This is the third video in our off-grid solar installation series, where we go step-by-step through the whole process of designing and procuring and installing a whole new solar system. Last one was on batteries.
This one is on the solar panels. I’m, going to talk a little bit about how we designed this. Why we designed it the way we did and then we’re, going to connect them up and take you along show you how that works? Okay, so when you & # 39, re, designing your solar panels or spec’ing out your solar panel array, you want to design it to the battery bank.
You’ve already designed that is based on the Sun hours available in your area, the size of the battery bank, the number how how quickly you want it to recharge in a day. So I wanted to be able to charge our battery bank within two hours in the morning to keep keep it topped off.
We have four to five Sun hours a day, and so the array size that we designed is 5200 watt array and what I’ve done is designed this for expansion. This will charge our batteries in two to three hours on a sunny day and a battery bank will, let us run three and a half to four days without any recharge.
So the way this is designed, there are 18 total panels. Each one is 290 watt from solar world. They have about a 17 and a half percent efficiency rating. Each one puts out 34 35 volts about seven and a half to eight amps, so we’ve strung them together in strings of three wired in series and when you wire in series, you increase the voltage and your amps stay the same.
So we & # 39, ve got 35 35 35 volts and then say about eight amps, so each one of these strings is going to produce about a hundred volts by the time it gets up the hill at that eight amps and we have those parallel together With two other strings, so there are nine panels in an array and we have two arrays.
So each one of these arrays will produce 2,500 watts peak Sun and again I designed it for expansion and that’s. Why? I split it into two arrays with two different combiner boxes. Each of these arrays will go to its own charge controller, so we & # 39.
Ll have to charge controllers each operating in about 60 % capacity. That’ll. Allow me to add two more strings to each array: adding a total of 12, more solar panels plug and play, and then I can add a battery to the end.
If I want to of the string that we’ve already designed for our battery bank, so it’s all designed to. We could probably go up to eight eight thousand watt hours and that’s way more than we need. So I’ll.
Take you around show you how this is all hooked up mmm? Who did that now? I spent about a week building these racks, taking the nine-foot pallet tearing it down and reassembling it to Iraq that fit these perfectly, and then I decided after the third one that that was just kind of a waste of time, and then I just switched to pallets This is all just a temporary install while we’re here at the camp until we moved to the house, and then I’ll set these up on a permanent ground mount or maybe a top of pole mount.
I don’t know yet, but we just needed to get it up and working and these racks work great for now. So I’ve got well all of the wiring done. I just haven’t connected each of these panels together and turned them on yet so that’s.
What I’m, going to do now. I’m, going to connect these three panels together in series, and then we’re, going to run a voltmeter on them and test them now any time you’re doing this in the daytime cover your panels because they Are under load you plug them in you’re working with high voltage, so cover your panels with a tarp and it & # 39.
Ll drop your current, so you’re, not working with dangerous stuff, [, Music, ]! Okay, I’ve, made my cables from the combiner box to each string and they’re just sitting here. I’m gonna plug those in now.
So I’ve got my pv 1 string 2 going to pv 1 string 2 and then the positive of this first panel goes to the negative of the second panel. Positive of the second panel goes to the negative of the third panel and then the positive.
This one goes back through to the combiner box, using the cable that I made so now this string is live. Now I’ll, go put a voltmeter on it and see what it looks like all right here. We are in the back of the array here’s, the first combiner box for this array of nine panels.
I use a little Clippy thing to hold the dead front to the lid, so I can work on it. This is it all wired up. We’ve, just connected the second string, which is here so we got one two three strings positives coming off the panel’s; negatives, coming off the panels to a common negative bus bar and then our big 4 gauge cable, each.
The positive end and negative going up to the inverter and then all of this is ground wire. Each one of these panels is grounded to the other and they’re all bonded together. They all come into this common ground bus and then they go down to a ground stake to ground the whole system and then also again, each of these combiners has an SPD, a surge protection device to clamp the voltage in case there’s.
Any weird lightning issues: ok, we’ve used the tarp to connect the panel’s. Now we can pull the tarp off [ Music ]. Now we’ll test our voltage. Alright, let’s test these strings. First string is already connected: it’s, pushing eighty five point, six volts, which is a little low.
I think it’s still in the shade. A little bit second string, which is the one we just hooked up, is almost 110 volts. So that’s, good third string is not hooked up yet so it still has. It still has voltage, though, so we’re gonna hook up this third string.
Then we’re gonna hook up all the rest of them flip all these breakers on, and we should have power up to the house when you’re looking for panels to build your array and you’re. Looking at all the different brands and models and wattages, and all of that they each of the manufacturers published the specs of it and there’s.
A thing called standard test conditions which gives you the voltage, the voltage open circuit and all the things you need to know usually go by eighty percent of that to get a kind of a real-world idea of what your panels going to be able to produce.
These. Actually produce exactly what they say they will produce. So I can say: solar world panels are pretty good. I wrote down a few things. I’m, going to talk about here with respect to how this matches up to our charge controllers and our battery bank.
You, like, I said you want to size your array to be able to charge the battery bank. You’ve designed and a shorter period of time as possible. Ideally a couple hours in the morning. Our charge controllers are going to be midnight, solar classic one 50s.
They’re tried-and-true for 20-some years. They’re built like trucks. They’ll, take 96 amps each the charging current for each of the batteries we’ve chosen is 34 amps. So since those are going to be hooked in parallel, we have six of them that’s 34 times.
Six is 204 amps of charging current that can go into them and so with two classic 150 s rated at 96 amps each. If they were maxed out that’s, that’s about ideal for that configuration so that you’re using the charge controller.
It’s, total capacity. We are only going to be using, like I said, 60 % of the charge controller right now later on. When we add panels, we’ll, be able to add 12 more panels, so that’s. The solar panels, pretty pretty simple.
To hook up once, you figure out the whole series parallel thing, so a lot of people always ask us where we get this stuff. We got all of our components for the system from all east or alt, East or com.
They’re, a great distributor, they’re tech. People were great to work with and they helped us. You know validate the design that we had come up with and they’ve got a good library of tech, information and things that you can use to learn.
If you’re just getting into this DIY stuff, they & # 39. Ve got a YouTube channel that has a lot of information about all the different things, so I do recommend all to each store comm and that’s. The panel array that we put together, and so next we’re, going to do the combiner box and go over how to put that together from pulling it out of the box and then hooking it all up so hope to see you then stay Tuned thanks for watching