A DIY Off-Grid Solar Power System Overview and Wiring


Hi this is Amy from the altE Store. We’re going to go over a brief overview of a typical off grid solar electric system. This is just a small demo, and it can scale up as your needs require. But this will give you a good overview of the different pieces involved.

Now I’ve got a lot of different electronics and wiring involved, so, what we did is we drew up a schematic, and you can check it out here. And click on this link and you’ll be able to actually have it up in another window so you can follow along at home.

All right? So, what we have are two 12V solar panels. They are wired in parallel, so that makes the plusses together and the minuses together. And that keeps it at 12V. So, I’ve done that within this combiner box.

This is a Midnite PV3 combiner box. And we’re just going to take a quick look inside and remove the protective face plate. So you can see that we have the plus and minus from solar panel 1 coming in to, the plus goes into its own breaker.

And the minus goes into the negative bus bar. Then the plus and minus from solar panel 2, the plus goes into a separate breaker, and the negative goes to the negative bus bar. The output of the breakers are combined with this included positive finger bus bar.

So it slides into the top of the breakers and that combines the positives. The negative bus bar combines the negatives. And that gives you your parallel wiring. And so I also have my lightning arrestor that will protect us from any lightning strikes.

And we’ve got the ground going to the grounding bus bar, the positive going to the positive bus bar, and the negative going to the negative bus bar. And you can see I’ve also got my ground coming from my racking going into the grounding bus bar.

Now I’ve got the rails grounded through this, and then I have a grounded mid-clamp from IronRidge, which is taking that ground, across the rail, up to the edges, the frame of the solar panels. So that is giving me a nice bonded connection through all of this.

I would then go off to a grounding rod, and that would give me my nice earth ground connection. So I’m coming out of here, in conduit. Now because this is a portable system, I’ve transitioned to “invisible conduit” here.

But know that this is going to be conduit all the way into the house. So now let’s transition into the house. Great, so now we are inside. So we’ve gone in conduit all the way into the house. And so what we have here is it is going to our DC Load Center.

Now the DC Load Center is really just a fancy way of saying breaker box. So we are going to take a look inside our DC Load Center, we happen to be using a Midnite Big Baby Box for this. So again, we’ve got our combined negative, positive, and ground, all coming into our DC Load Center.

We have it going into a breaker. It’s coming out of the breaker, into the PV In to the charge controller. My negative is also coming in, and it’s actually just transitioning right on out. It’s just going in there as a nice place to land my negative.

But it’s going in and then it’s coming right back out and it’s going to the negative PV In of my charge controller. So then I’ve got my battery out from the charge controller. I’ve got the plus and minus going into the DC Load Center.

The plus is going to a breaker, and it’s going to be coming out, and going to my positive bus bar. Now my positive bus bar is going to be going to my battery. So I’ve got the negative coming out of the charge controller, going to my negative bus bar.

And that negative is also going to be going to my battery. So I’ve got that going from the charge controller, to the battery. So basically, what these bus bars do, is these give me a nice easy way to connect everything to the battery.

So I only have one connection to the battery, because that’s connecting in to my bus bars. So anything I need to connect to the battery, I can just connect to the bus bar, through a breaker. So I have going from the positive and the negative, I’m actually going to a cigarette outlet.

This is very common to use for a DC connection. So if I have anything that would plug into my cigarette outlet in my car or an RV, I can just plug in and run it right off the battery. I’ve got a fuse in here, so I do have my over current protection, or If I wanted to, I could have put in another breaker and I could have gone through there.

So, I have that DC load. Now I also am going from the positive bus bar, to another breaker, and I’m going out to the DC input of my inverter. I’ve got a 12V inverter. So I’ve also got the negative coming from the negative bus bar, which is just acting like the battery, going to the negative of the inverter.

And I’ve got my ground. So, the inverter is turning that into 120V 60Hz pure sinewave, because I’m in North America. If I was someplace that used 230V 50Hz, I would just use a different inverter for that.

So it’s creating the AC power for me. It’s going to an AC breaker box. For this I’m just using a Midnite Baby Box, but if you’ve got a lot of AC loads, you would have a bigger AC breaker box.

So I’m going through my breaker, going out to an AC outlet, where I have my lights! So I have got the light going through a breaker to the inverter, through a breaker, to the battery. And I’ve got a nice meter, Morningstar happens to make both this inverter and the charge controller, and they’ve got a meter that I can actually connect to either one, and it will read different settings and different measurements based on what it’s connected to.

So that is just an overview of this demo system. We’re going to do a whole bunch of other videos based on this demo, so stay tuned. And I hope you enjoyed our video. You can watch more here, and check out more of us at altEstore.

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