Ground Mount Help

[erik.calco]

Good, so you can make the prototypes and post pics for us later?

Probably. Can use the 100W as my prototyping victim.

 

[Santa]

There SURE IS!
And the OP wanted my cobbled up BAD ideas!

That racking, 90° angle, 'U' Shaped, or full box is a deal on wheels when you DIY!
Since solar panel racks are 'Around' or 'About' This Angle or That Angle, the pre drilled holes are 'Close Enough',
We aren't launching a Mars mission here...

Just a couple days ago a guy was complaining about having to buy a $400 digital angle finder...
I use a plumb line (string) and $1 plastic protractor from the dollar store.
If you are a carpenter, my speed square has a 90° scale on it, and a hole for the string line was easy, I own drill bits...

Carpentry USED to be done with a string & weight (plumb-bob) for vertical, a string and bubble (spirit) level for horizontal, and 2, 3, 5 measurement for square (measuring stick).
While digital this and laser that works, it's not cheap or easy...

Square, 2 inches or feet (respectively) one direction, 3 inches or feet (respectively) the second direction, when 5 is the distance between the marks the corner is square...
Gravity ALWAYS pulls a plumb-bob weight straight down, no matter what the ground is doing...
A stretched string is ALWAYS a straight line...
Clear tubing with colored water in it, the two ends will ALWAYS equalize, no matter the distance, to show you horizontal level...

Gravity never fails, the batteries don't go dead, getting dropped never throws it out of adjustment, it never gets bent, or left at the shop...

Long carpenter Bubble levels are nice, but OFTEN too long, too short, won't fit, got left at the shop, etc.
A string & weight in your pocket doesn't get lost... Try putting a 4 foot long level in your pocket to plumb posts with...
You don't NEED $2,000 worth of 'Digital' to build a $100 rack.

Extruded aluminum rails, custom machined clamps, etc are 'Nice', but proprietary.
A bolt instead of a weld replaces/adjusts with hand tools, no cutting or welding machine required, a drill/bit at most to change things.

Try and find EXACTLY what you need 10 years from now when the 'Nice' has changed design and old parts are no longer available...

Build tall.
You can mow under it, it doesn't crack you in the head, and as long as it's braced, just as study as surface mount.
Want to weigh something down? Set your posts in 5 gallon buckets of concrete.
You can mix 5 gallons from bags in a tray with a garden hoe, and if you buy that 5 gallon bucket (wider hole) it will take a bulldozer to get that anchor out.
Disposable plastic concrete mixing trays are $7 at the big box stores...
(Bags of cement weight 80 to 100 pounds! I blow a tube trying to carry them around!)

A wide hole, 6 or 8 inches of concrete in the bottom, a long cross bolt through the bottom of your post to engage the concrete, and then dirt back in the hole to surface, it's an anchor that's actually stronger than pouring a skinny post hole full of concrete all the way to the surface.
I don't even use a long bolt anymore, just drill a hole and stick rebar through the hole at the bottom.

It's up to you, I don't know your situation...
In hurricane country I would build stronger,
In tornado country, if it's strong enough to stand upright in a strong storm, it's good enough.
Tornado force winds (up to 300 mph) will fold panels no matter how well your braced, while hurricanes push on panels...

Tornados exceed the strength of the glass, and there is nothing you can do about that except replacement cost insurance, it's nature and only fools think you can outsmart nature...
My panels are wired to the weather station, when winds exceed 40 MPH the panels go flat, like for noon day sun, and then you just HOPE it's not 'The Big One'.

With tall angled rack, trees or some wind break BEHIND helps a lot.
If the wind can't get under the panels, you will probably be OK.
Again, in a tornado, which comes from the West, all bets are off since you will go broke trying to build a tornado proof rack, nothing stands up to an F4 or F5 that's not a solid monolith...

What's a weather station?

 

[JeepHammer]

What's a weather station?

This is a modern version, mine is an old one from Radio Shack.

Wind speed, direction, temp & humidity.
I got mine because it had a buzzer you could preset for wind speed, I used that buzzer feed to trick the panels into thinking the sun was overhead, so they go flat/horizontal on the post & pipe installs.
That's the minimum wind resistance position.

Just hacking around seeing what worked and what didn't... That was something that worked (a bunch didn't).

 

[JeepHammer]

Depends on what you decide on...
Notice I don't speak in absloutles, the design has to fit YOUR situation, odd corners in property lines, codes about how far things have to be away from property lines, buildings and right of ways, etc.

The two biggest mistakes I made...
1. Too close to the ground.... WEEDS!
I HATE hand trimming, so panel rack version 2.0 came up off the ground far enough I could mow under it.
I use a big rider mower deck, and it throws rocks, dirt, sticks, what ever is around.

Just the shade from tall grass reduces panel efficiency dramatically...
Let some broad leaf weeds get started and you will have a constant fight on your hands, weeds growing faster & taller than grass...

I made the mistake of using English ivy for landscaping to cover some of the structure,
I'm still fighting that mistake 15 years later, not even ground killer takes out English ivy...

Bushy evergreen BEHIND the panels are OK, make a good wind break, but NOTHING in front!

2. Didn't kill the ground under the array.
Doesn't matter if you put down a ground sheet (usually plastic) and put gravel down (gravel comes back up),
Weeds STILL germinated in the rock...

*IF* you want to make it DEAD, the ONLY way I found is white rock and cast water softener or rock salt in the gravel.

.........

Two novel uses of that space...
A couple I helped a few years back turned the space into a chicken coop!
The rack was pre-planned and the highest part in the back is a chicken coop up off the ground.
The guy built pull trays to go under it so he could clean it.
A LOT of work (I didn't have to do! ) But the results were fantastic.
What crossed my mind was a power station building for someone that can stop over when something needs fixed.
(I can't stoop or squat, bad back)

What I finally did was use leaf mulch and grow mushrooms under mine.
Boxed in the ends, planted evergreens behind the panels, and cast mushroom spores, and they grew like crazy.
I consider it another income stream from the panels, some mushrooms go for big money.

I can't sell it as a home game, strictly a homestead thing...
Heavy framing, and if you plan posts at 4 or 8 foot, plywood/sheeting is pretty easy.
Screwing metal roofing UP instead of down took some getting used to, but you can make it rain tight enough for inverters, batteries, etc, chickens, mushrooms, the garden/lawn tools, etc.

I got the idea from the livestock shelters people weld up out of oil well pipe around here, or you could use treated lumber...
The rack on skids, just a big footprint to height ratio,
Anything on skids is NOT a 'Permanent Structure' or 'Dwelling' according to the state property tax laws..
That means NO INCREASE in property taxes, and I have taken full advantage of that.
I don't pour concrete footers anymore, I frame build and use screw in anchors to hold it down, NO PROPERTY TAXES!

Where 'Code' gets in the way in towns, we have taken to building 'Trailers'...
Doesn't matter if the wheels are actually functional, it has wheels and a ball hitch receiver (2"x2" ID tubing about 6" long) welded on the front,
And we pay $35 dollars to the DMV and get a 'Home Made' trailer VIN.
Now it's a 'Vehicle', no property tax, and trailers don't have to be tagged when they are 'Utility'.
All loopholes jumped through, now we can park them next to property lines, buildings, right of ways, places a standing rack couldn't be built.

If that 'Trailer' never gets on the highways, it can be wider than the 96" or 102" wide laws...
I've built than with fold out platforms on the sides to make them wider, the screw in anchors simply go on the corners like any other frame.

I built a couple 8-1/2 wide, 16 long deck trailers for job sites with batteries, inverters etc with a row of panels on top and bottom that hinge, fold out, once it's on the job site.
6 rows long and 6 rows high of sideways panels facing south will produce a LOT of power (and no noise) on the job site.

I just hate wasted space and anti-solar laws...

 

[JeepHammer]

GONE RANDOM AGAIN!

Solar 2 hole outhouse!

Pre-Built Shed?.... ?

Missed opportunity?... Maybe.
It CAN be added onto as budget/consumption increases.

First off, two posts INSIDE to support roof ridge (peak).
Should probably throw down 1 ft.sq. or 18" square pavers and run posts all the way down to pavers through floor.

A sloped 'Lean-To' side, deck for solar panels, shade/weather protection for 'Stuff'.
'Lean-To' is for solar, so the angle will look 'Weird' to most people...

Widens footprint so the shed withstands wind it's not designed for with panels attached.
Wind WILL twist/wrack those little buildings, opening corners, buckling roofs, pulling nails, etc.
The BEST anti-wrack is plywood sheeting all the way around on the interior walls, it SERIOUSLY STIFFENS the building... Use SCREWS, not nails to hang plywood.

Two upright (short) posts, cross beams between posts, about 6 long runners from roof peak to posts,
Roof decking.
Expand solar panel mount room, increased stability, added room for 'Stuff', shading for the 'Sun' side of the building keeping it cooler.

I would stop about 2 or 3 feet from the ground.
With hinges on roof line, the deck could be raised/lowered at posts for sun angle.
With hinges at the ridge line, the runners can be extended beyond ridge line, room for another row of panels past the peak of the roof.

For those wanting a solar shack (like Will has a thread on) this allows for expansion as your demand increases.
For us 'Tinkering' types, someplace to unload pieces & parts for future expansion/projects is good, even a small 'Shop' is solid gold, and as this expands, it's the base of operation for the solar/wind/hydro or whatever.

It doesn't have to be high dollar or wasted space, and it's only limited by imagination....

 

[erik.calco]

Depends on what you decide on...
Notice I don't speak in absloutles, the design has to fit YOUR situation, odd corners in property lines, codes about how far things have to be away from property lines, buildings and right of ways, etc.

Yeah, I was looking for building blocks -- or options -- and, you gave me a TON! I do have a problem with weeds on the paver patio I built, but primarily because I need to fix my pressure washer. I need to replace the carb. If I get that going this year, I can clear out the weeds, then re-apply polymeric sand for a few years of peace before I have to repeat it.

Now I know why I get these giant white soccer ball sized mushrooms. LOL None of the leaves that fall leave my back yard. I collect them and put them it in one of several locations.

I did build a dog house I never actually took outside to complete. The only problem with adding a structure like that is the rabbits will have another place to nest underneath it, and my dog already goes nuts hunting them. Rabbits are not the smartest critters.

I could create a location for firewood. I'll likely leave it open in the beginning until I get used to where I need to reach to adjust things, so I don't initially block things off. But, you're right that I'll have to plan the height to take into consideration what will be underneath it. One thing for sure is that the dog will pee on anything below 2'.

 

[JeepHammer]

Yeah, I was looking for building blocks -- or options -- and, you gave me a TON! I do have a problem with weeds on the paver patio I built, but primarily because I need to fix my pressure washer. I need to replace the carb. If I get that going this year, I can clear out the weeds, then re-apply polymeric sand for a few years of peace before I have to repeat it.

Now I know why I get these giant white soccer ball sized mushrooms. LOL None of the leaves that fall leave my back yard. I collect them and put them it in one of several locations.

I did build a dog house I never actually took outside to complete. The only problem with adding a structure like that is the rabbits will have another place to nest underneath it, and my dog already goes nuts hunting them. They are not the smartest critters.

I could create a location for firewood. I'll likely leave it open in the beginning until I get used to where I need to reach to adjust things, so I don't initially block things off. But, you're right that I'll have to plan the height to take into consideration what will be underneath it. One thing for sure is that the dog will pee on anything below 2'.

I have a friend that his solar panels were randomly dropping in efficiency, completely random and never when he was home...
SO...
We went out and had a look.

DOG TRACKS on the panels!
When he left for work his big lab would go lay on the panels for some reason!
When he was home the dog laid on the porch... (GOOD DOG! )

We solved the issue with an electric fence for about a month, then just left the wire up and moved the charger,
But if the dog hadn't had wet feet from dew, that would have been one heck of a 'Problem' to track down!
He already had plans to send his big all in one inverter back for service having had looked at the panels, no dog tracks then, he was SURE it was the inverter/charge controller...

Another customer had chicken roosting problems, but he knew what was causing it.

One customer installed a drip watering line at the top of his panels (which I copied),
He had mulberry trees behind the panels, and the birds would fill up on mulberries and perch on or fly over the panels, releasing a TREMENDOUS amount of 'New Car Color' on the panels.
He hated dragging out 300 feet of garden hose, so I just installed a drip water line at the top and used a long handle mop to clean panels.
(Cheap LONG handles that aren't flimsy or stupid heavy, any Pool Supply store)

You asked for ideas, there is a blue million out there.

As for fire wood,
I saw a picture of this,
A guy had posts/beams/slanted roof sections, long and skinny, up off the ground 7 feet or so.
It was cover for fire wood being seasoned.
The roof became solar panels on a single pipe that rotated to track sun.
Posts were already there for the wood stacks, a pipe & panels and he was off to the races.

I saw a picture of a roof over dog kennels that got solar panels, a producing dog house, shade for the dogs.

It's all in what you have and how you use it...

 

[Steve_S]

@erik.calco Start with the basics first, find out what angles work best for you, not only the average (used in fixed mount) but also what the optimal is in summer & winter so you know what the deal is if you want to use a tilt system.
Get a quick angle calculation here: http://www.solarelectricityhandbook.com/solar-angle-calculator.html

You mention potentially installing on a roof, so it's good to know what the roof pitch is relative to the degrees. For example 45 degrees = 12/12 pitch and that's a pretty steep roof to clamber around on.
Figure out angle to pitch here: https://www.blocklayer.com/pitchangle.aspx enter the angle an hit that button it will convert it to pitch. Note the numerous construction calculations on that site, very very handy to have. Keep in mind that if your doing a porch or pergola the correct angles may not be appropriate for the structure your thinking, therefore there will be compromises and that usually means over-paneling (cautiously to compensate) or other alternatives to get production up.

On a ground mount system, there have been some good tips here but I really feel I should point out something quite obvious which is a bugger.. Ensure your high enough and setup in a way that when you mow the grass, or weed whack that there is no way that flying debris hits the panels... Obvious yes but under-estimated as weed whackers can toss crap far, not to mention a mower.... One possible option in tough spots is to use a commercial grade landscape cloth covered with either gravel or a good mulch to reduce maintenance and pesky weeds, or plant something a low growing persistent ground cover.

Anchoring can be done in a variety of ways, planting PT posts to concrete blocks or poured posts. My own rack is built off the side of my 20' Sea Container with marine dock hinges at the top (originally planned to pivot but not practical in location) and the bottom is anchored to a 4x4 structure which used screw piles (they anchor up to 5500 lbs pull and twist in by hand using an 8' 4x4. https://pylex.com/en/products/10505-pylex-regular-black I have used these for 4x4 and the commercial 66 (for 6x6) https://pylex.com/en/products/10730-commercial-pylex-66-black All my wood work is brown Pressure Treated and so all the screws and attaching hardware is appropriately galvanised or stainless steel to prevent any corrosion and deterioration. The racking I used is made by Kinetic Solar (Rapid Rail) and is amazing stuff to work with and damned near foolproof and it provides a run for the panels wires as well... http://kineticsolar.com/racking/ Now in order to protect / isolate the Aluminium feet from the PT wood I got an old tire tube (commercial truck, so very thick) and cut 2"x2" squares and put them between the foot base & the lumber and used Stainless Steel Bolts to attach to the frame.

We have a lot of solar installations out here of every variety you can imagine (some truly creative ones too) but one thing I came across is several use a BigFoot concrete form to anchor their ground mount racks http://www.bigfootsystems.com/index.htm the most common being that form is below ground and only comes to 1' above grade which then has a heavy duty galvanised anchor for a wood structure similar to what is shown (BTW Simpson is top notch)

 

[erik.calco]

I have a friend that his solar panels were randomly dropping in efficiency, completely random and never when he was home...
SO...
We went out and had a look.

DOG TRACKS on the panels!
When he left for work his big lab would go lay on the panels for some reason!
When he was home the dog laid on the porch... (GOOD DOG! )

I've been testing with my 100W, taking it out on occasion and bringing back in by the end of the day. I have the 320Ws, but I don't want to carry them in and out to test. So, they are safe until I build a mount for them. I set the 100W on the ground and prop up with a chair, the arms holding it in place.

I have a solar lab (black). There is nothing he loves more than a cool sunny day, where he uses the sun to stay warm. I caught him lying in front of the panel, casting his shadow on the lower part. He is very trainable, so haven't seen him do it since. But, that did make it clear that when I build a mount, they have to be at least 2' off the ground.

The only time he's not trainable is when I'm rarely out there, usually because it is too cold for me. He prefers 30-40F lower than I do, and loves being outside. So, when the weather gets nice for me in the Spring (70s), I might have to retrain him to not piss on my patio furniture and not crap near the patio. He understands English very well. I usually just have to tell him in a calm voice, and he's good.

 

[erik.calco]

Thank you, @Steve_S . You gave me some good anchoring tips. I have considered screw in post mounting anchors, but until this thread, have only heard of them being successfully used for mail boxes, and didn't know how much they could really handle. Watching that video, I'm not sure I understood the corrections he was doing, how he decided to take it up and back down to only 6 inches.

I unfortunately have a lot of roots from very big nearby trees and plenty of clay. I could never of excavated for my patio w/o the help of my nephews. IIRC we put in something like 3 yards of gravel and 1-1.5 yards of sand. That was 8 years ago and it is still very nice today.

I am comfortable with pitch, and would not use an off-the-shelf pergola design because it is not designed for a roof. Code considers PV to be a roof, and you add wind and snow loads. Thus, if I go the Pergola route, I'll try to incorporate structural features of a Pavilion, which is designed to hold a roof. The only reason I'd go the Pergola route would be so that if I remove the PV, it will appear to be a Pergola. Otherwise, I'd lean more towards a Pavilion design.

IIRC, the overall ideal pitch where I live is near 44 degrees. But, I do want the pitch to be adjustable. So, if I build a Pergola, there would have to be an additional pitch for PV mounting, ideally adjustable 4 times a year. If I can't achieve adjustable, I'll shoot for something near 45 degrees for the panels. One of the many learnings from JH is ideally I'd be able to flatten to 0 degree pitch on high wind days. In a freezing rain scenario, I might want a steep pitch. One year, a limb took out my tonneau cover of my truck because freezing rain made all the branches of trees very heavy, then big winds came. My whole street was a disaster zone, and by Sunday, our tree lawns were piled over 8 feet high with tree debris collected from that event. It was crazy just looking down the street that day with a giant wall of tree branches on every tree lawn for refuse collection.




I have also lived through some amazing wind storms that took down a ton of trees. In one, I was on the 31s floor of a building that was swaying so badly (by design) I almost fell out of my chair. The coat hangers were smacking the doors they were on. I watched the black clouds fly by the window at a crazy speed while my girlfriend on the phone told me to get away from the windows. I did hold onto a very big heavy desk. LOL. I can't help but watch, though, being obsessed with tornados as long as I can remember. On my way home that night, there wasn't a side street without a big tree that was down. My small street had 3 big trees down. One of the bars had its front window blown in, but the patrons were already as far back away from the window as they could get, so no one was hurt.

My primary concerns are about stability of the structure. These events are common enough where you have to figure you'll get a bare minimum of 4-5 tests of your structure over 20 years.

 

[Deleted member 783]

Just my two cents (all I have left after buying solar components), wood warps, splits, rots and fails. Steel, aluminum and concrete last forever if done correctly. I used 2 windy nation pole mounts on a 3.5" steel pole set in concrete. Then I bought 2 eight foot long aluminum extrusions, and modified the mounts to use the extrusions. 4x100 watt panels on there, and there is no reason I should ever have to mess with it. Cost about $300.





If you do use wood, I'd suggest treated wood and liberal use of Penofin. It will drastically extend the life of the wood.

 

[erik.calco]

I like that. How are you mounting the panels onto those rails? Please share picts when you do.

I'd like to focus on a mounting frame then go from there, and you look like you have that covered there.

I finally brought my inverter online yesterday, which is acting as a UPS, connected to AC for charging and AC out is going to a 10 circuit transfer switch. That frees me to focus on the mounts. I'm giving myself a due date of March. I have to focus on my software over next two months (my business), so will just casually play with ideas until then. I'm in the NE, so you don't feel like you're missing too much sun in Jan/Feb. But, my 320W panels are sitting there waiting to be used. I'll play with a 100W just to test any mount I create and learn from that. I'll try to bring 2 of the 320Ws online at a time, so I can learn before doing the next 2, adding each pair to the combiner box.

There are really only two high priorities.

1> Ensure that the wind does not bend the panel frames. Thus, I'll focus a lot on how I'll mount the frames.
2> Ensure the wind does not blow anything over. Thus, stable weight on it.

I'll try to avoid pouring concrete as I want a mobile structure for now. So, I'll build something that can move, then tie it down with earth ties and weight. If I can pop the panels out, I can move them inside for the worst wind storms, or perhaps flatten them if I can add that ability. I'll consider tilt in the design. Not likely to worry about tracking anytime soon. That could be an improvement in a future year.

 

[Deleted member 783]

Sure, Ill share pics when I get home. They have been mounted for a while. I was going to add a 3rd mount at the bottom but it's plenty strong enough, so I didnt.

 

[Deleted member 783]

I'll post the specific pics you want as soon as I get a chance.

 

[Deleted member 783]

This funky looking thing is an aluminum extrusion. Their shape makes them very strong, yet the are very light, being solid aluminum, and will never rust. They come in many different sizes and shapes, so it's important to shop carefully. Zoro Tools has a good selection of them. I purchased two of these, each eight feet in length. Total cost shipped $99 USD. Here is a link: https://www.zoro.com/search?q=aluminum extrusion



You can see the hole drilled in from the top, through the center. You can mount these to anything you can bolt through. I've used Windy Nation pole mount parts, because I had them. Otherwise, it would be easy to make your own with U-Bolts (if using a round post like mine) and aluminum angle or bar stock.

This picture shows the "T-slot nuts" and washers/bolt, and the following pictures show how it attaches. Simply run the bolts though the holes on your panels. In my case, the holes did not line up, so I drilled new ones. I flipped the panels over ON A VERY FLAT SURFACE and placed a little piece of scrap wood under the rail, so I didn't accidentally smack the panel with the drill bit.







I hope that helps, but if not, let me know!

 

[Santa]

This funky looking thing is an aluminum extrusion. Their shape makes them very strong, yet the are very light, being solid aluminum, and will never rust. They come in many different sizes and shapes, so it's important to shop carefully. Zoro Tools has a good selection of them. I purchased two of these, each eight feet in length. Total cost shipped $99 USD. Here is a link: https://www.zoro.com/search?q=aluminum extrusion

View attachment 4069

You can see the hole drilled in from the top, through the center. You can mount these to anything you can bolt through. I've used Windy Nation pole mount parts, because I had them. Otherwise, it would be easy to make your own with U-Bolts (if using a round post like mine) and aluminum angle or bar stock.

This picture shows the "T-slot nuts" and washers/bolt, and the following pictures show how it attaches. Simply run the bolts though the holes on your panels. In my case, the holes did not line up, so I drilled new ones. I flipped the panels over ON A VERY FLAT SURFACE and placed a little piece of scrap wood under the rail, so I didn't accidentally smack the panel with the drill bit.

View attachment 4070

View attachment 4072

View attachment 4073

I hope that helps, but if not, let me know!

you shouldn't have changed your name New Mexico Will!

 

[Deleted member 783]

you shouldn't have changed your name New Mexico Will!

Too many people thought I was Will, despite my title being "NOT THAT WILL". It's not fair to him; people thinking my posts were his. It makes him look really dumb

 

[erik.calco]

@Lost In The Desert That makes perfect sense and seems very affordable. Definitely something I can play with while prototyping. Thanks!

 

[Deleted member 783]

Glad I could help! For what it's worth, I plan to add 2 more of these poles, switch to 10' extrusions, and connect them for an 1,800 watt array.

 

[erik.calco]

Glad I could help! For what it's worth, I plan to add 2 more of these poles, switch to 10' extrusions, and connect them for an 1,800 watt array.

Did you get the bolts and t-slot nuts from Zoro, too? Can you link to the ones you have if you did? I found a bunch of t-slot nuts there, but not one matching your pict. And, I like the bolts you're using, with both hand tightening and allen wrench, which should be good for tight spots.