Chemist Needed: Solar Power Made at Home? RP Says No Big Oil!

[Edu]

A few companies are making "thin-film" solar cells by painting on "nano" particles to a sheet of stainless steel.

I think you could build these at home.

Below I post a link that has a few seconds showing the painting process. It looks pretty simple, liquid just flows in a thin layer across the sheet. You don't need that machine to make a few panels yourself.

What if I took some stainless sheets, cleaned them and then spray painted a layer of this stuff on it? Like you paint a car.

What do I need? The "goo", paint stuff. Yes they might not end up the proper thickness everywhere, but maybe good enough if I made large sheets. Remember the price of this is really low, and some people have lots of room out back, so even if it's 50% less than the factory I am still way ahead, just make them 50% bigger. Plus it's a fun hobby.

I will try to research what they use chemical wise and post more info here. Oh, don't worry about the "nano" part, it's just for marketing, we are talking about mixing this chemical with that one and heating it to X and all that.

http://www.kqed.org/quest/television/view/399
http://www.nanosolar.com/

(the forum says "and whatever suits you" and RP talks about energy independence, getting away from big oil...)

 

[Peterjar]

Chemist here

I Have a Ph. D. in Chemistry. Proper thickness of the material will be real important for its efficiency. One can "spin-coat" the "goo" to get a uniform thickness. The whole process will take more than spray paint I think but it could be doable. I'll look in to it.

Peter


Ok. So I watched the video. Yes. They are spin-coating. There are at least 4 layers to the thing. I would rather invest in the company than try to recreate their process, which is the culmination of over 50 years are hard science and engineering. On the other hand these nano-particles are typically very easy to prepare. They can be made in large quantity in half an hour, are easy to analyze, and uniform in diameter. However, we don't know what ratio of particles they are using and so on. All these parameters are essential for the efficiency of the energy transfer.

On the other hand I think there would be real money in figuring out a way to get this stuff into an aerosol can. A good idea. You could turn anything into a light harvester.

 

[Edu]

Thanks, and I am thinking that $200 for a normal 30W panel is too much, so being a mickey mouser from way back, I would love to make these myself.

I am thinking the top layer might be able to be sprayed on a little at a time and then tested as you go thicker, the other layers may not matter that much. I am sure they had to do a lot of this type of experimenting in the lab, and small pieces could be done to get a idea of what I need.

The nice thing is we know this works, they tested and shipped these things. They survive weather and everything (and that gives us a clue that they are baked on like a car paint job).

As for the front electrodes, that layer could be done with glass and some thin copper wires crazy glued to the glass then pressed against the solar panel (maybe). I don't really care if it's flexible or not, doesn't really matter and glass is very cheap. You could make the bottom metal thicker to support it all.

As for the "spin coating", it looks to me as you watch that the paint is simply squeezed out under pressure against the rolling metal. You can see it start in the middle of the sheet and move to the edges. However, they do seem to be able to keep it off of roller somehow.

I see no motors or electrical connections to the "head", so I am thinking it's just pressure, we see a small hose going to it.

Have you ever looked at a car paint job up close? It's amazing how nice they can do that.

Anyone in Palo Alto willing to go to the factory and try to get a tour?

 

[Edu]

Looking again, I am sure that printing head says "Liberty" on it, a company name? I found a listing for "embossing laminating machinery", could be a standard part they use in printing? If there are electrical connections, they are under that metal mounting plate.

In the second part I think that other machine is part of the baking process, looks like the controls are for oven like stuff (just a educated guess). Lots of clues laying around.

 

[Edu]

Lots of info on this: CIGS "copper-indium-gallium-di-selenide" (CuInGaSe2)

"The quarternary CIGS nanoparticles for absorber layer of solar cells have been synthesized with various mole ratios by colloidal route. The CIGS nanoparticles were prepared by reacting CuI, InI3, GaI3 in pyridine with Na2Se in methanol at 0¡É under inert atmosphere. For Cu0.9In0.8Ga0.3Se2 and Cu0.9In0.7Ga0.4Se2 stoichiometric ratios, tube-type nanofibers were obtained with the widths in the range of 20-50 §¬ and lengths of 0.1-3 §* from reaction at 0¡É for 20 min. For Cu1.1In0.68Ga0.23Se1.91, and Cu0.9In0.68Ga0.23Se1.91 ratios, spherical nanoparticles were obtained from the same reaction condition. As compared to particles from Cu0.9In0.68Ga0.23Se1.91 ratio, more uniform and smaller nanoparticles with diameter in the range of 5-20 nm were obtained from the Cu1.1In0.68Ga0.23Se1.91 stoichiometric ratio. The morphology change of the CIGS particles seems to be closely related to the ratio of Cu/(In,Ga)."
http://www.mrs.org/s_mrs/sec_subscribe.asp?CID=2695&DID=115189&action=detail

Here's a picture of one manufacturing process:
http://www.flisom.ch/e/F_Techn_LCost.html

Some info, but I think this is a "invest in this" thing (no production):
http://www.daystartech.com/terrafoil.cfm

Here's an old article:
http://jcwinnie.biz/wordpress/?p=1919

They are saying "5 micron thick", how think is a coat of paint on a car or metal part?

These guys make a roll up solar panel, the encapsulation could possibly be used to "glue" copper wires against the front surface. "The polymer encapsulation is partially constructed of durable ETFE, (example, Tefzel®) a high-light-transmissive polymer."
http://www.uni-solar.com/interior.asp?id=102

Another idea, can we find some chemical house to turn out batches of this stuff for us? Have them make a batch and put it in small bottles so a group could do a buy all at once.

I see only two layers to worry about, there's the CIGS layer and some other one on top of that, then some sort of conductive layer on top which could possibly be exchanged for thin copper wires.

EDIT: Looks like car paint is about 125 microns thick, clear coat is about 50 microns, but they can buff it down a few microns at a time and you can buy a gauge to measure it, that may be a way to get it where you want it.

Another question is how dangerous is this stuff if you sprayed it on your skin or possibly breathed it while polishing?

 

[amy31416]

I'm a chemist as well, though I'm an analytical chemist. I'll check this out as it's something I'd be very interested in.

 

[jyakulis]

heh as long as you don't copy their methods of manufacturing, the solar panel compositions, the methods of using them, the structures of the solar panels you should be fine.

what i mean here is they probably have an extensive intellectual property library protecting their technology. basically, try not to get your ass sued lol. now if you can make a new and useful improvement to the technology under 35 USC 101 you could probably make and use it and obtain a patent.

35 U.S.C. 101 Inventions patentable.

Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.

if you really want to fool around with alternative energy stuff why not stanley meyer? most of his stuff has already passed the statutory 17 year period and is open to production by the general public. he has a huge patent library for his water fuel cell technology, which i believe is much different than just your typical electrolysis for reasons i'd rather not get into. i'm an examiner in art unit 1795 electrochemical cells at the USPTO and believe his stuff to be the real deal, though under no circumstances am i a spokesman of the federal government or the office.

http://youtube.com/watch?v=Jcy3JbGjQwo

complete writings:
http://waterpoweredcar.com/stan.html
intellectual property:
http://en.wikipedia.org/wiki/Water_fuel_cell

 

[Edu]

No patent violations if people make them for their own use and not for sale. You could make kits and sell them.

By posting the ideas here any "improvements" are now public domain. Putting this into spray cans for each layer or possibly in the future into one simple spray can is now public domain. Using thin wires as the top electrode is public domain now. Buffing the material to get it to the right thickness is public domain and somewhat obvious.

One more improvement, use a metal screen as the top electrode, for simple application and available everywhere.

Putting glass on top, well that's a little obvious.

The idea is to make this so anyone can do this in their garage for fun and hobby. Keeping something like this limited to a few factories that will pop up in 10 years isn't going to save the world.

It's been proven to work, it just needs to be made more simple so we can all use it right away.

 

[Mesogen]

There would be all kinds of red tape involved in selling the "goo" (colloid). You'd have to get EPA clearance and they'd have to make sure you were in compliance of all sorts of regulations.

And you'd have to know what you were doing when it comes to getting the layers right. It's one of those situations where it would be cheaper buying the finished product from them than it would be to fabricate it yourself at home. And you have to get the layers just the right thickness or it just won't work the way it should.

 

[jyakulis]

they aren't public domain. an idea is meaningless as far as intellectual property goes. you have to actively reduce it to practice. the only thing conception is used for is interference proceedings.
http://en.wikipedia.org/wiki/Reduction_to_practice

a mesh electrode is obvious not literally obvious...legally obvious:
http://www.patentstorm.us/patents/7022910.html
http://en.wikipedia.org/wiki/Inventive_step_and_non-obviousness

just because you would be selling the essential pieces to make their structure and use their method doesn't mean you aren't making profits selling their ideas. i have no idea of the scope of their claimed inventions though i will admit.

however, there is absolutely nothing stopping you from working on this kind of stuff in your garage, but to think you are going to make a new and useful improvement on this with absolutely no research funding, no research team, and not even that well acclimated to the field is a bit of a stretch. and not a literal "new and useful improvement," a legal NON-OBVIOUS new and useful improvement.


if you think you have some good ideas though by all means go for it. i've been researching stanley meyer's work myself and plan on building his water fuel cell when i get some more time.

 

[JordanQ72]

Thanks, and I am thinking that $200 for a normal 30W panel is too much

Yeah, it would take 15 years just for the panel to pay for itself. I have no clue how long they're designed to last or how much it takes to maintain them or the cost of any other part of the system, but that really isn't too fantastic of a margin to start with.

 

[Edu]

If I went back to the 1700's and I made some crude wire out of copper I melted and a took a few magnets and produced a telephone in my garage because of what I know now, would I need a research team and large funding? What about if I made a battery?

In the future, kids will probably mix this stuff and paint solar cells as a class project.

And I don't have to file something with the government to make it public domain. What I did do though is make it so greedy people can't patent these now obvious ideas and keep people from spraying this on with spray paint cans. These ideas have been publicly disclosed and are archived by google, wayback and a lot of other non governmental web archives.

Now, back to actually building something and pushing the technology.

I have searched a little and didn't find anyone working on this as a hobby project. if anyone finds info please post links.

Abstract

Chalcopyrite CuInGaSe2 (CIGS) nanoparticles for solar cell were successfully synthesized by using a relatively simple and convenient elemental solvothermal route. From the reactions of elemental Cu, In, Se and Ga powders in an autoclave with ethylenediamine as a solvent, spherical CIGS nanoparticles with diameter in the range of 30–80 nm were obtained at temperatures in the range of 180–280 °C, whereas plate-like particles were obtained at 140 °C. The addition of gallium to the elemental solvothermal route for CuInSe2 particles lowered the reaction temperature for the formation of the CIGS nanoparticles, which was studied with the Solution–Liquid–Solid (SLS) mechanism.
http://dx.doi.org/10.1016/j.tsf.2004.11.078

Abstract

A non-vacuum process for Cu(In,Ga)Se2 (CIGS) thin film solar cells from nanoparticle precursors was described in this work. CIGS nanoparticle precursors was prepared by a low temperature colloidal route by reacting the starting materials (CuI, InI3, GaI3 and Na2Se) in organic solvents, by which fine CIGS nanoparticles of about 15 nm in diameter were obtained. The nanoparticle precursors were then deposited onto Mo/glass substrate by the doctor blade technique. After heat treating the CIGS/Mo/glass layers in Se gas atmosphere, a complete solar cell structure was fabricated by depositing the other layers including CdS buffer layer, ZnO window layer and Al electrodes by conventional methods. The resultant solar cell showed a conversion efficiency of 0.5%.
http://dx.doi.org/10.1016/j.cap.2007.04.037

Abstract

A set of low cost techniques with realistic potential for direct manufacturing costs reduction were developed in the last five years while the industrial Cu(In,Ga)Se2 (CIGS) solar cell production is based on vacuum processes, which require high initial investment into production machines. The common properties of these low cost techniques are the use of simple and fast non-vacuum deposition methods and the prefixing of the film-composition on a molecular level in a precursor layer, which is chemically and thermally treated to form a high quality CIGS film. The paste coating approaches use premixed inks which are applied by doctor-blade coating to yield solar cell efficiencies of 13.6%, with the potential to reach 15% and more in the next years. The choice of the precursor material has to be made with respect to the used selenization conditions to avoid detrimental impurity phases. A new precursor material is discussed, which allows fast conversion in selenium atmosphere and was used to produce solar cells with 6.7% efficiency. The CIGS film thickness has to be increased for complete absorption of the incident light.
http://dx.doi.org/10.1016/j.solener.2004.08.015

If you read that far down, it looks to me that the CIGS layer could be thicker and that the top layer needs to be the one that is somewhat thin.

 

[JordanQ72]

In the future, kids will probably mix this stuff and paint solar cells as a class project.

Eh, I honestly have my doubts that trend will continue with technology. Even today, I highly doubt even in 500 years you're going to be able to home fab 45nm processors.

I've worked with semiconductors as an undergrad, and the physics behind it is highly specific to chemical concentrations and contaminants you won't be able to achieve in a home setting. But more important than that even is geometric precision. This technology doesn't really have any 'give' in those metrics, at least not in excess of 10% any parameter size. If you're off by ppm, or don't evenly distribute your dopant in a silicon substrate, you're left with something that shorts or an insulator, not a semiconductor. When you build a diode, if you're off by nm, again, you'll either never hit a depletion region before you hit electrical breakdown or you'll have a usually high leakage current.

Now I know this isn't the exact same thing as laying out traditional semiconductors, but I understand the process is very similar to how a normal solar cell works. In silicon, you're enabling photo recombination in the different layers. With these dyes, you're allowing electron transfer into some lower layer through a layer that acts somewhat like a diode. It seems you need to engineer the particles size and layer thicknesses down to the 10 nm degree for this to have utility.

Wiki had a good link to a government research paper about it
http://www.nrel.gov/pv/thin_film/docs/wc4papernoufi__.doc

I'm really not sure what you can use at home to do precision depositing at the 10nm level. Even the thinnest razor blade I've seen is over 5000x thicker than the layers you need to deposit.

 

[torchbearer]

In Louisiana, If i put solar panels on my house, its illegal for me to use my own power.
By state law, I have to sell the power to the city utility and then buy power from them with a credit given for the power I sell them.
That is why alternate energies are having trouble catching on here.

 

[IPSecure]

Check out the MEG:

http://www.cheniere.org/megstatus.htm

 

[JordanQ72]

Check out the MEG:

http://www.cheniere.org/megstatus.htm

I looked at http://www.cheniere.org/references/MEG_Patent.pdf page 5, and I don't understand how he's calculating his input/output power, unless his graphs are just wrong. Using his graphs, I calculated 78% efficiency. The guy made a switching twin flyback transformer as far as I can tell.

 

[Edu]

I looked at http://www.cheniere.org/references/MEG_Patent.pdf page 5, and I don't understand how he's calculating his input/output power, unless his graphs are just wrong. Using his graphs, I calculated 78% efficiency. The guy made a switching twin flyback transformer as far as I can tell.

The problem with coils is the back EMF, and a lot of volt meters don't handle that type of spike very well, plus the magnetic pulse that comes off of them screws up instruments. You really need to know what you are doing to get proper readings.

 

[Edu]

So can anyone tell me if a somewhat skilled person could mix this stuff himself? It would be OK if you had to buy a little bit of equipment, possibly used.

And could you pour this on and spin the metal backing to reach a thin coating? Or maybe just dip it and let it run off?

I'm just trying to think simple.

When I view the video I see what looks like pressure regulation and speed of the metal passing by while the liquid is being deposited. Calibration of that would be a trial and error type of thing, so there has to be room for thickness variations in the design.

Another common tool would be an air brush to paint this on.

 

[Mesogen]

Where would you get the colloid (goo)?

 

[Edu]

I would still like to know if the stuff I need is available, mixable at home with simple cheap tools and where I could get the supplies. Figuring the amount to apply and the mixture could be done on a trial and error basis by many people posting to a hobby forum.

http://www.thedailygreen.com/environmental-news/latest/solar-breakthrough-47022401

"A team of Northwestern University researchers have developed a new anode coating that, according to the paper they published in the Proceedings of the National Academy of Sciences, improve solar panels, making them convert sunlight into electricity more efficiently.

.....

Of the new solar energy conversion technologies on the horizon, solar cells fabricated from plastic-like organic materials are attractive because they could be printed cheaply and quickly by a process similar to printing a newspaper (roll-to-roll processing).

To date, the most successful type of plastic photovoltaic cell is called a “bulk-heterojunction cell.” This cell utilizes a layer consisting of a mixture of a semiconducting polymer (an electron donor) and a fullerene (an electron acceptor) sandwiched between two electrodes -- one a transparent electrically conducting electrode (the anode, which is usually a tin-doped indium oxide) and a metal (the cathode), such as aluminum.

When light enters through the transparent conducting electrode and strikes the light-absorbing polymer layer, electricity flows due to formation of pairs of electrons and holes that separate and move to the cathode and anode, respectively. These moving charges are the electrical current (photocurrent) generated by the cell and are collected by the two electrodes, assuming that each type of charge can readily traverse the interface between the polymer-fullerene active layer and the correct electrode to carry away the charge -- a significant challenge.

The Northwestern researchers employed a laser deposition technique that coats the anode with a very thin (5 to 10 nanometers thick) and smooth layer of nickel oxide. This material is an excellent conductor for extracting holes from the irradiated cell but, equally important, is an efficient “blocker” which prevents misdirected electrons from straying to the “wrong” electrode (the anode), which would compromise the cell energy conversion efficiency.

In contrast to earlier approaches for anode coating, the Northwestern nickel oxide coating is cheap, electrically homogeneous and non-corrosive. In the case of model bulk-heterojunction cells, the Northwestern team has increased the cell voltage by approximately 40 percent and the power conversion efficiency from approximately 3 to 4 percent to 5.2 to 5.6 percent.

The researchers currently are working on further tuning the anode coating technique for increased hole extraction and electron blocking efficiency and moving to production-scaling experiments on flexible substrates."