California To Install Solar Panels Over Canals To Fight Drought, a First in the US (cbsnews.com) 166
In an effort to combat the devastating drought conditions hitting California, the Golden State will become the first in the nation to install solar panel canopies over canals. From a report: The $20 million pilot project funded by the state has been dubbed "Project Nexus." It will consist of an estimated 8,500 feet of solar panels installed over three sections of Turlock Irrigation District (TID) canals in Central California. It is expected to break ground in the fall, and be completed by 2023. The project was first announced back in February. According to TID, the project aims to use water and energy management hand-in-hand. The project is designed to increase renewable power generation, while reducing water evaporation and vegetative growth in canals. TID states that the project will also serve as a "proof of concept" to further study "solar over canal design." The agency cites a 2021 University of California, Merced study, which showed that covering all of the approximately 4,000 miles of public water delivery system infrastructure in the state with solar panels could save an estimated 63 billion gallons of water annually, as well as result in significant energy and cost savings.
Panels on canals (Score:5, Interesting)
Third-world India has been doing this for years, it works:
https://www.google.com/search?... [google.com]
Good to see the USA catching up.
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Came here to post the same thing. Here is a good summary video of India's solar canals: https://www.youtube.com/watch?v=Ix9LNZIbTpc [youtube.com]
Go big or go home I guess. (Score:3, Interesting)
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Re:Go big or go home I guess. (Score:5, Insightful)
Solar panels also generate revenue when they are in place so it's an investment not a burden.
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Re: Go big or go home I guess. (Score:2)
Solar panel production is finite, and the build-out of 4,000 miles of solar panels will take a huge bite out of the available pool of solar panels for residential, industrial installations.
I wonder if CA lawmakers will require the panels to be made in the USA, driving everyone else to buy Chinese solar panels?
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>Solar panel production is finite, and the build-out of 4,000 miles of solar panels will take a huge bite out of the available pool of solar panels for residential, industrial installations.
[simpsons meme]"Hello? I need the shittiest take you have,,, no, that's too shitty..."[/simpsons meme]
Jesus fuck dude it hardly matters where they're installed in the grand scheme of things, and more demand drives more production and brings down costs through economies of scale. "We can only build so many solar panel
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Exactly - they'll generate revenue anywhere, but the cost of land limits where they can be profitably deployed.
The canals offer "free" land for solar deployment since the government already controls it. The fact that solar not only doesn't interfere with the canals, but actually makes them more efficient, is essentially an added bonus, further increasing the effective revenue they generate.
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Canals, parking lots, roofs - take your pick, there's a lot of "waste" space out there.
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The American Southwest, and California in particular, has never had a proper accounting of water, ever. It was just assumed that enough infrastructure could be built to gather, divert, mine, or in other ways extract all the water they'd ever need. So the loss of water from canals and reservoirs should have been a concern this whole time, but the proper costs had easily been neglected or externalized.
But as i
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I'll be curious about the life cycle and maintenance costs of solar panels over what will amount to basically a steam bath. Sure, they normally sit on roofs so water exposure SHOULDN'T be an issue but electronics and high, persistent humidity with high heat just isn't a great combination....
Also, waterballs work wonderfully are and long-since proved.
https://www.youtube.com/watch?... [youtube.com]
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It's almost like solving two issues at once is preferable than solving each independently. Now if only these solar panels would educate the stupid people we'd be on a real winning streak. In that situation the only losers would be Slashdot with its lower comment count.
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If the water loss was a true concern, much lower cost canopies would be under construction now. But instead lets require solar panels which involves a much stronger support frame, much more installation labor and tax burden.
Alternatively, perhaps installing panels by themselves isn't compelling, nor is canal canopies (or using pipes instead of open canals). But together they get over the worth it hill.
There's lots of empty, sunny land in California where solar panels could be installed (rooftops don't necessarily make sense to me). Canals seem a particularly good spot to put them because they don't get in the way (of much) and has the side benefit of reduced evaporation. Is it worth it? Don't know, I'd have to see the numbers.
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Water loss is likely not the primary concern here, but the reduced water loss represents additional value to the solar energy project, increasing the RoI.
Arguing against this is pretty silly, really, as it's otherwise unused right-of-way in a very sunny area that could add a not-insigificant amount of energy production without additional significant environmental harm. Should have been done years ago.
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Because I'm sure there's absolutely no way to temporarily remove the panels while doing said maintenance work, and nobody ever thought of that when conceptualizing the project.
Good idea (Score:5, Insightful)
Given that evaporation is a significant factor in water loss in open canals they should be covered anyway. Heck, open reservoirs should be covered, some improvement on the experiment LADWP did at Van Norman with the plastic balls. https://www.sciencealert.com/h... [sciencealert.com]
Covering with solar panels is fine as well - they're cheap and perhaps the power generated could help offset the cost of pumping the water. Here in AZ we have the massive Central Arizona Project canal which pulls water from the Colorado River and pumps it uphill to PHX, and worst yet, to Tucson. 30' wide, 170 miles long just to get to PHX, that's a lot of surface area in a desert landscape with exceedingly high evaporation rates. Just need to be covered no matter what.
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Yeah. Balls aren't really an option for flowing water (also, why are they black instead of solar white? But that's off topic.) And while soft canopies can be relatively cheap up front, they degrade rapidly and require such frequent replacement that they're generally more expensive over time (to say nothing of the waste generated from all the discarded plastic/fabric when it's replaced)
Which pretty much leaves rigid paneling and the attendant sturdy frames - a substantial up front cost to deploy. Once yo
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The balls are black because that radiates more heat. Same reason black thermal sinks have better properties than blank Aluminium ones or ones painted white (which nobody does). Yes, the black surface also gets hotter. So if you want to keep the temperature of the ball (at its upper side) down, white would be better. But since this is about the water below and the balls themselves have really low heat conductance, black is better.
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The GP was incorrect into the reasoning. You're not protecting the plastic, you're protecting the water. But the purpose is the same. Black plastic is far easier to make opaque than white plastic. Black is used in this case to prevent sunlight penetrating the water reservoir and breaking down the chemical treatment applied to the water and creating carcinogens.
They are "shade balls" not "cool balls", and were originally created to reduce bromate levels and prevent algae growth, not to prevent evaporation. T
Another boondoggle (Score:2, Troll)
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No, the solar panels aren't the pavement, so that analogy isn't right.
Re: Another boondoggle (Score:2)
OK, the road to hell is covered with solar panels, better?
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Well, the road to Hell is in a tunnel: https://www.google.com/maps/@6... [google.com]
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If they can do it with great results in India, our only excuse for failure is blinding incompetence.
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Well, probably they should also get rid of cave-men like you that think anything new or "green" must be a failure without ever looking at actual data. Here is a hint: In some regions of the world this has been done with good success for quite a while. The US is _late_ to do this and it is established, proven tech.
Cover everything (Score:2)
Rooftops, parking lots, cover it all with panels. So much empty space you could be harvesting free energy from.
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Indeed. It has been estimated that 100% of U.S. energy needs could be satisfied by 10,000 square miles of (well-sited) solar panels. That'd be a square, 100 mi (160 km) on each side plopped in the middle of the desert. That may sound like a lot, but the built environment - cities, roads, harbors, etc. - is something like 20x as much area (depending on who's counting). Deploying solar panels o
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Better yet, stop forcing property owners to have so much empty space.
Existing right of way (Score:5, Insightful)
Besides infrastructure and access, there is long term revenue and long term water savings. The concept has multiple benefits that make it more practical and affordable.
It makes so much sense that Slashdot idiots are already trashing it. No surprise there.
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install them over parking lots too (Score:3)
Using only... (Score:2)
Using only 40 million acre-feet of water for construction, this will be the the most water-saving project in the state's history.
- a failure of imagination - (Score:2)
As I mentioned in the last iteration of this story, this is a process of building a bridge over the canal. A bridge that supports only a few solar panels.
Bridges can do much more. Since ancient times they have been used as roads. They have supported massive buildings of stone. There are all kinds of bridges that serve many purposes. But these solar bridges serve only one purpose.
Why can't some of these bridges incorporate buildings and put the solar panels on the roof? Buildings could serve nearby farms for
I endorse this! (Score:2)
photosynthesis (Score:2)
Re:Wouldn't the water (Score:5, Informative)
They DO cover reservoirs already.
https://www.youtube.com/watch?v=uxPdPpi5W4o [youtube.com]
Re: Wouldn't the water (Score:2)
Are you going to talk about the size of those balls?
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Yes and no. Most canals in California aren't covered. Maybe a few experiments in some resevoirs though.
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You always can sell this surplus power for cheap for some immediate application like hydrogen
Re: Wouldn't the water (Score:2)
Surplus energy on sunny days during daylight hours is a very cheap commodity, CA 'd surplus energy will be competing on the spot market for buyers against similar surplus energy from Nevada, Arizona, and other states - line loss limits the 'market' for surplus energy.
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Instead of all the complex battery / energy storage devices, one can directly go to relieving the A/C load. Large insulated tanks of plain water, chilled during the excess solar production and cheap electricity rates can be used to cool the buildings when the sun goes down.
Should definitely work out for large commercial buildin
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Surplus energy on sunny days during daylight hours is a very cheap commodity, CA 'd surplus energy will be competing on the spot market for buyers against similar surplus energy from Nevada, Arizona, and other states - line loss limits the 'market' for surplus energy.
The surplus energy could be routed to desalination plants which is probably what California really needs if they ever want to get ahead of and solve the water shortage problem for good.
Re:Wouldn't the water (Score:5, Interesting)
But the sunlight hitting the water also generates heat. So it's not necessarily going to heat the water more to have a panel over it than it would have been directly exposed to the sun. One would think cooler, since at least some portion of the energy from the sun is converted to electricity instead of heat. Rooftop solar panels reduce attic temperatures, so I'm going to have to go with colder, not hotter, because of the panels.
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Rooftop solar panels reduce attic temperatures, so I'm going to have to go with colder, not hotter, because of the panels
I would also imagine this is the case. I have rooftop solar panels, and my attic temperatures are (slightly) lower now.
I would imagine that panels over a canal, with a substantial airgap, would radiate almost any heat away from the water.
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But the heat the panels "generate" would have been "generated" in the underlying water, so it's moving it from one place to another.
Add to that that panels would be above the water, able to be cooled by wind, it is moving that heat to somewhere it can be better managed.
I've wondered why the canals have been uncovered for the thirty years since I flew over them, and it seems silly to me that they're JUST now coming up with the idea.
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Re:Wouldn't the water (Score:5, Insightful)
Solar panes do NOT generate heat. They *become* hot, just like anything else you leave out in direct sunlight.
The dark panels absorb more sunlight than leaves or sand, but about the same or less than dark earth, or the water they're covering. So the energy absorbed into the local environment is about the same either way.
The difference is, if the heat is absorbed by the water then roughly 100% goes to raising the temperature of the water and increasing its evaporation rate. If it's instead absorbed by the solar panels they get MUCH hotter than the water (same amount of thermal energy / less thermal mass = greater temperature change). And hotter materials can shed energy much faster, especially as thermal IR radiation proportional to the 4th power of absolute temperature, roughly half of which will be radiated upwards into the atmosphere. The rest gets radiated down into the water and absorbed - but that's less than half as much energy as it would have absorbed otherwise.
End result the total energy absorbed is approximately the same, but the net change in energy of the local environment is *lower* than without the solar panels, by the combined amount of electricity generated and the radiated thermal IR.
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Unless they are breaking the 2nd law of thermodynamics, yes they are generating heat.
Re: Wouldn't the water (Score:2)
No, the panels donâ(TM)t generate any net heat, at least in the thermodynamic universe I inhabit. The sun warms the panels, which in turn re-radiate heat to the water. Net of the energy that the panels generate and the panels reflect skyward, the water runs cooler.
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Not really. _All_ electrical losses will have been part of what would otherwise have gone into the water from the sun. Solar panels _do_ _not_ generate energy of any kind. They just transform it.
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Solar panels _do_ _not_ generate energy of any kind. They just transform it.
Now you are nit-picking some else's use of the word generating. Hell by that logic power plants don't "generate" electricity. Better rename those pesky generators. The panel transforms some of the incoming light into electricity. Some of that electricity will be lost as resistive losses, as heat. This will be in addition to what the panel directly absorbs and re-transmits as IR. If the panel absorbed the sunlight purely has heat it wouldn't be a solar panel now would it?
_All_ electrical losses will have been part of what would otherwise have gone into the water from the sun.
No. Both the water and surrounding
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Re: Wouldn't the water (Score:2)
True, but pedantic.
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No they do not. They just convert some of the sunlight into electricity instead of being warmed up by it. Then a small fraction of that gets turned back to heat. It is always much less than what absorbing all sunlight would have done. So no, Solar panels _do_ _not_ generate heat.
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...The rest gets radiated down into the water and absorbed - but that's less than half as much energy as it would have absorbed otherwise.
Interesting. I've wondered about this in the context of rooftop solar panels. Would putting panels on my roof keep my attic a bit cooler? On the one hand, the panels are absorbing some energy to make electricity. That means less energy left to hit my roof. On the other hand, I've got reasonably light roof tiles so they'll reflect some light rather than absorbing it whereas panels, being black, ought to absorb a lot and heat up. On the gripping hand, the panels have an air gap behind them so much of that hea
Re: Wouldn't the water (Score:2)
Or as I like to say, it's cooler in the shade.
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Indeed. Surprising how many people here do not understand basic Physics...
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Solar panes do NOT generate heat. They *become* hot, just like anything else you leave out in direct sunlight.
Of course solar panels generate heat. They do so by absorbing energy from the sun.
The dark panels absorb more sunlight than leaves or sand, but about the same or less than dark earth, or the water they're covering. So the energy absorbed into the local environment is about the same either way.
Panels have anti-reflective coatings designed to minimize reflected energy losses normal structures would not have especially ones designed explicitly to reflect energy.
The difference is, if the heat is absorbed by the water then roughly 100% goes to raising the temperature of the water and increasing its evaporation rate.
Water absorption depends entirely upon incident angle. 100% is about right at local noon close to the equator. It's wildly inaccurate during mornings and evenings and higher latitudes especially outside summer.
End result the total energy absorbed is approximately the same, but the net change in energy of the local environment is *lower* than without the solar panels, by the combined amount of electricity generated and the radiated thermal IR.
The choice is not between covering water with pa
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The canals are under the solar panel canopy. Heat rises while cooler air will sink. Adding panels will not cause heat to drop down to water level.
It's not a bad place to put solar panels and it could help save some water but mostly it's probably just a decent spot to put panels since they do take up a lot of space.
We'll see how this turns out but other countries have done similar things. India has done solar panels over canals as well.
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Solar panels do not generate heat. They absorb energy including thermal energy from solar radiation. Without the covering, all that radiation will fall on open water and it would evaporate. Even plain non solar panel structures will reduce evaporation losses. Putting solar panels over the canals will side step one nimby issue.
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Cover yes, however, solar panels generate heat. That heat will likely go into the canal as it will also increase the efficiency of the solar panels.
No. The heat radiated is far smaller than that radiated by the sun naturally. Incidentally that is why solar panels in parking lots are so effective at providing a nice comforting shade to the people underneath.
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Re:Wouldn't the water (Score:5, Insightful)
I'd like to see panels also over parking lots. That would keep sun out of cars when they are parked and also provide power to charging of the cars.
If a car is in the shade it will require less energy for the AC to cool it down to a comfortable level in the summer.
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While visit Palm Desert a few years ago, we passed by their community college and their parking area was entirely solar panel coverings. Seemed like a decent idea though who knows how long before the investment comes out of the red.
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Many school districts in SoCal have done this with various taxpayer-funded initiatives. The two high schools, two middle schools and a number of K-8 schools in my district completed parking lot solar installs a few years ago. They generally built fixed-orientation panels on 14 foot tall steel beam structures. In some cases, they put solar up in the open fields around the school, if the parking lots weren't situated well or had tree cover already.
Re: Wouldn't the water (Score:2)
The idea is that by covering ALL canals they will reduce water evaporation in the canals. The water losses once the water leaves the canals would remain the same.
The issue I predict is homeless people setting up camp in these immense covered concrete basins curing dry seasons - some canals are more like storm runoff, and with precious few rainstorms, those canals are frequently 'dry' for extended periods... if/when the rainstorm comes, those camps, and the homeless, could be washed away.
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The issue I predict is homeless people setting up camp in these immense covered concrete basins curing dry seasons - some canals are more like storm runoff, and with precious few rainstorms, those canals are frequently 'dry' for extended periods... if/when the rainstorm comes, those camps, and the homeless, could be washed away.
I do not doubt that some homeless people will camp in less than ideal places, but I would think that some homeless people would have sense not to stay somewhere prone to a flash flood every time it rains. Also there is no shortage of concrete covered areas like highway overpasses in California. Also these canals can be very remote areas. That is not conducive to people who do not have easy transportation.
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Chemical contamination of water from panels (Score:2)
The issue I predict is homeless people setting up camp ...
The issue I sort of expect is chemical contamination of the water as we learn that foreign suppliers improperly used prohibited cleaners in manufacturing, or solder contain lead on components ... such things have already happened and created issues at landfills at decommissioning. With panel over drinking water such problem will likely be discovered at an earlier stage. Yes I am sure the specification say do not do such things, but foreign suppliers are well known for quietly implementing their own substitu
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Well, it's kind of a "Darwin's" approach to solving the homeless problem, no?
Re: Wouldn't the water (Score:2)
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" Why don't they cover a small resevoir first and test that ?"
The Romans already did all that.
Re:Wouldn't the water (Score:5, Informative)
Still better off than Texas. https://www.houstonchronicle.c... [houstonchronicle.com]
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WTF do tax rates have to do with this discussion?
Well since a moron brought up the connection between government management and moronness I think it is a relevant factor, especially since people that think taxes should be as low as possible or even not exist are extremely high on the moron scale [vox.com].
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A snag here is that there are many variants of libertarians. Some are smart and thoughtful people, and I know a few (not myself, not libertarian or thoughful :), but some are really jingoistic (not a libertarian ideal), others are just so tied up in idealism that they lose sight of pragmatism, others are Ayn Rand True Believer kooks, and quite a lot are just Republicans and who think libertarian just means small government (but libertarian also means social freedoms, which includes more gay rights, feminis
Re: Wouldn't the water (Score:5, Funny)
It's a favorite conservative talking point. California is so terrible and people are fleeing to the republican utopia of Texas.
Re: Wouldn't the water (Score:2)
They are 'testing' this as step one of a two step process. Once they prove it works on a mile and a half of canals, they'll cover the other 4,000 miles creating countless high-paying union jobs and an administration with countless full-time political-appointee positions to appease the politicos. Unless, of course, some environmental group files a lawsuit to protect some endangered (and previously unheard-of) animal.
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Re: Ecosystem destruction (Score:2)
If California really wants to "fight drought" then what they NEED to do is stop pulling water from rivers and Aquifers for agriculture and industry, and build desalination plants instead. Then they should be building MORE open air canals patterned after the original watersheds so that the local flora and fauna
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Re: Ecosystem destruction (Score:2)
When I lived outside SF in the 70s, we had a canal in our neighborhood (about 6' wide), and there were a huge number of bullfrogs that lived in the canal. I'm not sure how common that is today, nor am I certain how that fits into local food chain, but I think there may be an environmental lawsuit over some animals that live in the canals.
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The study they cite predicts a significant cost savings from reduced maintenance due to reduced plant growth in the canals.
I remain skeptical but am interested to see how it goes.
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I'm not a meteorologist but I think the system is a bit more complex then that. Just from watching the weather channel, often times you will see a storm travel from somewhere distance to a location and begin dumping water in the storm.
These storms never seem originate on top of where I live (San Diego), but usually come from up north (way up north) and travel downward or otherwise we'll get a storm pushed up from Mexico (and farther south) during their hurricane seasons.
A bigger affect on the available wate