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Solar panels, charge controllers, and system calculations

Posted: Sat Oct 10, 2015 2:28 pm
by OutOfPlaceNinja
Other than battery banks being complicated, it seems figuring out how many solar panels you need to match your battery bank is also pretty complicated. Hence, this thread all about solar panels, solar panel wiring, and solar charge controllers.

The battery bank thread is here.

As in the battery bank thread, I will say that I have been getting serious about going off grid electrically. The current timeline is by summer of 2016. It may get pushed around a bit. At present I use around 100-200kwh a month but it seems to live off grid using that much I would need a heap of batteries and panels so I will likely need to lower my electrical use.

This thread is all about solar panels, solar panel wiring, solar charge controllers, mounting of solar panels, angles of solar panels, brands of solar panels, so on and so forth. Everything solar panel related. I would like to see this thread as a good resource to those on the grid who want to get off the grid.

Do you have solar panels? If so how many? What are they rated for? How do you have them wired? What brand are they? Are they performing good? Did you make them yourself? Are they broken cell panels or new cell panels (if you made them yourself)? How are they compared to the size of your battery bank? If you could do anything different, what would you do? Any tips, hints, tricks, aimed at the newbies? So on and so forth.

Re: Solar panels, charge controllers, and system calculation

Posted: Sat Oct 10, 2015 2:40 pm
by OutOfPlaceNinja
So, talking about solar panels, let's talk about some costs.

I have been looking around and solar panels are still pretty expensive. The cheapest I've seen is when buying them by the pallet, however unless you have a huge electrical demand, you would probably need to go in with others in your local area to do such. The cost seems around 50-80 cents a watt.

Next next cheapest complete panels seem to be around $1.50 a watt and up. This figure includes shipping.

The cheapest solar I've seen to date is the DIY ones. You can get broken cells and cobble together a panel but the performance would probably leave much to be desired. However it should work and would be pretty cheap. However what I didn't realize is you can buy new solar cells and make a panel. Not including the encapsulation, the costs for such seems around 35-50 cents a watt. I found a listing on Amazon (B00IO4206G) titled "500 Watts Mono 6x6 Solar Cells DIY Solar Panel Kit w/Wire Flux Diodes High Power Cells Average 4w Per Cell" that seems a pretty good deal. The cost as of this post is about $215 USD. About the cost of a roughly 150-200 watt complete panel without shipping. However this brings up the question of encapsulation and the cost of such. Would doing a DIY solar panel (or panels) with new cells be cheaper overall or would it be better to just buy solar panels? As of this post I don't know the costs involved with encapsulation.

Then of course you have the charge controllers. I don't know much about them either but I hear MPPT charge controllers are better than PWM ones. MPPT charge controllers are also a lot more expensive than PWM ones. Then you have the question of sizing. To a newbie like myself, this is all pretty confusing and I can totally see how it would put off a lot of people. That is the purpose of the threads about battery banks and solar panels, to help the newbies get a better grasp of what they need to know and do to get themselves off the grid electrically. What kind of charge controller do you have? In a small system, does it really even matter which kind you get? How many charge controllers do you have? If more than one, how do you have them arranged?