Mount panels on Solar Pergola ? Anyone know a cheaper method for bifacial panels?

[BrickedKeyboard]

What I have noticed is that a residential solar install has all these unnecessary people with their hands out. The solar install company, the local county code, the power company, and the local guild of electricians at a minimum. And yet signature solar will sell us bifacial panels for dirt cheap, about 50 cents a watt not even including the contribution from the back side. Apparently the bifacial panels are exempt from a tariff, so they cost about the same to USA buyers.

So I had an idea: buy this. (about $400). Mount aluminum frame rails to the Pergola structure and panels to the frame rails.


Or, since the actual panels are about 6.8 feet long so you need about a 14 foot pergola, these:

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No roof to mess up, no middlemen to pay. Put your batteries and inverter and stuff into a metal shed or even cheaper,

30 inch hot water heater enclosure. ($168). One, maybe 2 of these next to each other depending on how many inverters/batteries you need. Use outdoor subpanels and install this setup near your main power input.

"BuT YOu NeeD a PerMit!". Maybe. You won't be selling any power back to the power company, they won't know you have this, and it's a myth that homeowners insurance won't pay if unpermitted work starts a fire. They almost always will pay or they would never pay - most areas of the USA, your neighbors have tons of unpermitted work, and licensed tradesman usually don't get permits even when they are required. This is not legal advice, your area may vary. (where I live I can see whole sections of a house added next door, permit free, somebody unlicensed rewired all the outlets but didn't install a ground, didn't torque down the screws, has run cables everywhere without conduit or protection, and so on. If this place burns down it will likely be from that and not this.

 

[crossy]

Yeah, I know the feeling, the "official" mounting hardware is $$$.

Here in sunny Thailand we went with steel on our steel-framed car port, cheap and works well. https://diysolarforum.com/threads/our-10-6kwp-grid-tie-hybrid-system-in-sunny-thailand.28321/

Watch your wind-loading, panels are a big, flat, not very aerodynamic lifting surface, you don't want the panels trying to emulate the ISS in a blow!

Our 12m x 6m car port is held down by 6 x 0.5m cubes of concrete buried in the ground. It's gone nowhere in the 6 years it's been up and we get some pretty blowy storms here during the monsoon season (but no tornados or hurricanes).

 

[schmism]

depending on your local jurisdiction any kind of "structure" to hold the panels is likely to draw the attention of the local building officials.

In my area with snow loads and thunderstorm wind loads I would not trust the pergola structure you listed to adequately support the panels.

Bi-facial unless you use the correct mounting orientation are going to produced about half the sticker watts. so that .50 a watt (sticker watts) turns into $1/w actuall output which no longer makes them competitive for "standard" installs.

 

[BrickedKeyboard]

depending on your local jurisdiction any kind of "structure" to hold the panels is likely to draw the attention of the local building officials.

In my area with snow loads and thunderstorm wind loads I would not trust the pergola structure you listed to adequately support the panels.

Bi-facial unless you use the correct mounting orientation are going to produced about half the sticker watts. so that .50 a watt (sticker watts) turns into $1/w actuall output which no longer makes them competitive for "standard" installs.

Ok the first part: I'm telling you in some areas like where I live, those officials are nowhere to be found. I look to the house to my left. "huh that guy seems to have slapped on a crappy extra building". I look right " wonder if he got a permit for that, don't see how".

So when do they get caught. As I understand it, they never will. In the current market, the seller can just say 'no inspections, take it or leave it' so the buyer won't know about the poor workmanship. And the local officials will never at any point check. Only way you get caught is if they somehow come by when you are building it.

For the second part: sure.

For the third part: I understand this is totally false. That the sticker watts are only for the primary face.

 

[bones1]

I understand where you are coming from. Permit hell. That's why I am looking at mounting my panels on two flat utility trailers I rarely use anymore. Portable, I can aim them where I want to and no permits are needed as it is not grid-connected. A few things to consider:
1. Is the large drop in power consumption per month using my solar going to send up a red flag on my smart meter causing a visit?.
2. This housing market, along with other institutions, will collapse very soon so we won't see buyers standing in line and willing to pay cash for our homes anymore. Folks will have to get an old-fashioned mortgage if available, which has always required a home inspection report to qualify for the loan. I thought about pergolas etc too then decided I want to take the inverters and panels with me if I have to scoot. Two LV 6548's and wiring mounted on one 4x8 sheet with 6 Zeus fasteners holding it on the wall and 50A receptacles to the cells and breaker panel. Battery using big Anderson quick connects.

 

[BrickedKeyboard]

Note that if you put in slightly more effort the inspection will pass. Home inspectors don't go to the city permit office and pull the records.

 

[Koert]

I've been waiting for the new semi-transparent solar panels to become available in California, but no luck yet. They'd be perfect for a solar pergola.

 

[bones1]

I've been waiting for the new semi-transparent solar panels to become available in California, but no luck yet. They'd be perfect for a solar pergola. View attachment 92508

That would be perfect.

 

[BrickedKeyboard]

I've been waiting for the new semi-transparent solar panels to become available in California, but no luck yet. They'd be perfect for a solar pergola. View attachment 92508

What does this do to the efficiency? In penciling in the numbers I noticed that actually the cost of the pergola, or some other mounting solution, is a substantial cost compared to the panels themselves.

 

[Rocknemo]

depending on your local jurisdiction any kind of "structure" to hold the panels is likely to draw the attention of the local building officials.

In my area with snow loads and thunderstorm wind loads I would not trust the pergola structure you listed to adequately support the panels.

Bi-facial unless you use the correct mounting orientation are going to produced about half the sticker watts. so that .50 a watt (sticker watts) turns into $1/w actuall output which no longer makes them competitive for "standard" installs.

I'm wondering why you say that about the Bi-facial's, have you seen Will's video when he did a review on them and he had them laid out flat on the ground, they pulled very impressive numbers.

 

[ko6kL]

depending on your local jurisdiction any kind of "structure" to hold the panels is likely to draw the attention of the local building officials.

In my area with snow loads and thunderstorm wind loads I would not trust the pergola structure you listed to adequately support the panels.

Bi-facial unless you use the correct mounting orientation are going to produced about half the sticker watts. so that .50 a watt (sticker watts) turns into $1/w actuall output which no longer makes them competitive for "standard" installs.

in my county, anything like a tuff shed that is less then 10x10 is no permit needed... pretty hard to get them to inspect and enforce anything... most problem will be at time of home sale.

 

[ungrounded]

What I have noticed is that a residential solar install has all these unnecessary people with their hands out. The solar install company, the local county code, the power company, and the local guild of electricians at a minimum. And yet signature solar will sell us bifacial panels for dirt cheap, about 50 cents a watt not even including the contribution from the back side. Apparently the bifacial panels are exempt from a tariff, so they cost about the same to USA buyers.

So I had an idea: buy this. (about $400). Mount aluminum frame rails to the Pergola structure and panels to the frame rails.

View attachment 88372
Or, since the actual panels are about 6.8 feet long so you need about a 14 foot pergola, these:

Wayfair.com - Online Home Store for Furniture, Decor, Outdoors & More | Wayfair

Shop Wayfair for A Zillion Things Home across all styles and budgets. 5,000 brands of furniture, lighting, cookware, and more. Free Shipping on most items.

www.wayfair.com

View attachment 88374

No roof to mess up, no middlemen to pay. Put your batteries and inverter and stuff into a metal shed or even cheaper,
View attachment 88373
30 inch hot water heater enclosure. ($168). One, maybe 2 of these next to each other depending on how many inverters/batteries you need. Use outdoor subpanels and install this setup near your main power input.

"BuT YOu NeeD a PerMit!". Maybe. You won't be selling any power back to the power company, they won't know you have this, and it's a myth that homeowners insurance won't pay if unpermitted work starts a fire. They almost always will pay or they would never pay - most areas of the USA, your neighbors have tons of unpermitted work, and licensed tradesman usually don't get permits even when they are required. This is not legal advice, your area may vary. (where I live I can see whole sections of a house added next door, permit free, somebody unlicensed rewired all the outlets but didn't install a ground, didn't torque down the screws, has run cables everywhere without conduit or protection, and so on. If this place burns down it will likely be from that and not this.

I mounted mine on a 40ft container that I use for storage. I have a patio awning that I am rebuilding to accommodate more panels. The roof will be panels. This is all off grid stuff. I dont connect anything to the grid nor to my roof.

 

[watchdoc]

I live in one of the least solar friendly counties in the state of NC. Permitting is a nightmare and netmetering here is a joke. That being said, with a small system like you are talking about, build a small DIY system on a shed, pergola, or portable ground mount and keep your mouth shut. If you want to be more official, have a generator manual transfer switch installed with a permit PRIOR to installing your solar system. That way if you ever get called out, just declare the whole thing a "solar generator".

 

[Rusty959]

For me permitting was easy. Just drew up some plans, probably paid $100, and they came by to check my work after. No big deal really. Utility was more annoying but that's not what's being discussed here.

 

[42OhmsPA]

View attachment 159881
For me permitting was easy. Just drew up some plans, probably paid $100, and they came by to check my work after. No big deal really. Utility was more annoying but that's not what's being discussed here.

Very nice!
That's one hell of an awning!

 

[Rusty959]

If anyone's curious, I got a few different plates plasma cut and most of my steel cut perfectly to length, even with the angle cuts, from a local steel place. Made it super easy, I just had to weld it all up.

I love the span doing it in steel like this allowed. That's a 24' spacing across the long side, and I have perfect openings for the bifacial panels with a decent seal using weather-stripping.

This is a bit of a big boi I realize so I still spent a decent amount in steel and concrete, but relative to other mounting methods all I'm saying is dont count out just snagging some beefy steel locally to you, it might be cheaper than you think.

I've got a timelapse of it, I'm pretty sure I can post it here since it's not monetized and doesn't have product placement?

 

[Rusty959]

Here's what I paid in steel. This doesn't include the 4x4 horizontal braces, I got that from another place locally. Wasn't originally planning on that design, was originally going to be 1x3's as part of a fence.

 

[MarkSolar]

Here's what I paid in steel. This doesn't include the 4x4 horizontal braces, I got that from another place locally. Wasn't originally planning on that design, was originally going to be 1x3's as part of a fence.

That is a higher cost than I would have expected. I paid $3200 for a ground mount system that's about 2-1/2 times that size, the big difference being yours is much taller and the span is larger. I have supports every ~9' and the front edge is only 40" off the ground. Curious how you attached the panel frame to the rails and how you insulated for galvanic corrosion between steel and aluminum.

Not sure how far south you are in Indiana, but if you get much snow, doesn't it collect in that V space between garage roof and panels?

 

[Rusty959]

That is a higher cost than I would have expected. I paid $3200 for a ground mount system that's about 2-1/2 times that size, the big difference being yours is much taller and the span is larger. I have supports every ~9' and the front edge is only 40" off the ground. Curious how you attached the panel frame to the rails and how you insulated for galvanic corrosion between steel and aluminum.

Not sure how far south you are in Indiana, but if you get much snow, doesn't it collect in that V space between garage roof and panels?

The big difference between the costs is that mine is taller and the span is larger. That 9" C channel that allowed the full span was expensive. Over $500 each. I also didn't use the $442 worth of 3x1 that was to be used by the fence. I don't doubt I could have saved a lot of money even more time if I went with a standard ground mount and only had to deal with a 9' span, but that's not the point of this thread. Dual purposing structures, especially with a bit more intention than I placed with mine, can help people turn a blind eye to the existence of a solar addition in the first place. Lucky for me that wasn't really a goal, and certainly seems have not been for you either since you have a ground mount which are generally unmistakable.

For galvanic corrosion I used some thick layers of rustoleum, stainless steel hardware, and a bit of hopes, dreams, and ignorance. I should probably get up there and check how they're doing, that's a good point you bring up.

There's a ~6" gap that snow easily falls through. I have a gutter that's been waiting to be installed for 2 years which will cause it to pile up, but we don't get enough snow that I'm really all that worried about it. I'm net metered so missing a day or two won't cause problems like if I were off grid. At 25° snow tends to blow off a lot more than collect. I think this was a 10+" snow.

 

[Texas-Mark]

In penciling in the numbers I noticed that actually the cost of the pergola, or some other mounting solution, is a substantial cost compared to the panels themselves.

But if one actually wants a pergola, then there is no real extra cost.

FWIW, I picked up two 10x10 metal frame pergolas from At Home for $250 each when they had a big sale. At some point, panels will be going on them. I also drove 8ft T-posts into the ground and then dropped the frame studs over them. It's not going anywhere.