Picture of Build a 60 Watt Solar Panel
Several years ago I bought some remote property in Arizona. I am an astronomer and wanted a place to practice my hobby far away from the terrible light pollution found near cities of any real size. I found a great piece of property. The problem is, it's so remote that there is no electric service available. That's not really a problem. No electricity equals no light pollution. However, it would be nice to have at least a little electricity, since so much of life in the 21st century is dependent on it.

I built a wind turbine to provide some power on the remote property (will be another instructable in the future). It works great, when the wind blows. However, I wanted more power, and more dependable power. The wind seems to blow all the time on my property, except when I really need it too. I do get well over 300 sunny days a year on the property though, so solar power seems like the obvious choice to supplement the wind turbine. Solar panels are very expensive though. So I decided to try my hand at building my own. I used common tools and inexpensive and easy to acquire materials to build a solar panel that rivals commercial panels in power production, but completely blows them away in price. Read on for step by step instructions on how I did it.

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.

Edbed3 months ago


SeosmartS4 months ago

howdy, your
websites are really good. I appreciate your work.

Home Prices In
Gilbert Arizonahttps://youtu.be/iHMkAQC_cmg

rexnamo7 months ago

I made it but the cells easily crack and also it makes it a bit difficult. The heat inside the cabinet bends the cells and to prevent further damage I removed it from solar. How to prevent it. I am using acrylic sheet to make window.

hassan.deq7 months ago

Please help me.
1. where can i get this solar cells ?
2. What is the difference between mono crystalline, poly crystal and multi-crystalline?
3. How many pieces of solar cells are there in 1 kg f it?

tinker2343 years ago
could i harvest solar panels from garden stakes and solar toys

You *could*, but they won't be very powerful and you will need a very large quantity. Also, if they aren't all the same type, putting them in series will only give you as much current as the smallest one.

rashaism1 year ago

thank you for this very nice project...

I want to ask you if i want to buy the solar cell what must be its power?

ppereira141 year ago

I was looking for a higher capacity Solar System (400W or more). I found a really nice instructable. Heres a linkhttp://www.instructables.com/id/Apartment-Solar-System/

nepwk3 years ago
Excellent project. HOWEVER, if you try to build this keep in mind that you will NOT get 60 watts out of it (as claimed by the author) using the cells that this author used.

The author claims it produces 18.88 volts OPEN CIRCUIT with NO LOAD. No problem there. This is pretty much typical for 36 cells in series.

The author claims it produces 3.05 amp SHORT CIRCUIT CURRENT. Again, no problem as this is typical of this size solar cell.

And it's true that volts x amps = watts.

However, you can not multiply 3.05 amps short circuit current by 18.88 open circuit volts and come up with ~60 watts (57.584 watts to be exact).


When the solar panel is short circuited you get 3.05 amps at ZERO volts. 3.05 x 0 = ZERO WATTS.

When the solar panel is open circuit you get 18.88 volts at ZERO amps. 18.88 volts x 0 amps = ZERO WATTS.

What you need to look at is the IV curve (I=current in amps and V=voltage in volts) for the solar cell being used. When the solar panel is producing the maximum amount of power that it can produce the voltage will ALWAYS be LESS than the open circuit voltage and the current will ALWAYS be LESS than the short circuit current. Do NOT expect to see anywhere near the 60 watts claimed for this solar panel if you decide to build it. Depending on the exact solar cells that you get, expect to see more like 30 to 40 watts under load and you will not be disappointed.

This author makes the same error in his "How I built a folding 15 Watt Solar Panel" instructable where he also multiplies SHORT CIRCUIT CURRENT by OPEN CIRCUIT voltage and comes up with 15 watts for 40 cells (or 2.67 watts per cell) which is impossible considering that those cells are only capable of producing ~0.25 watt per cell under IDEAL conditions and more like 0.15 watts per cell under typical conditions.

Again, NICE PROJECT but the author REALLY needs to correct the mis-information he is posting in these instructables and on his website.

you are absolutely incorrect. by ohms law itself. it takes one volt of pressure to push one current of power through one ohm of resistance. therefore 3.05 amps requires at least 3.05 volts. but the ultimate truth you are probably looking for is that direct current CANNOT, WILL NOT, and NEVER WILL BE measurable in watts. to this very day, and i fear, for quite some time the difference between AC and DC will be misunderstood by even PHD holding electrical engineers. i am currently part of a project to rectify the problem. but fighting academia is harder than one might think, unless you consider how many theses for doctorates that would be nullified are taken into account. good job on the instructable. and never trust a PHD. ;)

graphixv nepwk3 years ago
Good comments. There are way too many Pie-In-the-sky claims made by people who make panels. And, way too many claims you can save 75% off factory panels by making them yourself. I blame all this on the second hand, B solar cell peddlers out there. They try to convince people they can make a solar panel for pennies on the dollar by purchasing their junk cells. Only after purchasing, the buyer finds out that the panel cost is going to be much higher unless big corners are cut.
welfner1 year ago

This came up again in Instructables, I guess this video was made almost 4 years ago. Today you can find solar panels at less than $1 a watt, some as cheap as 60 cents a watt. cheaper than they can be made and they can live outside...

DayBowBow2 years ago
So how many total diodes were used on this?
useful12 years ago
Hi there,

I just wanted to say, I built 20 solar panels because of this instructable, so thank you. It helped me a great deal understand about solar power and saving real cash from buying from the electrical company.

Currently on top of my house, there are over 20 panels I made by hand using local materials here in asia using your specs. I bought solar cells from ebay marked as B grade or A grade, almost exact replicas of the images on this instructable. It took over 2 years to complete them (at least for me).

There are a few caveats I ran into while building the first panel, which I shortly learned then fixed on the 2nd panel. Then more problems happened on the 2nd panel until what I have is my 20th panel.

1) Rain. It rains about 6 months of the year. I used silicon caulk bought from Home Depot., to seal the panels as per your instructions. However, water eventually made it through the wood, regardless how many layers of external paint I applied to each panel and upped the amount of silicon to seal.
To solve the problem now, and in the future, I read somewhere else that people bury there solar cells inside clear epoxy. That did the trick. I no longer had problems with water seeping in. However, it did dramatically increase the cost of making the panels. Resin or Epoxy is not cheap even in big quantities.

2) Plexi-glass didnt cut it. It immediately warped the the shape and size and domed. I replaced the plexi-glass with standard window glass cut to size.
Due to the other 6 months, where it doesnt rain, nothing but pure hot sunlight.

3) Amperage is dropping over time. My panels are giving me an open voltage between 18V and 21V. Under load, the voltage drops to around 13.7. (when everything is all connected) The amperage is dropping on some of the panels
The amperage varied when first built gave around 1.8 amps to 2.4 amps.
Now each panel 2 years later, dropped to 1.1 amps to 1.6 amps.
That's a pretty big drop in total amount of wattage. Its also a huge red flag to anyone building their own panels.

4) Repair. If you ever need to repair the cells, you're going to need to open up the panel. For areas that doesnt have extreme weather, resin/epoxy is probably not necessary. But at first, one of the instructions was to glue
the solar cell to the wooden backing, so that it stays put. I'm sure this instructable, never thought about having to repair the panel itself. But gluing the cell to the wooden backing is an absolute no-no. Not only is it frustrating hard to remove, it is almost impossible ( at least in my own experience )

Anyways, thanks for the instructable. Im not sure if DIY is a good way to go now, now that I learned more about the process and building them. The factory stuff bought from the store is already pre-made for outdoor environments. The savings between a panel and building your own these
days is negigible.
robbytesla3 years ago
I have found that using a heat gun (very similar to a hair blower) in the low heat setting can do the trick of cleaning off the residual wax from the cells while athe same time using cotton cloth or paper towels to wick out the molten wax.
timmi6 years ago
Hello, could you possibly expand a little bit more on how you joined the strings of cells. Thanks
msavoy1 timmi3 years ago

this video goes into great detail
msavoy1 timmi3 years ago

this video goes in depth with the whole process
I'm having problems with this as well.
triumphman3 years ago
Exacty, still no lasting, affordable way to get electricity from the sun! When will this happen ? Not in our lifetime! So solly, cholly!
davecardin3 years ago
Could you show where you hooked up the tester to the wires? Did you just touch the electrode to each of the prongs on the plug?
Nick Dolan3 years ago
And this is just the same copper wire from earlier?
working_it3 years ago
You need to use a low iron glass.
Plastic of any kind will fade in time.
You will also need to pot the solar cells in a special silicone that
is way more translucent then regular silicone.
Otherwise the light is really not getting in.
If your solar panel gets way hot, you will need to spray the underside
to get the wattage back up...heat kills the efficiency of the cells.
graphixv3 years ago
New factory 100 watt Solar panels are currently available in the $200-$250 range. I wouldn't go the DYI route unless you are planning to do an assembly line quantity of panels.

The cost to self-make a 100 watt panel is not that much different than buying a panel if you build it correctly. You also have the possibility of running into bad cells, user error and poor materials.

I would only go the DYI route if you’re building a huge system like 1000 watts. You could save 50% over factory panels building a lot of them, then again you may get poor panels. Check Ebay and Amazon for new panels. And remember, don’t buy small panels <50 watts, the cost per watt goes way up due to labor and other materials which are involved in making a panel of any size.
mdavis19 (author)  graphixv3 years ago
The situation was different 3 1/2 years ago when I originally posted this instructable. Anyway, there will always be people who prefer to roll their own, no matter how low the price of commercially made units go. If you aren't a maker, you wouldn't understand.
I agree. I was just making sure people were updated. I also bought some cells to make a panel not knowing at the time what the real cost would be and ended up buying a panel instead. If someone goes the DYI route, they may want to spend another $2 and install some dypass diods to make their panel shade resistant.
jcvillar3 years ago
Nice construction, but I worry that you are not using an encapsulant, such as SylGard, to prevent degradation of the cells.
RisingSun4 years ago
If I was your panel I would be afraid of a critter jumping or climbing on me, although I don't know what your place is like. Really cool instructable btw
gneal4 years ago
Thank you so much for this instructable. I actually built a solar panel using your instructions and it works great. I hooked it up to my DIY electric fence and it works perfectly. My dog knows what its boundaries are now.
Valence_46 years ago
Another important thing to greatly improve the panel's efficiency: Solar cells do provide a 0.45volt FORWARD voltage when lit by sunshine but will act as a REVERSE biased diode if unlit. So if a leaf falls on one cell of your panel, the overall efficiency will be HIGHLY reduced by the unlit cell that will absorb a high reverse voltage. This will not only highly reduce the panel's efficiency but may also damage the unlit cell if the panel is loaded. To prevent this, i strongly suggest you to buy 3 ampere shottky diodes (1N5820 for example), one per cell, and solder them un PARALLEL with each cell. The polarity is important. For that, use one cell, put it under sunlight and using a voltmeter, test which side is positive and which is negative. If i remember well, the top side is negative. Then, solder long bare wire (AWG24 will do the job) to each end of the diode and then, solder the bare wires onto BOTH tabs of the solar cells with the CATHODE (banded) side on the POSITIVE side of the cell and the ANODE (no band) side on the NEGATIVE side of the cell. On normal use, the diodes will be REVERSE biased and will have NO EFFECT on the overall panel's efficiency. But in one or a few cells are shaded either by a leaf, a bird or a tree's shade, thee diodes will start to conduct as the solar cell is reversed biased. This way, the whole panel will continue to generate power and the shaded cell(s) will be protected by the diode that will limit the cell's reverse voltage to less than 1/2 volt. I suggest Shottky diodes rather than ordinary 1N5401because of their lower forward voltage (typ. 475mV) compared to classic PN junction diodes (1 volt Vf).
Or you can Buy more solar sells to provide power for fans to blow them off BTW he said his place is windy all the time.
so basically you're telling me that if a large leaf shades 1 solar cell in a series of 36 the voltage drops to 0 becauce it is essentially breaking the circuit that would be expensive to buy 1 diode per cell how come no one else mentions this
I highly recommend doing this as well. All those cells in series are all affected if one of them is unlit. The current drops to the one cell that is unlit (0 amps).
raja6814 years ago
what is a good price for 120 of these
ezrablu4 years ago
AWESOME instructible...THANK YOU for sharing this with the world who would otherwise be prisoner to purchasing panels for big bucks or not being able to afford them all.
My thought exactly. I want to build a solar system, but can't afford the high cost of panels.
sspence6 years ago
I thing something less susceptible to moisture (the peg board we get is really pressed paper layers and delaminates easily) would last longer. Just a thought.
What do you think is better than peg board?
white melamine. which is similar to pegboard, but it seems to have more binder material pressed into it. It costs a little less than pegboard (if I recall) and is in the same aisle of your home improvement store.
 Marine plywood maybe? Or a sheet of plexiglass (expensive but durable).
warren43214 years ago
For the latest update on DIY solar cells you can refer to http://www.buysolarpanelweb.com
king70704 years ago
i want to buy 3 X 6 mono-crystalline solar cells !!! please tell me the web site where i can buy these cells . i am waiting for your's reply
Ebay, you also could read the instructable to find out...
ourmoneypit4 years ago
I save those little packets of silica that come packed with everything these days. Could you tuck one of those into each unit to address the moisture issue?

Good 'ible and all the comments/discussion has been helpful, too.
edraq584 years ago
Can I put the diode to the negative side of the panel? If not, what is the effect if diode install to the negative?
kktwags5 years ago
I made 4 60 watt solar panels , they work great for the most part , we installed them on our awning with 2x4's unerneath for air to get through however we are having major moisture issues.  when we built the first two we thought it was because we used to much silicone and didn't seal up the sides good enough but we just built two more with alot less silicone and we sealed the sides with aluminum tape however there is still alot of moisture in the panels.  It always starts with a fog and then turns into alot of water droplets.   Do you or anyonelse have any suggestions on how to fix this or why this is happening. We can't haven't been able to come up with any other reason.
If you can get ahold of a vaccuum pump, such as the kind used in the refrigeration/air conditioning field, you could conceivably pull a vaccuum on the almost-sealed panel, then seal it... Now that I think about it, I should write an instructable on how to do this! Anyhow, you're getting condensation because of the air trapped inside, and as long as there is any air with any moisture trapped in it, you'll always get that fog. Just a last minute thought- what if you didn't completely seal the panel, allowing someplace for the moisture to go? It would simply evaporate, and you'd have no more fog problems.
I had this kind of issue when the first dual pane thermal windows came out. It has to do with how much humidity was in the air when the windows were sealed.  A couple of thoughts on how to solve..... Get some decissent packs used to keep moisture out of cameras ect... put them inside before sealing.... or get your tires filled with nitrogen ( some tire stores fill with nitrogen now ) and use the nitrogen to displace the air in the panels... I hope this helps.....NMF
mnc_co_uk5 years ago
just to clarify, wattage(otherwise known as power) is volts * amps. Connecting panels in parallel or series will both increase wattage. However it does give you the abilty to adjust your current / voltage rating. Say you had 2 equal panels they both give 12volts 5amps. connected in series would give you a overall solar panel of 24volts 5amps. connected in parallel they would give 12volts 10amps. Combined in either combination would give power of 120watts.
@LVGene: Harbor Freight's panels are 4-5 times the price ($380 for 50w, $500 for 75w), and if you don't like to "tinker", why are you perusing a do-it-yourself website?
No. If you are buying solar panels.. ONLY. Then you need to make further decisions. I was and still am talking about the Harbor Freight 45 watt KIT. Not high wattage panels. If I take your word for it. Your "Panel" costs $100 all in. The result is totally sub standard in every possible way. And (as you continue to ignore) Harbor Freight has sales all the time. So to say they are 4 - 5 times the price is incorrect. If the buyer takes advantage of a sale.. (every week they have a sale) the builder will get a solar panel that is warrantied and will most likely last for 70 plus years. A wood housing can NOT stand up to sustained heat, UV, and weather. But the Harbor Freight design is built using aluminum not wood. It will last the "Tinkerer" a lifetime. There is a reason why they sell solar cell 2nds. Because they most likely will not last. I'm sorry if this comes off harsh. But I'm not the one creating an Un-Supported "How To" web pages that have undisclosed affiliate links in them. IMHO it is 100% Unethical to do what you are doing. I also believe that an Honest Builder (or Tinkerer) will end up spending a whole lot more on his duplication of your simple panel.. and kicking YOU back his/her hard earned $$$. If you disclosed that you earn money if the builder clicks on your affilaite links.. Like for Ebay cells or Solar Books. Yes that would be ethical. Also.. since you earn money off of the "Builders"... You should offer support. Reading your page.. you do not. I just joined Instructible's a few days ago. I'll post my own Instructible in a while. But I'll also do it ethically. Not using Instructible as a way to pimp my kits and earn extra dough.
I don't usually get involved in these flame wars but in this case I'll make a exception. first and foremost this guy is amateur astronomer  that built himself a solar panel for his hobby in the desert. Not a lot of rain there. Yes there are some flash floods but as a rule not much rain so the wood aspect of his construction shouldn't be a issue and he does have ventilation in it. He also covered it in metal tape (used a lot on the outside of commercial airliners)   later on so there should be no moisture or very little moisture getting into it. He also painted the wood. now I don't know what type of paint he used but I'm pretty sure it was a good outdoor outdoor paint (a person could use marine paint if they wanted not cheap but no moisture issues). as for him buying "seconds" who cares? he took into account they weren't perfect and bought extras it's still cheaper. So what if he has affiliate links on his website? Most anybody who uses the Internet knows that ad links earn the website owner a little money and he puts it to running his website so that he can provide the public at large FREE information. So don't slam a guy for showing people how to do something. Remember he didn't have to tell anyone how to do it. I personally think its awesome.
lloydrmc LVGene5 years ago
How's the view from your high horse?  This site is about building stuff.  Who said it had to be better in ANY way than something available commercially?

For example, a modern automobile is superior in almost every way, to a street rod (except perhaps power/weight and general fun), yet the latter can cost many more times than the former.  Still, people build street rods, some of which wouldn't be caught dead in a modern car.  Go figure.
Seems rather contradictory that you should flame the action of this how this man chooses to give credit where it's due, when your actions of obvious advertisement (Seriously, you mentioned Harbor Freight with a consistency of a televangelist <.<) ends up pretty much nullifying any argument you can make on that matter.

If he misses a deal, big deal, it's not the end of the world. Besides the shipping end of things tends to be another hinderance most people don't take into consideration when people talk about cost. With his remote location I'm sure shipping must come at a heavy cost in either case.
A good honest builder tries to make the best product he can while not spending a huge amount of money. Sure this panel won't last super long but it was fun to build and does the job.
Deschamps5 years ago
 Seems like a good project and I would love to make one of this babies, but just for the fun of it. There's really not a huge price advantage, if it gives you 60 W for 104$ the unity price is 1.73 $/W and you can easily find someone who would match this price:

Construction materials are always measured in imperial in Canada and the US so don't worry about it :)
americanguy6 years ago
Another word of caution about using silicone is that IT IS CONDUCTIVE. BE VERY CAREFUL not to short solder tabs.
 I had no idea this was true. Luckily the panel I made worked well. I used silicone in strips. 
~boots~6 years ago
unfortunately i chose to solder the tabbing wire to the negative side of my cells but they seem to not just pop off, but pull the whole contact point off the cell itself and refuse to stick back on. any suggestions?
 flux is your friend, I would advise to get a flux pen and try again. 
 It is possible that your soldering iron is to hot. When I first started soldering my cells together I burned off a couple contact points to. You could also be holding it there to long. So either switch to a lower temperature soldering iron or don't hold it there as long. Good luck
raisor blade it off
 Not sure if you ever handled individual solar cells before but they are very fragile. Imagine a piece of paper but that piece of paper was made of glass. They break really easily. You could try a razor blade but you might end up with a bunch of broken cells. 
speedstix5 years ago
 Hello, very nice my group and I did the exact same thing for a final year project. We actually made a Maximum Power Point Tracker for solar panels. I wanted to clear something up in step 1. Yes it is true that you need a voltage higher than 12 V to charge a batter (assuming lead acid here) but keep in mind that the panels themselves will only produce a higher voltage IF the load permits. This means that if the battery requires 14.4 V to get charged the panels will operate at that voltage. You have no control over that. Also if say those panels are at that point you might not be getting the maximum power from them. Check out a Maximum Power Point Tracker and you will see why. Here is a typical current vs voltage and power vs voltage curve of a typical solar panel. Typical curve keep in mind that the panel can operate anywhere from 0V to 18V. Somewhere at that voltage you will get maximum power. It was a really cool project, we were able to extract 10% more power using our circuit then without using it. 

How heavy fo you think it is?
Instructibles should remove this project.

1.) No price advantage.

You can buy a 45 watt "Kit" unit for $179 from Harbor Freight when they have a sale. (They always have sales)

2.) The author does not disclose his Affiliate links.

That means.. if you click on one of the Solar books listed on the authors web page.  As an Affiliate he gets a Kick-Back $$$.

Ebay Kick Backs.. He makes money if you use his Ebay Links. 

3.) The finished product is a painted plank of wood. 

Getting past the fact that the author is Unethical by not disclosing his Affiliate links.. After all of your hard work and DIY efforts.. all you end up with is a 3rd rate solution to a real problem.

Please Instructibles..  Remove this and other "DIY" scams.  They really hurt your site as well as your loyal members.


scob89 LVGene5 years ago
So, um, when is $179 plus tax more than $104.85 that cost him to make his panel? Plus if you already have the wood on hand and don't plan to use a jones plug, you can save even more.

Also, you get 15 more watts that the harbor freight and this panel is way more durable than harbor freight, This one is made of wood which will absorb shock if hit or dropped, the HF panels are just one big sheet of glass that is easy to break.

I currently have 4 DIY 100 Watt panels 3 are tide to a micro inverter to back feed the grid(It has Island protection) and the 4th if hooked up to a charge controller to charge a 75Ah 12V battery that powers a standard car inverter to run some CFL's for light at night.

The first solar kit i had was the HF kit, and it only lasted a tear before one panel was broke, and another was just not putting any power out, so I only had 1 15 Watt panel left which died last month.

DIY it the way to go.
scob89 scob895 years ago
Sorry, got the 2 prices backwards.

When is, $104.85 more than $179 plus tax?
mikecee1 LVGene5 years ago
are you sure you do not work for Harbor Freight? For those outside of the "Harbor Freight" shipping area (outside of the US) this may be a decent alternative. NOW...Should the author use referral links... probably not but you may have to wait until instructables.com cuts the links.
LVGene mikecee15 years ago
No I don't work at HF.  But I do own the "Kit".. and I payed $179 plus tax.

Also no matter HOW you look at this DIY project.. the end result is Painted plywood, 2nd's and 3rds for your solar wafers..  Total JUNK.

The "Author" should disclose his LINKS..  but I think that goes to the "Type of person" we are really dealing with here. 

A junky project.. that actually makes him money. 


I've given up (for now) going Solar.  Instead I'm thinking of using a 1000K (1400 peak) low wind turbine. (Find on Ebay and their website)   Add to that the new Grid Tied Inverter Technology.. and I might save as much as $20 - $30 a month on power bills. Maybe more..

If I do the work myself.. Most likely $2400 all in.

My friend has Rural land where he is "Off Grid" with Solar.  We will be adding in the 1000k turbine soon.  (The sun doesn't shine 24 hours a day)

If his survives 6 months or more.. I'll be doing the Grid Tie system (as I wrote above) for my home.  It's a crime Las Vegas collects 1.21 KWH (more during peak times)


Hmmm  Mine has 3 panels.  The total system weights in at 9.7 lbs.  Also will last probably 30 years.
I wish to build solar panel for my country Ghana, i need a partner who we can work together..
Franklin P.J. Appiah
CEO.Managing Dir.
Babahub Travel
 Dear Mr. Appiah,

I am very interested in helping you start a solar panel company in Ghana.

Please e-mail me at DPTMORRIS@YAHOO.com so we may talk some more.

Yours truly,
Daniel Morris

klutzrock5 years ago

please, this place is so great for real polite discussions. Dont tar and feather the guy for his website, you dont have to go to it and he is giving information that is helpful even if you don't buy his kit!

What you should do instead, is make your own instructable and if it really is better, people will use it more than this one and you will be proven right! That fits within your ethical boundaires right?

Cheers Gene, tone it down and chill out a bit. Go pick a fight and go on a crusade somewhere else please.


patenaude5 years ago
 It appears that you are soldering them in parallel, not in series. Are the tabs set up so that allows for a series by soldering straight across?
 Nevermind... I just figured out that both wires are anodes, and the tabs on the back are all cathodes (or vise versa.)

it is not mandatory to have mono-crystalline or multi-crystalline, and modules made up of both works fine. The only difference is that mono-crystalline cells provide higher power, compared to multi-crystalline cells. Conversion efficiency of multi-crystalline is around 16% while that of mono-crystalline is around 17-18%, and hence for mono-crystalline cells you have to pay more, but on the other hand to produce same power, you have to install less cell modules for mono, therefore you save space. Its a compromise between cost and space.
alex young5 years ago
Hi how are u your project looks real good. What I dont understand yet is how u arrive at the current. U show how each cell add up and produce 18volts but how do I know how much current I will get when I am finish and how do I increase the current (wattage )Thank u
To increase wattage connect two panels (or two sets of panels) in parallel. This is described in any school physics textbook ;)
The current of your solar panel depends on the cells you are using. Usually the bigger the cell, the more current you can expect to get out of it. Go to http://solarwindsusa.com/catalog/index.php for some good quality cells at a good price.
m15cell5 years ago
I checked out your website. You sir are my hero. 
F16BMATHIS5 years ago
I've made 6 of these panels, connected to a "plug in true sine wave grid tie inverter", (another e-bay special) was putting in 250 watts on a sunny day! If you haven't figured out how to wire the cells yet, basically, reverse every row so the top wires go to the next rows bottom wires. Plus to minus to plus to minus..... Helps power my Electric Chevy S10. www.evalbum.com/1752
Alien3nema5 years ago
Wanted to say that i used your guid to build my first panels.  working great. I have some pics of the setup that id like to share.  thanks so much. i will make a forth like this and this set will likely be used to power outside lights and an electric fence. for now.. they are my main power at camp. i intend to move to an aluminum frame when installing on the powerstation.  yes im off grid. i catch water too.
pls help me to build mine in The Gambia here
Email: studentofengineering@hotmail.com
suzylennox5 years ago
If you are looking for a source in the UK, you can buy direct from Sharp. Their minimum order quantity is 40kg. Cells are damged and are classified as either potential halves (£60 per kg) or potential quarters (£45 per kg) depending on how much undamaged cell is available. If you want further details email suzy.lennox@sharp.eu
Highjump445 years ago
dont u need an inverter
not if you are just running things like a radio and chargers or relay anything that can run out of your car 
That's what I've always used so I'm assuming you always need them. Inverters are used to supply AC power from DC sources like solar panels or batteries... 
I use both solar panels and storage batteries so thats why I go with inverters. You can probably find a cheap one on ebay or any hardware store.
Valence_46 years ago
Go to eBay and write, in the search box, "Photovoltaic" or "solar cells".
thank  u  V
I just take the solar cells out of old, broken solar garden lights. they produce 4.5 volts each!
4.5 they aren't that high are they?
viacin6 years ago
$104 for almost 19 volts...not too bad..cheaper than buying a kit. But when, ooh when, will they make these things more powerful?! I have seen a lens that you can put on top of each cell (in rows) that will (it's been proven by the discovery channel) increase the power by 8 fold. where, and how expensive these lenses are, is a mystery. It's some sort of frensel lens concaved in a certain way. Sorry for spelling, it's late.
Nitack viacin6 years ago
The lenses you are referring to are called Fresnel lenses. They are not the miracle solution for solar cells/panels though. Cells convert the light energy on their surface to electrical energy. They have a specific conversion rate or efficiency. In order to increase the energy 8 fold, you would need a lens that has 8 times the area as your cell, all focused on your cell. You would also need to constantly adjust it as a Fresnel lens needs to be properly aligned for the focused energy to hit the target.
not to mention possibly burning/melting the cell(s) :P
dkelly19665 years ago
Jos4816: Nice catch on the pug change need... power sources always get the female.
thanks for the writeup Do I need a shottky diode per 18 solar cells? or per 36 solar cells? Because the output on 36 for me is 3.5 which is higher than the 31dQ03's maximum of 3.3. Thanks for any pointers. Tony
Here is a link to a website with detailed info about diodes:


You will need a diode per 18 cells when you're talking about bypass diodes. Bypass diodes protect a cell when it is in the shade while others are not. One cell can consume about the production of 15 cells before breaking. 18 is safe enough because they most likely wont produce at max capacity when only one cell is in complete shade, at least that is the idea.
erosser6 years ago
This is fantastic! Very nice job.
dark sponge6 years ago
Is something wrong with those links or is it just me? Every ebay link takes me directly to the ebay homepage.
same thing with me. could the author please fix that.
elpidiode6 years ago
I notice that you are using a different cell now not the same as was started. Anyway, I am getting the guest. I would like you to be specific on where the positive or the negative are. Give us where the main wire (negative or positve) came from . I could see the wiring of your panel connected to all the tabb.
sddhhanover6 years ago
i can't seem to find a charge controller to fit 18 volts. could somebody help me please?
what do you need 18 volt charger for???
my panel has 18 volts. To install it, i need a charge controller to regulate the charge that gets to the battery.
i don't think there is one, but you can use those 18 volts to charge 12 battery.
I guess, but all of the charge controllers i have found will eliminate some of those extra volts so the panel's energy will accommodate to the battery's capacity. i have already started building the panel and i think it will end up having 14 volts (28 cells).
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 (author)  silverknight156 years ago
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.
avi6256 years ago
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
Is there something simular to these instructions that has an audio commentary ? ie. someone talking you through it as well as pictures ??? Peter King.
What's the voltage?
jos48166 years ago
Please exchange the male and female plug.
bwpatton16 years ago
The price of 36 3x6 solar cells on ebay at this point run about 110-120 But I found some for 100!!
hey im a really unexperienced teen looking into making a cheap solar panel, like one that would charge my phone and maybe something else, ive seen your windmill intractable i find both solar and windmill instrucibles very cool but i cant afford that much how could i go about making one of these for chep or buy one off ebay thanks
So you are getting right at 60W from these, for the price you were able to make them thats a really amazing deal. 60W normally retail for around 250$. Im really tempted to build one of these, I life in florida so we have lots of sun. Not many trees around my house and the slope of my roof faces east. By estimating around 12 hrs of fairly direct light each panel could save me around 14-15$ per month on my electric bill, so it would pay for itself in 9 months AND I could get state rebates :)! Thanks for the HowTo!!
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.
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.
intentsly6 years ago
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.
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.
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.
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 rusty01016 years ago
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.
hi buy how do i know on a solar cell, where is positive and negative
Use your multimeter it will tell you.
bruces6 years ago
another way to attach your cells would be to line them up perfectly on a table upside down,then put a dab of silicone in the centre of each cell ,then place your backing on the cells ,after curing you can turn them over and install them in the cabinet .
dalecarlile6 years ago
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.
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 wupme6 years ago
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 wupme6 years ago
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. dacarls@gmail.com
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.
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 kadris36 years ago
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 kadris36 years ago
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 static6 years ago
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.!!!!!!!!!!!
treyvo6 years ago
Any specific kind of caulk? Lowe's and The Home Depot have different kinds.
mweston6 years ago
This is a very helpful guide! I just ordered a bunch of solar cells and am planning on making a 3+ amp panel to help keep the charge on a battery for a trolling motor when its not in use. It needs to be relatively small and I saw in the pictures that there was a small gap between the cells; is this gap there to serve a purpose or is it possible to make a panel with about 1-2mm between cells? Any other helpful tips are appreciated!
you can put the panels as close together as you can manage
annchanted6 years ago
I have meager electricity needs. I live in an RV partially for that exact reason; so I will have meager electricity needs. How much energy will a 60 watt panel give me? Will it keep my fridge and blower for a propane heater running?
maybe the blower, probably not the fridge, though. Think in terms of a 60-watt lightbulb. For reference, a typical family house is generally considered to run between 1.5-2.5kW (1500 - 2500 Watts)
Valence_46 years ago
Another way to glue the solar cells in place is NOT to glue the cells themselves. Instead, start to solder all the cells together as shown in this instructable but with leaving 1/2 inch extra tab length between each cell. Place the solar cells on the pegboard, front side up then, using fine long nose pliers, form, with this extra 1-2 inch tab, two "U" shaped bridges, one on each of the joined cells and the "U"'s being bent on the FRONT side of the solar cells. and then tack the TABS, between the "U" shaped bridges, on the pegboard using silicone putty drops leaving the solar cells themselves free to fully expand/retract. And if ever one solar cell breaks, it will be much easier to replace by simply cutting the "U" shaped bridges and removing the broken cell away.
sspence6 years ago
Blocking diodes are not necessary when using a charge controller. The charge controller performs this function. Bypass diodes may be necessary when using high voltage strings in case a panel gets shaded. I run my panels in series for 80 volt strings. I use a Outback MPPT controller to convert it to battery voltage (24v in my case). This way I consistently produce more power than the panel is rated for, even in winter (I'm in NY).
mdavis19 (author)  sspence6 years ago
My charge controller is home-built. It doesn't have any blocking diodes in it. So they are necessary in my application.
sspence6 years ago
In the HAM radio scene, we user anderson powerpole connectors to good effect. http://www.powerwerx.com/
sspence6 years ago
I've found that the heat of the soldering iron will melt the wax off the tabs, and the heat of the sun will get the wax off the cells, so separating the cells is the major concern. as you say, do it carefully.
sspence6 years ago
What ebay sellers did you get these from?
This Instructable is great and very inspiring and I understand that you need electricity for your astronomy gear, but I don't understand why everyone else is going on about using electricity while camping. I also don't believe that camping is camping if you are with your car. Maybe it's just the culture of the outdoors in my country, but it seems a little weird. I thought the purpose of camping was to get away from things like electricity, cars, TV's, etc.. Can someone explain these cultural differences to me, or is it just some people who do this?
It is a bit mind boggling as to why one goes away from civilization to sit among nature and then can't turn off the AC/DC devices to actually appreciate the natural surroundings. If people could learn to remove themselves from their appliances they may beable to appreciate nature. A few items for comfort such as a lamp and stove are understandable, but keep the noisy radio, TV, DVD players at home! Listen to nature. You'll be astounded at what your devices are covering up.
thepelton mmh6 years ago
I agree. I detest those who drive out into the wild, but can't separate themselves from their precious music or sports programs, especially if they can't keep it to themselves.
To my wife, camping is staying in a hotel room with less than a 3 star rating. To my brother camping means survival training with a knife and the clothes that you're wearing. I'm somewhere in between. Everybody is different. I think one of the reasons I like camping is to get away from these things you mention, but I also think one of the reasons that we live indoors now (for the last several thousand years) is because it is nicer than camping. It is possible to do a mixture of the two without being absolute in either.
Just because someone else's idea of camping is different from yours doesn't really give you any right to say they are wrong. Just accept they may want electricity for something (Heck, maybe they have an illness where they need to power something or another so they actually NEED the electricity) and you wouldn't want it. I've gone from having to carry everything on my back and prepare for anything, all the way to having a camper and a generator. Maybe you want to call it different things, but peoples' choices are their own, so trying to explain how you think your ways are better is somewhat rude to say the least.
Photography is one of my hobbies. Digital cameras eat through batteries like crazy. So I use rechargable batteries, but then I need a power source for the charger. I also need power for my laptop computer so I can dump images from the camera when the memory card gets full, and then edit the images. I like to have a radio and MP3 player with me while camping (I don't need television, and specifically go on vacation sometimes just to get away from the idiot box). My electric razor is a must have or I start looking like Grizzly Adams after a couple of days (beards are itchy), but of course it requires power too. My cell phone needs charging after a while, etc. But the camping power requirements really go up when I take my girlfriend along. She likes to watch TV and DVDs. She also has her own slew of power hungry devices. and she won't be happy on our camping trips until I can make enough power for her to use her blow dryer. That aint gonna happen any time soon.
As they say different stokes for different folks. For some "camping" means getting away from the routine grind A dead end trying to explain cultural differences. They are always going to be there, as long as they don't intrude into your space, why sweat them?
I thought the purpose of camping was to get closer to nature, not to escape comfort. If I go two days without a shower, I get oily and my scalp gets itchy, so I like to shower when camping...if possible. Perhaps you have dry skin, so don't experience this discomfort.
wupme Sam Grove6 years ago
Thats the only problem i would have. My hair gets oily and itchy really fast, i have to at least wash my hair with my special shampoo every 2nd day (wich the doctor orderd me to do). But there are also some soaps wich are enviroment friendly, and don't polute the water to at least wash your hands and some sensitive areas.
Crucio wupme6 years ago
You can use little apple cider vinegar and baking soda as a green way to wash oily hair and skin on camping trips--or even at home, everyday.

E.g., http://www.instructables.com/id/How-to-Go-No-Poo/
wupme Crucio6 years ago
For Skin i could use that, but not for my hair. I got special really expensive shampoo by prescription (is that the english word for it?) from a dermatologyst. If i stop using it for a week (already tested it) i start getting problems with the skin under my hair. Tryed different stuff over all these years, and only this one special shampoo helped.
Well, it's understandable in your case. For me, if I feel dirty, I just take a dip in a river of the sea.
I don't take things like TV's or stuff with me when i go Camping.
But its nice to have at least a battery powered light for the night. Flashlights and the campingfire sometimes are just not enough. And maybee i need to recharge the flashlight.
Because if would go camping, then a whole week at least (don't wanna waste to much batteries...)

But beside that, yeah you don't need an power source. I don't understand why people take TVs, Radios and other electrical sh** with them.

I just need my food, something to sleep, maybee a small gas cooker, and my handy utility knife.
Well, even if you don't bring your car, you're still taking a part of society with you. Wearing shoes? Clothes? Any other man made materials? I think that it's a matter of what you're the most comfortable with. I understand your point: where's the sense of personal accomplishment/independence of technology? Some people just don't go for that.
Oh, yes we do take technology with us. There is no doubting that. Gas cookers, torches, watches, tents, nice shoes and packs, etc... One thing I wouldn't be comfortable without is my sketch book and a good set of pens and pencils(when I get inspiration I don't want to lose it because I'm out tramping), but that doesn't really help with making it easier to live in the wild, except maybe mentally.
Hello Bottomless, This is just the preference of some people. I would have to agree with you. When I go camping, I make sure I am as far from civilization as possible. To be honest, our society as a whole has become very dependent so it is actually quite rare to find people really "roughing" it in the outdoors. I only have one friend that will go to those lengths with me. Where do you live? Joey
I live in New Zealand. Here you're either roughing it or it's not camping, I have barely ever seen another Kiwi with more gadgets other than a gas cooker, a torch and navigation equipment (cellphones don't work in unpopulated areas, so there's no point in taking one). It's a little different if you're on a rock climbing camp or something like that, then you understandably need extra gear. We also go on outdoor trips with cars and other items of comfort such as showers, stereo, etc... but I have never heard of it as camping, more of a holiday from routine. It is usually a family/friends affair where a small community of tents, outdoor kitchens, camper-vans, utes and so on are set up on some remote idyllic beach and everyone spends several weeks away from what they would normally do just enjoying the freedom. I've done it quite a lot, never considered it camping, though.
dustyplans6 years ago
How difficult is it to convert solar energy to electricty that can be used in something like a water pump? And will this 60W solar panel work well enough to run a pump that uses 12 volts???? Kind of new to this way of thinking..sorry
mdavis19 (author)  dustyplans6 years ago
Sure this panel can run a water pump. It can run anything that uses 12 Volts DC. It only produces 60 Watts though. You may need more and/or larger capacity panels to run the pump. It depends on what Wattage the pump requires. You could always use the panel to charge a battery bank and then run the pump intermittently from the battery bank.
I build a smaller panel with 1-1/2 x 3" cells. 35 cells made a little over 20w. I used a painted plywood backing, foam weatherstripping for the sides, a sheet of lexan, and a speaker terminal. I bought a charge controller on ebay for $20, and I'm using an old 12v 10va battery from an alarm system. I plan to build a larger panel with 3x6" or 6x6" cells soon. Maybe 150w or so. I just gotta add a small wind generator and I can run my computers off of it.
DanwiseG6 years ago
Fresnel Lenses were on the Discovery Channel's "Project Earth" show. It was amazing what it did to increase the output of the individual cell. Don't remember much else about it besides me on the couch going "wow.." LOL
DIYDragon6 years ago
"The type of paint and color was scientifically chosen by shaking all the paint cans I had laying around in my garage and choosing the one that felt like it had enough left in it to do the whole job." Nothing quite like scientific deduction. haha I've always been very interested in solar energy. I keep waiting for somebody to come a long, and make it much cheaper, and applicable. I'm watching a company who claims they can make this happen, but no word on their work so far. Oh well!
What company might this be? :D
They're called Sunrgi.
sammilo6 years ago
I like the bits and i will like to get the ideas mor an dmore
panstar16 years ago
I like your design ,it is a lot more practical then others I have seen on this site. Even though solar panels are a pain in the butt ,they beat carrying gallons of gas for a little unforgiving noise box for hours on end. why they don't sell them with liquid cooled engines to cut down on half of the noise ? But the solar panels still cost you at lest 78 American which is some where around $100 + CND which makes it expensive to build b/c you can buy a ready made one ( I can't remember the rating I think 18 + ) for less then 90 dollars on sale which is a less hair pulling aproch for some ! also shipping is also a big tie breaker as well ,but the price of gas has been rising so if you like playing with delicate items then why not ! The only bad part is the expensive batterys we have some from that were used for power back and are really heavy but have a lot of juice iron lead I think they said on them the problem lie in having enough power to charge them do you have such problem ? & is there a special angle the panel's have to be placed at & would having them follow the sun make more power for the fuss ?
wupme6 years ago
Thats a nice Project. A fresnel lens probably would enhance the panel, you can get those from broken back projection TVs. A tracking system wouldn't be that hart. Just a photo sensor that stars an motor when it gets light. I still wonder about those 18volts, my 12 Volt charger only gots 13,5 volts, but maybe its because it gots more ampere. If i had a property in Arizona, i definitely would have build my self a huge array of solar panels. But.... i live in Germany, directly in the city. So the only solar powered thing is gonna be my decorative light :(
stoobers wupme6 years ago
a fresnel lens won't change anything. the solar flux coming through the lens it is proportional to the area of the lens. Unless you make the area bigger, no additional light will come through. the lens might trap some extra heat, and the heat will build up, but solar cells work on light, not heat.
wupme stoobers6 years ago
A few months ago, leading companys for solar panels came up with the fresnel lens, directly onto the solar cell, and it gives more output. You can buy those.
stoobers wupme6 years ago
I encourage you to try this experiment and make an instructable about this. If you can get it to work, it would be a boon for the solar industry. I would be VERY interested in the outcome.

solar panels = expensive
lenses = cheap

If the output of a panel can be increased by a cheap fresnel lens, wahoo!
wupme stoobers6 years ago
I would love to do it, but i already struggle to find a lense for the solar grille i planned. In Germany Backprojection TVs are really rare, so nothing to scavange :(
matroska wupme6 years ago
What about using a Stirling engine as the source of energy? :) Requires a bit more work and a dynamo, but I believe the ouput would be greater in theory, as solar cells will keep energy as heat and they can't threat that, but a stirling engine runs solely on heat. I'm planning to try this out soon!
Lots of experiments have been done with this. There are significant problems. The biggest is heat - if you use a lens that puts a lot more lot more heat on the cells, and so you need a big heatsink to get rid of it. Last I heard (10 years ago) a cell that would last for 50 years normally only lasts 5 years when you use a lens to put 10 times the light on it, put 50 times the light on it and you get 1 year of life. In short over the long term you use just as many cells, plus you get to deal with a lens (slightly more complex), and maintenance. With the cost of cells, plus more production going online, it might be worth doing this for a few years, replacing the cells all the time - until production goes up enough that you can just buy cells. Maybe - for most people they want a set it and forget it system so it isn't anyway.
ac-dc wupme6 years ago
I'm sure it costs a pretty penny, this project was about a DIY power source that is very cost effective. If cost were not an object there are lots of things one could do differently to improve upon it but sometimes cost really does matter - like when you could just build a second panel with the extra money because there's no specific space constraint.
wupme ac-dc6 years ago
You can salvage those lenses from old back projection TVs. Then its still DIY and cost effective :)
ac-dc wupme6 years ago
A fresnel lens would cause too much addt'l heat, destroy the wood frame and paint. It would have to be built to handle the higher power and that includes a different type of solar cell as these would degrade too quickly.
wupme ac-dc6 years ago
There won't be any additional heat, and the frame wouldnt be affected, they're directly in front of the solar cell
ac-dc wupme6 years ago
How would you make this work? Right in front of the solar cell you are refocusing sunlight away from the outer portions of the cell so it's the same amount of sunlight. If you mean at enough of a distance to focus more than the original light onto the cell in theory that could work but many individual little lenses and a good focal system frame for them would tend to raise price as much as buying more solar cells. Without that frame and precise aiming, if you were refocusing light from a greater area it would tend to heat up the enclosure more. Plus, as stated previously it will wear out the cells faster. The cheap cells are not meant for long term use, they're mostly meant for hobbyists. So I suppose in theory it is possible to do what you suggested but it's not likely to be practical in this particular implementation.
wupme ac-dc6 years ago
As far as i understand it (have beend to one of those manufactures few weeks ago) in that close range, it won't refocus it away from the edges, because its really directly put onto the cell. But because of the slight breaking of the light beam, they can use the power better. So the cell doesn't take more or less light, thats correct, but somehow it still affects it. To get a good explenation, we shoudl propably consoult an profesional, maybee someday ill be back there, and ask them more about this :)
wupme wupme6 years ago
Geez where did all those typos came from? Shame on me, why is der no edit function ;o)
fulcrum6 years ago
There are three types of camping, and they all have their place. Backpack camping where all your gear is ultra-light, Car camping, where there is mor "family" heavier gear, and trailer camping, especially "boondocking" where there is no AC for your trailer. I have a very similar system with twin 3o Watt panels, two inverters (one small, one large, and two 90 Amp/Hour batteries. If I'm on the 'grid', I still use my solar input, and let a charger kick in after sunset.
TFrosty fulcrum6 years ago
Where did you get your 90AH batteries? Do you know how much a 7AH can be used for????
fulcrum TFrosty6 years ago
The 90 A/H batteries are lead acid "Car Battery' size Deep Discharge recreation vehicle types. Cost is the same or less than a car battery. NOTE: Do not use standard car batteries for this application, they are designed for heavy starter currents, and will die prematurely if you trickle current in and out of them over extended periods. Also "starter" car batteries are NOT designed to be discharged to under about 80 to 85%. Deep discharge will kill them quickly. A fully charged 7 ampere-hour battery will light a ten Watt bulb for four and a half hours, or a thermoelectronic cooler for about an hour, max. It will live for about 3 to 6 years, whether you use it or not!.
TFrosty fulcrum6 years ago
Thanks!!! what is the formula you used to calculate the 7AH 12V?
fulcrum TFrosty6 years ago
Multiply the numbers for power. volts times amps equals Watts. In this case its 7x12=84 Watt/Hours. But you can't get at the last 20% of the juice, because the voltage is too low to push enough current through the load as the battery dies, and it's bad for the battery not to leave a remaining charge. you can do this in an emergency, but it will shorten the life of the battery. Yo can rely on about 65 Watt/Hours in this case, so a 50 Watt cooler will run for 65/50 hours. An hour and a bit. A 10 Watt lamp would last for 65/10 Hours, That's a theoretical 6.5 hours on a brand new, fully charged battery. Unfortunately, a fully charged 2-year-old 7AH will be closer to 5AH, so the numbers are reduced to allow for real-world performance. Dropping this by 20% only allows you to design for a 40 Watt/Hour delivery. Admittedly, the numbers are rather conservative, but if the system were to be used in a life or death situation, these numbers would be safe. For general use, I would call it closer to 55 Watt/Hours.
fulcrum6 years ago
Just to clarify for Tfosty, The batteries I am using are type 24 classified. You can get type 27 (larger size) batteries with 120 A/H capacity. Starter batteries shouldn't be discharced to less than 15% from full, leaving a minimum of 85% charge!!
wally336 years ago
I heard this guy talking about this project on an adelaide radio station down in australia
I would like to mention, folks, something I read off an eBay auction.
There's a seller who sellers 60 chipped cells, and claims that each cell puts out about .55 volts. Round that off to .5
He said that each cell gets about .25 to .5 amps each. Round that off to .3, because I think that's a liberal estimate.

Now then, that leaves you with 30 volts, and 18 amps. Plug that into that great little formula james joule cooked up. P=V(I)
P being watts, V being volts, I being amps.
P = 30(18) = 540 watts

Meaning that one large panel could be split and put into parallel, yielding 15 volts and 36 amps, no? Is it not possible to hook that up to a strong 12v power inverter and run strong appliances off of it?

I feel that I must have missed something rather obvious, as no one else has brought this up before me. Did I miscalculate?

Please advise guys! (pardon the rhyme...)
mdavis19 (author)  guitarman63mm6 years ago
If the cells are wired in series. The voltage adds but the current is limited to the output of the smallest cell in the array. So it would be 30 Volts at .3 Amps If instead they are wired in parallel it would be .5 Volts at about 18 Amps. Either way, you get a total of 9 Watts out of those 60 cells. The best application would probably be to make two banks of 30 cells producing about 15 Volts at about .6 Amps to charge a 12 Volt battery. The total is still 9 Watts though.
I live in Florida, and when your car heats up to 95˚ daily, you look for some sort of way out. My idea was to get a small air conditioner->A/C Timer->Inverter->Separate car battery. Then, it would be set to kick on about 30 minutes before I got out of class, so my car would be like an icebox for me. Plausible? Is there a way to increase wattage without increasing voltage/decreasing current? I have rack mounts on top of my microbus, I was simply going to place the panels up top, secure them, and have at it.
some guys at college did that to get their degree... they placed a big cell on the roof of a 4 door sedan and secured it in place with fiberglass, but they placed 2 fans in the car, one pushing air inside the car from the front (engine compartment i suppose), and another fan pushing air out to the trunk space.... but thay made a big mistake IMO they used an inverter! (bcuz they used a 24V AC fan i have no idea where theyd get such a thing).... there is such a thing as a DC FAN (and they are more common than AC's) and using an inverter is wasting energy , its entirely possible in a microbus, and using a charge control for the batteries. I dont know if an air conditioner would need too much power but fans are an easy solution Good luck!
by the way... one way to increase your available power would be getting either more modules or more batteries i guess, the only thing is that more batteries will require more charging time
Okay just a quick question, have you ever tested to see what the temperature gets up to in the box during the day? I assume in Arizona it could get to be rather warm, just wondering if this additional thermal energy could be captured and harnessed for something?
i've seen that the hotter it is, the worse it works- you can check out the info at youtube, its in conjunction with google.
you could put some sort of fan in the back A few 12 volt ones under a voltage regulator?
i guess you could, but surley using energy to cool down the panel will make the task useless. plus you would need more circuit wizardry to stop the fans blowing on a cool day... On the google video the guy throws a bucket of water over the panel and booyah- job done. Just to be honest, the power loss for hot weather is about 10%. also, every year the panel becomes less efficient by 0.25% (if we are to believe everything endorsed by google)
Lego man6 years ago
where in Arizona? I live in Kingman and there is alot of open space here.
Have you built one of these Lego? I too live in Kingman and want to build solar panels for my place. And if you have made them then I know who I can ask that is just around the corner.
mdavis19 (author)  Lego man6 years ago
My property is in rural Apache county. About midway between St. Johns and Snowflake, and maybe 30 miles South of the Petrified Forest National Park (as the crow flies).
NetReaper6 years ago
What if you set them up in a 3d ring pattern, put it up on a poll, and put lots of mirrors around it? would that give you more power?
helllllll yes and i say do it and make an instructable
Sunkicked6 years ago
Great Instructable! My only question is about purchasing the cells. Is there a commercial vendor that sells these cells (sorry for that choice of words)? I've found that when people post that they gathered their supplies from eBay it can be maddeningly hard to find another auction for the same material. Thanks!
I'm not a skilled ebayer, but can't you configure it to send email alerts, when desired items are posted for sale?
xenor static6 years ago
You can create a custom search that will email you when a matching listing appears, but it's only as good as the search you create.
Sunkicked xenor6 years ago
I love this site. Ask a question and have an answer within a day or two. Thanks guys!
DavyBaby6 years ago
Well Done!! Maybe swop the connectors and have the female one connected to the "live" side ... ie the cells. I am inspired to build.
mdavis19 (author)  DavyBaby6 years ago
I put the male end on the solar panel and the female end on the cable to the batteries and charge controller because if the cable to the batteries shorted, it could potentially have several hundred amps flowing through the short circuit. That would be bad.
jerriel6 years ago
I really like your instructable. It is very informative and useful. I wish I could make like this at home, but unfortunately we are poor here in the Philippines. It is very nice to have a source of energy which is environment friendly and free.
i'd regulate it down to 12v and plug a car inverter in to turn it into 120v AC
I think that's a good idea in theory, but the amperage was only 3 amps. Which, if I'm correct, isn't enough to truly power many "real" electronic devices (TV, etc.) However, if it is, I think I just found a really smart way to camp and use electricity, without running my engine!
Why don't you step this down to 12V, add several lead acid or other batteries, and then step the output up to 120VAC? That way, you would have a system that would work all of the time and if necessary be charged up by your car, or by a hand powered generator.
ac-dc Xellers6 years ago
There's no need to step it down, you have to have a voltage above the peak charge voltage of a 12V SLA battery (roughly 13.8V?) to fully charge it in the first place. The higher the voltage potential above the battery peak voltage, the faster you can charge the battery. For most purposes a hand powered generator would not produce enough power, if someone is fairly athletic they might consider a bicycle-like pedal generator but really in extreme cases where the sun isn't sufficient it might be as well to keep a backup gas powered generator around. Better to have one and seldom if ever use it than need one and not have it.
Crucio ac-dc6 years ago
In the same vein, since his property is so remote, I would suggest Mr. Astronomer buy and carry around in his truck a small emergency backup scooter.
kadris3 ac-dc6 years ago
unless you are an endurance bike rider the best you can do with a pedal generator is a max of 100 watts for about one hour. usually 40 is more like it. my kids did about 40 with their "pedal vision".
i have too many good ideas "in theory"
Camping with electricity? Canadians >.> j/k Canada's awesome.
the average crt tv uses 100watts of power at 110v that's .9amps lcds use a lot less if u use it to charge 1 or more car type batteries the panel can charge the batteries up about 800watts a day alone u could run a tv for about 10hrs without taxing the batteries since there is also a wind generator there is over 1Kw of power to use a day before the batteries start to drain at all. with that amount of power u could use a computer or play a game system all day if u really wanted to but if u are that lazy being off the grid with this setup is not for u. u need to be alittle power conscious. if u have the money u could use a much higher output system such as 200 or 300 watt panels
No point in regulating it down, using it to charge a 12V battery (array) is effectively doing that for you. If you have certain gadgets that must use 120VAC, you simply can't find 12V alternative devices, then of course you will need an inverter for those but might I suggest something a bit better than the typical cheap car inverter so you gain efficiency in conversion?
Too many conversions and you get power lost through heat.
fimjox6 years ago
Another way to go is to use he double sided tape they use for hanging Masonite. You can get it at any decent hardware store. It is gray and mailable and should work fine
I'm not sure I'd use caulk as a glue. I've seen cheap caulk give out in moist conditions and it takes forever to dry in the absence of good airflow. Flexible epoxy sticks much better and is impervious to moisture. Mixing it is a pain in the butt, but it will cure in the absence of air. At the very least, I'd use RTV silicone.
darkavatar6 years ago
Make sure when you buy plexiglass or lexan that it is NOT the one that filters UV or you will loose some power xD
Lexan by its very nature will block UV. I doubt it will make much of a difference anyway since solar cells are the most sensitive to IR.
SacTownSue6 years ago
It would be really nice if there was a shopping list in the first step. And a list of tools so one doesn't have to hunt for the info. Along with estimated prices and retailers if items are not easy to find.
oniman76 years ago
You should save $100 every month (you can change it from 1 week to every 2-3 months depending on how much you earn ) and build a new one of these on your property. I am not familiar with how these work, but I am sure you could plug these into a generator, and rewire it so that your house is run off the generator. You could also put the solar panel on the roof. An additional bonus: if your house is run completely by this generator, you don't have to worry about the power going out during storms
oniman7 oniman76 years ago
I meant put a row of solar cells on your roof like shingles, if you were confused
opusnz6 years ago
Excellent Instructable. Thanks very much. The only thing I can add is that maybe you should use electronic grade silicone caulk. It's a little more expensive than the typical home silicone but the typical home stuff has ascetic acid in it. The ascetic acid can corrode metal over time and smells like vinegar.
coocha6 years ago
Excellent job, excellent write-up. I know you're in Arizona, but I'm curious as to how this setup would vent water vapor in more humid areas. I just bought some cells, and I think I'm going to use glass so it won't discolor due to UV exposure in a permanent outdoor installation. I can't think of a good way to ensure that Appalachian humidity won't cause condensation. Ideas anyone?
How about a handful of the desiccant packets that are always packed in with leather shoes and what not?
cool guys, thanks for the thoughts. My cheap cells are en route, and after I finish the latest woodworking project, I'm gonna fire up the soldering iron!
ac-dc coocha6 years ago
No need to vent water vapor, seal it so excess doesn't get in. You could do as jkster107 suggested and put some pre/re-dried desiccant packets inside before sealing to remove more vapor. It would be important to re-dry the packets because they're already ineffective by the time they've sat around in open air as you're receive them in an unsealed product. Put them in an oven on low heat for an hour or two to dry them out.
Padlock6 years ago
Here's where I'm really stumped: If you use a telescope at night, then you would be on your property at night. And at night, there's no sun...So why not just charge them at home? (Unless you camp there for a week or so.) Also, why not just charge them from car battery?
mdavis19 (author)  Padlock6 years ago
Yes, I often do camp on the property for a week at a time. The batteries in everything would run down after a couple of days. I would always worry about running down my truck battery too (miles from the nearest jump start). I'd leave it idling a lot of the time, when I was running equipment or charging batteries, burning up expensive gas. This is a lot better.
Are you using a leisure (deep cycle) battery with this solar/wind turbine rig?
yetunguez6 years ago
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.
denport6 years ago
great story and easy to follow. Thanks for sharing.
ic5176 years ago
great Instructable . you should check out his link to his site. some really interesting links and stuff on there to . good job
Mikey D6 years ago
Excellent job! A few comments: PV cells get less efficient as they heat up. Putting them in a shallow box like this may enhance the heating. The way the commercial folks do it is to lay the cells face down on the protective glass (or plastic in this case) then hold them in place with a layer of sticky plastic (I'm thinking contact paper) This will be less expensive (and probably easier) than building a frame & box set up. It will also let them shed heat more efficiently. The only down sides are your frame (think picture frame around the PV window) would have to be beefier to strengthen the panel, and you would need to test your array before encapsulating it in the plastic. Once again, Great job! Mikey
Plasmana6 years ago
Wow! This is an really good instructable! I will build one someday... 5 stars!
=SMART=6 years ago
wow very nice ! and anly one hundred $
Scurge6 years ago
Nice I-ble! Just what i've been looking for! i was just looking at solar panels the other day. and i found out that just looking makes your wallet hurt.. lol
Padlock6 years ago
Also, for your next one, (if you make another one) you might try making it out of broken solar cells. Not as space efficient or pretty, but MUCH much cheaper.