Solar DIY

[ken800]

Several people have messaged me about my grid-tie solar install after posting in a thread so I thought I'd share what I have learned from my own install. My total install cost is listed out below. With a 26% federal tax credit for 2020 (22% for 2021), that left me with about not much to recoup. Feel free to add to this thread. I have a few links at the bottom to help you plan.

I live on 5 acres and couldn't bring myself to put panels on my roof so I chose ground install as I couldn't bring myself to punch a bunch of holes in my brand new roof. I also didn't even look at batteries (more on that below) because they are extremely expensive so this is a grid-tie discussion. The Tesla Powerwall, for example, might run your critical appliances for a day or two, depending on load and what's "critical" to you. It's $10K. If you want to live off grid like you do on grid, you aren't reading this post because you can afford a $50K system installed.

There are 3 main parts to consider:
-Panels
-Type of Inverter (string or micro)
-Type of racking (roof or ground)

Panels have reached the 400w mark pretty rapidly. Just 8 years ago, 250W panels were top of the line and 500W is the peak today. In the next handful of years I suspect we'll be pushing close 1kW panels. I purchased Talesun 405W panels as I got a really good deal on them (about $135 all in per panel). You will need to find a true wholesaler to buy them or you'll pay through the nose! Pick them up and don't ship them and save about 1/2 the cost. I purchased 22 panels though I'm only deploying 20 so that I'd have 2 spares in case I break one. Shop around and you're fine with any of the tier 1 manufacturers. Half-cut panels are more efficient as each side is essentially an individual panel and monocyrstalline are usually more efficient than poly. That's what I got - half-cut monos.

Second you will need some type of inverter. You basically have two choices though there are hybrid systems. String inverters take a "string" of panels and convert them at the end of the string from DC to AC. They are cheaper but the problem is that if you shade one panel in the string, it affects all panels in that string so if you have occasional shade, that's a major issue. Micro inverters cost a bit more but they convert DC to AC at each panel individually and optimize output for just that panel. This means if one panel is damaged or in the shade, it doesn't take the whole string with it. For my setup, I chose the AP microsystems QS-1 which hooks 4 panels per micro inverter. Each panel is still individually optimized and it has a smart controller that allows you to remotely monitor them.

Third you will have to have a way to mount them. Again, I have no experience mounting roof racks and wouldn't do it on my house as I wouldn't want to deal with inevitable leaks down the road. YMMV. Instead I chose ground mount. I went with Unirac ULA model racking as it is extremely well made, has a great planning tool, and uses local-sourced 2" galvanized pipe for major support beams and vertical poles which saves cost on shipping. Their designer tool (link below) will help you plan your system and then give you the complete bill of materials and full engineering drawings for setting up your racking.

First and foremost, PLAN. The best website to start your plan with is PVWATTS. You start with your address and go from there.
https://pvwatts.nrel.gov/

Panels:
Tier 1 list https://review.solar/latest-tier-1-s...els-list-2020/

Once you identify your panel and micro inverters, you'll need to develop your racking plan. Unirac (there are others) has a tool called ubuilder that will let you plan everything and then find out every nut, bolt, and screw you'll need. Ubuilder is here:
https://design.unirac.com/

Before you buy anything, reach out to your power company or coop and find out how they deal with grid-tie solar. My coop is Pedernales. The require you to go through a brand new as of 2021 process for approval but the end result is the same. Once you are installed, they will put a bi-directional meter in place of your old one. If you are pushing back more power than you are pulling during the day, the meter "runs in reverse". Essentially the credit me back the cost of each kWh that I put on the grid at my regular cost of .093. At night, when I'm not generating, I use up what I have "stored" at PEC. Essentially I use them as a battery. If I ended up pushing back more than I use over the total billing period, they buy it at just the base electricity cost not including delivery which I think is about 3.5 cents per kWh.

Note that your Coop or power company may be more or less generous though I will say PECs is about as good as I've seen. NOTE: Your power provider will have one requirement regardless of who they are/how they operate: A lockable cut-off that is externally accessible. The power company will come to see it in place and it must have a locking ring on it. If they are servicing poles nearby, they'll come shut you off and lock you out until they are done so you don't fry their workers. Seems fair enough.

If you have any further questions, post them up and I'll try to help. I'm sure there are others that have built off-grid systems, but remember that batteries are seriously expensive. You simply aren't going to have an on-grid experience without MAJOR expense.

My system cost breakdown was as follows:
$3048.32 for panels (including 2 extras)
$1514.49 for Unirac Racking
$1718 for micro inverters and all cabling, clips, connecters, etc.
$500ish for pipe, wire, breakers, and blade cutoff

$6,280.61 minus 26% tax credit leaves me with 4647 to amortize. I'll generate right at $1300/year in energy which means 3.58 year payback.

[Chew]

Great breakdown. Thank you.

[Drop Tine]

Excellent contribution on the detailed information. Thank you!

[dhall1414]

how much space did the solar panels take on your property?

[ken800]

Todays solar panels are all very similar in size. They are about 6’x4’. I went 5 wide and 4 deep laid horizontally so 30’ by 16’ array.

[Texas Grown]

Great thread and info Ken800!

[sahunter]

Tagged, thank you for the info.

[BigYoung]

thank you for info, great writeup.

[rowdybass]

Tagged, I’m in Bertram and on pec as well. If I decide to do this I may see if I can check out your set up.

[Reaper]

Thanks for the breakdown

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[Wits_End]

How long have you had the system and what has the real life output looked like? Do you have a controller/monitor?

What is your aiming like? Do you adjust the panels multiple times a year to follow the sun?

I haven't found prices that cheap on a system, I was seeing a little over $1/kw. Where did you buy the panels from?

After each microinverter it is AC, did you combine those wires and simply run into your breaker box?

Appreciate the help.

[hog_down]

can you post pics of your setup?

[tpepper70]

Can you explain to a very interested newbie what all your system will run/energize? Whole house? Just fridge/lights? We are fixing to build a new house, downsizing, and I've always been interested in going solar, but have never researched it much. I could easily do something like this. Thanks

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[stoic]

Great write up. A couple of pictures would be awesome too.

I would also appreciate if you could update this over the next couple of months/years to see how closely the planned ROI schedule matches the actual ROI period.

[ken800]

Sorry, I didn't see the responses! I'm in the hospital with my son this week. I'm going to move my solar array from one side of my property to over behind the barn. I'll get some pics up soon.

[ken800]

Originally Posted by Wits_End

How long have you had the system and what has the real life output looked like? Do you have a controller/monitor?

What is your aiming like? Do you adjust the panels multiple times a year to follow the sun?

I haven't found prices that cheap on a system, I was seeing a little over $1/kw. Where did you buy the panels from?

After each microinverter it is AC, did you combine those wires and simply run into your breaker box?

Appreciate the help.

Originally Posted by tpepper70

Can you explain to a very interested newbie what all your system will run/energize? Whole house? Just fridge/lights? We are fixing to build a new house, downsizing, and I've always been interested in going solar, but have never researched it much. I could easily do something like this. Thanks

Sent from my SM-A716U using Tapatalk

First, I'm "grid tie". I push about 40 amps directly into my service panel through a cutoff switch. Pedernales has bi-directional meters and anything I don't consume at that moment in time is put on the grid and I draw my electrons back when I'm not producing. So, in other words, I don't energize any specific item. If the grid went down, I'd be able to run about 40 amps (at noon, lol) of stuff. I have no battery system.

Aiming is due south 25 degrees. I played around with the nrel calculator for optimal angles and that was about as steep as I wanted to get so I could reach to clean and it still provides near optimal output. You can tweak for summer or winter then the other suffers. It's really a compromise no matter what. You could by those adjustable posts but it's expensive and by my calculations it is impossible to recoup the cost on a small system.

My QS1s are currently two separate Alternating Current strings of 20A each to two 20A breakers in my main with simple knife cutoffs. As mentioned in my above post, I'm going to move my array over behind the barn so it is less visible. I'll have to cut down some big cedars, but no loss there, lol. When I fire it back up, I'll be putting a 60A sub-panel on the array to combine the two strings and run a single 40ish amp feed through the back of my barn to the service panel there. That is a 125A panel coming from my 320A main at the house so it is more than capable of carrying the load back to that panel without overloading. I'll probably lose 5% from the distance but I'm not that worried about the loss and I can always add more panels behind the barn.

As far as prices, I ordered them in bulk from a wholesale outfit and picked them up myself. You can't order from the companies that do the installs as they mark up the panels. 400W solar panels at the wholesale level are $125-$135 per panel plus tax. Double that from the installers...

[DesertDug]

good info and write up. Subscribed.

[Aggies96]

This couldn't come at a better time. Thank you so much for sharing. I'm on Pederinales as well!

[MedicineMan7]

Tagged for later. Thanks for the breakdowns and info

[3ChordTruth]

Excellent detailed summary of this important technology. You had me at “If you are pushing back more power than you are pulling during the day, the meter runs in reverse". Your solar energy system likely got a lot of us thinking how we can get in on something like this. Thanks for posting.

[mdb0531]

great detailed info