Posted by admin | Posted in Miscellaneous | Posted on 27-12-2009
It is becoming more common knowledge now that broken, chipped or otherwise damaged solar cells can potentially be used to make a homemade solar cell capable of producing electricity. Basic electrical wiring of several of these panels together has the potential to boost voltage so it can charge a few batteries in a bank, and at least partially power an appliance or two (when connected to a power inverter, of course.)
To many homeowners and do it yourselfers, this is a dream – a really cool project that isn’t too expensive and can reduce electric bills. The more electricity you can produce, after all, the less demand there is for it from the power grid. This lowers your bill. Or, if you are really adventurous, you can even get an electrician to connect your system to your house, and thus produce power that is fed into the grid. In theory, if you produced enough excess power, your meter will actually reverse and you will see credits on your energy bill!
Whoa! Hold on. Nothing we talked about here is illegal, but its time for a reality check. First of all, depending on your energy usage and demands, you would need to produce a lot of power to have an excess in the first place. And based on the solar panels available today, it is highly unlikely you will produce enough power to become a part time energy supplier.
But, it is entirely possible to produce just enough power to reduce your energy bills by $10 or $20 bucks per month.
You can go about this a couple ways, in regards to solar power. You can either build the solar panel array yourself using old broken solar cells and wiring them together yourself, or buying relatively cheap larger solar cells from a wholesaler and wiring them together.
I am currently writing another more detailed article on how to wire together broken solar cells to make a working panel, but the basic concept is this. Gather broken chips or cells of approximately the same size. I’d also recommend taking a multimeter or voltmeter and measure the approximate power output. The reason you want to do this is because when you wire solar panels in series, the power produced will only be as large as the lowest power cell. In other words it makes no sense to group a cell that gives off 200mv with one that produces 65mv, because the 200mv will fall to the 65mv level.
Once you wire and solder the cells together, you connect the cells to a bus, or larger gauge wire that collects the power. Now you just seal the cells (which are placed on wood, or another material), place plexiglass over the cells, seal the unit that that’s it. Connect the two bus leads to another array for increase your power, then to a battery.
You can also add a charge switch or charge controller which avoids letting the battery become overcharged, a diode which prevents power from flowing to the panels at night, a power inverter so the battery power can be converted to A/C, etc.
Building a panel out of new or slightly used solar cells that are whole involves the same basic process, except there is less soldering and electrical construction. The cells are already whole and probably wired. Plus, if you buy or obtain several cells that are rated the same, you can be confident connecting them in series without a serious drop in power.
The process of enclosing them, sealing it, and connecting it is the same. So, which is better? Which gives you more power? And which is more cost effective?
Well, you can generally get broken solar cells relatively cheap or even free if you know where to look. (Call your local highway department, hint-hint). Whole solar cells you will almost always have to pay for, and they can get pricey. However, you may find that more than a few cells in your bargain bag of solar cells do not produce any power at all and are worthless. And each one will produce sometimes wildly different power amounts.
Whole solar panels will almost always give you more power than broken or chipped ones, piece by piece. Five whole solar panels even at 9×9 inches will give you more power generation capability than five chipped pieces.
If you don’t mind doing quite a bit of work yourself, discarding cells that don’t work, and soldering cells together, then the DIY method of building a solar panel out of chipped cells may be for you. You can build the panel as big as you want and get the most bang for your buck.
The whole panel method is easier, requires less work, but still lets you make your own enclosure. However, it is definitely more expensive. Let’s talk costs. Whole panels around 9×9 inches may run you $6-$10 each. By contrast you may be able to score 20 or 30 2″x2″ or 3″x3″ chipped panels for around $25, which is a little over a buck each.
The power each produces will vary on how many cells you connect, and what each cell can produce. (Also, don’t forget the brighter the light source is, the more power is produced.)
Look for future articles on building practical solar panels, experiments, and how much raw power can be generated from each soon.
David Anderson continues to be so completely obsessed with home energy and finding ways to reduce energy bills that he’s now losing sleep over it. He is a regular contributor to the Utility Bill Busters Blog, a site updated (almost) daily with a ton of free tips and resourced for helping homeowners save money on their energy bills. It can be found at http://www.utilitybillbusters.com, and you can check out Dave’s other money saving articles: here
