Build a 60 Watt Solar Panel

Step 17: Counting the cost

So how much did all this cost to build? Well, I saved all the receipts for everything I bought related to this project. Also, my workshop is well stocked with all sorts of building supplies and hardware. I also have a lot of useful scrap pieces of wood, wire and all sorts of miscellaneous stuff (some would say junk) laying around the shop. So I had a lot of stuff on hand
already. Your mileage may vary.

Part                       Origin               Cost

Solar Cells                Ebay                 $74.00*
Misc. Lumber               Homecenter Store     $20.62
Plexiglass                 Scrap Pile           $0.00
Screws & Misc. Hardware    Already on hand      $0.00
Silicone Caulk             Homecenter Store     $3.95
Wire                       Already on hand      $0.00
Diode                      Ebay                 $0.20+
Jones Plug                 Newark Electronics   $6.08
Paint                      Already on hand      $0.00

Total                                           $104.85

Not too bad. That's a fraction of what a commercially made solar panel with a comparable power output would cost, and it was easy. I already have plans to build more panels to add to the capacity of my system.

* I actually bought 4 lots of 18 solar cells on Ebay. This price represents only the two lots that went into building this panel. Also, the price of factory second solar cells on Ebay has gone up quite a lot recently as oil prices have skyrocketed.

+ This price represents 1 out of a lot of 25 diodes I bought on Ebay for $5.00.

You can learn more about this project and my other alternative energy projects, including my home-built 15 Watt solar panel, my home-made wind turbine, and my biomass gasifier on my web site.

Comments

[m15cell]

I checked out your website. You sir are my hero. 

[silverknight15]

I feel the same as justinrobert "Very nice detailed instructions! I wish you would give some more examples of how your a putting the power you are generating to work. What the battery is that you are charging, what you can power with that battery, some real world examples of how your are utilizing this energy. " Please and thankyou :)

[mdavis19]

Hello, My wind turbine instructable has more information on what I do with the power I generate. The solar panel gets hooked into the charge controller circuit of the wind turbine and supplements the power it produces. I guess I figured that rehashing all the charge controller and battery info from the wind turbine instructable was a little redundant.

[avi625]

I agree with intensely give us a better view of the wires, i am also not too knowledgeable of solar panels and would request more intructions on making the panels and hoooking them up

[justinrobert]

Very nice detailed instructions! I wish you would give some more examples of how your a putting the power you are generating to work. What the battery is that you are charging, what you can power with that battery, some real world examples of how your are utilizing this energy.

[Atv02]

I have made two of these panels to charge a portable automotive jump start unit. (not really the right kind of battery) I have been saving for a sealed deep cycle because the battery will be indoors. I live in an apartment and have the panels in the window. When my Fluke Scopemeter battery died I used the jump pack and inverter to recharge it. I only get about 2 hours of direct sunlight but between the two panels, during that timeframe, I am pushing 8A at 20v, no load. Indirect sunlight I get about 2A at 16V, no load.

[intentsly]

The construction details were good. For me the wiring details were lacking. Perhaps a wiring diagram would have helped me understand what wires go to where. I'm not at all familiar with solar cells, as far as their wiring goes. As justinrobert said above; examples of how you are actually using the power would be also be a great addition! Thank you for sharing this.

[silver912targa]

If you connect the plus (most of times Red wire) from the first panel with the min (black wire) from the second panel and then again the + from this second panel with the - from the third panel and keep on doing this you made a "series" connection, meaning you can add the voltage. So in this case you add every 0.5volt for every panel you connect in series but you won't gain Amperes. On the other hand if you connect the panels "parallel" meaning + from first panel with + from next panel and - from first panel with - from next panel you can add the Amperes but you won't gain Volts. The same goes for batteries. Hope this makes it bit more clearer for you.

[intentsly]

I guess I'm just having trouble seeing this in the pictures. I understand parallel and series wiring, its just that the leads on the solarcells do not appear to be colored. Perhaps adding polarity signs to the pictures would assist in understanding what goes where. I'm assuming that the cells have a designated + and - lead. If that's not the case, then I get it.

[rusty0101]

More accurately with cells that he is building the panels out of, the loose tab that you see, which looks like a metal ribbon, is part of the front or top surface of each cell, and has a positive charge when the cell is in sunlight. The back of each cell has solder points where he has been soldering the loose tabs onto to join the cells. That solder point has the negative charge when the cells are in sunlight. (Note, I may have the polarity reversed, in which case my apologies.) One of the things that could use clarification is that the 3 rows of cells are oriented so that the positive charge end of one row is at the same end as the negative end of the next row, and so on. Similar to folding a row of 3 AA cell batteries. Hope that's a bit more helpful.

[Atv02]

The cells the author purchased off Ebay are NPN. The front / blue side is negative, and the back / silver is positive. To make a series of cells, hook up - front, back, front, back....... However many you need.

[dalecarlile]

FYI, Silicone contains an acid and can result in electrical connections corroding over time from the outgassing. Not all of the acid evaporates in the initial curing. So I would recommend keeping it to a minimum and opening the panel or venting it very well after it is hot. I found that some silica gel packs with the color indicators for moisture work very well at keeping condensation out of panels I have built. I also learned to use a voltage regulator to limit the charging voltage to a maximum of 14.2 volts on a 12 volt battery. Batteries get cooked/damaged from excessive charging voltages. I also use anderson pole connectors on my DC Systems.

[wupme]

Didn't knew that, and whats about aquaristik silicone, used to build fish tanks? As far as i know, its free of that stuff after it cured.

[starphire]

What you'd ideally use is "electronics grade" RTV, such as GE RTV162. This uses an alternative curing agent. It's pricey, though. Common grade hardware store RTV uses acetic acid as the curing agent, and it's readily identified by the smell when it's uncured - it smells just like vinegar. That's the stuff you want to avoid using with electronics. You could also consider a non-RTV solution, such as a MS (aka STPE polymer) urethane sealant - room temperature curing, one-part application, excellent adhesion, flexibility, weatherability, and safe for use with electronics. This stuff gets used for automotive windshield glazing

[dacarls]

Wupme, Down lower you describe an antibiotic soap. Please share name and if its prescription, as I have the same problem: hair follicle inflammation problem. I've been thru coal-oil stuff, various antibiotic soaps, even phisohex, benzoyl peroxide treatment, 3% aqueous peroxide for years. I might have gotten some of it in the African jungle (Mali, this is not a joke). Soap every day is the best. This has been a long term problem (many years). Now I have to go out and finish my solar cell array..... Suggestions welcome. [e-mail]

[dalecarlile]

Put some on a piece of foil and let it cure overnight. Then place it in a sealed jar. Place the jar in the Sun for a day and then check for a thin film of out gassed stuff on the inside of the jar. In a low temperature environment, you will get less out gassing per unit of time.

[kadris3]

batteries fry a lot lower than 14.2vdc. 13.8vdc fm a car system will boil them good . you need 13.2 vdc for a float charge to keep the batteries fm boiling. at 13.2vdc or 13.25vdc they won't boil, but will charge up nicely. if u use full array power to charge them it must be reduced as the batteries reach full charge. they must be switched to the float voltage to save electrolite. as they get almost dry the hydrogen in them blows. this can occur with as little as a one(1) amp charge. good 'structable. i was never that brave. those things are as brittle as sugar glass(used in movies). the alternative cost 4 or 5 times as much as your investment. many people like a little power in the woods; i.e., ham radio, some light, astronomy, camera, glucose meters, etc. gater clips are less expensive than power pole connex which while tidy, and pushed by ARRL, are overrated.

[ac7ss]

Yes, powerpoles are over-rated. Most people will never need a 45 amp bi-polar connector in .21 inches square, however they do make a handy 12 volt standard for your personal grid. I find that few connectors work as well, can be easily connected/disconnected, have self cleaning contacts, and can be panel mounted as the powerpoles.

[static]

I haver never read the ARRL adopting the power poles as a standard, as they did the Molex/RS connectors. That's not say individual ARES groups haven't adopted them a a standard connector for the sake of equipment interchangeability. Power poles can be quite inexpensive if a groups get together and makes large purchase.

[kadris3]

ARRL IS definitely pushing them for emergency service. i didn't care for them as they tend to disconnect too easily for my liking. also they want all to have them so we can share power in an emergency deployment. if i come to a disaster prepared to operate and someone else comes w a dead battery in his walkie it is my responsibility to take care of his need as well as mine???? i don't think so. it's just another would be helper who becomes part of the problem. these are given runner duty or sent home.!!!!!!!!!!!

[yetunguez]

wow, that is awesome! one day I'll do this, and maybe be a able to power my whole house. thanks for a great tutorial.

[denport]

great story and easy to follow. Thanks for sharing.