Solar Install

I have been wanting to install solar since I moved into my house 5 years ago.   When I bought my place I also purchased the empty lot next door with plans to put something over there with solar on it.   I finally decided to build a solar setup once I saw how cheap used commercial solar panels were.  When I came across santansolar.com and saw their used 260 Watt Grade A panels for $70.00 each (at the time of writing this) I thought no way, plus why would they have so many used solar panels, who would put them up only to take them down?   After calling the company and speaking with their sales guy, he said "we get that a lot" he also said they purchase used solar panels from commercial solar farm operators.  Maybe they have limited land space, and a newer higher wattage solar panel comes out, well its easier to replace them all then buy more land and add to their existing array, and that is where they get so many used panels.     
With a 25 year manufactures warranty and santansolar.com's 1 year warranty I decided to buy 4 panels to check them out.

   

My first 4 "test" solar panels.  

Q.PRO-G4/SC 260 Watt Hanwha Q CELLS panels are what I received.

Ok, so I didn't plan this solar project out.....  I have 4 solar panels, no inverter to hook them up to and test them out.  I originally wanted to go with a battery system, which would (usually) mean a single string inverter DC to the array, a battery bank and the inverter grid-tied to the house power.   But then I got to thinking, man batteries getting replaced every so many years, and battery maintenance...   Meh....     I guess I can look into a grid-tie battery system later. 

So I started googleing and reading into different string inverters, and microinverters, cheap ones, expensive ones, Chinese, US, and German made.   I came across the AP Systems microinverters.  Looking through their site I really liked their QS1 microinverter. This inverter has 4 panel inputs instead of the usual 1 microinverter per solar panel.  Each of the 4 panel inputs have their own MPPT controller, so it's like having 4 microinverters in one box.  Got a price on them, about $250 bucks each, not super cheap but cheaper than 4 separate decent microinverters. 

So I bought one of these to build my test system, an AP Systems QS1 Microinverter.  

Hooked everything up and.....  Everything worked as it should! It put out almost what the solar panels were rated for..    So I called San Tan Solar and ordered 16 more solar panels, and 4 more microinverters. San Tan Solar was super helpful, they made sure I got 16 matching Q-Cell's to go with my 4 test units.

So far for 5.2 KW of Solar panels and microinverters has me at $2,650 plus I think it was around $250 in shipping, so $2,900 in solar hardware.   I still need something to put them on, about 250 feet of underground power cable, and some other odds and ends. 

I want a ground mounted system, I just don't want to worry about my solar setup whenever I re-roof, plus I don't want to worry about leaks, heat, fires and all of the other worst case scenarios I've read about online lol.     So ground mounts, lets look at those cheap uni-strut looking setups, those can't cost that much right? Wrong... Over $4k just for the ground racking that doesn't even get me proper footings to mount to....   Hum....  How about those pole mounted racks, less footing work for me, again cant cost THAT much, wrong again, almost the same price as the ground racks.  I got to thinking if I go with either of those it's just wasted yard space. What if I built a pavilion or something and put solar on top of it, maybe have a nice bench swing, maybe some kids swings under it? YEA......   

So I got to googleing what others have done, I want to do it on the cheap, but at the same time I want it to last a long time, as well as be sturdy and safe.  I did some looking on how to build pavilions, and they didn't seem "beefy" enough, I then started looking at pole barn construction, and ended up going with a mix of the two. I drew up something quick, based on solar panel sizes, and came up with a 32'x14' structure with a "lean-to" roof. I then priced out beefy 6x6 posts, 2x12 headers, and 4x6 rafters to support the panels, total Menards cost.....  $815 bucks!  That's not horrible, lets move forward with this, order placed!

I'm now up to $3,715.

I guess I better make some quick drawings.....

I was originally going to cement the 6 posts in the ground but later changed to just burying them directly in the ground. A lot of those old pole barns have been up for YEARS and just have the posts in the ground without cement.    I also purchased CCA .60 Pressure Treated 6x6's, which are a commercial product. Tests show 60+ years in the ground with CCA .60, I would be happy with 20 years, I'll probably build it bigger in 10 or so years anyway.



Ok, lets get started!  I'm not really a wood worker, I have worked with steel a lot, but this is my first wood project.  I'll figure it out as I go I guess.  I marked where my posts should go with wood stakes, and went off to the hardware store to rent a one man auger to dig the holes so I can set the poles. Augured down 4 feet then used the post hole digger to go down a bit more, I had to dig below the frost line in my area which is 50". Some crushed rock in the hole.  I then drug the posts over to the build site, put one end over the hole and lifted the other and walked the posts into the holes.  Held them level and backfilled/compacted the sand around them.

Here I have the posts set, the eight 2"x12"x16' bolted up to the posts and I have notched and mounted two of the rafters to mount the solar panels on. I'm going with a low angle, 13 degrees. The panels should be at about 40 degrees but that makes the underside useless.  Did the calcs and you actually don't loose too much efficiency with them at only 13 degrees, so I'm going with it.

Installing the rest of the rafters.

Solar panels have sat in the garage so long they have dust on them!   First four panels going up!

This is a closeup of how I mounted them down.  This is the only part of this build I'm not super comfortable about, I did it on the cheap.  Not sure with expansion/contraction how the clips and GRK Structural screws will hold up, not to mention the CCA pressure treated wood against the anodized aluminum frame.  Even though CCA is far less corrosive compared to the new pressure treatments. Clips are in the manufacturers mounting zones, I guess time will tell how it holds up.

Underside with all of the panels mounted.

Marine Duplex cable

First microinverter mounted.  The white cables are 10ga DC romex like cable, its actually marine duplex cable, I made two PV extension cables to reach the last two panels in each row, since I didn't mount the inverter in the middle of the 4 panels.  I wanted to hide all of the electronics from the street view, so they sit behind the headers.  You will also notice I ran a row of conduit with single gang boxes, this is the 240vac "bus".  Its actually two 16 amp circuits, each capable of three inverters.  I have five inverters total so three on one circuit and two on the other. 

Here I have all of the inverters mounted and wired up, the AC sub panel with a two-pole 50a MCB main and two 16 amp MCB's for the two buses.

Just a close up of two inverters, no grounding hooked up yet.

Main underground feed to the sub panel.  Contains 4 conductor 8ga. I went with 4/8 so I had a full size ground and I wanted a neutral in case I put 120v lights or an outlet out on/near the array.

You can see the panel and microinverter grounds running to the ground bus.

6ga solid grounds ran to 2/0 ground bus.

2/0 Ground bus connectors, there are two 10' ground rods this
is the second one tying into the main ground bus.
Connectors are tin plated aluminum suitable for copper or al wire.

Just a shot from the yard.  This looks really crooked for some reason, not sure if the outside posts are due to lens distortion on the camera? But everything is LEVEL and straight I promise, you can see my property is on a hill, which also adds to the crooked effect LOL.

Ok now to trench for the underground cable.  I have to go about 240' at 24" deep (direct bury) on top of that I have to go under 30' of driveway...  Not sure if I'm going under or going to saw cut yet, I'll trench the rest first.

The funny Z shape is because I decided to go under the driveway, after I already started trenching on both sides of the driveway.

CALL 811 Before you DIG!    Actually don't call, use their website, otherwise you'll sit on hold forever.  This area I will have to hand dig. Here lies my power, gas, fiber, phone, water, AND cable TV lines.   Lots of stuff to tear up if I tried to use the trencher.  Little marker flags were all over the place!

Went to the local rental place, and rented this trencher capable of doing a 24" deep trench. First time using one of these puppies, should be fun.

Wow!  that was easy!   Started trenching from the array to the driveway.
My property is mostly sand anyway.

Trenched across my yard, trying to avoid big tree roots.
I got pretty lucky, only ran into one, and the trencher ate
right through it!

Crap, I didn't finish in time, our first snow..
Humm.... that's going to be an issue at my low 13 degree angle.

Now to go under the driveway, I wish I would have taken more pictures of this, but I didn't think it was going to work and I would have to saw cut..  But it did work!    I cut the end of SCH40 PVC conduit to look like a big hypodermic needle, then I made an adapter out of scrap PVC that let me put my garden hose on the other end.  I turned the water on and started shoving it as straight as I could under the driveway.  Once I was in about 3' I added another 10' section of conduit with the hose on the back again, kept pushing..  Huh this is easy!   I'm almost 20' in and its getting rough, its not pushing right through any more, I have the third piece of PVC conduit attached and I'm having to ram it through.  Pull it out a foot or two and ram it in, repeat.   This gets me about an inch each ram.  The last 10' section took about 45 mins, the whole process about an hour or so.  The picture above is when I finally made it to the other side!  To my surprise the bore was perfectly straight and popped out right where I had dug.  Not sure if I just got lucky? But I was expecting to dig all over the yard to try and find the other end.   

Laid the cable, and back filled the trench.

Back filled the trench.

Now on to getting the solar array cable into the house.  The utility requires a lever style safety cutoff switch.  I chose a heavy duty 60 Amp (AC/DC) stainless steel version.  I hate rusty enclosures. This is a two pole switch, but they just jumper the third pole for extra effort? I pulled the jumper it wasn't needed, just left one pole open.

All wired up, Labels installed.  Purchased the labels from PVLabels.com

Inside the house, My main breaker panel (top) was pretty much full.  So I added a sub panel (bottom) and moved all of the single pole breakers to the sub panel, kept all two pole breakers in the main panel, this includes the 50A solar back-feed breaker.

Sub panel where I moved all of my single pole breakers.  Was able to clean up some past owner double-taps and issues where they had moved stuff putting the L1 and L2 circuits that shared a neutral on the same L1 bus using the tandem breakers.  If you guys use tandem breakers and your house is piped with conduit they sometimes share a neutral you have to keep the reds on the red feed and the blacks on the black feed.   Or L1 with L1 feed and L2 with L2 feed.  Otherwise the neutral will take on double the rated load and could overheat and cause a fire.
Oh I also have my Sense power monitor mounted in this panel, the CT's are wired in the top panel to the main feed and the Array feed.

My NET metering is not enabled yet.  But I fired up the array for testing on Oct 14th.  The utility noticed I back-fed for like 4 hours, they came out to say hi.  lol  They actually wanted to see what was going on, they were aware what I was doing, I had already applied for net metering prior.   They said I could keep generating, it's free power for them lol.   Anyway, with no net metering yet, can you tell when I turned on the array in the graph above?  Net metering should get me down to almost a $0.00 bill I hope, and this is not even summer.   My power cost is $0.095/kWh 24-7 my net meter payback is the same $0.095/kWh 24-7

A view of my solar dashboard just starting out in the morning!

PART 2
03/01/2020

Additional 5.2kW (10.4kW Total)



Well I was pretty happy with my first 5.2kW, Though I have not had it for a summer yet, during the winter it has cut my bill in half.  I ran across some more solar panels at a great price, again through santansolar.com.  I saw these 96 cell 327 watt each SunPower E20-327 panels for under $100 bucks each and they were selling fast, so I ordered 16.  Pretty much free since I just received my tax credit from the first solar install I completed in 2019!  I just impulse bought $1k dollars worth of stuff...  and I'm not done, I have to install these things now!  What did I do lol....

Anyway, so I started drawing up things, figuring out where I would add them, calculating the costs of building the racking, buying more APSystems QS1 micro inverters.   I started downloading all of the spec. sheets on everything.  Then it hit me... Oh crap! These are 96 cell solar panels, they run at a much higher voltage, huh I hope the QS1 micro inverters can take it..  Looked into the spec sheet of the micro inverters, and......  NO the 96 cell panels Voc is 64.9vdc.  Oh no the QS1 can only take a MAX Voc of 60vdc.  I thought well that's not far off, but after some research that removes all of my MPPT's ability to adjust, and its not good for the micro-inverters.  Crap! I already ordered these panels and they are already on a train to my state...

So, I hit google looking for a solution, and not a lot of people make 96 cell micro-inverters, APSystems doesn't make one at all.  Looks like I'll have to go with a string inverter.  But I wanted to use micro-inverters due to their higher output and better efficiency, especially if one panel has issues or is shaded. Searching and searching for hours, I became a solar pro, lol.  From my searching a string inverter will be much cheaper, easier to hook up, but the shading issue still worries me.   I had already decided to go with SMA's SunnyBoy 5kW inverter, its pretty popular, and they have a cool "SunnyIsland" inverter that lets you add storage batteries later for a full off-grid setup if I loose utility power.  Reading every bit of technical document on the SMA website, I ran across the Tigo Energy TS4-O optimizers for about $35 bucks each.  These optimizers go on the back of each solar panel, and lucky for me the SunPower panels have the bases built in!   These TS4-O's make a string system act like a micro-inverter system, so if one panel is failing or shaded it doesn't affect the whole string. Great!  The SMA SunnyBoy inverter also has 3 MPPT string inputs, with 16 panels, I'll probably use two inputs for two different strings 8 on each.Ok, cool, so hardware taken care of:

16 x SunPower E20-327 Panels
16 x Tigo Energy TS4-O covers
1 x SMA SunnyBoy 5.0-US


Racking System

I originally designed the first "Pavilion" to be able to extend it lengthwise, but its already 32' long, this would make it more than 60 feet long, not sure how that will look, and how I will use that pavilion space. Well for far less cash I could add 5 beams to my existing header, and angle these further down for good winter coverage.


I put it to paper and came up with this quick drawing

4x4 its a little over 20' x 14' and angles off the back side of my pavilion. Gives us a little more shade for our hanging swings, future fireplace, and outdoor dining table. 

For this install instead of mounting the panels directly to the wood beams like I did for the pavilion roof, I decided to use aluminum uni-strut on top of the beams, and stainless steel solar panel clamps made for the task. 

Everything went up in one weekend by myself, so I don't have many pictures.  I can tell you I didn't sweat once during this install compared to the last one!



Here is what the final setup looks like, I still need to trim some of the long uni-strut, I'll try to add some more pictures of the electrical and string inverter once I tidy everything up. One thing to note in the thermal image of the whole solar array, you can see the difference between the top panels and the ones at an angle..  The Angled panels have an anti-reflective glass and shows as a very cold surface, where as the top panels do not and you can see the infra-red reflecting, nearby hot objects, off of the panels like a mirror.   Both of these solar panel brands were supposed to have anti-reflective glass but obviously the Q.Cells do not.

You can see in this thermal image that my "Solar Array" breaker is the hardest working breaker in my distribution panel, when its sunny out.  This may "look" bad but its not, the hottest spot is 100F which is only a little warmer than room temp, you can see the 4 main breakers at the top of the thermal image are warm as well. I am pushing this breaker to 80% of its rated value, which within specs for a 100% duty cycle load.