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MIT Envisions DIY Solar Cells Made From Grass Clippings
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!"
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."
Let's call it what it is, Anti-Social Media.
Let's see what XKCD says about it...
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.
SJW: Someone who has run out of real oppression, and has to fake it.
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.
And yet another 10 years later they find that those "cheap chemicals" cause cancer...
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.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
If you need to blanket a whole country with solar cells and still don't have enough power for all people, you shouldn't talk about a drawback. You should talk about it being useless for this purpose.
... or an unblocked view of the sky for that matter.
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
I wonder if you wouldn't get a lot more bang from your compost heap by putting a tarp over it and collecting the gasses rising out of it to burn?
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.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
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).
The continental US receives about 192,000 Exojoules of solar irradiance per year. We currently use about 91 Exojoules of energy from all sources. At .1% efficiency, and calculating extra for peak needs, intermittency, and transmission losses, 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.
They were right - the revolution did not get televised. It was posted on YouTube instead. All in 120 characters. SLOOSH!
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 ...
They figure with $30-40 million in government grants they may be able to double that.
Paying taxes to buy civilization is like paying a hooker to buy love.
1) reduce electrical demands 2) use more land 3) ...
So do expensive ones. Demand the best!
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?
Faster! Faster! Faster would be better!
Definitely better for the environment at these efficiency numbers. Better to burn methane than to let it escape.
"When information is power, privacy is freedom" - Jah-Wren Ryel
Everybody needs to remember.... It's cost per watt that will drive this industry. Make it so the cost/watt is at or below the cost of buying power off the grid and the stuff will sell like hotcakes. Until then, it will be a small market.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
1) reduce electrical demands
Yeah, good luck with that.
How does it feel to be a liar with pants constantly on fire?
A modified type of dye sensitized solar cell, nothing new.
https://en.wikipedia.org/wiki/Dye-sensitized_solar_cell
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?
"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?
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
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
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Just curious if one side always has to be connected to ground?
Cheers!
If you have no electricity to start with, even a little is a huge improvement. This is not meant for industrialized places.
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
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 railroads"
you:
"more than railroads! I denigrate that which is provably a waste of time and money based on known workings of this universe."
you're a dolt. stick to engineering and implementing technologies other people create, and stop showing off your colossal lack of imagination
actually, engineer is not a term you deserve. a plumber fixes toilets. an engineer designs new uses for technology, creatively. a scientist invents new technology. based on your lack of imagination and lack of appreciation for mankind's historical achievements in the striving for new technology, you rank somewhere below plumber. at least a plumber has to get creative now and then
seriously: you are on the wrong website
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
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?
Probably easier to build a methane digester such as http://www.small-farm-permaculture-and-sustainable-living.com/methane_generator.htmlhere. There's even a cool video to watch. IIRC from my old hippie days, there's an economy of scale involved, so you might wanna build one with a couple neighbors...
Understanding the scope of the problem is the first step on the path to true panic.
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
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.
Blasphemy is a human right. Blasphemophobia kills.
The good news is, we're only 20 years away from fusion power.
Understanding the scope of the problem is the first step on the path to true panic.
How do you say "Nuttin' don't get done wit'out it don't get done by da union" in Swahili?
I used to fear clowns...but I'm discovering that chimps are far, far, worse.
FYI, the "lead a horiculture" quip was invented by a woman.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC