Check out our extensive FAQs:
Q: Is 'multi-crystalline' cell the same as "poly-crystalline' cell? What is the differences betwen monocrystaline and multicrystaline?
A: Multi-crystalline and poly-crystalline refer to the same thing, which is the base wafer type on which the solar cell is made. Monocrystalline's based wafers (cells) are made from a single crystal that's round like a big cylinder and the cells are typically higher in efficiency.
Q: What other components I need to buy in order to assemble a complete solar panel. Do you sell these other items? What else do I need to make a complete off-grid power generation system?
A: You will need the following other components:
1) Tabbing wires to connect the cells
2) Bus wires to connect the series sections
3) Flux to help you solder the wires to the solar cells
4) Solder to help add additional bonding needs at the back.
We provide all these items in our DIY kit listings.
You will also need:
5) Junction box to help the wire connectors connect between your tabbing wires and your inverters or charge controllers
6) Depending on your encapsulating techniques, EVA, TPT backing
7) Glass, ideally solar glass, but other types of glass may be the substitute because solar glass is very hard to find and ship. So purchase it at your local Home Depot or other hardware stores. 8) Sealants - you want to make sure that your solar cells are protected against impact and moisture for it to last a long time.
9) Did we forget to mention soldering iron? Get 90 watt or above rated soldering irons.
Items beyond the first 4 will be selectively added to our future offerings. So check back with us soon.
After you have made the panels, then you can put together your off-grid solar system this way:
1) Solar panels that have 18+ volts for 12 volt nominal
2) Charge controller
Q: Different categories of solar cells.
A: The NEW cells are our 2009 shipment from the original manufacturer and most of them are high power cells, the wattage per cell falls between 1.6 to 1.85 watts. Category A cells are original good cells; A- cells have minor chips on the edge; and B cells have slightly bigger chips on the edges. ALL these cells work perfectly fine, the wattage per cell for A, A- and B falls between 1.4 to 1.75 watts.
Customers purchase A- and B cells mostly because they are making panels for themselves and don't care much about the cosmetic look; or some beginners want to experiment. We also have Pre-Tabbed cells, which may save you a lot of labor, they are the A cells with tabs. We also have tabbing wire, bus wire, flux pen and lead-free solder.
Average Power (Watts): 1.75 Wp
Average Current (Amps): 3.5 Imax
Average Voltage (Volts): 0.5 Vmax
Thickness 200 μm = 0.2 mm
Exact dimension: 3 1/4 inches x 6 inches, or 80 mm by 150 mm
Weight: Just above 6 grams, or 0.2 oz.
Q: Customer asking about solar cells' wattage for 108 cells.
A: The factory standard wattage per cell is around 1.75 watts, so 108 cell panel will THEORETICALLY gives you 189 watts. But then cell production quality varies and some cells can have lower power than the standard rated cells. According to Evergreen Solar, 2% of the unsorted cells can have low power, and if you connect all the cells in series, the panel wattage power will be a multiplier of the lowest power cells. Just like the water flow is determined by the narrowest pipe in your whole plumbing system. Before connecting all the cells together on your panel, you need to test each cell and take out the very low power cells. But the cells that we are currently selling are mostly with good, known power, so we are fairly confident with the solar cells, but we never give any guarantees that EACH and EVERY cell will perform to the specifications. We give some bonus cells to compensate for the lack of guarantee from us, and so far our customers have been very happy with the deals they have got.
The other reason for your panel to not have the total possible wattage power is your panel production techniques. Your soldering of tabbing wires on the cell bus bars may not be optimal; the glass you buy may only take in a certain percentage of the sun, etc... The reasons are many, but the joy here is to learn about Solar and still generate power at much cheaper rate than the professionally made panels.
Q: My question is what type of Glass -- Acrylic, Plexi glass should be used to construct these? Can I use old sliding glass doors?
A: Ideally you will want to use solar glass, which has three properties:
1) It has surface treatment to reduce sun light reflection when it hits the surface of the glass
2) It is ultra white in the sense that it has very low iron content in the glass. This increases the absorption rate of sun light that doesn't get reflected
3) It is tempered so that it becomes strong enough to withstand the assault from hail, flying little rocks etc. And it also won't shatter.
The question is where to get them. It's not easy, and we are not carrying them at the moment. They usually need to order directly from the solar glass manufacturer because they can not be cut once it's tempered. Solar glass manufacturers don't take orders from individuals like DIY folks though. We are thinking of getting them because we have the scale but we are not there yet. Therefore you might have to live with the glass that you can get from your local hardware store. Prepare to lose 12 to 13% of the power of your solar cell because of not using solar glass. If you have access to the people who build green houses with glass, perhaps that's a better choice than sliding glass door glass.
Q: What kind of backing panel do you recommend for these to be mounted on? How many cells would you put on each panel? Where can you purchase the cover material for the finished panel?
A: We suggest that you encapsulate the solar cells between two layers of EVA, and than at the back of EVA, use TPT backing. On the front side, use solar glass. That's the most ideal. These materials are hard to find, so you can use sandwich the solar cells in two layers of glass and seal the edge of the glass with silicone and that's a slightly compromised solar panel. Not ideal, but you have to do what's practical sometimes. And even if you can get the most ideal backing material, laminating them requires a big industrial size machine.
I would start with building panels containing 36 cells, with 4 columns of cells, and 9 rows. And then after you are comfortable, increase to 72 cells. And don't go too much beyond that. Going beyond that, things get more complicated than what a beginner is ready to tackle.
Q: EVA, encapsulation.
A: We suggest that you encapsulate the solar cells between two layers of EVA, and than at the back of EVA, use TPT backing. On the front side, use solar glass. That's the most ideal. These materials are hard to find, so you can use sandwich the solar cells in two layers of glass and seal the edge of the glass with silicone and that's a slightly compromised solar panel. Not ideal, but you have to do what's practical sometimes. And even if you can get the most ideal backing material, laminating them requires a big industrial size machine. I would start with building panels containing 36 cells, with 4 columns of cells, and 9 rows. And then after you are comfortable, increase to 72 cells. And don't go too much beyond that. Going beyond that things get more complicated that what a beginner is ready to tackle.
Q: Do you have these cells all the time? And if so, can I get a steady supply when I order?
A: Yes we have these cells all the time at least for the next few months, because we have mountains of the cells in stock. In fact we are going to have more sizes going to be released to the market because a lot of the chipped cells are waiting to be cut into customized sizes by our laser cutter. Our supply is probably as steady as you can possibly get. We literally have hundreds of thousands of cells in stock, and some people have seen them. We have been exporting these cells to Asia for a long time and we are now retailing them to the DIY market in the US. We wholesale a lot of custom cut cells to the panel making training teachers in the US also. Whether you want to start a business in solar by making solar panels yourself, or you want to start a training program, you will find the best supplier in us. We sell in huge quantity other solar material, such as virgin poly silicon, ingots, wafers, solar cells, and solar panels. Whatever you what that's crystalline based, we have them.
Q: Do you offer volume discount?
A: Of course! We offer volume discount when you purchase more than 500pcs solar cells. Please write an email to firstname.lastname@example.org with your name, quantity, and special requests for custom quote.