[HN Gopher] A 100MW solar farm in Texas will mount panels direct...
___________________________________________________________________
A 100MW solar farm in Texas will mount panels directly on the
ground
Author : orangebanana1
Score : 318 points
Date : 2022-12-09 21:33 UTC (1 days ago)
(HTM) web link (www.canarymedia.com)
(TXT) w3m dump (www.canarymedia.com)
| reddog wrote:
| Will Prowse did something similar (much smaller scale) on his
| YouTube channel last year. He set up a 6000 watt ground mount
| array in about 40 minutes and discusses the trade offs here:
|
| https://youtu.be/71vME5k-oiw
| rhacker wrote:
| His is more or less temporary.
|
| What's great about him though is he already has a link up to
| the power company, so as he sees fit he can just reduce his
| bill by flaying them out in his courtyard. That or just mine
| btc/etc...
|
| He's still an awesome dude and has helped me set up my own
| solar in the number of videos. Even better is his forum:
|
| https://diysolarforum.com
| blamazon wrote:
| Temporary solar panels are interesting to me - where I live
| there's a large chunk of the year where weekly solar output
| plummets. Stacking them in the garage overwinter is
| appealing, I might try this soon.
| cinntaile wrote:
| I would assume the risk of moving them each year is much
| bigger than any reduction in loss of function?
| blamazon wrote:
| Meh. Throw a moving blanket over it and bungee it on.
| Could weld up a cart to roll them all at once sideways.
| Could use spring casters like for gates as a suspension.
| Or hold them in place with low durometer rubber. Or both.
| Probably want them sideways for footprint in my garage
| anyhow. It would be fun to optimize the process more each
| year.
| bushbaba wrote:
| Why bother stacking them in the garage during winter. Are
| you afraid of winter panel damage?
| blamazon wrote:
| My property is very small and I currently use that back
| space to park my nice car during the winter so the daily
| is in the garage and the front driveway is easier to
| plow. Sounds weird to me typing it out, but I promise
| this arrangement makes more sense when living here.
| [deleted]
| latchkey wrote:
| Definitely love me some Will Prowse. I bought one of the LiPo
| batteries he recommends for my campervan and have been super
| happy with it.
| ketralnis wrote:
| Generally if you're grid-tied your setup needs to be approved
| by the power company and they have a surprising amount of say
| in what specific equipment by what vendors you can use. If
| you watch his videos on his specific home setup, he has a
| separate grid-tied system and his testing system and they
| don't touch. He even remarks that some of them wouldn't have
| been his choice.
| Dwedit wrote:
| I watched a video from the 8-bit guy about tying solar
| panels to the grid. He said that if you do that, your power
| fails at the same time as the grid's power, so you don't
| get any backup electrical power. For that reason, he
| recommended against tying your solar to the grid.
| gorbypark wrote:
| It's completely possible to have backup power and be
| grid-tied. The main issue is your panels feeding the grid
| during a blackout, which can be dangerous for people
| trying to fix stuff. All that's required (requirements
| will vary widely per region) is an automatic disconnect
| that disconnects your setup from the grid when the grid
| goes down. For example, Tthe new Enphase EQ8 micro
| inverters have an optional controller to do this. AFAIK
| the Enphase systems are the best selling micro inverter
| systems out there so new installations should have no
| issues being self sufficient during outages.
| rini17 wrote:
| Anything that can be legally connected to grid has to be
| certified to stop supply back to grid in case of
| blackout. Is there any region where this isn't the case?
| I doubt it.
| photochemsyn wrote:
| Interspersing standing panels with crops looks to be an
| effective strategy, some crops suffer from too much sunlight
| and require a little shading for optimal production (many
| vegetable-type crops fall into this category). Some strategies
| employ vertical bifacial panels. See:
|
| https://youtu.be/lgZBlD-TCFE
|
| Solar Panels Plus Farming? Agrivoltaics Explained
| thehappypm wrote:
| Vertical panels strike me as needing quite robust supports
| for windy days.
| tomrod wrote:
| Don't do singular poles, mesh them together?
| conor_f wrote:
| Really I don't care where or how the panels are placed.
|
| All movement towards renewables is good, no matter how
| "inefficient" it is vs fossils
| p1necone wrote:
| Yeah I don't understand people getting hung up on efficiency
| with solar panels. The sun is always up there producing the
| exact same amount of energy with zero input from us. We're not
| doing any work to get the input energy for the panels.
|
| Efficiency would only matter if we'd already covered all the
| available area with panels and needed to start replacing
| existing ones, otherwise $/watt hour is the only metric that's
| important.
| kragen wrote:
| until only a few years ago solar panels were enormously more
| expensive per square meter and per peak watt, so doing things
| to increase their efficiency was a great way to reduce $/watt
| hour
| ummonk wrote:
| Does solar panel efficiency get affected much angle of incidence?
| I.e. are you losing out on any power by using large panels to
| cover the ground instead of having smaller panels that are
| steered to cover the ground in shadow?
| rootusrootus wrote:
| Interesting idea. I've been toying with the idea of doing a
| ground mount install at home, but maybe I should try this instead
| to get more density. I love toys...
| toss1 wrote:
| Sounds great, but the land underneath is absolutely killed as if
| it were paved over, no grass, ground cover, crops or anything.
| That said, it seems to be less than half the amount of land.
|
| Nevertheless, it seems that the innovative German installation
| method of using vertical panels in between agricultural rows is
| better [0].
|
| [0] https://cleantechnica.com/2022/07/25/new-research-says-
| verti...
| thehappypm wrote:
| Who cares? Honestly, a hundred acres of scrubland turned into
| green energy is a steal compared to everything else we do on
| this planet for food, energy, and material
| toss1 wrote:
| Sure, on a scale of comparative bad things, e.g., vs strip
| mining...
|
| But if you don't have to kill the entire soil microbiome, why
| do it? Just questioning whether this is as good as vertical
| panels + farming.
|
| I agree, if it really is nearly devoid of vegetation, it
| seems better to use the least possible amount land and also
| not use the metals for the racking.
| tuatoru wrote:
| No, not as if it were paved.
|
| No aggregate is laid down, nor is asphalt put on top of the
| aggregate. No toxins are put in, nor does the topsoil need to
| be scraped off.
|
| End-of-life reinstatement of the land shouldn't take more than
| ten years of seeding a sequence of plants that specialize in
| colonizing and re-aerating bare compacted soil, and
| revitalizing the soil ecology. (Weeds.)
| toss1 wrote:
| Yes, EOL recovery could be quicker than if it were paved
| (assuming that paving strips the topsoil completely and not
| just paves over it) but much slower than if it remained
| growing all the time.
|
| The problem is that soil is not just inert, and completely
| covering it like that kills the entire microbiome -- the
| fungi, bacteria, and myriad of multicellular micro-critters
| that make the soil good for plant growth will be long gone
| when they take up the panels.
| maxnevermind wrote:
| Is that really a startup? It seems pretty straightforward, no
| uncertainties. Or there is some legal \ approval challenges I'm
| not aware of? That solar panel Roomba seems to be the only unique
| thing about the project.
| melony wrote:
| I do not believe their claimed savings. Steel is a very cheap
| building material and at the scale of solar farms, the cost
| should be very low. (As an alternative to stainless steel on the
| other hand, it may make more sense)
| adaml_623 wrote:
| Show your calculations. So lazy
| tinglymintyfrsh wrote:
| _Hail enters the chat_
|
| Maybe they should prop them up on cinder blocks at a minimum?
|
| What about flooding?
| deepsun wrote:
| If they lie on a flat, impact absorbing material (i.e. sand),
| then hail would do less damage than for standing panels. One
| could walk on them. If, as you propose, put flat rigid cement
| below, I'd thing you could drive on them.
| TheRealPomax wrote:
| Good luck replacing the ones in the center, I guess?
| 9935c101ab17a66 wrote:
| You can walk on them? So i don't think it'll be much of an
| issue.
|
| Link from someone else's comment:
| https://www.erthos.com/reducing-degradation-rates-with-earth...
| [deleted]
| matt3210 wrote:
| My panels were cheeper than the mounting equipment... If I had
| tons of space I would scale up panels and put them on the ground
| instead of mounting/tilting gear.
| ElijahLynn wrote:
| From the picture, it looks like the dirt will eventually wash
| onto the edges and it will be difficult to clean as you can't
| just spray it off and have it wash off with gravity. I'm confused
| as to how this will stay efficient in the long run.
| motoxpro wrote:
| Build a 1ft tall platform out of dirt/gravel and tilt the whole
| thing a few degrees. Solves this probs.
| miohtama wrote:
| They clean it with robots
|
| > Automated nightly robotic cleaning of entire array prevents
| hot spots due to soiling.
| mycall wrote:
| > "Install in half the cost, half the time on 33% of the land"
|
| If the panels don't point directly at the sun, then you lose much
| of the efficiency.
|
| I wonder how the robot cleaner handles bird poop.
| sorenjan wrote:
| I don't understand why they cant dig some kind of trench or
| mound to put them on at least, to angle them more towards the
| sun. There's plenty of agricultural equipment designed to
| cultivate soil (first example I found[0]). That could take care
| of the drainage as well, although I don't know how much it
| rains in Texas.
|
| [0] https://www.asa-
| lift.com/asalift/producttypes/bodenbearbeitu...
| JumpCrisscross wrote:
| > _why they cant dig some kind of trench or mound to put them
| on at least, to angle them more towards the sun_
|
| Trench will flood. Mound needs to be maintained. Cheaper to
| put more static panels flat than trying to get every electron
| out of them.
| [deleted]
| rootusrootus wrote:
| > why they cant dig some kind of trench or mound to put them
| on at least
|
| Just use the rack then, it's exactly the same result.
| sorenjan wrote:
| I think using the dirt that's already there and building
| the structure with some kind of machine would be cheaper
| than having someone mounting them on a steel rack. See for
| instance large potato fields [0]. The point is instead of
| putting them on flat ground, make the ground have a better
| shape first.
|
| [0] http://www.thompsonpotatofarm.com/common-tater/banking-
| the-p...
| rootusrootus wrote:
| The racks are really easy, well known technology. That
| was my point. If you're going to give up the entire
| reason for laying them flat on the ground, you're going
| back to the way existing solar farms work, so just use
| the same proven technology.
| dahfizz wrote:
| > If the panels don't point directly at the sun, then you lose
| much of the efficiency.
|
| This is true for a single panel. But the amount of sunlight
| which hits an acre of land is constant. If the land is 100%
| covered with panels, the panels will collect 100% of the
| available sunlight.
|
| Installations that tilt the panels have lots of space between
| the panels.
| t3pfaff wrote:
| > This is true for a single panel. But the amount of sunlight
| which hits an acre of land is constant. If the land is 100%
| covered with panels, the panels will collect 100% of the
| available sunlight.
|
| That is not true from my understanding. The increased solar
| angle of incidence effects how much of the energy reflects
| back into the sky. Having more panels next to it without a
| gap won't change that. Yes you can fit more panels in the
| same area without putting them on an angle but they will be
| quite a bit less efficient because more light will be
| reflecting back up per sqft of panel which is what matters
| cost wise.
| nick4780167 wrote:
| The anti reflective layers and texture on the panels are
| usually pretty good, such that then reflection is less than
| the area loss due to the angle.
| tuatoru wrote:
| Yes, one of the many areas of improvement of PV modules
| in the last couple of years has been reducing reflections
| from the surface of the glass and from the glass-cell
| boundary in panels. Also changed cell technology
| (n-TOPCon) helps with reflections and recombination
| within the cells.
| sacred_numbers wrote:
| There is a small loss of efficiency (<2%) at extreme
| angles, but it is not too significant[1]
|
| [1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6611928/#
| :~:tex....
| [deleted]
| kragen wrote:
| it's true that you get 100% of the sunlight that falls on the
| land, or near enough (albedo is not literally zero at any
| angle) but you need more solar panels per output watt
|
| it'll be interesting to know if they're derating the
| nameplate capacity by cos(latitude) as they should be
| tuatoru wrote:
| Their agreements with their local grid operator will
| specify power delivery. Marketing numbers like an
| individual panel's nameplate output are not important at
| utility scale, which this is designed for.
| kragen wrote:
| probably the local transmission companies are interested
| in not only average ouptut but peak output, but also,
| there were a number of numbers in the article cited as
| "per watt" which look like they might be talking about
| peak watts
| drumttocs8 wrote:
| Most utility scale installations don't track the sun- too much
| cost. This takes cost-saving to a new level though.
| Hermitude wrote:
| Horizontal panels also collect dust, so they still need to be
| propping them on the north side.
| avip wrote:
| All panels collect dust, but this setup is much more
| challenging to clean (and to generally service, i.e to
| replace a faulty panel)
| nimos wrote:
| This seems much easier to clean? A gigantic flat slab is
| pretty easy to automate something vs disconnected racks.
| avip wrote:
| (Modern utility scale PV installations are already using
| automated cleaning solutions).
|
| It is much better from POV of the cleaning robot
| maneuvering requirements. It's also much better in terms
| of single robot can access the entire installation.
|
| But it's worse in terms of how much distance the dust
| should be pushed before it's off panel (as I don't see
| any gaps there)
| jacoblambda wrote:
| Alternatively if the robot is a vacuum or something of
| the like, it could just store the excess dust and dump it
| at a station on the edge.
| s1artibartfast wrote:
| Service trade-off seems pretty marginal. They say the
| panels aren't tied down to the ground in any way, so you
| might be able to just pick one up and disconnect it
| elihu wrote:
| They have a robot that cleans the panels. It's a big, flat
| surface so they don't really need anything much more
| advanced than a Roomba.
|
| Apparently they also have special shoes that maintenance
| people can wear that distribute the weight properly so they
| can walk on them if they have to.
| gleenn wrote:
| They don't look propped at all in the photos. Also I think
| propping would be hard for the cleaning robot as it looks
| like is a super simple little robot with small wheels and
| just rolls straightened over them.
| StillBored wrote:
| Yah its probably a case that designing a vacmop style
| device (possibly purchased off the open market?) and having
| it drive around on a flat surface is both cheaper and keeps
| the panels cleaner than a custom bot that doesn't clean as
| frequently because it costs to much.
|
| My question is whether sitting on the ground itself causes
| problems with efficiency due to the panels getting hotter
| than they would with some airflow under them.
| tuatoru wrote:
| Erthos spend quite a bit of time designing their own
| autonomous cleaning and repair robot.
| pnw wrote:
| According to the research on their site, ground mount
| solar has better heat dissipation than roof mount solar,
| and isn't that far behind racked systems, so it's not
| really a concern. The ground ends up acting as a heat
| sink.
|
| https://www.erthos.com/modeling-heat-dissipation-in-
| earth-mo...
| constantlm wrote:
| Sounds like they're pretty confident this isn't an issue:
|
| >Our fees are based on the plant producing at its optimal
| performance. If the plant underperforms for any reason, we
| curtail our fees - creating strong incentive and perfect
| alignment with the long-term asset owner.
| legohead wrote:
| You get the majority of the power when the sun is directly
| overhead. You can make up the lost difference by the space
| saving and just adding more panels.
| PaulDavisThe1st wrote:
| The sun is never directly overhead except on the summer
| solstice at noon, assuming you're in roughly the part of your
| timezone.
| JoeAltmaier wrote:
| And then only at the equator. Here in Iowa at 42' North,
| you'd want a panel tilted 42' South to start with.
| s1artibartfast wrote:
| It all comes down to the economic tradeoffs. Panels are cheap
| and everything else is expensive.
|
| If you can get 75% efficiency for half the cost, your return on
| investment is 50% higher
| tuatoru wrote:
| What you lose with Erthos' approach is any possibility of
| using bifacial panels.
|
| In regions that get snow, bifacial panels (that use light
| reflected onto the back of the panels as well as light from
| the front) get a lot better output in the winter, increasing
| the annual capacity factor and therefor return on investment.
| (Winter electricity can be more valuable too, in those
| regions.)
|
| Horses for courses.
| DaniFong wrote:
| you can have a back mirror on this, they probably do
| tejohnso wrote:
| Solar in Texas seems like an obvious win in just about any
| configuration. But I wonder how this would work at higher
| northern latitudes in the winter. I suspect efficiency would
| be pretty bad with a 20 degree incidence.
| chefandy wrote:
| Doesn't have to be effective everywhere for it to be
| useful.
| nine_k wrote:
| Panels may be cheap, maintenance / replacement is less so,
| because humans at work.
| dahfizz wrote:
| Everyone is talking about maintenance ITT. Is it that big
| of a concern? My parents have had solar on their roof for
| almost 10 years now with zero issues. I imagine newer
| panels last longer.
|
| So what's the actual maintenance cost? I could imagine it's
| going to be cheaper to just install new panels every few
| decades than constantly maintaining the installation to be
| 100% capacity.
| 0cf8612b2e1e wrote:
| For a grid scale installation, let's say 5% of panels are
| dead due to whatever failure. I am not sure the rational
| response would be to do any maintenance vs installing
| more capacity. Twenty years later rip out all of the old
| panels, replace with new. Repeat forever.
| theptip wrote:
| They use a robot for regular cleaning; looks like the
| design will make that cheaper too as it's basically a fancy
| Roomba.
| s1artibartfast wrote:
| Replacing might be cheaper as well without any mounting
| racks or tracks.
| kragen wrote:
| the unintuitive part is that land is even cheaper than
| panels, so you'd think that spending more panels to use less
| land would be a losing proposition
|
| the interesting question is whether the costs of racking,
| grading, cleaning, repairing, etc., go up or down, and if
| they go down, whether it's enough of a reduction to make up
| for the larger amount of solar panels per average watt, as
| they say it will be
| sacred_numbers wrote:
| Based on my calculations, at my latitude (40 degrees
| North), you would need about 16% more panels to generate an
| equivalent amount of energy per year. This isn't taking
| into account potential issues with snow buildup (which
| theoretically would be worse with flat panels) or the
| effects of cooling (which theoretically could be better due
| to contact with a thermal sink, the ground), but it's
| probably pretty close. Even if 20% more panels are
| required, that means capital costs are superior as long as
| panel costs are less than 5x racking material and labor
| costs. Currently panel costs are more like 3x racking costs
| and will probably continue to decline. Racking costs will
| probably not go down unless steel prices go down pretty
| significantly. The only thing that surprises me is that
| there are not more companies doing this. Perhaps there are
| factors that neither Erthos nor I am properly considering,
| but I think this is how most utility solar projects will be
| done in 5-10 years.
| kragen wrote:
| steel prices are probably not a significant component of
| racking prices; scrap steel costs 50C/ a kg
|
| the numbers they gave make the pv module prices seem
| slightly higher than the cited racking prices (15C/ per
| watt) but it's a little hard to be sure because of the
| numerous kinds of watts involved
| s1artibartfast wrote:
| We put in 40 KW and in the racking was a nightmare. The
| government required soil analysis, reinforced racks, and
| cement pilings 4 ft deep. Probably could have put in
| double the panels if we didn't have to deal with the f***
| racks
|
| I think this approach has interesting applications for
| small-scale solar in rural environments if the permitting
| can be streamlined
| ummonk wrote:
| I mean with erosion, flooding, and the like, I'm not sure
| this sort of mounting on the ground would be any less of
| a hassle...
| s1artibartfast wrote:
| Most of those things seem nonissues in desert climates
| with flat Terrain.
| t0bia_s wrote:
| Land for planting will be replaced by Made in China products that
| makes energy only during sunny day. What a green deal!
| Dazzler5648 wrote:
| It's hilarious how some commenters are concerned about bird poop,
| when fact of the matter, birds die by the thousands each year in
| California alone either mistaking solar farms for lakes and
| attempting water landings, or by dying by fire in panels'
| collective solar flux. This pond will be covered in carcasses.
|
| This type of solar farm is doomed to spend that money saved in
| either prevention and/or cleanup and repair.
| hwillis wrote:
| > by dying by fire in panels' collective solar flux
|
| That is exclusive to concentrated solar[1], which is
| essentially obsolete.
|
| > birds die by the thousands each year
|
| A BILLION birds die each year from flying into windows in the
| US[2]. In fact the majority of birds killed at Ivanpah are
| killed by flying into the tower, not from being cooked.
|
| > This pond will be covered in carcasses.
|
| Nope! If a bird tries to fly into a rack-mounted panel, it'll
| probably die, because it's basically flying directly into the
| surface. If it tries to land on a FLAT panel, it'll be totally
| fine. Birds don't try landing on water by smashing directly
| into it.
|
| Also, I have never heard of this "water landing" theory, I
| suspect its bullshit, and I'm very skeptical that there are
| many birds trying to do water landings in Texas due to the fact
| that there aren't a whole lotta lakes there because it's
| _Texas_.
|
| [1]: https://en.wikipedia.org/wiki/Ivanpah_Solar_Power_Facility
|
| [2]:
| https://en.wikipedia.org/wiki/Bird%E2%80%93window_collisions
| asciimov wrote:
| Not sure where they are building these but I'll tell you hwhat,
| fire ants love electronics and they are found in the majority of
| this state. Putting these right on the ground is just inviting
| destruction by critters.
| DaniFong wrote:
| i swear those buggers sense where the volts are
| djcannabiz wrote:
| thats really interesting, thanks for sharing! a google search
| for fire ants electrical equipment brings up a website on ants
| conducting electricity and shorting circuits. I had no idea
| that was an issue
| anakaine wrote:
| So we are fighting fire with electricity?
| Smoosh wrote:
| Pikachu > Charmander
| Mistletoe wrote:
| Bizarrely, ants were attracted to our Tesla power connector
| on our previous car. We googled it and it was a common
| problem, ants seem to love electricity.
| randyrand wrote:
| Solar inverters are always water proof, sealed, and potted. The
| ants will have their work cut out for them.
| chillingeffect wrote:
| an install is expected to last 10-25+ years... that's a long
| time....
| dreamcompiler wrote:
| Can't tell from their website but I really hope they're not
| using per-panel "solar inverters" at all. The whole ground-
| touching array should be DC with no electronics whatsoever
| (except maybe for diodes, and with no significant shadows
| they might not even need those).
|
| Any inverters present should be large, few, and in their own
| weatherproof housings above the ground.
|
| I think per-panel inverters are a stupid idea, especially for
| large utility-scale installations. Sorry if I misinterpreted
| your comment and you meant something else.
| dwighttk wrote:
| even worse: Rasberry crazy ants
| bottlepalm wrote:
| Doesn't sound eco friendly. Panels off the ground a little leave
| some space for plants and animals to get around.
| JoeAltmaier wrote:
| No solar panel is 'eco friendly'. It's a complete ecosystem
| teardown.
| bottlepalm wrote:
| Are you talking about the manufacture or operation?
| JoeAltmaier wrote:
| Operation. Any time you profoundly change the terrain
| (soil,water,sunlight) you catastrophically upset the
| ecosystem. It may come to another equilibrium over time,
| but that's just nature doing its good thing. There's a
| finite capacity for that etc.
| ush wrote:
| I own and operate a utility scale solar plant and i've always
| found it inefficient to spend 180k USD per MegaWatts for steel
| and aluminum structures to hold those panels. I've always dreamt
| of "my next plant will not have these steels" and my friends in
| the industry say it's impossible (like they all do say for new
| things). I hope this solution is a good one. The challenges are:
| 1) Snow: when it snows, inclination (22degrees in ours) helps
| snow blocks slide down usually in 2-3 days. when panels are
| completely flat, snow can stay on panels for weeks. how to solve
| that in large scale plants? 2) Natural vegetation that grows by
| itself: We deal with them with the help of sheep. They grow
| everywhere, under the panels, around the panels. As the panel
| covers 100% of the surface, no sunlight means no vegetation
| beneath? Is this for sure? Because there is no access to do any
| work beneath the panels after the installation. 3) Underground
| animals: Moles, mice (even snakes) etc live beneath the soil and
| they open holes to the surface and come up. Before, they could
| not access the panels because they are 1 meter up on the steel
| structure. Now they will have easy access to panels and cables.
| Will they cause harm? A snake sliding on the panels is ok? 4)
| Earth moves. After 5 years, some structures went deeper into the
| ground. I don't know if it's gonna cause a problem
| vasco wrote:
| I don't operate one but back in university did some
| calculations around these and another factor is that efficiency
| goes down with rising temperatures. If the panels are all on
| the ground, during summer they will heat up and there won't be
| much air circulation beneath them to help cool them off. So
| efficiency will go down for sure, and I'm not sure the 20% one
| time savings will compensate a forever-less-efficient running
| operation. I guess it depends where in the world you install
| them, if more towards the north it might be ok.
| pifm_guy wrote:
| When experimenting with solar efficiency, I noticed that
| spraying the panels with water every half hour increases
| efficiency pretty dramatically.
|
| The wet surface seems better at absorbing sunlight than the
| 'anti reflective' glass surface, and the evaporating water is
| a great cooler.
|
| Since it uses so little water, I don't know why industrial
| installations don't do it.
| TaylorAlexander wrote:
| In some areas, the water use just from cleaning solar
| panels becomes a serious issue (let alone using more water
| to cool them). It's not much water to spray on some panels
| you are experimenting with, but for a large installation it
| seems like it would be a lot of water.
| gregoriol wrote:
| The best areas for solar are hot, those are also likely
| to be the areas where water supply is the most
| constrained, so this is definitely a no-go solution
| pooper wrote:
| Sorry if this is too basic of a question but for places
| close enough to the sea, would sea water for cooling and
| cleaning be an option? Too much salt residue?
| 2ICofafireteam wrote:
| Now I'm waiting for the seaside solar power plant/salt
| works proposal to pop up!
|
| Seriously: Maybe residue wouldn't be an issue if it was
| never allowed to dry, but the corrosion-proof
| construction, drainage system, and pumping costs would be
| considerable. Then there's the 100 problems we're not
| aware of yet...
| nkmnz wrote:
| salt crusts are highly reflective, driving down light
| exposure pretty fast. Plus, salt water is corrosive.
| danuker wrote:
| > salt crusts are highly reflective
|
| I think this will not be a problem, as the salt would be
| continuously washed away with new water. But the
| corrosion would be a problem indeed.
|
| Maybe some plastic/epoxy/glass casing would help, but it
| might also hinder recyclability.
| Pigalowda wrote:
| This is in Texas which is hot but there's water.
|
| Additionally power stations use steam turbines which
| require a lot of water. Some cooling water for misters
| would probably be a rounding error.
|
| https://www.eia.gov/todayinenergy/detail.php?id=50698
|
| https://www.seia.org/initiatives/water-use-management
| jeffrallen wrote:
| The water would need to be demineralized in order to not
| leave deposits over the long term. That alone probably
| makes the idea unprofitable.
| sebazzz wrote:
| Don't try this at home. Cold water can crack the glass or
| cause other thermal stress.
| pifm_guy wrote:
| True. But most panels are rated and tested for icy hail
| to hit it on a hot sunny day with the panel surface at 70
| degrees C.
|
| But obviously doing this repeatedly might not be good for
| it - naturally hail on a super hot day is rare.
| schiffern wrote:
| >spraying the panels with water every half hour
|
| Sounds like a job for center-pivot irrigation! Just choose
| a model that can rotate at 2 revolutions per hour.
|
| I never really appreciated how brilliant these are until
| watching this video:
|
| https://youtu.be/7j1lMs7fcIQ
|
| For large deployments of Earth-mounted PV you'll need a
| grid of drainage ponds to buffer runoff water, so you might
| draw from those. A control system would monitor
| temperature, PV output, and water turbidity.
|
| The latter is important, since there's no sense dumping
| dirty water on the panels! Give the suspended solids time
| to settle out, or even add flocculants via a dispenser.
| scotteric wrote:
| I wonder how much of that is the water increasing the
| effective surface area of the panel be acting as lens?
| ush wrote:
| this is a very good point. would be good to see data for a
| couple of years of production and compare vs. traditional
| system. it's most of the time better to spend upfront for
| ongoing production increase. If 5% loss during 25 years, 20%
| upfront saving might not look that good anymore for a plant
| that pays back in 7 years or so.
| neltnerb wrote:
| The response of the company when the issues of heating,
| vegetation, snow, and rain is... I guess I am not
| impressed.
|
| > The expert added, "I'm also concerned about the lack of
| airflow around the module in this system design. Glass-
| glass modules provide a good moisture seal, but I suspect
| the back of the module will have very high humidity with no
| airflow. Damp-heat testing will be important. Not sure what
| other organic stuff could grow back there, like fungus or
| mold or things that get in the J-box," referring to the
| junction box that houses the equipment that carries
| electricity from each panel.
|
| > Daniel Flanigan, chief marketing and product officer at
| Erthos, offered this response: "No developer is going to
| install an Erthos system without proper diligence and all
| of these issues...being resolved. Yet we are engaged in
| over a gigawatt of pipeline."
|
| Okay, got it. So because people are paying for it people
| should pay for it. Everyone knows something no one knows.
|
| https://www.canarymedia.com/articles/solar/utility-scale-
| sol...
| ush wrote:
| I agree. sounds like a red flag when they reply with
| "yeah everyone is buying it so your question is
| irrelevant" instead of providing a technical
| explanation/response. I am also skeptical on companies
| that raise too much funding (I can not imagine why they
| need $18million)
| moron4hire wrote:
| That's what they said about Theranos, too.
| Temporary_31337 wrote:
| Consider the difference in borrowing costs now too. A 20%
| higher upfront cost means a 30% higher cost if you include
| financing over several years. So it will be good to see how
| the alternatives work out
| blkhawk wrote:
| Thinking about it there aren't many things that are as cheap an
| durable as steel and aluminum. You surely know how the amount
| of energy you get out of the panels changes with inclination
| and just laying them flat is only feasible if you aren't
| concerned with that loss per unit of energy output or your
| plant sits on the equator. But in that case you can massively
| simplify the mounting system and raising the panels up would
| make maintenance from below easy.
|
| It doesn't feel like masonry or poured concrete walls will be a
| much cheaper substitute either. Wood might do in arid
| conditions with well behaved weather but you may pay in
| maintenance over time what you save at the start.
|
| I think a better approach is to improve the yield per unit with
| either better panels (split-cell bifacials currently seem to
| offer a nice bonus in yield just from back-reflected light) or
| some other thing you can do to improve overall profit per unit
| land.
|
| Of course there are situations land is so cheap it doesn't
| matter as a cost factor but after a point you would pay more in
| other infrastructure than you save again.
| strainer wrote:
| Wooden structure is as durable as metal, it can rot if wet,
| but metal rusts if wet. Both can be painted, but its
| expensive and a bit polluting. Wood can be produced in
| systems vastly more friendly to environments than any current
| way to produce metal. Perhaps one day dropping it in from
| foundries in space might compete.
| quickthrowman wrote:
| > but metal rusts if wet.
|
| Aluminum does not rust, and galvanized steel will easily
| outlast a solar panel.
|
| https://en.m.wikipedia.org/wiki/Hot-dip_galvanization
| emeril wrote:
| Well, this is texas but who knows... It's def unclear but
| maybe, among other things, they poured some minimal concrete
| underneath in a matrix for earth movement (?) and some basic
| cooling/heat sink with it to address these issues at least
| nominally?
| sgt wrote:
| How about a modified approach that raises the solar panels. One
| could use wood poles with steel wires to suspend the panels.
| That way you could service from underneath and even manually
| wash from underneath (e.g. using a custom made roller that you
| swipe from underneath).
| pmontra wrote:
| Lay those panels flat on a slope? Of course you need a slope to
| start with. What does cost more, steel frames or digging the
| ground to create rows of triangle shaped embarkments /\/\/\ ?
| nubela wrote:
| Is there a way I can contact you personally? I am looking to
| start a solar plant business in Southeast Asia and would love
| to connect.
| [deleted]
| ramraj07 wrote:
| How does one get about starting a solar farm for commercial
| purposes? Do you have any guidelines or resources?
| ush wrote:
| Hi. The most important step is permitting as it's a highly
| regulated industry. The rest is easier. Every jurisdiction
| has its own rules for permitting. Some govs want to push it
| more and make it easy (like Spain used to do it). Some don't
| need solar plants (like Switzerland). I heard Maryland in US
| is pushing it. I was planning to visit Maryland ministry of
| energy to learn more actually.
| dbrgn wrote:
| Why do you think Switzerland doesn't need solar plants?
| We're still in the middle of an energy crisis: While we
| have more than enough energy in spring and summer (lots of
| hydroelectric power plants), we don't have enough storage
| capacity to make it through winter with renewables alone.
| And plans to make an energy deal with the EU have failed so
| far.
|
| Alpine solar power plants are a huge deal right now, and
| cause a lot of discussions. They provide big benefits over
| solar on rooftops in the valley, because they are usually
| above the fogline and provide better efficiency during
| winter.
|
| This is the first alpine solar power plant that's fully
| operational since August: https://www.axpo.com/ch/en/about-
| us/energy-knowledge.detail.... It's mounted on a dam and
| thus had less issues with permissions (as it's mounted on
| an already existing structure with existing power
| infrastructure).
|
| Here's an English article about two big planned projects in
| Gondo and Grengiols:
| https://www.swissinfo.ch/eng/mountaintop-solar-farms-
| spark-t...
| ush wrote:
| I had _really_ wanted to setup a utility scale solar
| power plant in Switzerland and did some research and
| could not find a way to do it nor en example of it
| (except rooftop solar panels which is common).
| Switzerland is already energy independent (60% of
| electricity generation is hydro, 34% is nuclear). This is
| a great mix comparing to fossil sources in many
| countries. And mostly explains low inflation in the
| country I think.
| panick21_ wrote:
| For 20+ years I have wish we literally had just build one
| more nuclear plant, we could easily have done this and
| would be fine and independent by now. But sadly we have
| to investigate all these ideas instead of just going with
| a solution we know works and is literally just a matter
| of spending the money to solve the problem.
|
| Relaying on EU is just a terrible idea.
|
| I'm not necessarily against some things like these solar
| on a dam, but I wish we just look at the problem, picked
| a solution, took on the debt needed and comprehensively
| solved it in one project.
| ldbooth wrote:
| The 2 biggest problems you'd want to solve for first are (a)
| who will buy the power("offtaker") and (b) where the solar
| project will be placed. If it's commercial, often it will be
| at the offtaker's location. There is a competitive industry
| competing for these customer already of course.
| gorbypark wrote:
| Are you an owner/operator at a "smaller" scale? I've always
| dreamed of starting a "DIY" commercial solar farm. I've
| recently moved to Spain from Canada and have been looking at
| the news of these flat installations recently. Seems pretty
| ideal for the climate here (no snow!), land is cheap and
| there's no frost line to deal with.
|
| I was thinking that maybe it makes sense to have each corner of
| a panel on a concrete block to keep them up off the ground a
| bit and promote some air flow and keep the temperatures down.
| That might make it hard to walk on them to clean, though. But
| if I had some sort of Roomba like device to do the cleaning
| that might not be an issue...
| KaiserPro wrote:
| how do you clean it?
|
| Sand and crap is going to blow across that and I don't see a
| practical way to get it off.
|
| I'm not sure those panels are rated for people walking across
| them, so robots?
|
| I can imagine that moss/algae is going to be a problem, as it
| start growing in the corners where all the dust gets trapped
| and is kept moist.
| slyall wrote:
| They have a little robot that cleans it every night. Watch
| the video on their website.
|
| https://www.erthos.com/
| algo_trader wrote:
| 1/ Would this effect the interest rate for the first couple of
| plants?
|
| 2/ Do you think there is a future for robot cleaner? Some new
| companies are already 90% down from recent SPACs.
| lofaszvanitt wrote:
| They don't have elephants there, so good for them, but what about
| Texan wild pigs roaming around? :)
| drumttocs8 wrote:
| Should be an interesting experiment at a decently high scale.
| Time will tell if degradation due to dust, pests, etc is
| negligible enough to make the avoided maintenance costs
| worthwhile.
|
| I think we would all argue that the opposite is better long term,
| though: we should be installing panel covered parking across the
| nation. Certainly more cost, but so many benefits. Including
| serviceability!
| osigurdson wrote:
| Seems that it would be harder to clean. The closer to the equator
| the better.
| kumarvvr wrote:
| I am curious, how much does a sturdy stand cost for a solar panel
| set? Are there significant cost savings on the support structure?
| EDIT : Ok, its 20% of total cost. Significant.
|
| Also, being completely flat, dont they lose avg. units generated
| per day? I though placing them at a N-S inclination helps with
| capturing more energy.
| Havoc wrote:
| What about dust? Texas isn't exactly know for being spotless
| gumby wrote:
| The price of panels has fallen so much that installation is now a
| significant proportion of the cost. So this is a good idea.
|
| But without any airflow behind the panels they will heat up,
| which will reduce efficacy. This is the main reason BIPV (solar
| roof tiles, in this case) has failed for decades. So this is a
| bad idea.
|
| Which is it? I suspect, based on the BIPV example, that this will
| probably not work. It would be cool if this suspicion turned out
| to be wrong!
| tuatoru wrote:
| With the ground covered, evaporation is greatly reduced, so the
| soil stays moist. Water is a good heat conductor.
|
| Having the underlayer for your roof solar tiles be full of
| water is considered undesirable by most permit-issuing
| authorities, so roof tiles must use air cooling.
| deepsun wrote:
| Then it's better to basically float them on water. That's
| what US Army is experimenting with:
| https://thehill.com/changing-
| america/sustainability/energy/3...
| alexose wrote:
| In this case, I think the earth acts as a heat sink. Or so they
| claim on their website (https://www.erthos.com)
|
| Neither their press release nor the article says where exactly
| in Texas it is, but I bet it would make sense to put it in the
| desert where it gets cold at night.
| deepsun wrote:
| Earth is a much worse heat sink than moving air. You can
| check it while stepping on the earth on a sunny day.
| hammock wrote:
| What has driven the cost of panels down? Do we have more mines
| now, or cheaper labor, or something else?
| tuatoru wrote:
| Economies of scale, better energy efficiency in smelting
| polysilicon and making ingots of purified silicon, better
| ingot quality, more wafers per ingot, more usable cells per
| wafer, new cell manufacturing that reduces the number of
| steps and produces better cells, bigger panels so there is
| less dead area around the edges, better glass that is
| stronger so can be thinner and less reflective so the panels
| perform better,optimized wiring inside the panels, better
| cheaper wiring connectors...
|
| A zillion tiny improvements, at every stage in the
| manufacturing process.
|
| The next quantum leap is coming soon: two-layer cells with an
| efficiency jump from the current 22% to over 30% sunlight-
| electricity.
| kragen wrote:
| multijunction pv cells with better than 30% efficiency have
| been around since the 01970s; the best research cells are
| over 40%
|
| those are used almost entirely in space applications
| because they cost so much more per watt
|
| is there some reason to expect that to change
| tuatoru wrote:
| Yes, high-efficiency cells have been around for a long
| time for cost-no-object applications, mainly space.
|
| What's changing is commercialization. Two or three of the
| big Chinese manufacturers have pilot projects going for
| two-layer cells. Of the order of 10 MWe, that sort of
| size. (I can't remember which companies, sorry; it was a
| few weeks ago I read about this. Probably at least one of
| Jinko, JA Solar, or LONGi is in there, as well as one or
| two of the second tier.) Also in the West there are a few
| startups working on two-layer cells, either perovskite on
| silicon or perovskite on perovskite.
|
| (Perovskites are more easily "tunable" in terms of which
| frequencies of light they absorb, apparently--that's one
| of their attractions.)
| kragen wrote:
| i see, thanks!
| philipkglass wrote:
| The big change in recent years is the explosion of
| perovskite-family cell materials. There's a huge variety
| of perovskite materials offering tunable band gaps and
| they can be processed at low temperature, so they can be
| used as top cells over silicon. That promises a big cost
| reduction from conventional multijunction cells built
| with III-V compound semiconductors on germanium [1].
|
| There are a few problems so far:
|
| - The perovskite materials containing organic moieties
| tend to be sensitive to degradation by moisture and/or
| oxygen. They need to demonstrate 20+ years of service
| life to match silicon.
|
| - The purely inorganic materials like cesium lead iodide
| are more stable but have yet to attain high cell
| efficiency.
|
| - There is no proven high-volume way to deposit the thin
| films of perovskite materials, which have different
| handling characteristics than anything previously used in
| solar manufacturing.
|
| I would say there's a good chance of silicon/perovskite
| tandem cells taking off this decade but it's not yet a
| sure thing.
|
| [1] https://eom.umicore.com/en/germanium-
| solutions/markets/multi...
| kragen wrote:
| thanks for the explanation!
|
| i'd say they need to demonstrate 50+ years of service
| life to _match_ silicon, but at 10+ years they 'd be
| marketable at conventional utility discount rates, and
| beyond 20 years the npv doesn't change noticeably
|
| it'll sure be interesting to see what happens here, but
| it's going to be really tough to match silicon's cost per
| watt, much less beat it, unless you can dispense with the
| glass or something
| gumby wrote:
| Because of performance degredation panels are rated over
| 20 or 25 years and generally need to be replaced after
| that.
| kragen wrote:
| while they are indeed rated for 20-25 years, as you know,
| in silicon panels most of the degradation happens in the
| first couple of years; additional degradation in the
| following 30-25 years is measurable but fairly minimal
|
| as i understand it, panels are rated for 20 years not
| because they need to be replaced then but because 30
| years ago nobody knew what would happen over that time,
| and also manufacturers didn't want to set themselves up
| for unlimited liability
|
| usually it's more advantageous to add more panels than to
| replace the existing ones at that point, though rooftop
| installations are often an exception due to the extreme
| space limitations
|
| i think if you sold a perovskite hybrid panel that cost
| half as much per watt as existing silicon panels, but
| degraded down to 70% of its rated capacity at 10 years
| and rapidly down to 50% after that, i think it would
| still sell in a lot of markets
| coderintherye wrote:
| There's no one thing, though increased solar cell efficiency
| has been a major factor:
| https://news.mit.edu/2018/explaining-dropping-solar-
| cost-112...
| Euphorbium wrote:
| They could do water cooling underneath. Probably not worth it
| though.
| EricE wrote:
| "If the Erthos approach is viable and financeable" Ha!
| bilsbie wrote:
| We'll the cost isn't just the racks
|
| You've got to deal with permits for the structures. Installation.
| And then you have to do lawn trimming around all the racks. This
| can save on all of that.
| [deleted]
| felgueres wrote:
| The reason they are tilted is to maximize irradiance hitting the
| panel. At a 0 degree angle (flat on the ground) you get a a lot
| around noon and then very little.
|
| This approach surely reduces land usage but what is the output
| per acre?
|
| I'd be really surprised if it's higher than with tilted modules.
| celtain wrote:
| I expect that they are getting lower output per acre, but in
| places where land is cheap and as solar panels continue to get
| cheaper, the money saved on building the support structures
| could be worth those losses.
| rootusrootus wrote:
| They're getting quite a lot more output per acre, by being
| able to use more panels.
| HellsMaddy wrote:
| Seems lying them flat also makes their cleaning robot able to
| easily maneuver, meaning they don't need to leave any space in
| between panels for humans to perform maintenance. Pros: reduces
| land usage as you mention, but also less humans needed for
| maintenance.
| JoeAltmaier wrote:
| Per day? Per acre? Per dollar?
|
| It's all about the metric you choose. That's the true issue.
| nimos wrote:
| Texas is pretty far south. If you use
| https://pvwatts.nrel.gov/pvwatts.php there is about a 9%
| increase in total output over the year for optimal tilt(27 vs
| 0) but then you also need to space modules.
|
| There is hourly data if you are interested but even Jan 1 the
| panels produce for ~7-8 hours. The 3 hour around noon it's
| about 1/2 the output for the day (for Jan 1).
| mkl wrote:
| The article claims it's much higher output per acre:
|
| > conventional solar technologies, which typically require five
| to 10 acres of land per megawatt of capacity. Erthos claims
| that its mounting scheme requires less than 2.5 acres per
| megawatt.
| fulafel wrote:
| Going to the other direction, I wonder what would be the
| maximum archieveable output per acre without height
| limitations.
|
| Would you have a forest of tall towers, or one really tall
| panel covered building, or something in between?
| s1artibartfast wrote:
| They claim the power per acre is 4x higher than tilted panels.
| Seems like a stretch, but I don't know how bad the density is
| in tilted installations. I guess I have seen some where you can
| drive between rows
| sacred_numbers wrote:
| Density in tilted installations is quite bad. If you want to
| capture morning and evening sun at an optimal angle you have
| to space the panels out a lot, like 5-10 panel heights. You
| can have them closer, but then you get shading, which defeats
| the purpose of tilting the panels.
| whatshisface wrote:
| The amount of power landing on an acre is fixed, what you can
| achieve by tilting is having less solar panel surface area per
| ground cover area. If solar panels are cheaper than the
| mounting hardware (wow) then there is no reason not to let them
| lie flat on the ground (it's not as if the racks were holding
| them above tree shadows, or anything).
| michae4 wrote:
| The solar radiation wattage per unit of surface area is
| dependent on the angle that surface is to the sun. The angle
| is dependent on the season and time of day, so the amount of
| power is not fixed.
| apendleton wrote:
| Per unit of panel surface area, not per unit of land area.
| If the sun is coming in at an angle, you'd be able to
| collect all that's available with less panel area than
| total land area by angling them (or equivalently, in this
| new configuration you need more panel area than you
| otherwise would), but in their estimation, it's cheaper to
| just get more panels than it is to buy and install racks.
| imtringued wrote:
| >The solar radiation wattage per unit of surface area is
| dependent on the angle that surface is to the sun.
|
| A tilted solar panel casts a shadow that is bigger than its
| actual area. Mounting the panel flush to the ground means
| it casts a shadow exactly equal to its area.
|
| The shadow represents the captured sunlight so the first
| panel covers more surface area than the second panel, which
| allows you to reduce the number of panels to cover the same
| amount of surface area. The entire point of this article is
| that you can just put the saved costs into buying more
| solar panels.
|
| Used solar panels are very cheap but usually only the solar
| panels are replaced and the mounts are kept and fitted with
| new panels. So for companies that want to use used panels
| their primary cost is actually in the mounting hardware and
| not the panels.
| danbruc wrote:
| What the comment wanted to say is that the power per unit
| of ground surface area is fixed for a given location and
| time, i.e. it does not matter [1] whether you cover a given
| area with panels angled towards the sun or lying flat on
| the ground, at least if one only looks at the available
| power. There is of course a difference in the solar panel
| area required to cover a given area of ground surface -
| solar panels lying flat on the ground will obviously have
| to have the same area as the ground surface area while
| panels angled towards the sun will only require a fraction
| of the ground surface area equal to the sine of the angle
| of the sun above the horizon.
|
| [1] For a sufficiently large area so that effects on the
| edge are negligible.
| whatshisface wrote:
| You could write a few pages of all the things that the
| power available depends on, but you don't need to because
| it's fixed relative to the variables under consideration.
| guerrilla wrote:
| > If solar panels are cheaper than the mounting hardware
| (wow)
|
| I'm surprised this surprises people... Every electronics
| hobbyist knows that electronics are cheap as dirt while any
| kind of box, mount, rail or whatever is BY REALLY FAR the
| most expensive part of a project, even when buying massivly
| mass produced cheap Chinese junk.
| DoesntMatter22 wrote:
| You are surprised that this surprised people because
| electronic hobbyists know this? Most people are not
| electronic hobbyists so this should probably not surprise
| you
| guerrilla wrote:
| I just find it interesting, the difference different
| perspectives can make, especially on a website where
| people are often bikeshedding things they have no
| experience with.
| whatshisface wrote:
| The electronics you're talking about are rice grain sized
| little things, while the solar panels are big sheets of
| silicon inside of glass, etc.
| imtringued wrote:
| Those grain sized things have pretty high packaging costs
| in relation to what you are actually buying.
| guerrilla wrote:
| Economies of scale make that irrelevant.
| davelondon wrote:
| It's amazing how so few people understand this.
| whatshisface wrote:
| I think people are imagining that solar panels have
| directionality like most photodetectors do.
| nkurz wrote:
| This is a great way of thinking about it, but don't you lose
| a bit more due to increased reflection from the glass surface
| at low incident angles? Probably not enough to make a
| difference a low latitudes in the summer, but at high
| latitudes in the winter I think it might be a significant
| difference: https://en.wikipedia.org/wiki/Fresnel_equations#/
| media/File:...
| nkurz wrote:
| Partially answering myself, 'sacred_numbers' posted a link
| elsewhere in this thread that suggests this effect might be
| quite small:
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6611928/. The
| paper concludes that for a cell with a good Anti-Reflective
| Coating (ARC), the reduction in efficiency due to
| reflection at a 60 deg incidence is only 2%.
|
| On the other hand, the incidence for a flat mounted panel
| beyond 37 degrees of latitude on the winter solstice is
| greater than 60 degrees, and it's not clear (to me at
| least) how well the ARC on an average panel will continue
| working after years of outdoor usage. My guess is
| reflection is probably a real issue, but not a stopper
| unless one is already in a marginal situation.
| fy20 wrote:
| The biggest issue going north is probably snow.
|
| I'm at 54N and my output has been 0 for the past month as
| we've had a lot of snowfall. My panels are at 20 degrees,
| so even in the few sunny days we've had it's not been
| enough to melt the snow. A steeper angle probably would
| have cleared it a few times.
|
| Usually the beginning of the year has more sun but it's
| colder, so I'll see what happens then.
| kragen wrote:
| the article claims 15C/ per watt of mounting hardware; last i
| checked solarserver says pv modules are about 20C/ per peak
| watt
|
| presumably that was 15C/ per peak watt but the article
| doesn't actually say
| rootusrootus wrote:
| > you get a a lot around noon and then very little.
|
| That's a little harsher than reality. You get a very pretty
| bell curve. I have a flat panel on the roof of my RV and I
| track the output over time. I'm not 100% how much of the loss
| in output is because the incidence to the panel is changing, or
| because the light from the sun is going through more
| atmosphere. Probably a little of both, but in any case the
| panel is still plenty useful even when not pointed directly at
| the sun.
| hindsightbias wrote:
| Seems like they would have to do some grading to clear anyway,
| why not grade with some tilt.
| elihu wrote:
| With tilted modules, you'd normally space them out quite a bit
| so the shadows of one aren't falling on the module next to it.
| If they're all flat, that's not a problem so you can space them
| closer. So, it makes sense that they'd get more power per acre
| than the conventional approach -- the panels are individually
| less efficient, but there's a lot more total solar panel area
| per acre.
|
| That might not always be a good tradeoff, but maybe at least
| some of the time it is.
| avip wrote:
| They don't claim to outperform fixed-tile or SAT on that KPI.
| They claim to reduce upfront cost of installation, construction
| time, and general project risk.
| anko wrote:
| aussies are doing a similar thing although they install by
| pulling via tractor and the panels concertina out see
| https://suncable.energy/
|
| they are doing an underwater cable to supply energy to singapore
| 1024core wrote:
| > From 2010 to 2021, the levelized cost of installing utility-
| scale solar fell 88% .... But in the last couple of years,
| supply-chain issues have halted these price declines globally
|
| How many "couple of years" have there been between 2021 and now?
| kube-system wrote:
| The two time periods you have quoted are not necessarily non-
| overlapping time periods. Nothing from your quote implies that
| the couple of years begins at 2021.
|
| Falling between two dates does not imply that it fell uniformly
| or that it fell for every year between those two dates.
| Retric wrote:
| At scale there is probably a fair bit of dead time if you want
| to get 100+MW of solar panels. So, it might be well over 2
| years at this point.
|
| Aka companies had agreed to deliver in 2020 for X$, but took
| longer to actually deliver.
| tbihl wrote:
| I think "couple" is pretty typically accepted as being "two",
| at least in most US settings; I can't speak for international
| variations. In my home area of central Pennsylvania "couple" is
| a more general, meaning anywhere between 2 and 4, but I think
| that usage is rather the exception than the rule.
|
| Nonetheless, we can probably give them a pass for saying
| "couple" instead of "nearly three" since January 2020.
| jwilk wrote:
| https://xkcd.com/1070/
| zargon wrote:
| A rare instance of xkcd being just plain wrong. ;)
|
| "a couple" = 2
|
| "a few" = 3 (maaaybe 4)
|
| "several" = 4 to 7
|
| "a handful" = context dependent, usually ambiguous
| quickthrower2 wrote:
| A few: count of 2 to 10% of a sample in my book.
|
| There are only a few people who understand quantum
| mechanics, for example
| zargon wrote:
| Yeah I guess that works for me.
| TecoAndJix wrote:
| Also from central PA: my dad and I had this discussion years
| ago and he argued the syllables made the count: (1)A (2)Few
| and (1)A (2)Coup (3)le. I was in the other camp that a couple
| is two (husband and wife) and a few was much more loose on
| definition (2-5).
| marcosdumay wrote:
| There has been one couple of years since the beginning of 2021
| and now. Quite exactly like the text you quoted says.
| deathanatos wrote:
| I suppose if we're charitable, maybe "From 2010 to 2021" is
| programmer style [2010, 2021), i.e., ending at 1 Jan 2021. Then
| all of 2021 & 2022 form "a couple of years". (The book is more
| or less closed on 2022. Given that my "2 day shipping" from
| cyber Monday took 8 days, I'm not holding my breath on "the
| supply chain" fixing itself prior to people giving it up for
| the holiday retreat.)
| pugworthy wrote:
| From the land topography fitting perspective, it's too bad panels
| are triangular. Then one could essentially create a triangular
| mesh overlay of panels over all kinds of uneven terrain.
| soorya3 wrote:
| This is still inefficient use of space, no? and subject to
| elements at the ground level.
| thehappypm wrote:
| Space is cheap, and there is a LOT of it in Texas.
| Jweb_Guru wrote:
| Space efficiency is not a real concern for grid scale power, at
| least not in the US.
| Klasiaster wrote:
| Dead ground is not so good for biodiversity, with the standard
| way you have wild grass and flowers beneath.
| interestica wrote:
| 'agrivoltaics' is a cool thing:
|
| https://kansasreflector.com/2022/02/14/lets-grow-a-brighter-...
|
| https://www.nature.com/articles/s41598-019-47803-3
| PaulDavisThe1st wrote:
| agrivoltaics requires more space between racks to provide
| sufficient light for the plants to grow. that's neither a
| good or a bad thing - it's just a statement of fact about the
| paired compromises that arise from combining PV generation
| with agriculture. It is still likely a good idea in many
| places.
| epistasis wrote:
| But still better than growing corn or soybeans on the ground.
| therealdrag0 wrote:
| Maybe more efficient but also more sterile.
| elihu wrote:
| Covering the ground with impermeable surfaces isn't great
| either. (Maybe they have drain holes at regular intervals so
| that's not as much of a problem?)
|
| I'm guessing they will probably need a tall fence around the
| outside to keep deer away.
| unyttigfjelltol wrote:
| The optics are bad-- like this advanced civilization here on
| Earth decided to make a Dyson sphere of our own planet.
| zahma wrote:
| I take your point, but arguably the optics of burning up
| every last drop of fossil fuel are worse.
| micromacrofoot wrote:
| probably better than mining it
| im3w1l wrote:
| Already, 96% of mammal biomass is humans and livestock. No
| one has the power to stop this process, to do what it would
| take. Enforcing a strict max-2 child policy on the whole
| world and/or telling people to live in the pods and eat the
| bugs. Hopefully, once our civilization goes interplanetary,
| we can try to restore a bit of what was lost.
| vidarh wrote:
| Fertility rate is already below replacement for all of the
| world except sub-Saharan Africa, and it's dropping there
| too. We're headed for population decline within a century
| unless something changes dramatically.
| infogulch wrote:
| Finally someone saw the light and accepted the superiority of
| Factorio's flat solar panel design. Why dump so many resources
| into fixtures to eke out every last drop of efficiency when
| panels are cheap enough to just spam as groundcover? :)
| JoeAltmaier wrote:
| From one point of view, they are exactly as efficient as tilted
| panels? If your metric is sunlight intercepted per acre, then
| 100% is as good as it gets.
|
| Tilting gets a better angle of incidence with the sun, which
| matters if that improves conversion rate (does it?).
|
| If you have plenty of land and cheap panels, then your metric
| might be dollars-per-watt. Then this solution is a big step up.
| Less cost per install means more money for acres. You end up
| with more acres installed, you have more electricity.
|
| And I suspect this is the right metric for some areas (like
| Texas), since panels are cheaper every year and they have
| plenty of acres.
| otabdeveloper4 wrote:
| Seems like an unmitigated environmental disaster.
| pjio wrote:
| s/Factorio/Rimworld/
|
| tilted: https://wiki.factorio.com/images/Solar_panel_entity.png
|
| flat: https://rimworldwiki.com/images/b/b4/Solar_generator.png
| jacquesm wrote:
| This has been exactly my strategy. My first setup had two leafs
| of 8 panels each, tracking both azimuth and elevation. It was
| fragile, finicky, required a lot of active components and
| ultimately cost more per Watt that it put out than if I had
| simply laid the panels flat. Which is exactly what I did with
| my current installation (16x265 and 26x365). Another advantage
| of panels that are flat is that they are much less prone to
| being lifted up by the wind, you can mount them flush and the
| wind barely has any grip on them. They also do not shade each
| other at all, no matter what the angle of the sun.
|
| Double axis tracking systems when they work are very pretty and
| technically satisfying, but ultimately those are not the right
| criteria by which to evaluate a system that has to be reliable,
| storm proof and that has to last a decade or more after
| installation, preferably without any service.
|
| The weak point in the current installation is the cables and
| the connectors, that is something you can't really get away
| from. After dismantling a few older setups and having a good
| look at what remains there are two things that stand out for
| me: Make sure all cable joints are made in the shadow of a
| panel and tie down your cables on the underside of the support
| structure so they don't flap about in the wind and are not
| exposed to direct sunlight. Over time they'll get killed and
| especially with series connected panels (the bulk of them) this
| can lead to spectacular results (of the wrong kind).
| tbran wrote:
| Could you post a couple pics of your setup? Did you just use
| an off-the-shelf support structure?
| killjoywashere wrote:
| Covered parking and rooftop make so much more sense though.
| Why do we want to cover _more_ of the natural world, our only
| world, with more of our silicate-derived trash?
|
| Parking and rooftop ensure the structural protection of your
| cabling, while at the same time optimizing the positioning of
| your servicing ports. Slightly elevated rooftop solar can
| also significantly reduce the a/c bill of a structure
| (especially smaller houses in sunny environments) and parking
| helps protect the paint of cars.
| ClumsyPilot wrote:
| Because on the ground you have have 5 hecrates of solar
| panels accessible by any joe for repairs and inspection,
| the same panels on the roof require specialists to climb
| and inspect, and they are now spread across roofs of 10
| different buildings, making maintenance a nightmare
| mgerdts wrote:
| The typical Home Depot store is 105,000 sq feet, which is
| about 1 hectare. These tend to exist in the same general
| area as other big box stores and similar huge flat roofed
| buildings. Those are much closer to where a bunch of
| electricity is used than the undeveloped or farm land
| just outside of the burbs.
|
| Add in covered parking lots and distributed batteries
| (dedicated batteries, cars, etc.) and I bet that we would
| reduce the need for building even more high voltage lines
| across the countryside.
|
| We should be looking for ways to generate and store
| electricity close to where it is needed where we have
| already destroyed nature.
| midasuni wrote:
| My company has a warehouse in west london, we looked at
| putting solar on the roof, but it's not strong enough.
|
| You can't simply put solar on a roof
| 2ICofafireteam wrote:
| Why? What actually killed it?
|
| Do you mean that you can't meet 100% of your demands, or
| it can't be done for some other reason?
|
| You could reduce, but not eliminate, the demand for
| purchased energy. Would that be unacceptable? Is there
| not a net metering programme there?
|
| For me the big deal is usually demonstrating payback. I'm
| in British Columbia and my solar experience is only with
| single family homes; on and off grid.
|
| There was no big cost analysis with off grid homes. You
| need power, or you don't. It's just another category in
| the budget and the cost decisions are about balancing
| desires and cost.
|
| With grid-connected homes, we don't even try to sell it
| now. Nearly all our customers have mortgages to pay for
| their new house and factoring in the interest paid makes
| it much less attractive.
|
| A few years ago, low interest rates and high energy costs
| made it an easier sale. If you were in the position of
| having money in the bank, you could get a better return
| on that money by upgrading your home to save energy. Of
| course it could only scale as large as the cost of
| improvements.
|
| Even then, a lot of homeowners didn't intend to own the
| home long enough to realize the returns, and I don't
| think small solar systems improve resale value. The
| feeling in the office is that if you're planning to
| resell, the money is better spent on the kitchen.
| ARandomerDude wrote:
| > Why? What actually killed it?
|
| I think the parent was saying the solar was too heavy for
| the roof to support. The physical structure of the
| building was not strong enough.
| 2ICofafireteam wrote:
| Thanks! If the guy with pinkie ring won't stamp the
| plans, it's not going anywhere.
| calvinmorrison wrote:
| Because the usa is huge and full of low value arid desert
| near areas that need lots of power. In short, economics of
| the sun God
| maxnevermind wrote:
| Can it be delivered from the desert without rising the
| total cost to high?
| fbdab103 wrote:
| High voltage transmission losses can be low, <3%. I have
| seen previous reports that 5-7% of all electricity is
| lost to transmission. For a backbone (highly maintained)
| electrical network, I think that would be fairly marginal
| cost vs everything else involved in the calculation.
| seanmcdirmid wrote:
| There are plenty of cities near the desert to suck up the
| power without ultra high power transmission. Like
| phoenix, Vegas, LA...I'm guessing all those opportunities
| will be soaked up before they start putting them in them
| in the middle of nowhere.
| Mildlypolite wrote:
| Yes the first step should be to cover every rooftop and
| parking. I think a law exist in some states that new
| construction has to have solar panels on. The law should be
| passed everywhere.
|
| And it's just the first step.
| chasd00 wrote:
| government is like XML, if it doesn't work just use more.
| TaylorAlexander wrote:
| Okay but what if we cover all the roofs with rooftop
| gardens and cover all of the ground with solar?
| dieortin wrote:
| Rooftop gardens are not nature, so it's the same thing
| TaylorAlexander wrote:
| It was meant to be a silly comment, though normally I'd
| have added some emoji to make that clearer.
| jasonwatkinspdx wrote:
| This can make sense to do, but it ends up being a lot less
| cost effective than utility scale solar.
|
| A friend of mine lives off grid in Mexico, and he got
| double duty out of his solar array by making it a big
| carport and workshop area. So yeah that totally works.
|
| But, if you're going to invest $X in solar, it's better to
| spend it on utility scale stuff than even commercial
| versions of covering parking lots. This is because the
| utility scale operation better amortizes the equipment
| needed to tie into the grid, as well as operationally will
| keep the panels clean and working at peak efficiency.
| cortesoft wrote:
| There is SO MUCH empty land out in deserts. We aren't going
| to run out of space.
| shapefrog wrote:
| There is SO MUCH empty land on the roof of our buildings
| - and electricity using devices within said buildings.
| JoeAltmaier wrote:
| Rooftops are not that much land area. A few percent of a
| city landscape?
|
| Further it's dangerous. Installation, maintenance become
| a headache and a risk.
|
| Then, so many rooftops are not in optimal 'viewing
| locations'. Shaded by trees; shaded by neighboring
| buildings especially in a city.
|
| It seems natural to a non-engineer to 'make electricity
| where you need it'. But rooftops don't scale with need,
| not at all. An apartment building on a lot with 3 stories
| or 30, same rooftop area. Terrible economics.
|
| And electricity is fungible! Make it over there; use it
| over here. Almost free. Certainly cheaper than struggling
| to mount something delicate in the hardest place you can
| find.
| masklinn wrote:
| As I was told last time I noted there's lot of arid
| places you could put panel in, aside from ecological
| concerns arid places tend to be dusty and abrasive.
|
| Wind kicks up dust, dust clings to panel, no rain for
| months on end, panels get covered up and scratched. Turns
| out there's issues to using these spaces, and you need
| additional hardware (and thus have additional failure
| modes) to mitigate them.
| justinator wrote:
| Deserts [?] wastelands. They're home to their own
| ecosystems.
| imoverclocked wrote:
| Yes, they are also very fragile and take a long time to
| recover.
|
| I think solar panels done right could actually help a
| desert though. Providing shade can allow some plants to
| thrive but most solar developers aren't thinking about
| the ecology of a region.
| jacquesm wrote:
| Large installations usually come with mandatory
| ecological impact assessment requirements.
| imoverclocked wrote:
| How many of these mandatory impact assessments are
| identifying ways of improving the ecosystem with their
| installation? Obviously I don't mean by by displacing
| carbon.
| chrisbaker98 wrote:
| From a purely selfish human point of view, how important
| are desert ecosystems to the overall health of the planet
| and the planet's ability to support human life?
|
| I feel like sacrificing the deserts to save the
| rainforests is a trade worth making - but is such a trade
| even possible, or is it not that simple?
| justinator wrote:
| _> From a purely selfish human point of view_
|
| Well that's a point of view that's never steered us
| wrong.
| StanislavPetrov wrote:
| Deserts are a critical part of our ecosystem just like
| every other part of the planet.
|
| https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/
| 201...
| dr_dshiv wrote:
| This article actually suggests that desertification is a
| critical part of the Rainforest ecosystem.
|
| There are important deserts and there are important
| grasslands and important forests. It seems a valid point
| that not all ecosystems are of equal importance.
| neltnerb wrote:
| It would be interesting paired with some kind of heat
| sink.
|
| Solar cells need a heat sink to keep them cool or else
| the efficiency sucks.
|
| Deserts tend to be cold at night.
|
| Capture heat during the day as a byproduct of using the
| solar panels, and use it at night for heating homes?
| Maybe I'm being too optimistic, usually things that
| improve efficiency don't actually work for some reason.
| escalt wrote:
| That might be true in some places, but in Europe for
| example there really isn't that much room left. And
| moving large quantities of electricity from a desert to a
| place where people actually use it is also a challenge
| j-bos wrote:
| If land cover is the issue, isn't this a great use case for
| the airship tech that refuses to die? No land issues, no
| roof issues, relatively clean area, movable according to
| weather.. It would be crazy expensive, but airships are
| keep getting invested in anyway, so why not try adding
| solar?
| usrusr wrote:
| Another advantage of flat: when angled panels are placed wide
| enough to not shade each other at noon they will at all other
| times of the day allow light to hit the ground (and it gets
| worse with seasons, far worse with 2d tracking). That's good
| when you want some agrovoltaic dual use, but not good when
| you want to maximise electricity from a given acreage. Only a
| flat layout will at any time of day and season collect 100%
| of the light that would hit a given ground area.
| jacquesm wrote:
| Yes and no, yes, all the light will _initially_ be captured
| but if the angle is off then a part will be reflected and
| if the angle is off > 45 degrees then most of it will be
| reflected.
| usrusr wrote:
| Surface reflectivity can be an issue, that's true. And
| the numbers aren't as easily compared as the simple
| geometry of casting shadows. And I assume that there must
| be large differences between different module types?
| jacquesm wrote:
| The big difference is the kind of glass and coatings
| used, this can make a few % difference at the same angle
| of incidence. Typically the yield below a 45 degree
| mismatch is the maximum panel yield x cosine(angle of
| incidence) x transmissions (anywhere from 90 to 95%
| depending on coating and base material). Beyond 45 degree
| mismatch there is a sharp drop off.
| usrusr wrote:
| Certainly a topic where it's impossible to judge without
| knowing actual curves. Even looking at actual panels
| (without measuring output) you'd be prone to misjudge
| because some that look promisingly low in terms of
| specular reflection might pay for it with higher diffuse
| which won't notice as long as it's not particularly
| bright.
|
| That leaves armchair-level pondering to theoreticals: is
| the perfect "any angle" surface even physically possible
| or are there physical limits that only leave tradeoffs?
|
| And another aspect I don't know: do the cells mind? Does
| that "punch an electron" principle still work out when
| photons come in almost parallel to the electrodes? (in
| practical terms: if we compensated the lower effective
| cross section and reflectivity with higher light
| intensity, would we still get the same voltage?) When I
| was a kid I had a miniature cell in an experiment kit
| that had a deep plastic top layer with angled prism
| structures under the surface almost like those of a
| retro-reflector and I always wondered why it would have
| that. Was it because the cell could only collect from
| photons coming in almost perpendicular, and the job of
| the plastic structure was to make sure that there would
| always be _some_ photons making the angle threshold
| (certainly by sacrificing a huge amount of power in the
| well-aimed case)
|
| This all almost sounds like an argument for heliostats
| (which get the best yield per module surface, but the
| worst yield per acre), and which would be a perfect match
| for agrivoltaics. But that's an approach that hinges
| entirely on the cost and (far more importantly, at scale)
| resource use of the mechanical structures required. Which
| is a mechanical engineering problem that you'd have no
| problem explaining to a victorian era engineer. Genius
| "inventors" to the rescue?
| jacquesm wrote:
| I have 26 panels set up like that of two different types
| and the figures pretty much match that formula.
|
| I've used two heliostats in the past (see other comment
| in this thread) and on a $/Watt basis you're better off
| putting them flat, regardless of the perceived
| advantages, after all is said and done you will have more
| power, be out less money and have a more reliable system.
|
| Now if only the sun would shine...
| usrusr wrote:
| That possible heliostat future I keep bringing up
| wouldn't be about $/Watt (that was an argument for
| helostat back when modules were much more expensive, but
| certainly isn't the case anyone), but about finding a
| sweet spot in agrivoltaics between energy and nutrient
| harvest: Watts per impact on farming. Or more
| specifically, electricity dollars per impact on farming.
| Because when there is a large installed base of
| photovoltaics, watts at noon won't be worth much compared
| to watts at deeper sun hours. And for the same amount of
| off-noon watts, a heliostat setup would cause less
| shading to the plants below than any other setup. And as
| a bonus benefit, the east/west spacing inherent to
| heliostat installations would give a nice distribution of
| shading, at least nicer than with fixed east/west lines.
| I believe that the advantages are quite clear, but of
| course only if the mechanical parts can be cheap enough
| (in terms of resource use). Flat north/south lines that
| only pivot east/west would surely be a sweet spot, up to
| a certain latitude.
| overboard2 wrote:
| But tilted panels will collect from a larger area than the
| ground area they occupy (collecting from the area of the
| shadow they cast)
| usrusr wrote:
| A larger area per panel, sure. But not a larger area per
| ground area, if you look at a larger installation than a
| single module (or a single row of modules)
| smadge wrote:
| Aren't the factorio solar panels propped up on little steel
| struts?
| elihu wrote:
| Actually, the game art uses tilted panels (crammed closer
| together than they'd be in real life, so the shadow of one
| falls on the one behind it), though I admit I did think of
| Factorio solar panels in the sense that in the game you can
| make an area inaccessible to pedestrians by spamming the ground
| with them.
|
| https://wiki.factorio.com/Solar_panel
| infogulch wrote:
| Time to open a bug report :S
| TOGoS wrote:
| Harkonnen had a long-term project to make dynamic shadows
| that would change throughout the day, which would result in
| the solar panels being fully lit for at least a moment at
| noonish, but I got the impression that side-project was
| eventually canned due to, uhm, personnel issues.
| aardvarkr wrote:
| Did something dramatic happen?
| rootw0rm wrote:
| Yes, Paul of house Atreides happened
| infogulch wrote:
| Aren't shadows baked into the texture? Adding another
| dimension to the texture matrix of all structures seems
| dubious.
| trhr wrote:
| It's SOLAR FREAKIN' PARKING LOTS all over again.
| idiotsecant wrote:
| Seems weird. How do you service it? How do conductors work? How
| do you keep random junk from blowing on top of it? How do you
| clean it? The photo in the story just looks like a giant square
| of PV material. Is that really what this is?
| pavon wrote:
| First, they are banking on the fact that solar doesn't need a
| lot of repair and maintenance in general, and their design
| decreases some of the stresses that racked solar panels
| encounter. I imagine they are also over-sizing the system, and
| adding remote disconnects so they can disable a certain number
| of panels and still meet the contract.
|
| And then when repair is needed, they just walk on it[1].
| Seriously. I'm very curious as to what these pads they mention
| are like - big foam snow shoes, or walkways they rollout along
| a seam?
|
| [1] https://www.erthos.com/reducing-degradation-rates-with-
| earth...
| avip wrote:
| Likely something akin to deminers weight-spreading shoe pads.
| They have to meet panel manufacturer's certified pressure
| spec.
| baking wrote:
| I assume they need to worry about scratches. An XXXXXL
| clean room bootie wouldn't work because it would pick up
| sand and grit as you walk across the panels.
| kadoban wrote:
| A few scratches aren't going to be a big deal. Not like
| they not going to get dirty and dinged up from the wind
| anyway.
| etrautmann wrote:
| The real world just isn't that clean. There's no way that
| a weight spreading shoe will do more than some random
| frequent dust cleanings
| jsight wrote:
| Oh, that's interesting. And I guess if they do manage to
| break a few panels, they can be replaced cheaply. Its
| probably still cheaper than dealing with racking.
| jacquesm wrote:
| They are ridiculously strong. I've had a set of 8 on a
| tracker be blown over by the wind (in spite of ample
| foundation according to the people that sold me the gear),
| land on the edge and not get damaged at all. That was a
| pretty heavy impact too, the whole thing was 30 cm into the
| ground.
| jl6 wrote:
| Maybe if it reduces installation cost enough they will be able
| to tolerate some inefficiencies.
| [deleted]
| function_seven wrote:
| There's another link with better details on all of that:
|
| https://www.canarymedia.com/articles/solar/erthos-rakes-in-1...
| bushbaba wrote:
| Install cost is ~50-75% the total cost of the system. If you
| can bring install cost down your tolerance for panel failure
| can be quite high while still having a better roi
| luhn wrote:
| Re cleaning, they have a cute little robot that you can see on
| this page: https://www.erthos.com/energyservices It's also
| visible in the photo in the article.
| hn_throwaway_99 wrote:
| Thanks for posting that! Made me realize that when all the
| panels are laid over a huge area in essentially the same
| plane that it must be so much easier and cheaper to clean.
| Just put this robot on it and let it go, roomba-style (OK,
| not exactly roomba-style of going over the same spot 50
| times, but you get the idea). Seems like it would be a lot
| cheaper than what would be needed to keep rack-mounted
| systems clean.
| thinkmcfly wrote:
| They should fix the wheel spacing so it rolls on the metal
| frame and doesn't scuff up the edge of the panels
| happyopossum wrote:
| > They should fix the wheel spacing
|
| Sounds like they optimized it for their use case:
|
| "The load of the robot is distributed almost entirely to
| the module frames rather than the glass module"
| ElijahLynn wrote:
| Thanks, I was wondering how they were going to keep it clean,
| and the linked article doesn't have the word "clean" in it at
| all, so it could be improved by discussing more about that. I
| also see now that the little robot is in the pic in the
| linked article too.
| nine_k wrote:
| The robot is cute!
|
| I wonder what happens after a major rain though. I suppose
| the panels are weatherproof. But they lie _directly_ on the
| ground, and I did not notice any mention of a drainage
| system. The panels will eventually sag under load from
| rainwater, preventing it from flowing off them.
|
| They mention that their installation can withstand a
| hurricane. I understand how it works for the wind load, but
| every hurricane I witnessed brought a lot of rain.
|
| EDIT: Apparently they embrace flooding, and say that their
| panels and connectors can withstand being submerged in water.
| That's the spirit.
| xnx wrote:
| Reminds me of M-O from Wall-e
| https://pixar.fandom.com/wiki/M-O
| [deleted]
| jsight wrote:
| Presumably the plan is for them to be high enough relative
| to the surroundings that the water runs off rather than
| pools.
| leobg wrote:
| Cool. I can see myself using a Scooba. I'm serious.
| pugworthy wrote:
| Wish I'd had that at Burning Man this year. Getting dust off
| a 200 panel array was no fun job...
| akiselev wrote:
| I doubt this robot would last long with gypsum dust.
| robocat wrote:
| I wonder how they manage drainage and surface flooding?
|
| Image of robot on panels: https://static.wixstatic.com/media/
| 3b0818_1667facfc56e475e8f...
|
| The image also seems to show water damage in the corner of
| the closest panel.
|
| At a guess, they target areas without heavy rainfall, and
| fast draining soils. I didn't see any drainage works in the
| video https://vimeo.com/556421759, nor did my google-fu help
| me find anything where they address the issue.
|
| Edit: from https://www.canarymedia.com/articles/solar/erthos-
| rakes-in-1... How do the installations
| perform in the rain and snow? "Our hydrology report proves
| that an Erthos plant is almost the same as native soils with
| respect to accumulated water depth and velocity in
| rainstorms. All of our designs include professional civil
| design that includes water runoff management and containment
| basins as per the jurisdiction's application of building code
| and other local requirements." What about
| flooding? "The glass/ glass modules and the connectors we
| specify are all rated for submersion, so flooding is not a
| catastrophic event in case it does occur."
| latchkey wrote:
| Blemishes on solar panels aren't necessarily bad or have a
| huge effect on generation or durability. These could also
| be previously used panels in the image, which are often
| sold at enough of a discount to offset the loss in power
| generation.
| maxerickson wrote:
| A site graded to slightly angle towards the sun would also
| keep the panels drained.
| Maursault wrote:
| > Re cleaning, they have a cute little robot
|
| Ever cleaned dried bird droppings off a windshield? I'd be
| pretty surprised if solar-farm Roomba was up to it.
| mrcartmeneses wrote:
| Shouldn't matter in the grand scheme and it will probably
| be clean after 5-6 passes
| geysersam wrote:
| Any solar installation will face that problem though
| Maursault wrote:
| My point only concerned the robot. Other solar
| installations won't have a tiny self-driving Zamboni
| that's ineffective at cleaning bird poo and is bound to
| be stolen. They use renewable and cost-effective elbow
| grease instead.
| ClumsyPilot wrote:
| > won't have a tiny self-driving Zamboni that's
| ineffective at cleaning bird poo and is bound to be
| stolen
|
| Why do you think it's ineffective, they could have a
| pressure washer inside that thing
| pulvinar wrote:
| I can't see how bird poo could be a problem here: there's
| no food, nesting site, nor high spot to hang out anywhere
| near it. Theft could be a problem, though I'd assume
| they'd have some sort of protection hidden on it.
| mgerdts wrote:
| The solution here seems to create a zone that is
| completely inhospitable to the ecosystem that should
| exist in that spot. In the picture in the article, the
| bird poop will be highly concentrated in the forest area
| that is nearby. While there will be some birds that fly
| over this dead zone, I bet the droppings will be minimal.
|
| Edit: The article mentions a 100 MW installation. At 2.5
| acres per MW, that is 40 acres or 0.25 miles x 0.25
| miles. While there will certainly be some service roads,
| no matter what the ecosystem was before, it will be
| covered with something that doesn't support plant
| material, insects, etc. that may be consumed directly by
| birds or the small animals upon which birds prey. Birds
| will find a more hospitable place to poop.
| kragen wrote:
| maybe use a little potassium carbonate to convert the uric
| acid in the bird shit to dipotassium urate, thus increasing
| its water-solubility 300x, and follow up with a strong
| buffer that's mildly acidic like monopotassium phosphate to
| prevent any stray residues from the solution from causing
| alkali corrosion of the glass when it dries
|
| probably there are a lot of possibilities you haven't tried
| on your windshield yet
| rkagerer wrote:
| Why is that not sold as a specific bird droppings
| cleaning product yet?
| kragen wrote:
| i don't think i've ever seen a specific bird shit
| cleaning product of any kind, much less one specifically
| for glass
| quickthrowman wrote:
| > How do conductors work?
|
| I assume the conductors will be direct burial cable or single
| conductors run inside PVC conduit, just like any other outdoor
| electrical installation. The connectors and junction boxes are
| probably IP68 rated to handle flooding.
| 88913527 wrote:
| I would have expected it to be like agricultural products --
| rows of corn with spaces between rows, so you could access the
| interior without stepping over the outer panels.
| tuatoru wrote:
| That's a different approach, called agrivoltaics.
|
| 3 meter high frames with the panels on top, wide row spacing
| (about 10x), and crops in the ground. Minimal harvest yield
| loss (sometimes even improvement, as the shading reduces
| stress on the plants), and selling power from the same land.
| It could be marketed as "zero land needed" PV power.
|
| With Erthos's on-ground panels, a robot with fat soft tires
| rolls over the panels. No walking needed.
| necovek wrote:
| That comment seemed to only refer to spacing panels like
| rows of plants are spaced in agriculture to allow easier
| access.
| micromacrofoot wrote:
| yeah good point, why not walking/drain space between rows?
| optimizing for minimal area?
| [deleted]
| mc32 wrote:
| Agreed. The dust is likely to stay there and not blow off and
| also type of installation does not allow of undergrowth much
| less dual use of land (parking lot or other potential land
| use).
| jacquesm wrote:
| I have a similar setup and rain takes care of the dust. A
| bigger problem is the leaves and bird droppings that get
| stuck, even that gets dealt with by the rain (eventually) but
| it has to be a pretty good downpour for that to wash off.
| Fortunately here in NL we have no shortage of those.
| Retric wrote:
| They have a little robot for the dust.
|
| Land costs are still generally irrelevant for solar as in
| well under 5% the cost of this install and you can recover
| that after at the end of the panel lifespan.
| Kye wrote:
| It looks like they work in a similar way to wood floor panels.
|
| https://vimeo.com/556421759
| idiotsecant wrote:
| Huh, interesting video. Seems like a cool idea.
| ETH_start wrote:
| In the long run, these should not be paving over natural
| habitats. There are plenty of life-devoid environments outside of
| Earth where these can be positioned.
| walrus01 wrote:
| It is correct that mounting costs and labor can be a large
| portion of the total BOM.
|
| Even for a large off grid whole home PV system that can operate
| through December/January at high latitudes.
|
| Let's say for an example you wanted to DIY a PV system that would
| be much too large to fit on the roof of a normal sized house.
|
| Go calculate the cost of buying 30000 kW of good quality 72-cell
| PV panels rated at 380W STC each. It'll be something like 80
| pieces at about $130 per piece.
|
| Usually would ship as 20 panels per pallet, so call it four fully
| loaded pallets of 72-cell panels.
|
| At 34 cents/W STC rating, PV panel cost from distributor
| something like $10,400 to $12000 USD.
|
| The foundation work and poles/racking to do a basic ground mount
| will be a huge cost on top of that. Labor is a big part of it. If
| you're hiring people to build it the labor and ground mount gear
| and things like basic foundation work/screw piles/steel tubes set
| into concrete could easily cost you another 10 grand from a local
| contractor.
|
| Something generally along these lines or an industry competitor
| of it:
|
| https://www.ironridge.com/ground-based/
|
| (Not discussing inverters/charge controllers/batteries/disconnect
| boxes and wiring here).
| pontifier wrote:
| I bought 20kw of solar from China that arrived this year, the
| quote I got for installation was about what I paid for the
| whole system. I'm thinking about just installing it myself.
| prawn wrote:
| As a probably silly idea, I wonder if the panels could each sit
| on an inflated/foam and buoyant pad, be chained by flexible
| cables and then be pinned to the ground at intervals. That
| might give it some flexibility in the event of flooding.
| discordance wrote:
| Sun Cable's 10GW in the Northern Australia is also ground
| mounted:
|
| https://www.solarquotes.com.au/blog/sun-cable-5b-solar-mb118...
| JoeAltmaier wrote:
| Australia, Texas. In common: lots of sun, no snow.
|
| Here in Iowa we have different issues. E.g. we're at 42' North
| lattitude. So we want at least that much tilt to get (any) good
| sun exposure.
| moffkalast wrote:
| Both talk a lot about time and material saved, which I guess is
| also important, but neither gives any figures as to how much
| efficiency will be lost.
|
| Isn't the whole point of trackers and optimal angle
| calculations that regular panels are kinda crap if not pointed
| directly at a 90 degree angle to incoming light? If I recall
| right some installations have almost got half more output by
| going from fixed to trackers. This would be even worse than
| fixed at the optimal angle...
| PaulDavisThe1st wrote:
| When I was installing my 6.6kW array, I was pissed that I got
| the southern orientation of 1 half of the array off by a few
| degrees. Turns out I was going to lose about 1% of
| production. Out of interest, I looked up what the drop would
| be if I had actually installed them all, at a 30 degree
| slope, _facing north_.
|
| 15%
|
| !!!
| Mistletoe wrote:
| Googling shows gains of 25-35%. Dual tracking adds another
| 5-10%. I can really see how just placing more of these simple
| flat ones would be more economical than a complicated racking
| and tracking system.
|
| https://news.energysage.com/solar-trackers-everything-
| need-k...
| dreamcompiler wrote:
| It's all about the cosine of the angle between the panel's
| normal and the direction toward the sun. If that angle is 0,
| the cosine is 1 and you get maximum efficiency.
|
| The error angle has to increase to _60 degrees_ before the
| cosine decreases to 0.5. Meaning you can tolerate a lot of
| slop before you lose half your output.
|
| Trackers were a big deal when PV panels were 10x or 20x more
| expensive than they are now. Back then every bit of added
| efficiency was worthwhile. Not so much now.
|
| Edit: It's more complicated than this: You have to compute
| two cosines (azimuth and elevation) and average over both
| days and seasons, but the basic point is still true.
| liketochill wrote:
| I hope the fields never flood and the solar farm is under water
| function_seven wrote:
| > _The glass / glass modules and the connectors we specify are
| all rated for submersion, so flooding is not a catastrophic
| event in case it does occur._
|
| From: https://www.canarymedia.com/articles/solar/erthos-rakes-
| in-1...
| tbihl wrote:
| Maybe I'm just being pessimistic, but the failure mechanism
| is the erosion of the underlying denuded ground in a large
| storm to the point that the underlying structure moves.
| function_seven wrote:
| I don't think that's being too pessimistic. I didn't think
| about that. The solution would be some sort of concrete
| footing or something--but I'm sure that is more expensive
| than just mounting these panels in the air.
| idiotsecant wrote:
| It looks like they're probably targeting places where huge rain
| isn't an issue and it looks like they do some site work to
| raise it up a bit? Theres another photo here :
|
| https://www.canarymedia.com/articles/solar/utility-scale-sol...
| adwww wrote:
| Would it not contribute to flooding as well, unless drainage is
| somehow improved around each panel.
| sieabahlpark wrote:
| lai-yin wrote:
| Birds and little critters to be relocated to affordable housing
| in San Marcos.
|
| But seriously why can't we just start building more net-zero
| natural gas plants that take up 1/100 of the land area? This is
| insane.
| emsimot wrote:
| How can natural gas be net zero?
| sschueller wrote:
| This reminds me too much of solar roadways.
|
| What about heat dissipation? Don't you want airflow under the
| panels?
| enragedcacti wrote:
| https://www.erthos.com/modeling-heat-dissipation-in-earth-mo...
| dokem wrote:
| laluser wrote:
| > less than 2.5 acres per megawatt
|
| This is actually quite amazing. I wonder what the lifetime is for
| the panels.
| AnimalMuppet wrote:
| That sounds like if I have a decently-sized suburban yard, I
| should be able to throw enough of these out there to run my
| life.
| tuatoru wrote:
| Yeah, nah, these are for utility scale PV plants, sorry.
|
| In a few years, you might be able to buy a roll of PV film in
| a box and unroll it in your yard. The box it comes in would
| have all the gubbins to connect up to the house.
|
| Not quite here yet, though.
| toomanybeersies wrote:
| You don't even really need to tile your yard with solar
| panels. Depending on location, you could be self-
| sufficient(ish) with 10 kW of solar, 25kWh of batteries, and
| a 10 kVA generator for cloudy weeks.
|
| Total cost is around $40k.
|
| However, unless you're rural or somewhere with poor grid
| reliability it's probably not worth the expense of being off-
| grid. Generally speaking, due to generous feed-in tariffs you
| would be (financially) better off staying connected to the
| grid than spending the additional money required to handle
| periods of cloudy weather.
| Tade0 wrote:
| My co-worker did just that, but at a much higher
| latitude(49deg) than Texas - he couldn't be arsed with
| building racks for the panels himself and having people do it
| for him would cost too much in his view.
|
| While the panels are indeed cheap this, along with the DIY
| wood gas combined heat and power generator, are measures
| taken for energy security, not profit.
| jsight wrote:
| Usually the expected life is ~30 years. They may last longer. I
| do wonder if pests and moisture will be early failure causes in
| this configuration though. Then again, if it saves enough
| money, maybe that doesn't matter.
|
| TBH, the part that lasts the least amount of time is often the
| inverter.
| 8bitsrule wrote:
| Flat makes more sense the closer the panels are to the equator.
| At high latitudes, the more atmo the solar must penetrate -and-
| the less efficient a flat panel is. Some good diagrams here:
| [https://www.altenergymag.com/article/2005/08/solar-energy-po...]
| jacquesm wrote:
| This is true, but even then the area required is _much_ larger
| than if you were to simply stack them side-by-side. It helps if
| the whole surface is inclined as well, ideally on the Northern
| hemisphere a South facing roof.
| timzaman wrote:
| Why not mount them on a slope?
| throwaway81523 wrote:
| "Erthos claims it can build a solar power plant in half the time
| on one-third of the land" sounds like red flag to me. They have
| not tripled the solar flux or the efficiency of their solar
| panels.
| tuatoru wrote:
| On most solar farms, the panels only cover about a sixth of the
| land area, or less. The rest is taken up with accessways
| between the rows of panels, and roads around the outside. Check
| out some photos, for example https://energy-cc.co.uk/wp-
| content/uploads/2020/09/Benbole-S...
|
| The reason the rows are widely spaced is to minimize shading by
| a row of the one behind, when the sun is low in the sky.
|
| With the panels being flat on the ground there is no shading
| problem. Laying them side by side eliminates the gaps and they
| plug together so there is no wiring to do. Omitting the racking
| eliminates its cost, the time to install it, and the wiring
| between rows.
|
| Etc.
| jonnycomputer wrote:
| Not impressed.
|
| - harder maintenance
|
| - more heat, less efficiency
|
| - will accumulate dirt and other debris with no tilt
|
| - will be damaged by animals and platnts
|
| - bigger ecological footprint (not everything is carbon; we share
| this planet)
|
| - better not be in any sort of flood plain (unless you think
| it'll survive the removal of an inch of silt across its whole
| surface)
| hwillis wrote:
| - easier maintainance, since you can clean panels with a
| roomba-like rover instead of walking down with a hose.
| Replacements don't require ladders and cranes, since panels can
| be smaller without requiring more support
|
| -more heat may be irrelevant and anyway it's speculative
|
| -no plants growing under them to constantly be trimming
|
| -most places are not flood plains
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