small thin solar cells of high energy output

Brant · July 2009

say you had somthing the shape of a DVD movie box, only thiner, and you wanted to mount solar cells and other esential components to it, and each of theese connect to annother DVD box shaped object passing the elelectricity on to the next and the next. What type of solar cell would be used and why? The cells need to be small, thin and produce as mutch electricity as possible from a solar cell.

BB. · July 2009

Re: small thin solar cells of high energy output

Brant,

That is a pretty wide open question... The most efficient cells are Gallium Arsenide Solar Cells which are used on space craft... But instead of $1-$10 per watt (mono or poly crystalline silicon cells), you are probably looking at $100-$500+ per watt--very wild guess... Somewhere around 30-35% efficient (vs ~12-15% efficient silicon PV cells).

Assuming that you don't want to spend that much money, then you should stick with mono-crystalline cells (a bit more efficient, a bit more costly) or poly-crystalline (a bit less efficient, a bit less costly).

A standard silicon solar cell generates about 1/2 volt--I am guessing that you will want more volts, so you will have to have a set of smaller cells soldered together to obtain a higher voltage (at a lower current).

Weather proofing solar cells is a pretty big issue--if you want your panels to last 25-40+ years. Obviously a CD Case is not going to have a great seal, and they are not the best optically clear material (low iron glass is typically used).

You certainly can go on EBay and search for bare cells (a few threads here about people building their own arrays)--but beware the typical "large" format silicon cell is almost paper thin--and just about as strong as wet Kleenex (thinner cells use less of the expensive silicon to make).

A 5"x5" CD Size case cell will be able to generate, roughly, 2 watts.

What is it that you are trying to do or what are your requirements for the solar cells?

-Bill

Brant · July 2009

Re: small thin solar cells of high energy output

I am actualy looking into using carbon fiber fabrications rather than a DVD case. The sise will be about that of a DVD case and around two and a half centimeters thick. I want the cells and semicunducting material atatched to this and coated with a weather protectant seal all together no thicker than a half inch--thinner would be even better.

dwh · July 2009

Re: small thin solar cells of high energy output

There are a whole LOT of products like that on the market. A quicky google and taking one of the first links that comes up netted me this:

http://store.sundancesolar.com/solbatchar.html

Brant · July 2009

Re: small thin solar cells of high energy output

Ok if I got this, I checked ot the link, cool stuff and I will look at it more later. I realy don't like sorting through all the options and guess I need to narrow it down. I'll work on a cleaer description of what I want and ask you about it later. Thanks, very interesting stuff.

BB. · July 2009

Re: small thin solar cells of high energy output

Brant,

Search on EBay for "vw solar panel" -- you will find a bunch of panels that came off of VW cars used to keep the battery charged during shipment and storage until they got onto the dealer lots.

I am not sure they are "sealed" construction (are installed with suction cups to the inside of the windshield--so they don't have to be weather proof).

Might be about right to prototype your product without spending a bunch of time and money on the initial packaging... Also, the VW are available in both Thin Film Panels (uniform black panels) and poly-crystalline (blueish fractured look). I would recommend you stick with the crystalline panels (should be more efficient and longer life at higher power per sq. inch).

-Bill

Brant · July 2009

Re: small thin solar cells of high energy output

"suction cups isnide a window" sounds like a garfield toy-- what?

BB. · July 2009

Re: small thin solar cells of high energy output

They are just a square ~3-5 watt solar panel that trickle charges the car's battery by sticking to the windshield and plugging into the ODB II receptacle (some have cig. lighter plug ends).

The panels roughly 12" square.

Just a "cheap" source of large numbers already packaged cells...

-Bill

Brant · July 2009

I'd like to simplify comuniction

I am new here and prefer not to read through all the threads here--need direct responses. I should also point out that my knowladge of solar tech. is, well, undeveloped. I'm interested, and I've had an idea pop in my head. I know I can't biuld it on my own and realy have no idea if it is even possible. But, well here it is---- Solar cells assembled in a grid each cell or group of cells should be the size of a single roofing shingle and of comparible thickness and used to replace a roof of shingles entierly using carbon fiber as the backing or housing placing cells and all on top and sealing it all together.
Imagine a roof only insted of shingles you see solar cells and under them the strength of carbon. Can you cover a roof of an averge home, provide enough power and even create an excess--proffitble excess???? Please use your emagination here and try to educate me. I would like to see groups of home owners together becoming indepent energy providers selling off thier excess energy to local buisnesses and to those who cannot afford their current energy providers. A net work of homess rooved with carbon reinforced solar roofing shingles generating enough power fo their homse and their comunity.

stephendv · July 2009

Re: I'd like to simplify comuniction

You mean like these: http://www.solarcentury.co.uk/Residential-developers/Smaller-Developers-Self-Builders ?

The problem with this type of technology is the cost... which IMO is the biggest hurdle in widespread adoption of residential grid tied solar. Take Germany for example, they offer something like 30c per kWh guaranteed for 20 years and adjusted for inflation. Which means that solar becomes a secure and worthwhile investment, especially in this climate where you'd get 4% interest on a saving account and between 10-15% on an investment in solar.

If you read through the German photovoltaic forums you'll see the vast majority of people posting questions don't have clue about renewables or solar panels, they're installing purely as an investment.

Financial incentives like that are what will drive widespread adoption, and not necessarily technological advances in PV mounting systems (unless they also bring the price of the installation down

)

Brant · July 2009

Re: small thin solar cells of high energy output

oh, sorry if I seem clueless but I truely am. So I take it that it is used to generate power for an automoblile. I want somthing to power homes and I want to use enough to create an excess amount of engery that can then be sold off to others not using their own solar power. And I wnat this to replace the old way of roofing a home--two jobs in one that make money for the home owner with an energy providing roof.

Brant · July 2009

new idea? can you tell me? solar roofing

HEy guys, all you advanced geniuses, has any one used a carbon fiber shell to house solar cells to replace a roof? Can you cram everything needed into somthing as thin as a roofing shingle, cover a roof with them and provide enough power for the home and then some? If so why not yet? And if not, how come?

BB. · July 2009

Re: small thin solar cells of high energy output

I see you have already asked about Solar Roofing Tiles/Shingles... There are already vendors making various types of them out there.

To date--solar roofing tiles have not been that popular. Generally, when all of the issues have been weighed--the standard solution of using silicon solar panels under tempered glass, sealed, and mounted in an aluminum frame (on mounting rails/structure for support of wind/snow/etc. loads) has been the most cost effective and longest life product (25-40+ year life).

The basic system you are asking about is called Utility Interactive or Grid-Tied solar inverters (same thing, just different names).

Basically, connect solar panels to a specially designed (and safety certified) AC inverter (typically 200-600 VDC around 3-10kW of panels per inverter), and get 240 VAC 60 Hz out that sends power into your home, and if there is enough power, back out through your meter (turning it backwards).

And, with variations, the GT Inverter can connect to wind turbines, water turbines, and other sources of power.

You can also get GT Inverters down to ~200 watts in size too--but they tend to be pricey.

You can visit our host's webstore and see the products and FAQs (frequently asked questions) scattered throughout their site.

Much of what you are asking about has already been made into products and is for sale right now... Do you have something specific you need (power solution) or are you looking to get into the industry (sales and installation of solar power), or what?

-Bill

Brant · July 2009

Re: I'd like to simplify comuniction

I skimmed through but, no, those pictures don't look like what I had in mind. Check out the 3D cells at Georgia Tech. The prototypes are about the size of a quartar, thin and have semi conducting material on the flip side. Could that work? Could you put like a dozen or so on a piece of carbon conect them all and cover a roof, provide enough power for the home and combine that with the excess power of ones neighbors, using the same tech, and then sell the power splitting the proffit????

BB. · July 2009

Re: small thin solar cells of high energy output

Brant,

Since you are asking related questions--I have placed them all in one thread--makes ongoing conversations much easier to follow.

Regarding Carbon Fiber for solar panels... Besides expense of carbon fiber and the polyester/epoxy binder (and UV sensitivity), the issue that CF blocks sunlight, and being conductive under 600 volts and 5-10 kWatts of solar panels, issues of fire / fuel load of the binder/resins--it probably does meet much of the average solar panel design requirements.

Roofing materials tend not to be structural--but protect the underlying structures from water/wind/snow/sun/fire etc...

If you where building something that needed both solar power and lightweight structure (such as a solar powered/assisted aircraft)--perhaps this would make sense (where weight is at a premium).

-Bill

BB. · July 2009

Re: small thin solar cells of high energy output

3D cells only increase off-angle absorption efficiency--does not make the underlying cell any more efficient when exposed to on-axis light/energy.

While it is always nice to increase overall power capture--this just addresses a specialized part of the solar industry (I think)--Appears to be only practical in space applications where the cells would not be contaminated by water/dust/bird droppings. As soon as you add a glass cover--you are right back to cosine issues and indexes of refraction reducing energy capture for terrestrial panels.

-Bill

Brant · July 2009

Re: small thin solar cells of high energy output

Thanks. I'm a hands on kind of guy. I figure things out by taking it appart, putiing it together and so on. All the numbers you just gave sound like this to me--jewnfwiofgjwio0fwefsji4094560. Sorry, I'm just a GED kid with a lot of big useless dreams. I found this site and was hoping, just hoping it could work. However, from the replies that I have gotten, I think returning to school in oder to have a carreer in this field would be very satisfying. If you guys don't mind though, I may stick around. I think I can learn a lot from the people who visit this site. In fact, I now have a great deal of techno stuff to learn and to add to my vocabulary. That in itself is very, well, worth the time so far. Thanks.

Brant · July 2009

Re: small thin solar cells of high energy output

Yep, what about carbon nano tubing incerted with electrical conducting molocules. Can you make a 12" by 3" and have a grid of incerted conducting molocules---no soldering--no wires??

Brant · July 2009

Re: small thin solar cells of high energy output

so a light wieght supuer strong roof that creates electricity using carbon fiber and small solar cells is a no go???

Brant · July 2009

Re: small thin solar cells of high energy output

Yes I would like to get into the indistry. In fact I had this idea without any out side influence or previouse knowladge--intuition. I live in Manchester PA outside of York. I'm dirt poor. Where do I to school for this--solar, carbon fiber instalation.

BB. · July 2009

Re: small thin solar cells of high energy output

Probably not--Semiconductors (like Silicon and others) are not very good conductors of electricity... They would need current carriers of some type. You see copper "fingers" on most solar cells today to gather the current and channel it to a solder pad where multiple cells can be attached.

And even if you had a 6x6 in cell--without on board "wires"--they still need to be connected to their neighbor cells (just like batteries in a flashlight) to conduct the power to where it is needed.

And arrays are not small things for a home...

My house uses 280 sq. feet of solar panels (think 17'x17' square) for 3,500 watts of solar panels (equivalent to a 4.5 horse power electric motor) to supply 100% of the power used by my suburban home with 2 parents and 2 kids... To make something safe (no fires please) and reliable (hopefully 40+ years of solar panel life in rain, sun, snow, hail) take a lot of effort and design work.

-Bill

BB. · July 2009

Re: small thin solar cells of high energy output

Engineering school was a blast for me (knowledge wise)--after 12+ years of pure boredom for me.

Reading was also helpful--in the "pre-web/computer days" -- going to the library and reading various magazines (Popular Science/Mechanics when younger, Scientific American when it was better, and just anything "interesting") was really helpful.

The ability to put together solutions from a wide range of knowledge was very helpful for me.

But--the basics are going to be important. Math, Chemistry, Physics, and even shop classes / real world experience and work will help you a lot.

I got my High School Diploma--but did not go to college for my Engineering Degree for almost 4 years--I hated school so much.

If you can get any work in the field you are interested in to get experience--save and go back to school--you will be much better off. One guy I knew--took ~15 years of night school to get his engineering degree.

However, with the economy today--getting work is going to be tough. Moving to where the jobs are (or might be)--will probably be a help (energy jobs in the middle of nowhere as an example???). You will have to be flexible.

-Bill

dwh · July 2009

Re: small thin solar cells of high energy output

Brant wrote: »

Yep, what about carbon nano tubing incerted with electrical conducting molocules. Can you make a 12" by 3" and have a grid of incerted conducting molocules---no soldering--no wires??

If you want to get into the nano level - first you should read Wil MacCarthy's "Hacking Matter":

http://www.wilmccarthy.com/hm.htm

And K. Eric Drexler's "Engines of Creation":

http://e-drexler.com/p/06/00/EOC_Cover.html

Both handily available online to read for free.

small thin solar cells of high energy output

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