Solar panel mounted flat on the ground.

No racks , no tracking, no concrete.
Claims to save 20% on costs and use 1/3rd the land.
Cleaned automatically via a Roomba style robot.
Uses the earth as a heat sink.



https://youtu.be/ifNp6ueUsmQ

Erthos, Inc. Earth Mount Solar™ PV

https://www.erthos.com/

Growing crops or better still deep rooted prairie grasses between rows of solar panels can let solar farms sequester carbon.
This isn't possible in this system.
There seems to be a perimeter of bare looking land around the installation, to prevent shading no doubt.
I'm not sure if they include that space in their land use numbers.
I think adding a moat might allow some function stacking.

By running loops of pipe across the earth but under the panels, we have an opportunity to heat water while further cooling the panels.
The earth under these panels adsorbs roughly 2% of the precipitation that falls on the panels.
The rest runs off, which gives an opportunity  for water capture.
My thought is to use this space for storing water/growing biomass.

For temperate locations, I think you need to de-rate the solar output of the panels to just 60% of nameplate.  This is a common number for RV trailers with the panels mounted flat.  So, you take up less land, but you also take up less of the total solar energy, so that is likely to be a toss-up.

Cooling the panels with water pipes I believe has been shown to not be worth the effort.  That is, little or no extra production, and little water heating.

I don't believe there doesn't have to be any racking or concrete footers.  The panels MUST be solidly anchored, or they will go off, flying in the wind.  It's happened to the neighbors down the road.

The water heating/panel cooling thing is an added idea of mine.
It seems like it would be a very small investment, since no attachments would be made.
Without it, the estimates are that the earth itself provides a rather good heatsink.
The top of a building or RV, not as much, I imagine.

The de-rating of the panels was taken into account.
The savings in labor and materials are deemed to make it worthwhile.
I think 15 cents a watt was the expected savings, roughly 20% of the instalation cost.


Having installed solar on racks, I can tell you, the labor savings are bound to be substantial.
The last solar job I had we were getting a premium on top of journeyman union electrician wages, because they had tried to use laborers, got bas results, tried to use non-union electricians, still got bad results, and they were at that point desperate for someone who could do the work.
We were puzzled, because it was work we would have assigned to our  union apprentices, just follow instructions and bolt stuff together.
We knocked out the remain work in two weeks.
Good money, and they had more work going forward, but the travel was too much for me.

This system looks even simpler.
Hopefully some construction worker still gets paid top dollar, but less hours lowers costs anyway.

There is some square tubing involved,  apparently.
There also seems to be some proprietary hardware.
One notable thing is a plastic(?) edge piece that connects the panels together.
It is slanted from the top of the panels down to the ground.
This , plus each panel being tied to the the one next to it, combines to keep winds from getting a grip.
The wind tunnel tests rate them resistant to winds up to 190 mph.

The flat,empty "no shade" zone around the panels bothers me, but maybe it shouldn't.
It's probably included in the land use numbers, it is certainly inside the fenced in area.
Anything you could add there would increase either initial costs or maintenance,  or both, so it would need to be compelling in someway.

This flat installation needs less human intervention, , and that might not be a good thing.
Yesterday I tested some fire alarm devices at a store front.
It was a Bank of America location that has no one who works on site.
Instead, there are two video conference rooms and the  bankers/tellers deal with customers remotely.
Having worked in customer service on the phone and in person,  I am certain that the tellers are getting less slack and are more stressed than if they were working face to face with customers.
That is assuming they don't have to do that as well.

.
Rows of racked solar with deep rooted plants in between would need regular maintenance, and that could be a good thing.
Cleaning solar panels and mowing prairie grasses may sound like an unpleasant job, but I've dones worse for a living
Land with these racked solar installations has show marked increases in  water retention, and a subsequent improvement in fodder growth.
Being part of a team that sequester carbon, maintains solar panels and herds sheep sounds pretty good.

One last thought.
What if carefully sculpted earth could support solar panels?
The panels would still be "ground mounted" only the "ground" would be in the form of barrows or berms.
Mimic the angles that steel racking grants by forming earth into geostabilized mounds.
This would be way more complicated than simply building racks, and more expensive than flat grading the land.
It would have a low embodied energy, low materials cost and it should last a long time , being protected from weather by the solar panels.
It would also leave room for human workers to clean and maintain the panels and the spaces between the berms.

William Bronson wrote:
What if carefully sculpted earth could support solar panels?
The panels would still be "ground mounted" only the "ground" would be in the form of barrows or berms.
Mimic the angles that steel racking grants by forming earth into geostabilized mounds.
This would be way more complicated than simply building racks, and more expensive than flat grading the land.
It would have a low embodied energy, low materials cost and it should last a long time , being protected from weather by the solar panels.
It would also leave room for human workers to clean and maintain the panels and the spaces between the berms.

This I think is a valuable idea.  With the implementation of swales for water retention, you could combine solar racking there as a two for one construction project.  You would of course be limited to the topography of your land.

Flat on the ground people and animals are more likely to walk on it and break it.
Its easier for vegetation to block sunlight
On a slope it is self-cleaning but flat ever spec of dust or leaf stays and reduces the power that the system makes.
I dont think the inspectors will pass it

I agree with the risk of breaking due to something stepping on them.
If I can put something that likes shade below the panels, why not do it and use the space twice?

From my experience working on due dillegence of large scale solar farms, I see one big problem here which is maintainance.
I would flag a huge risk on any project trying to get funding for this because if one panel gets damaged by a bird dropping some stone or big seed, it would be a nightmare to repair.
And because of the (lack of) angle, damage is more likely to happen.
Also, the steel used to raise solar panels makes up only about 10% of the total installation costs.
Ofcourse production per panel is less because of the angle to the sun, therefor much of the land space savings are nullified.
Lastly, ventialltion, solar panels need ventilation to cool down for better efficiency. When angled and access to free air, this happens naturally.

There is a slightly different arrangement that is worth considering, particularly for ground mounting.  The east-west solar array, with two identical panels arranged as two sides of an equilateral triangle (the third side being the Earth or bottom support) so that one panel faces roughly east while the other roughly west.  This arrangement has been shown to produce a very "flat" power curve across the solar day, permitting it's use for many functions without batteries, or minimum batteries.  One function that comes immediately to mind are direct connection to a well pump, one that is properly sized to the solar array for near-maximum flow rate across the solar day.

Alternatively, the east-west array can be mounted on just about any shed roof that the apex of the roof roughly runs north-south.

William Bronson wrote:No racks , no tracking, no concrete.
Claims to save 20% on costs and use 1/3rd the land.
Cleaned automatically via a Roomba style robot.
Uses the earth as a heat sink.
Growing crops or better still deep rooted prairie grasses between rows of solar panels can let solar farms sequester carbon.
This isn't possible in this system.
There seems to be a perimeter of bare looking land around the installation, to prevent shading no doubt.
I'm not sure if they include that space in their land use numbers.
I think adding a moat might allow some function stacking.
By running loops of pipe across the earth but under the panels, we have an opportunity to heat water while further cooling the panels.
The earth under these panels adsorbs roughly 2% of the precipitation that falls on the panels.
The rest runs off, which gives an opportunity  for water capture.
My thought is to use this space for storing water/growing biomass.

Laying them flat on the ground is certainly a different idea. I like your idea of a moat to capture the water, especially if it is sent to a cistern or perhaps a trough with an overflow for chickens, sheep, cattle. [As you can tell, I'm not sold on a array flat on the ground: I'd like for that land to do double duty). I am pretty sure that most homesteaders would too.
I didn't understand that "The earth under these panels adsorbs roughly 2% of the precipitation that falls on the panels". As soon as the water runs off to the edge of the panels, it falls on the ground and gets absorbed, no?  [You have the same amount of water falling, whether or not the panels are inclined, so..?].
They do have a wide area around the panels with no vegetation. Mother Earth abhors emptiness, so I'm pretty sure they would have to weed or use herbicides [yuck] to keep it that way. They may save some $$ on the upfront costs but if you need a barrier, a safe way to anchor the panels so they do not get blown in the wind,  they still need to hold all the panels together, no matter which way the panels are oriented. Maybe they save on racks but they do need some sort of a device to keep the panels even Steven in all directions, so I'm pretty sure they have a racking system, even if it isn't as "beefy'.
They didn't mention deer movement, but here [Central Wisconsin] you would have to install a high physical barrier  all around or deer will walk all over it  and frolic with the disastrous effects you can guess. Not a big cost, but if the panels were slanted, you would not need this high fencing maybe.
I raised some ducks and wanted to kill a tiny area of grass so I placed a shiny TV screen flat on the ground. A couple of days later, I saw them walking all over it, trying to drink the 'water" and bathe in it, even though I had a little pond just for them! Poor little ducklings! I wonder what would happen if a few Canada geese decided to land on these panels?
I totally agree with you on storing the water that falls on the panels: What a waste to let it run and not use it for something...
Maybe some areas of California are almost dry and a Roomba-like device can work to clear these panels of dust? snow?. [How about scratching the panels with the bristles?] but if you get a couple of feet of snow, or even just 1/4"of ice, I don't see a Roomba taking care of the job.
Also, California has a lot more sun than Wisconsin: Here, you would have to slant the panels to allow maximum exposure but also snow shedding: I suspect that panels laid flat could not absorb the rays very well around here. Up North, like in Price county, the roofs have to be constructed especially beefy to deal with the heavy snows.
The company makes a lot of hay out of saving money by not having to install posts. There are machines that are quite efficient at quickly digging holes for these posts. Perhaps, they fear winds and tornadoes. That is a more valid reason to lay them flat, IMHO. Perhaps that is a big plus if you live in an area that is prone to high winds. Here, tornadoes are very rare. If the North end of the panels could be raised but the panels in a row being kept as a solid unit, they should be able to secure them quite well, I would think. We do get some hail, once in a while. Perhaps slanted panels could deflect the worst of it? On a homestead, which would not be too many panels and considering the cost of the whole installation, I would want to install regular shutters that I could cover the panels with or have a way to quickly make the panels vertical so as to be missed by most of the hail?
They deplore the land that is "wasted" in a more conventional array. That is not quite true: When you have a solid, flat array, that land is truly wasted because you can grow nothing else on it. There are row crops that would love a little shade in the heat of summer and chickens would love the shade, not to mention the cover to keep them safe from  aerial predators, especially if the panels in the array are placed closely enough and slanted so as to not allow chickens roosting, of course. [If the top edge was, say 7-8 ft., there are not many chickens that would even attempt to roost on the top edge]. Mushrooms, sheep, short bushes like  blueberries, gooseberries, black currants are all possibilities. You would have to choose wisely, of course, depending on what will grow where you are. (Chickens and gooseberries are not good companions. Ask me how I know.)
One size does not fit all and it is great that some folks are thinking out of the box. Panels laid flat may work in certain places...

IMHO solar panels should not be arrayed in large numbers to be controlled by power companies, but be on individual buildings (homes and businesses) thereby not requiring extra land, eliminating the need for transmission lines, and making large scale power problems (due to weather, greed, or sabotage) history.

Barbara Kochan wrote:IMHO solar panels should not be arrayed in large numbers to be controlled by power companies, but be on individual buildings (homes and businesses) thereby not requiring extra land, eliminating the need for transmission lines, and making large scale power problems (due to weather, greed, or sabotage) history.

In Germany it is common to see the ubiquitous large agricultural or commercial buildings covered in solar panels. It’s rather impressive effort and the most appropriate place for panels IMHO. I’d rather see land restored to habitat for  the many threatened species than covered with panels. What is really need is much more efficient panels so less space would be needed.

While it’s a interesting concept the  ground mounted panel is not new. RVers have been setting panels out on the ground for years. And they do get broken.

I saw this story elsewhere about a month ago. I asked my good friend Steve, an engineer with a special interest in solar for his thoughts:

“Thanks for the link. I beg to differ a bit with their claims- I think they are hyping their idea a bit.

Firstly laying a panel flat reduces output by typically 20-30% compared to a fixed tilt (latitude dependent), so 20-30% more panels are required for the same energy output. This then calls into account their claim of half the land required. Tilt frames need more space to avoid overshadowing from one row to another, but require less panels.

Next the claim of 70% less cable, most cable is used along a row (in on ground or tilt panel), very little between, maybe 10-20% between. 70% saving would be for a very difficult site for tilt panels, which would probably require massive earthworks for flat on ground.

70% less trenching- as above

70% less water use- I think they need the robotic cleaner as they are flat on the ground (video says every night) arrays on a tilt may need cleaning 2x a year to once every few years. I think these flat on ground panels may use more water (not that much is used anyway so quite a spurious claim)

Cost saving- Panels typically make up about 60% (commercial scale) of a solar install budget, tilt frame 15%, inverters and balance of system 25%. So the savings are 15% on tilt frame but with 20-30% more panels required 12-18% more all up on panel cost. Seems about breakeven to me.

A verbal claim on the video using the cooling of the earth to increase efficiency- I think the reverse is likely, heat is trapped under the panel and makes the ground hotter, this radiates back into the panel and heats it up more reducing output. A panel on a tilt frame gets fresh air both sides giving it air cooling.

Hurricane proof. Maybe. I could not see how the panels were anchored, they just seemed to be laying them on the ground. If that is the case then the pressure differential of a hurricane between the front (low pressure) and back (high pressure) will see them pretty much blown off the ground. Generally panels do not like hurricanes in any format.....

Definitely less visual impact on flat ground.

Reduced geotechnical risk- not a big one. Tilt frames now use screw piles, they just screw in to resistance and if that is not achieved back it out and screw in a longer one. Bigger issue is subsurface stone preventing achievement of depth, but usually pretty easy to determine and classify prior to starting project.

All up, they have their place but not a be all and end all in my view.”

I would think that this system would work best nearer the equator due to more consistent angles of the sun.  What this system does not address is the fact that high winds carry large amounts of often dense debris.  In Puerto Rico after Maria, I saw a major solar field with massive debris damage.  In addition, thunderstorms often provide hail and a panel lying flat on the ground is more subject to hail damage than a slanted panel - more direct energy in the hit.  In warmer climes there will be heavier vegetation and dust storms, often mixed with rain and in colder climes, there will be snow and ice.

There have been some good designs for wood solar mounting systems that reduce cost from commercial metal systems by an order of magnitude.  If you keep the wood off direct contact with the ground and no not leave flat surfaces for moisture to gather, even non-treated rough-cut lumber holds up for years.  Just look at an old barn.  If one wants to hold the system down, use manufactured home anchors set a few feet into the ground at an angle to the primary pullout forces.  Quite frankly, I have designed a system to automatically cover solar systems with a net made out of kevlar reinforced material.  That will anchor the system in place, prevent debris damage and even allow partial power production during operation.  Kevlar netting has been used in Florida to hold down buildings.  Fire stations have used them to allow doors to be left open in hot weather even in major events.  I know of one station where the fire crews sat in  doorways with that netting overhead and watched Hurricane Charley roll overhead with barely a decent breeze felt.

Solar arrays tend to provide 60 to 70 percent shade, which is exactly what many crops prefer.  Keep the panels higher and one could graze small livestock around them and that keeps maintenance costs minimal.  Building stone or hugelkultur systems in key locations would hold runoff on the land, minimize noxious insect populations and the shade would reduce evaporation, allowing better grazing production.  I would have to see really good numbers on results to go to laying solar panels on the ground, unless one is using a steep hillside to begin with.  Even then, moist soil and insects/rodents would have a field day with wiring under ground mounted panels.