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Comment by walrus01 | Hacker News Reader

Ignoring for a moment the cost of inverters and storage...

With the cost of big-ass 400W solar panels as low as they are now, in the pallet load or container load, much of the cost is actually the labor and the mounting.

$150 per panel x 22 on a pallet = $3300

For a ground mounted PV system, you can easily spend far more than 3300 on the foundation work, concrete, steel erection and frame than the raw solar panel costs now. Randomly chosen 40kW theoretical would be $15000 in panels plus LTL truck cargo, the rest of the costs for a working system would be much more than 15k.

It's also possible for a roof mounting system to cost more than the panels in materials and labor and time.

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Which is why I am a fan of this simple idea, just put them flat on the dirt. Stick a fence around it to stop deer, and see what happens. One company is trying it[0]. I am not sure if water drainage, plant growth, whatever might be a problem, but for the cost of installation, seems worth exploring.

[0] https://electrek.co/2022/12/12/texas-solar-farm-flat-on-the-...

There is also this company [0] The founder is a friend of mine and they’re growing very quickly particularly across mining and remote sites in Australia.

Interestingly he said the efficiency loss from having panels mounted at the ‘wrong’ angle is essentially nothing particularly when you consider the increased density and reduction in site prep/installation. They can literally install a couple hundred kW in an afternoon

[0] https://5b.co/

If I'm understanding this right, it looks it comes packaged in a 40' ISO standard cargo container, then you use some piece of construction equipment to pull it sideways (on a skid?) out of the container, then pull the string lengthwise across the ground to unfold it to its full length.

The website says "shallow ground penetration" which sounds to me like some sort of anchors that are drilled into the surface then bolts run down into them (such as with a construction team using the largest size of battery operated Milwaukee hammer drills?), or similar.

https://5b.co/en/5b-maverick

Yep that’s pretty much it as far as I know. I think they’ve been floated as the deployment mechanism for the SunSolar/sunCable powering Singapore from the NT (…if that ever happens)

I think it comes in pretty useful at temporary sites and for disaster relief but not sure if it’s been deployed for that yet

With the cost of panels as cheap as they are these days it makes much more sense to buy more panels rather than spending lots of money on trying to have everything like a perfect 35 degrees south facing angle. Even on a house, if you have a north facing roof, put up a separate string on that side if the budget permits.

This is also why 2-axis and 3-axis tracker mechanisms are rarely seen these days, the cost of foundation/structure to build a thing on a concrete and steel pier that can 'steer' just six 1.65x1.0 meter size panels is extreme. It's like a big sail in wind loading so it takes a lot of steel and structure to resist that.

Hi, I've got a project that your friend's company would be perfect to help with - any chance of an intro?

Australian tech is so mining and property focused its crazy to me sometimes (especially here in WA)

reminds military pontoon bridge deployment.

There's a few different companies selling roof intended mounting systems that use weight/ballast to hold down panels at about a 20 degree angle (facing south, in the northern hemisphere), which are basically big plastic trays with some clips to hold the panels and a place to put concrete blocks. Some care has to be taken to prevent gaps that let wind get underneath them for worst-case windstorm scenarios, but it's definitely a product that exists.

If the panels don't have a slope of at least 5 or 10 degrees dirt can easily accumulate on them and may not wash off effecively with rain. I have a couple near flat on my porch roof for example, that suffer from dirt accumulation more than others in my off-grid and grid-tied systems that have inclinations ranging from ~23 degrees to vertical.

5-10 degrees of slope often isn't enough to keep panels clean on their own, depending on the climate and dust environment, some form of mechanical cleaning is still needed. This video is from a multi megawatt scale ground mount PV system in Rajasthan, India.

https://www.reddit.com/r/Damnthatsinteresting/comments/18p1q...

https://www.naturaecoenergy.com/robotic-solar-panel-cleaning...

How frequently really depends on the local climate, but at least a few times a year even in a place that doesn't have dust storms.

I did this at my house.

A couple of hundred panels just laid on the ground.

Even strong winds didn't lift them.

But after just a few months they're kinda covered in mud.

Would be interested in seeing photos of this if you have any, for comparison to other very low cost mounting systems

> It's also possible for a roof mounting system to cost more than the panels in materials and labor and time.

Probably. The fix would be for the panels to be an intrinsic part of the roof, meaning they don't have to be separately installed.

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