred thousand dollars worth of extremely complex gear.
And so on.
Apparently "science" journalists are too
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Unfortunately most of their audience seems not to care, but would rather repeat cool-sounding but meaningless words than learn anything about actual science and technology.
I virtualize 3D crowdfunded clicktivism in the social cloud ecosystem via the hypernet with my OLED phablet!
MOAR. SQAR. METRES! (Score:3, Informative)
Re:MOAR. SQAR. METRES! (Score:5, Insightful)
The first step is rarely the last one.
utter un-sightful bullshit (Score:2)
The Wright Flyer III, built within TWO YEARS of their first flight, had a range of 25 miles! As an engineer, I can tell you this articles technique is useless, even if ten times the efficiency process would not be worthwhile.
Re:utter un-sightful bullshit (Score:5, Insightful)
what is useless is to denigrate basic research
to do that, as an engineer, you should be ashamed of yourself
the common joe might bloviate ignorantly about how silly basic research is, and confuse basic research claims and evidence with the end-all be-all of claims and evidence, but you really should know better
yet, looking at other comments here on slashdot, it seems the intelligence to appreciate basic research has indeed been replaced by this kind of ignorant jump to judgment
you know what? paint on grass clippings does sound silly. but i thought we had a scientific bent here, and this would be EXCITING
imagine that
so shame on you slashdot
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I do not denigrate basic research that has even the remotest hope of producing something useful. I denigrate that which is provably a waste of time and money based on known workings of this universe.
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you:
"what are you doing?"
wright brothers:
"we are assembling basic materials into an interesting shape"
you:
"that's not very descriptive, what is the goal of your efforts here?"
wright brothers:
"ok, you asked, but we don't say what we are trying to do because we get laughed at by simpletons. since you are an engineer, and have some appreciation of what mankind can do with his imagination, we'll level with you: we hope to build flying machines that someday will whisk people around the globe, used more than rail
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no, good comparison. the methods used to arrive at INITIAL results doesn't change the fact we are talking about INITIAL results
what is with the anti-basic research prejudice on slashdot of all places?
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The history of science is chock full of naysay
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do you know how long and how many iterations it took before we finally had an incandescent bulb?
the basic idea is sound. it is hard. plenty of roads are dead ends. but the naysayer adds nothing but the desire to kill the will to try. they also add nothing we don't already know: it's hard. no, really?
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Even if this proves to be unworkable, it advances our knowledge. If grass clippings aren't good enough, perhaps we genetically engineer some bug to make the right mix of materials for us to give us a 5% efficient cell that costs ten cents a watt. Combine that with other advances, and maybe we get a 50% efficient cell for 1 cent a watt. Who's to s
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we would have to cover nearly 100% of our continental land mass with this stuff to replace our current energy sources. Seems to me like smoking the other kind of grass really is a better deal.
We need our land. Something tells me, we'd be better off with vertically-oriented towers collecting solar energy on all surfaces or reflecting light onto point targets, and floating collectors in the oceans.
But towers have the advantage that if they're tall enough, wind collectors can be added on some of the hi
If it sounds too good to be true, it probably is. (Score:2)
Would not surprise me at all. I suspect somebody is looking for grant money, and "a few years" will turn out to be very, very long, possibly infinitely long.
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And have been for about 50 years now. Some things are dependable at least!
Okay, stupid question time (Score:1)
How much energy would I generate simply by cutting the same amount of grass and burning the clippings? We are talking carbon neutral since the grass continues to grow.
This seems as good of a solution as the one being proposed.
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But to answer you question, it appears [remarkable.com] that leaves have approximately 61.5% of the calorific energy value of coal, so I am assuming that grass would be similar.
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Consider density too. Even a dense bamboo is pretty light.
Here's hopin! (Score:2)
Maybe there's a simpler solution (Score:2)
Let's stop polluting the world and let the natural photosynthesis do the job.
Fraud - be careful (Score:5, Interesting)
A modified type of dye sensitized solar cell, nothing new.
https://en.wikipedia.org/wiki/Dye-sensitized_solar_cell [wikipedia.org]
You can easily make those at home: Take a piece of conductive glass, coat it with titanium dioxide (yes, exactly the pigment used for white paint, I tried the commercial pigments myself), dip it into a dye (yes, I tried chlorophyll, these things were known at least 15 years ago, this is when I did it), put on a second piece of glass and fill with electrolyte.
I have made hundreds of those, you can do it at home it a toaster oven, google for "graetzel cell video".
This type of cell has several very serious issues:
1) The efficiency is very low
2) The cell uses a liquid organic electrolyte. Of course there are tons of problems with leakage, toxic solvents etc.
The electrolyte often breaks down from the light, you'll always have oxygen diffusion into the system and react with all the chemicals. It is extremely difficult to make anything organic that can withstand light. Have a look at your painted garden chairs after a few years in the sun.
3) The dye breaks down quickly. Make a simple test. Take a few grass clippings and put them into the sun. You'll notice that they change color from green to brown.
The reason is that the chlorophyll degrades very rapidly in the sun. Grass makes new chlorophyll all of the time.
4) Titanium dioxide (and zinc oxide as well) are highly reactive materials under illumination. This is why you use them as white pigments. The sunlight creates free electrons, and those decompose a lot of the dirt in contact with the stuff. A white wall in the suns cleans itself to a large part.
Of course, you'll have the same effect in the solar cell, the TiO2 will act as a catalyst and degrade dye and electrolyte.
Make a simple test at home: Take a wall painted with titanium or zinc white. Dissolve some grass clippings in alcohol and spray the green stuff on the wall. Expose to sunlight and see how quickly it bleaches.
As a scientist myself, I find it very sad and unprofessional, how MIT is lying to the public.
A statement like
"If all goes well, in a few years it should be possible to gather up a pile of grass clippings, mix it with a blend of cheap chemicals, paint it on your roof and begin producing electricity. Talk about redefining green power plants!"
is very misleading, unethical and close to being a scientific fraud. Of course, you could never paint it on, how are you going to put on the electrodes?
My Big Question... (Score:2)
Just curious if one side always has to be connected to ground?
Cheers!
Photo-oxidative damage protection? (Score:2)
Without a continuously active protection mechanism excess energy will destroy the light harvesting molecules due to photo-oxidative damage. So you might have to continually repaint your roof which could get quite expensive and be labor intensive.
I thought they'd use photosynthetic chemicals (Score:2)
to separate the hydrogen from water. That would seem like a better use than making electricity, but I'll take either.
Hype hypetty hype hype (Score:2)
Would I order the chemicals online using my dual boot Hurd/Linux desktop, or collect them myself in my flying car that I built using my 3d printer that I bought with the profit I made speculating on the bitcoin/facebucks exchange rate?
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And even if you get through with that, good luck if you live in a HOA mini-dictatorship.