A 100MW solar farm in Texas will mount panels directly on the ground
canarymedia.com
canarymedia.com
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...
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.
Nuclear isn't doing fantastic, but new reactors are still built.
Switzerland has now overthrown the idea to shot down the reactors and they will stay open for many years more. But we don't plan to build new reactors either.
Had we built a new one, I don't think we would have voted to shut it off.
We could also get in contact with GenIV companies and try to be world leading with some next generation reactor.
My approach would be to build 1 Gen3+ reactor such as APR-1400 or something like that we start to build as soon as possible.
Then we also plan on building GenIV reactor such Terrestrial Energy ISMR or Moltex Energy Stable Salt Reactor. Eventually when we actually want to replace our existing fleet, we build more of that type.
I got mine during my windfall cash earning years in big corp. Great economics for a large W2 earner: 30% funding from gov, 30% funding from immediate depreciation, and you can lever the rest. Infinite IRR.
There are a whole network of developers who package the deals and then match it with financing. I still can't believe every dentist in America doesn't own one of these....
> 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...
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.
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.
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...
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.newindianexpress.com/states/kerala/2021/dec/13/c...
But obviously doing this repeatedly might not be good for it - naturally hail on a super hot day is rare.
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:
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.
The plants under the panels also reduces the heat under the panels and thus increases the efficiency of power generation.
This can be a nice way of getting additional income from the land and also tackles the problem of plants growing under the panels.
https://www.newindianexpress.com/states/kerala/2021/dec/13/c...
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.
2/ Do you think there is a future for robot cleaner? Some new companies are already 90% down from recent SPACs.
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.
Aluminum does not rust, and galvanized steel will easily outlast a solar panel.
While technically true, since rust is an iron oxide, the meaning behind the "metal rusts if wet" statement was more generic and less scientific. If you are a bit more forgiving in the interpretation of what was said, you could have acknowledge that aluminum does indeed oxidize over time. Aluminum just happens to have a nice property where the oxidation process creates a protective film that helps prevent further oxidation. Aluminum can be exposed to elements that destroy that film and result in accelerated oxidation.
And if you want to see something extra fun, look at what mercury does to aluminum without that protective film.
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…
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).
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.
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.
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?
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/201...
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.
Well that's a point of view that's never steered us wrong.
The only way we've done it is by eliminating everything in our path. We've been excellent at justifying eliminating entire ecosystems - when will we stop?
Probably right before we've justified eliminating entire countries of people with the weapons of death we've developed by extracting every last resource for the ground by digging it up.
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.
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.
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.
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.
You can’t simply put solar on a roof
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.
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.
Not at today's power prices. A typical kitchen will easily cost as much or more than solar and solar ROI is about 20 to 25% right now, no kitchen will come even close to adding that kind of value to a house. If you can afford to do both, do both, but if you have to choose solar is #1 from an investment perspective (assuming you already have a kitchen...).
Being in a rain forest doesn't help. Don't get me wrong, the summers are as bright as anywhere else, but the cloudy winters are brutal if you want sunshine.
If it's financed with a mortgage that's another thing to consider.
I just don't ever hear solar come up in conversations about resale. I've heard a couple Realtors mention that energy efficient design is something coming up most often. The big questions are still about the area and how many bed/bath rooms there are.
>(assuming you already have a kitchen...).
You can always get a second kitchen....a summer kitchen.
And it's just the first step.
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.
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?
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...
As for the support structure: the ones on the flat roofs are part homebrew and part standard components, the ones on the slanted roof are on a standard off-the-shelf support.
I'm not agile enough any more to work on a roof so I had the slanted roof done, the other part I did myself.
tilted: https://wiki.factorio.com/images/Solar_panel_entity.png
flat: https://rimworldwiki.com/images/b/b4/Solar_generator.png
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.
Less cost smells like cutting corners in this case. Kinda of like saying concrete and rebar are expensive and you could build a bigger house without them.
Is that true though?
Flat panels may be good enough but slapping such a high tech piece of equipment on the groud sounds suspiciously too good to be true. I suspect the cost per panel to be insanely high if not upfront then in maintenance.
Slapping high tech panels on the ground seems peculiar.
https://www.canarymedia.com/articles/solar/erthos-rakes-in-1...
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"
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.
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.”Ever cleaned dried bird droppings off a windshield? I'd be pretty surprised if solar-farm Roomba was up to it.
Why do you think it's ineffective, they could have a pressure washer inside that thing
It appears too small to have enough mass to use gravity to be able to do a thing with dried guano. Also, because it has wheels, it gives me the impression that it moves along and does whatever cleaning its capable of as it goes rather than lingering anywhere to thoroughly clean one spot.
> they could have a pressure washer inside that thing
How big of a water tank do you think?
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.
probably there are a lot of possibilities you haven't tried on your windshield yet
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...
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.
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.
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.
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:
Solar Panels Plus Farming? Agrivoltaics Explained
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).
https://www.solarquotes.com.au/blog/sun-cable-5b-solar-mb118...
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...
15%
!!!
https://news.energysage.com/solar-trackers-everything-need-k...
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.
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.
I'm guessing they will probably need a tall fence around the outside to keep deer away.
https://kansasreflector.com/2022/02/14/lets-grow-a-brighter-...
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.
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.
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.
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.
https://www.erthos.com/modeling-heat-dissipation-in-earth-mo...
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)
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.
>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.
If you can get 75% efficiency for half the cost, your return on investment is 50% higher
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.
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
I think this approach has interesting applications for small-scale solar in rural environments if the permitting can be streamlined
the numbers they gave make the pv module prices seem slightly higher than the cited racking prices (15¢ per watt) but it's a little hard to be sure because of the numerous kinds of watts involved
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.
[0] https://www.asa-lift.com/asalift/producttypes/bodenbearbeitu...
Trench will flood. Mound needs to be maintained. Cheaper to put more static panels flat than trying to get every electron out of them.
Just use the rack then, it's exactly the same result.
[0] http://www.thompsonpotatofarm.com/common-tater/banking-the-p...
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.
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.
[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6611928/#:~:tex....
it'll be interesting to know if they're derating the nameplate capacity by cos(latitude) as they should be
All movement towards renewables is good, no matter how "inefficient" it is vs fossils
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.
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.
> 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.
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.
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.
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.
[1] For a sufficiently large area so that effects on the edge are negligible.
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.
presumably that was 15¢ per peak watt but the article doesn't actually say
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.
That might not always be a good tradeoff, but maybe at least some of the time it is.
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).
Would you have a forest of tall towers, or one really tall panel covered building, or something in between?
It's all about the metric you choose. That's the true issue.
How many "couple of years" have there been between 2021 and now?
Falling between two dates does not imply that it fell uniformly or that it fell for every year between those two dates.
Aka companies had agreed to deliver in 2020 for X$, but took longer to actually deliver.
Nonetheless, we can probably give them a pass for saying "couple" instead of "nearly three" since January 2020.
"a couple" = 2
"a few" = 3 (maaaybe 4)
"several" = 4 to 7
"a handful" = context dependent, usually ambiguous
There are only a few people who understand quantum mechanics, for example
they are doing an underwater cable to supply energy to singapore
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!
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.
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.
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
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.)
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...
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
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
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.
This is actually quite amazing. I wonder what the lifetime is for the panels.
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.
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.
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.
TBH, the part that lasts the least amount of time is often the inverter.
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!
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.
> Automated nightly robotic cleaning of entire array prevents hot spots due to soiling.
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...
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.)
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.
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.
https://www.canarymedia.com/articles/solar/utility-scale-sol...
From: https://www.canarymedia.com/articles/solar/erthos-rakes-in-1...
Link from someone else’s comment: https://www.erthos.com/reducing-degradation-rates-with-earth...
Maybe they should prop them up on cinder blocks at a minimum?
What about flooding?
What about heat dissipation? Don't you want airflow under the panels?
- 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)
-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
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.
Where I am there is not exactly a solar farm, but there is a maybe half megawatt array on a flat canopy over a parking lot. This is in an area of expensive real estate, and there is almost no wasted space.
As for spacing to avoid shading when the sun is low, obviously that is an optimization problem and in all likelihood they have worked it out. Don't forget that when the sun is low, the flat array produces almost no power.
This type of solar farm is doomed to spend that money saved in either prevention and/or cleanup and repair.
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
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.