Ground Mounted, Wood Racking, Pergola 5.2kW Self Install - Looking for your input

[Pir8radio]

Hi, I was looking for your input good and bad on my self install. All info and pictures are on my blog post here: https://notallmine-net.blogspot.com/...r-install.html

Please be gentle, this is my first solar install, and my first Wood project. And..... GO!

[Ampster]

Nice installation. In my area a building permit is not required for a patio cover. Now I want to add some solar panels. Did your jurisdiction require a building permit for the Pergola or the solar panels? What state and/or county are you in?

[Pir8radio]

Nice installation. In my area a building permit is not required for a patio cover. Now I want to add some solar panels. Did your jurisdiction require a building permit for the Pergola or the solar panels? What state and/or county are you in?

It's funny you ask... I live 1.96 miles outside of the closest town, I'm in an unincorporated county.... I called the county and no I do not need a permit... GREAT.. got the posts in and solar panels installed, came home and there is a big red tag "STOP WORK!" from the town 1.96 miles away... Come to find out the town has jurisdiction in a 2 mile buffer zone around the town. Even though I cant vote or use any trash, leaf pickup, city water, sewer, or police services they still dictate what I can and can't do.. lol Well according to that towns code anything that is attached to the ground, has supporting posts, and has a covered top is considered a building. So I had to get building and electrical permits as if I was building a home or garage... I had to submit plot, building, and electrical drawings, pay for the permits... I'm an engineer so the autocad part was easy even though I was working from drawings on a napkin for myself.... A month later (hence my pictures going from sunny to fall/winter) they approved my install and gave me a permit, thankfully the building commissioner was all about renewable energy they didn't make me tear down what I had already put up, and they were pretty lenient with the install. Long story short I needed a permit when I didn't think I did.

[J.P.M.]

It's funny you ask... I live 1.96 miles outside of the closest town, I'm in an unincorporated county.... I called the county and no I do not need a permit... GREAT.. got the posts in and solar panels installed, came home and there is a big red tag "STOP WORK!" from the town 1.96 miles away... Come to find out the town has jurisdiction in a 2 mile buffer zone around the town. Even though I cant vote or use any trash, leaf pickup, city water, sewer, or police services they still dictate what I can and can't do.. lol Well according to that towns code anything that is attached to the ground, has supporting posts, and has a covered top is considered a building. So I had to get building and electrical permits as if I was building a home or garage... I had to submit plot, building, and electrical drawings, pay for the permits... I'm an engineer so the autocad part was easy even though I was working from drawings on a napkin for myself.... A month later (hence my pictures going from sunny to fall/winter) they approved my install and gave me a permit, thankfully the building commissioner was all about renewable energy they didn't make me tear down what I had already put up, and they were pretty lenient with the install. Long story short I needed a permit when I didn't think I did.

Any design calcs required ? External loads such as wind ?

Add: Why such a low slope on the array ?

[Pir8radio]

Any design calcs required ? External loads such as wind ?

Add: Why such a low slope on the array ?

None required for the permit. But the pergola is overbuilt, it could be a pole barn.... Low slope: I should have made it a little more steep but I originally went with a slope that would allow me to walk under the low end without hitting my head... I'm 6'5". I either would have made the tall end much taller or the short size much too short.. I wanted usability of the structure too.. The calcs i ran for the 13 degree angle didn't show too much loss in output, I figured I would be doubling the array size soon anyway, Or if i needed to make up for any of the loss i could go with higher wattage panels maybe...

[J.P.M.]

None required for the permit. But the pergola is overbuilt, it could be a pole barn.... Low slope: I should have made it a little more steep but I originally went with a slope that would allow me to walk under the low end without hitting my head... I'm 6'5". I either would have made the tall end much taller or the short size much too short.. I wanted usability of the structure too.. The calcs i ran for the 13 degree angle didn't show too much loss in output, I figured I would be doubling the array size soon anyway, Or if i needed to make up for any of the loss i could go with higher wattage panels maybe...

You get much snow ?

[Pir8radio]

You get much snow ?

Not really. I'ts low enough to broom it off from the ground, I intend on getting rid of any accumulation in the morning so I can keep producing. Why thinking the 4x6 rafters are not going to hold up?

[J.P.M.]

Not really. I'ts low enough to broom it off from the ground, I intend on getting rid of any accumulation in the morning so I can keep producing. Why thinking the 4x6 rafters are not going to hold up?

Since you ask:

I'm just not a big fan of wood frames/assemblies for panel arrays, but opinions vary.

I was wondering more about why low slopes in latitudes high enough to have snow when ground mounts can have higher tilts more easily than a fixed roof. I'd also wonder how long it will take for brooming from a ladder in snow will become a PITA.

Then, there's the deal about low slopes increasing the rate of panel fouling from dust/dirt, etc. when it's not precipitating.

I always figured one big advantage of ground mounts was panel accessibility. Being 6+ft. off the ground takes away some of that advantage from my perspective.

But, all that's NOMB. As long as you're having fun, and doing it safely, amen. Enjoy.

[bcroe]

That looks like a rock bottom cost system, ground mount is the way to go if practical. Others
write that treated wood is not good against aluminum, I put linoleum spacers between. Being
in sight of the road does make it more prone to inspections. Mine is surrounded by woods,
far from a road, county says I can build about anything short of a building without a permit.

Your getting under the driveway is impressive, I am just concerned about
getting under a really big tree root I would rather not cut.

I just finished cleaning the snow off a hundred plus panels, not difficult because of snow rejection
features. Read about that on the STICKY Snow Tolerant PV Mounting. You may find snow
clearing a lot of trouble, but that could be changed.

That wiring is just too neat. A lot of it, that is part of the price of using micro inverters. Note how
little is on this 6KW string array with high voltage DC. My estimate is you will lose around 6V in
the long feed, some 2% which is around double my DC losses on a much longer run. Can you
check that all components are performing? Mostly done with a clamp on ammeter here.

I threw some 12-2 direct burial wire in the trench for convenience outlets seen here (and for an
electric fence). good luck, Bruce Roe

TreTerm2.JPG

[Pir8radio]

That looks like a rock bottom cost system, ground mount is the way to go if practical. Others
write that treated wood is not good against aluminum, I put linoleum spacers between. Being
in sight of the road does make it more prone to inspections. Mine is surrounded by woods,
far from a road, county says I can build about anything short of a building without a permit.

Your getting under the driveway is impressive, I am just concerned about
getting under a really big tree root I would rather not cut.

I just finished cleaning the snow off a hundred plus panels, not difficult because of snow rejection
features. Read about that on the STICKY Snow Tolerant PV Mounting. You may find snow
clearing a lot of trouble, but that could be changed.

That wiring is just too neat. A lot of it, that is part of the price of using micro inverters. Note how
little is on this 6KW string array with high voltage DC. My estimate is you will lose around 6V in
the long feed, some 2% which is around double my DC losses on a much longer run. Can you
check that all components are performing? Mostly done with a clamp on ammeter here.

I threw some 12-2 direct burial wire in the trench for convenience outlets seen here (and for an
electric fence). good luck, Bruce Roe

I guess one of my worries more than the long cable run, which I oversized anyway, was going with a string and loosing efficiency there, for example if one panel outputs less the whole string is pulled down. Like in this image, if I was on a string 162watts out of my weakest panel would hurt my output. Plus I can upgrade one panel at a time if for some reason I wanted to slowly start switching to higher wattage panels.

thanks for all the info, that’s what I’m looking for to make my system better! I’ll checkout the sticky thread too.

950F6D67-28B4-43CA-BC95-176C603398CF.png

[Pir8radio]

Any other input?

[Buck Rogers 2000]

It seems to me you thought it through pretty well. Congratulations! My only potential improvement has already been mentioned...the angle. If there was some way to add adjustment brackets (and figure out what you want to inhibit corrosion) it would improve things a little.