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This looks pretty awesome, but any reason you don’t use these in a central location to make foldable preassembled racks, instead of transporting the factory to

by ericd 3y ago

This looks pretty awesome, but any reason you don’t use these in a central location to make foldable preassembled racks, instead of transporting the factory to the site? Seems like you could fold them like an accordion into whatever max size can be carried by a forklift, drop them in place, pull them out to unfold, screw the whole prewired assembly down with ground screws, and plug it into the neighboring assembly? This would probably work best with E/W racking, would go from tightly packed to corrugated. I’m sure there are challenges I’m not considering, but with modules getting insanely cheap, it seems like racking/assembly/inverters are starting to dominate, and scaling up from single modules to full assemblies assembled in factories seems like a good next step. (I’ve been building my own 20kw ground mount array, so I’ve had plenty of time to daydream about something we could’ve just dropped and pulled out)

deleted 3y ago
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justicz 3y ago
Hey thanks! The trouble with the origami racking approach is that the engineering decisions you make to build a portable, foldable racking system go in some different directions from what makes the best hardware for long-term, large-scale installations. A couple of ways this shows up: 1. making your system rugged to handle extreme weather. These sites need to last 30-40 years without breaking, which pushes you to use pretty heavy + large components. Piles get driven several feet into the ground, so even with unfolding systems you're still probably pile driving. 2. tracking -- adding the complexity to enable rows to rotate to face the sun makes it harder to make the system portable. Basically all large-scale solar getting built is single-axis tracked. 3. module cleaning -- it's important that vehicles can traverse rows to clean dirt off of modules on a regular basis. Having structure that connects the rows together may make this more difficult. None of these are intractable on their own but together they make the approach you describe very difficult.
- ericd 3y ago
  Thanks for going through that! We used aerocompact, with 18” ground screws/anchors (a lot of them), and their engineering plans for our anticipated wind load didn’t even require all possible ground screw spots to be filled, so it seems like piles might not be strictly necessary? With panels getting so much cheaper, is tracking necessary still? Maybe if land is at a premium, but I know the aerocompact commercial deployments don’t support tracking.
  - justicz 3y ago
    Fascinating! My initial thought is that this is going to be very soil dependent. Is this the system you were using? Was it ballasted? https://www.aerocompact.com/en-us/products/ground-mount https://www.aerocompact.com/en-us/products/ground-mount
    - ericd 3y ago
      Yeah, we used the g20 south-facing ground mount, no ballast, about 40 18” ground screws for a 48 panel array (relatively small 108 cell panels). Soil is clay, for reference, not very rocky, so might be unusually well suited for the screws. Easy to drive with a socket wrench or impact wrench, 1” heads.
- mxfh 3y ago
  30+ years sounds excessive for managed installations (anything thats not just sitting inaccessibly on a roof with prohibitively expensive access costs), would think max 10-20 years, if you have the option to upgrade some higher efficiency panels for maintaining best ROI given current trends continue and land being a cost factor in most regions.
glumreaper 3y ago
Your description almost exactly matches the Maverick solar array produced by the Aussie company 5b (https://5b.co/ https://5b.co/) - you are definitely on to something. Factory assembly and field deployment is a far faster, safer, and higher quality method of building solar farms.
- ericd 3y ago
  Ha awesome, that looks almost exactly like what I was imagining. I guess it was somewhat obvious to anyone who’s used racking like the one I used and thought about it. I wonder how well their system works in practice, but I can’t imagine it’s less efficient than positioning/attaching these things and wiring them up in the field, and then crawling under and tucking tons of wires away with painful little clips. Now that that’s taken care of, we just need some way to get the interconnection queues moving faster :-)

by ericd 3y ago

deleted 3y ago

[deleted]

justicz 3y ago

Hey thanks! The trouble with the origami racking approach is that the engineering decisions you make to build a portable, foldable racking system go in some different directions from what makes the best hardware for long-term, large-scale installations. A couple of ways this shows up: 1. making your system rugged to handle extreme weather. These sites need to last 30-40 years without breaking, which pushes you to use pretty heavy + large components. Piles get driven several feet into the ground, so even with unfolding systems you're still probably pile driving. 2. tracking -- adding the complexity to enable rows to rotate to face the sun makes it harder to make the system portable. Basically all large-scale solar getting built is single-axis tracked. 3. module cleaning -- it's important that vehicles can traverse rows to clean dirt off of modules on a regular basis. Having structure that connects the rows together may make this more difficult. None of these are intractable on their own but together they make the approach you describe very difficult.

ericd 3y ago
Thanks for going through that! We used aerocompact, with 18” ground screws/anchors (a lot of them), and their engineering plans for our anticipated wind load didn’t even require all possible ground screw spots to be filled, so it seems like piles might not be strictly necessary? With panels getting so much cheaper, is tracking necessary still? Maybe if land is at a premium, but I know the aerocompact commercial deployments don’t support tracking.
- justicz 3y ago
  Fascinating! My initial thought is that this is going to be very soil dependent. Is this the system you were using? Was it ballasted? https://www.aerocompact.com/en-us/products/ground-mount https://www.aerocompact.com/en-us/products/ground-mount
  - ericd 3y ago
    Yeah, we used the g20 south-facing ground mount, no ballast, about 40 18” ground screws for a 48 panel array (relatively small 108 cell panels). Soil is clay, for reference, not very rocky, so might be unusually well suited for the screws. Easy to drive with a socket wrench or impact wrench, 1” heads.
mxfh 3y ago
30+ years sounds excessive for managed installations (anything thats not just sitting inaccessibly on a roof with prohibitively expensive access costs), would think max 10-20 years, if you have the option to upgrade some higher efficiency panels for maintaining best ROI given current trends continue and land being a cost factor in most regions.

glumreaper 3y ago

Your description almost exactly matches the Maverick solar array produced by the Aussie company 5b (https://5b.co/ https://5b.co/) - you are definitely on to something. Factory assembly and field deployment is a far faster, safer, and higher quality method of building solar farms.

ericd 3y ago
Ha awesome, that looks almost exactly like what I was imagining. I guess it was somewhat obvious to anyone who’s used racking like the one I used and thought about it. I wonder how well their system works in practice, but I can’t imagine it’s less efficient than positioning/attaching these things and wiring them up in the field, and then crawling under and tucking tons of wires away with painful little clips. Now that that’s taken care of, we just need some way to get the interconnection queues moving faster :-)