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Discussion Starter · #1 · (Edited)
Hey all

I have all the electronics for my new PV system and started installing them today. My solar panels are due in tomorrow, I have 12 x 240v panels to install on my garage roof for a 3000 watt system. here is the roof which is exactly south facing:

P1010097.JPG

Just to remind people, my system is not intended to be an off grid system as I have too many modern convienences that I am not willing to give up yet. Although I do plan on replacing my electric clothes dryer with a LP powered one which will make this a almost off grid system if I can give up my microwave.

I started with assembling the "combiner box" which is where each string of solar panels goes before sending the amps to the charge controller.

I am doing a 48volt system so it takes 3 solar panels per circuit, that makes 4 x 15amp breakers, one for each set of 3 panels.

P1010103.JPG

Here is a shot of the area that I am putting the charge controller, batteries, inverter. You can see my 2 chest freezers in the front, at the rear is my 4500w propane generator and on the wall at the rear is the charge controller and inverter

P1010098.JPG

Here is a close up of the system, inverter, and (black) charge controller. The lower box is a consolidation point for all the wires (the larger open white box below the inverter), from this spot I can add generator feed, battery feed, output to the home system or to the power pole for a grid tied system. I highly recommend a combiner box for those that don't really know what they are doing, the labeling is so clear it is hard to mess up. The Charge Controller (black Outback box on the right) is the unit that takes the raw amperage from the solar panels and feeds it to the batteries. This is a MPPT controller which is the most efficient kind.

P1010101.JPG

My inverter can do 220v which I need to run my 200 foot well 1/2 horse pump. It is a 4400 watt inverter (surge to about 8K) to start up the freezers and the pump and the refrigerator I plan to run on the system.

Here are my batteries, I have 8 x 8L16 Deka brand 6 volt batteries which should last about 10 years. They are not in place or wired up as I purchased these last year on a mega local sale for $215 each which is a freekin steal. Batteries need to be set up in an area where they have a vent to outside air because when the charge control equalizes the batteries they give off hydrogen that is very explosive. I am going to build a platform over the generator to keep the batteries with the required vent outside.

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I am going to build the frame for the solar panels myself at my shop, I'll try to remember to take pictures of the process.

I am getting all my parts from :

Backwoods Solar Electric Systems

If you ask them, they will send you a really comprehensive book about how to set up a system for any budget.

I don't have any affiliation with the company but the prices are fair and the help seems to be really good.
 

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Hey if you don't mind take some pictures of brackets and wire hook ups and the small stuff that we never get to see.
Also any special sealers or hole fillers
 

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As per the LP clothes dryer, I think you will find it uses LP for the heating but still needs electricity for the timer & the motor to spin the drum. Most combination dryers use 120VAC instead of 240VAC.
 

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Discussion Starter · #5 · (Edited)
Here is an update, things are crazy for me in the summer with planting, irrigation, plus I'm helping 2 of my daughters put Laminate flooring in a 14x70 mobile home.

I purchased the metal locally using 3/16" stock both "L" shaped and straight bar, the price from the dealer for the rack I am building is $850 and I'll get the job done for about $300

I am putting up 12 panels each one is 39" x 66" and for my 48volt system I need to run them in series of 3, so I decided on building 4x racks that hold 3 panels each, here is a pic of me putting the first one on the roof:

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I'm doing this all solo so the tractor loader takes a lot of the grunt work out of it, with 3 people we could have done this by hand as the racks are only about 80# of metal each.

I put 2x4 blocks on the corners of the racks when I put them on the roof to save the paint finish and make them easier to slide around:

P1010112.JPG

Here is the attachment point, I drilled 7/16" holes in the roof and bolted them down and then spread a liberal amount of clear silicon both underneath the bracket when I placed it as well as around the edges and a liberal amount over the bolt. I've used this system before on my camper and it is a leak proof application.

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Here I am installing the 2nd of 4 panels, I needed to avoid my septic tank cap so I couldn't put it straight on, but like I said they are not heavy racks so I just grunted it into position from there:

P1010110.JPG

I didn't do any photographs of cutting the metal or welding it up as you either know how to do that or you don't. I have a metal band saw in my shop which is the coolest thing, so much better than a chop saw I cannot even start. I use a 175 Lincoln wire feed welder and a craftsman drill press. Other things that were really handy was my bench grinder, free standing vice, grinder, and some saw horses.

I put 2 coats of Rust oliem paint on each panel, not sure how it will hold up over time but it was cheap.

Each rack is held in place by a bracket on each end using 7/16" bolts into the roof and from the roof bracket to the panel rack itself. My thought was to make it possible to build "legs" so that I can increase the angle of the solar panels in the winter time so they will face the sun more directly.

For those that do not know here along the Canadian border the sun swings wildly from season to season. In the summer it is almost directly overhead and our nights are only 7 hours long. In the winter the sun moves far south and the angle of the panels needs to be adjusted up for maximum efficiency. In winter time we get about 7 hours of daylight so it helps to maximize your solar intake in the winter, that is when a off grid system will not hold up.

More to follow, I should have the racks done tomorrow, and the panels mounted within the next 4 days.
 

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Nice.

Just out of curiosity, did you give any thought to mounting them on the ground? Will they be angled enough so the snow slides off by itself, or are you gonna have to get up there and sweep the snow off? Or do you have a really long handled broom?
 

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Discussion Starter · #7 ·
Nice.

Just out of curiosity, did you give any thought to mounting them on the ground? Will they be angled enough so the snow slides off by itself, or are you gonna have to get up there and sweep the snow off? Or do you have a really long handled broom?
Hello
Yes I did look into a ground mount, but they are even more expensive than the roof mounts, I was quoted $1500 for a 8 panel ground mount. It is true they are easier to move and position for maximum intake, but a book I read suggested for the extra money for the ground mount, just buy more panels and permanently fix them, it is a wash on total power (say 8 panels pointed correctly and 12 panels fixed are the same amperage) and so much less work.

I am directly behind a 9000 foot mountain which absorbs most of the snow in winter, it is unusual to get more than 4 inches a day and 30 inches a month here, and it melts off really fast. The big kahuna mountain can have 40 feet on top, which is my irrigation water in the spring.

With a long handled broom I could easily brush them off.
 

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Very nice work Montana!

Please send some photos of your shop too. I love comparing shop photos.
 

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Discussion Starter · #9 · (Edited)
Ok, panel racks were fully up yesterday, this picture was taken this morning and the pallet on the tractor is the solar panels

P1010113.JPG

For those interested here is a label on the solar panels, made in USA, can't beat that.

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Drilled a 1 3/4" hole in my new metal roof (Gah) and placed a 1 1/2" galvanized pipe "U" with a 5" extension out the bottom so nothing would blow up and get into my garage. This is where all the 10ga wires from each set of 3 panels I wire in series will enter my garage. All this will be under a solar panel and is sealed and resealed with silicon, I am confident it will hold up to weather.

Wire Feed.jpg

Generous duct tape as I was working on this and wiring as the silicon was curing.
 

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Discussion Starter · #10 · (Edited)
Wiring is straight forward, each panel has a positive and negative out with one being male and the other female. It is possible for an idiot to plug the two together and ruin the $300 panel or start a fire so you need to pay attention.

I am running 3 panels in series which means I am hooking the positive of the first panel to the negative of the 2nd panel, and the positive of the 2nd panel to the negative of the third panel.

This give me a positive and a negative connector left, which I will run to my "combiner box" where all the solar panel strings of 3 will come together.

The roll of wire is a 30 foot extension which I cut in half, the one end hooks to the bottom of the 3 solar panel outputs, and the other hooks to the top of the 3 solar panels and then I run them down the hole mentioned above to the "combiner box"

Cabels.jpg

3 feet under the hole in my new roof is a combiner box, it is positioned directly overhead of my attic access panel so it is not only easy to wire, it is easy to access if I need to turn off the panels.

P1010132.JPG

The Combiner box allows me to put each string of 3 panels on a 15amp breaker which could save the whole system in case of a short. Also it allows me to isolate each string of 3 using my volt meter to determine if there is a bad panel in the array by measuring the output of each string.

The glowing bulb on the right hand side of the box is a 300volt surge suppressor in case aliens attack of Obama flies overhead in AF1
 

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Discussion Starter · #11 ·
Anyway here is my first solar panel mounted

P1010120.JPG

And my home made retainer to hold the top of the first panel down, used throughout the system:

P1010126.JPG

Each panel "locks" into a L shaped bracket on the bottom and is held with the above bolt/half washer on the top. So each string of 3 panels can be accessed, removed, replaced, without needing to disturb the other sets of panels.

P1010119.JPG
 

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Discussion Starter · #12 ·
So here is the panel array 2/3 done, below the red bucket is the entry point to the garage attic which is the last panel I will put in.

P1010127.JPG

The completed job, from start of installation to end it was 4.5 hours solo. with 2 people it would be a 2 hour job.

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And the satisfying window from my Outback charge controller

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Tomorrow I will actually hook my 2 chest freezers to the system and take them off grid, I am jacked. I finished at 2pm and my system logged 1.7kw of power and fully recharged my 8x 6 volt batteries by the end of the day.

Just so you know I didn't take the day off, I got in my tractor, drove 30 minutes to a custom hay job and cut 9 acres of hay in the afternoon

P1010133.JPG

It was a good cut, at $200 per ton for hay I'll make $1000 for 9 hours work.
 
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Discussion Starter · #14 ·
In the summer they are very close, as winter progresses they will need to be raised to point further south. I have built in the ability to put in "arms" on the top mounts and raise the angle if I feel I need it.

My caveat is the freezers you saw in the battery/generator room are actually outside and in the winter time the consumption drops from about 3K a day down to 1.4k a day because (omg its colder in the winter)

So I am hoping I will not have to mess with the angle as when the weather gets colder it works for me in lowering my power consumption.

The issue in raising the angle of the panels is that it exposes the back of the panels to the north winds which here are the worst, and unless I back them it may take them right off the roof.
 

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Discussion Starter · #15 ·
I actually have room to mount 3 more panels on my garage, I will seriously consider this as opposed to messing with changing the angle several times a year.
 

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That is really NICE work MR! Consider yourself having received several "atta-boys" from me.

Please let us know how well they work over the coming weeks. (I am still working on ideas for the home we are building soon and alternative energy is one of them.)
 

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Great thread MR. If you do the one more set of panels you can set that one set at a steeper angle just to help with winter charging which should eliminate the need for adjusting panel angles threw the year. Just food for thought.

I too used angle iron & welded up my own panel frames. But I scavenged bed frames from the dump to make mine.
 

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My little 520watt system easily keeps a 5cuft chest freezer charged plus some power left over for lights & such.

Winter you will find a severe drop in charging not only due to as much as 30 degree difference in angle but half the sunlight hours.
 

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I am doing a 48volt system so it takes 3 solar panels per circuit, that makes 4 x 15amp breakers, one for each set of 3 panels.

Wish you would explain the above. Are these 48VDC that you are wiring in parallel to keep the voltage the same & increase total amperage of the three panel string? Picture of the panel tag is too small for me to read.
 

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Discussion Starter · #20 ·
I am doing a 48volt system so it takes 3 solar panels per circuit, that makes 4 x 15amp breakers, one for each set of 3 panels.

Wish you would explain the above. Are these 48VDC that you are wiring in parallel to keep the voltage the same & increase total amperage of the three panel string? Picture of the panel tag is too small for me to read.
Here is a link from the company I purchased them from:

Backwoods Solar - Helios 250 Watt Mono Module * - Solar Modules - Products Backwoods Solar

Here is a break down of the stats (these are peak output)
Voc 37.8 is the peak voltage the panel will give you without a load, good for testing but not much else.
Vmmp 30.7 is the peak voltage put off under a load
Impp 8.14 is the peak amps put off by the panel

Obviously "Peak" is the perfect condition of which they don't always exist (like in the winter, overcast days, etc). So even though each 250watt panel is capable of putting of 30 volts DC that is peak which isn't always realized.

So they suggest 1 of these panels for a 12 volt system, yes on the peak day it will put out over 30 volts but on crappy days you can expect at least enough to power a 12volt system.

2 Panels are suggested for a 24 volt system, which COULD be 60 volts coming in on perfect days but even at 40% they can still charge batteries.

3 panels are suggested for a 48volt system which is 90 volts maxed out but reasonably easy to power the 48 volt system at 50% sunlight.

The 3x panels are wired in series so each panel "could" put off 30 volts each and the string of 3 could put off 90 volts.

Of course the charge controller takes whatever is coming in and tailors it to maximize the charge to the batteries dependent on the draw.

I hope that is clear as mud
 
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