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Power Earth

What If We Put Solar Panels on California's 4,000 Miles of Canals? (electrek.co) 169

Posted by EditorDavid from the bright-ideas dept.
Electrek writes: Nearly a year ago, Electrek reported that scientists published a feasibility study about the benefits of erecting solar panels over canals. That study is about to become a reality in a [one-mile] pilot project in California.

The California Department of Water Resources, utility company Turlock Irrigation District, Marin County, California-based water and energy project developer Solar AquaGrid, and The University of California, Merced, are partnering on a pilot project named Project Nexus — a "nod to the water-energy nexus paradigm gaining attention among public utilities."
California has about 4,000 miles of canal transporting water to 35 million California, explains Roger Bales, a distinguished engineering professor at the University of California, Merced (who is working on the project). "It's the largest such system in the world.

"We estimate that about 1% to 2% of the water they carry is lost to evaporation under the hot California sun." In a 2021 study... we showed that covering all 4,000 miles of California's canals with solar panels would save more than 65 billion gallons of water annually by reducing evaporation. That's enough to irrigate 50,000 acres of farmland or meet the residential water needs of more than 2 million people....

Shading California's canals with solar panels would generate substantial amounts of electricity. Our estimates show that it could provide some 13 gigawatts of renewable energy capacity, which is about half of the new sources the state needs to add to meet its clean electricity goals: 60% from carbon-free sources by 2030 and 100% renewable by 2045.

Installing solar panels over the canals makes both systems more efficient. The solar panels would reduce evaporation from the canals, especially during hot California summers. And because water heats up more slowly than land, the canal water flowing beneath the panels could cool them by 10 degrees Fahrenheit, boosting production of electricity by up to 3%.

These canopies could also generate electricity locally in many parts of California, lowering both transmission losses and costs for consumers. Combining solar power with battery storage can help build microgrids in rural areas and underserved communities, making the power system more efficient and resilient. This would mitigate the risk of power losses due to extreme weather, human error, and wildfires....

Another benefit is curbing aquatic weeds that choke canals. In India, where developers have been building solar canals since 2014, shade from the panels limits growth of weeds that block drains and restrict water flow....

Building smart solar developments on canals and other disturbed land can make power and water infrastructure more resilient while saving water, reducing costs, and helping to fight climate change.
"The project is anticipated to break ground in fall 2022," writes Turlock Irrigation District, "and be complete by the end of 2024."
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What If We Put Solar Panels on California's 4,000 Miles of Canals? More

What If We Put Solar Panels on California's 4,000 Miles of Canals?

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  • I'm guessing the world would be a little bit better place if they did that.

    This is California though so there'll be plenty of political infighting and misinformation to overcome.

    • Yes, there will be I’m sure as well, but efficiency and cost need to be factors in what accomplishes the most good. For example we could just cover the canals with the least expensive method, perhaps floating plastic balls similar to a ball pit, accomplishing far more coverage and thus far more benefits from that and yet at a tiny fraction of the cost. The real question should be does it make economic sense to place panels over or is it more cost effective and efficient to place conventional panels t
      • It seems to me that the balls work well for reservoirs, but that they might not work well for canals since the water is "on the move". You would have to keep adding balls at one end, and perhaps removing them at the various destinations, etc.
        • Depends on the flow rate. Most canals are minimally sloped where the water is deep and moves slowly, they aren’t raging rapids. One way to constrain them is to use a floating chain, and perhaps a minimalist net over the area if there is considerable wind.
          • This seems pretty plausible. You could just put some type of retention mechanism every so often in the canal so the balls can't escape. OK. Solvable in principle then. Details TBD.
            • The idea behind using panels is the panels are more efficient at making power when they are cooler, and the canals provide cold water (especially since that water will be shaded. It gives you more water, and because of the waters cooling capacity, better bang for your buck on the panels. Maybe negated by transmission losses.
              • Mounting panels in this fashion is quite expensive, maintenance costs look substantially higher. This results in less kWh per dollar even if it’s 3% more efficient. The dependence of canal optimization and grid generation and distribution is not clear.

      • Re: (Score:2)

        by dgatwood ( 11270 )

        Yes, there will be I’m sure as well, but efficiency and cost need to be factors in what accomplishes the most good. For example we could just cover the canals with the least expensive method, perhaps floating plastic balls similar to a ball pit, accomplishing far more coverage and thus far more benefits from that and yet at a tiny fraction of the cost.

        That seems like it would be an ecological and health disaster (adding lots of microplastics into the water supply, not to mention leaching monomers, oligomers, additives, etc.). [diva-portal.org]

        The real question should be does it make economic sense to place panels over or is it more cost effective and efficient to place conventional panels to optimize grid use. The dependence of canal optimization and grid generation and optimization seems forced and contrived and will only lead to greater costs for less return.

        I'm assuming this would use conventional panels, just mounted on beams that cross the canals instead of on a metal and concrete pedestal over dry land like a traditional solar farm. So the comparison, assuming that the solar panels would be installed either way, should be between the cost of building concrete pads with a metal suppo

        • Land is really expensive in California. If you already need a canal to transport water around, there is effectively "use-able" space directly above the canal.

          The fact that the panels could help reduce evaporation by blocking sun is an added bonus. You could still do the ball trick in conjunction if you are that worried about water evaporation.

          They've done this India and it went pretty well.

          • Land is really expensive in California.

            Land on the coast is expensive. Land in the desert is cheap.

            There is no lack of space to put panels.

            Putting them over the canals will expose them to humidity from the evaporating water, make maintenance access more difficult, make the support structure more expensive, make them vulnerable to theft and vandalism, and finally, not do so much to prevent water loss from the canals.

            Also, terminators tend to pursue their prey into the canals. Imagine the damage to the solar panels from a rampaging and exploding

    • Instead of homeless people living under bridges along canals, they'll live along the entire canal! This is a great thing. Sort of. Wait, not really. Maybe?

    • Well, according to the same story last month [slashdot.org] they would generate about 13GW of power and save 63 billion gallons of water per year.

      This month it seems to have increased to 65 billion gallons saved per year so they had clearly better hurry up and build them before all the water evaporates!

    • This has been discussed for at least a decade already, so in another 10 years it should be finished.

      (Better than my state though, which broke ground on a mass transit project in 2008 and it won’t really be functional until 2035 by current projections.)

    • Add in small turbines underneath the solar panels, and the flow of water might hit 100% of needed renewable energy.

  • I don't even see any cost estimates. And this 1-mile project is gonna take 2 years to complete. This sounds like one of those brilliant ideas with absolutely no basis in reality.

    • Re: (Score:2)

      by Chas ( 5144 )

      Average commercial solar panels are 5.4 feet by 3.25 feet.
      An average industrial panel is 6.5 feet by 3.25 feet.

      If we use industrial panels for maximum coverage and assume a double row of panels (in a "landscape" style configuration along the length of the 1 mile stretch, you're talking about something like 3250 panels.

      If they're able to get 350W panels at rock bottom prices ($245/panel), you're talking $797,000 dollars. Just in panels.
      There's the mounting hardware, wiring, inverters, etc, etc.
      Then there's

      • Then there are the normal maintenance costs, which can be extrapolated from industrial solar power installations.

        ... then there are the fukwit sabotage/vandalism costs, as industrial power installations can be guarded. A mile (or 4,000 miles) of canal cannot, in any cost effective manner. And you know how People are.

      • Re: (Score:2)

        by v1 ( 525388 )

        You also need to factor in that a person is good but PEOPLE are terrible, and will strip the panels for the copper or vandalize them etc so you have to deal with that too.

        Lots of "looks good on paper" ideas fail due to "people are terribe". Just look at the fate of poor HitchBot.

        • Heck why take them for copper. Take them for solar panels with no clear security except maybe cameras. I've spoken with numerous clerks and in a store now they are told to let theives walk.

          • Re: (Score:2)

            by v1 ( 525388 )

            Because thieves tend to be stupid. I've read stories of a thief stealing manhole covers and burning $20 of acetylene to cut them up (reduce identifiability) for $10 scrap price.

            And it's not uncommon for the cost of repair for damage the thieves didn't have to do in order to steal, to exceed the replacement cost of what they stole. Think cutting through a chain-link fence to steal $50 worth of copper. And that's why sometimes that stuff isn't locked up. it's not that the facility managers are stupid - it

            • Re: (Score:2)

              by narcc ( 412956 )

              Because thieves tend to be stupid. I've read stories of a thief stealing manhole covers and burning $20 of acetylene to cut them up (reduce identifiability) for $10 scrap price.

              What if they also stole the acetylene?

            • Re: (Score:2)

              by Chas ( 5144 )

              Makes you think certain legal systems had something right with chopping the hands off thieves...

      • Some of those commercial ones are even 1*2m!

    • Re: (Score:2)

      by HiThere ( 15173 )

      Cost estimates are important, but judging what a real project would require on the basis of what a study requires is a bit unreal. Studies are always going to be more expensive, and real projects are always going to have more pork. That the study takes 2 years says nothing about what a real project would take unless you make a lot of unrealistic assumptions about various things. And how long the study takes to complete doesn't tell you much about how long it takes to build.

      FWIW, I don't think a decent st

    • Re: (Score:2)

      by AmiMoJo ( 196126 )

      Whoever owns the canal could become a major energy supplier. It would be a great return on their investment.

      The state should really be looking at investing in solar too. They can borrow very cheaply and the returns are guaranteed. They could establish a sovereign wealth fund.

    • Re: (Score:2)

      by swell ( 195815 )

      There doesn't have to be a cost. This is California, the entrepreneurial capital of the world. These structures bridging the canal can be more than solar panels. This is new real estate. There can be buildings: homes, retail, warehouses, service industries on these structures. Instead of a flat panel on a bridge, a structure on the bridge and a flat panel on the roof. Farmers and remote communities will welcome a small general store, a fast food outlet, a place to store their equipment and harvest, and a p

    • Re: (Score:2)

      by PPH ( 736903 )

      And this 1-mile project is gonna take 2 years to complete.

      And that's only after all of the environmental studies, public hearings and interminable permitting processes that all power generation projects must endure have been completed.

  • What if Slashdot could do a simple search through its history [slashdot.org] to see whether this story was a dup [slashdot.org] before posting it to the main page?

  • What if California built high-speed rail over the canals and then covered that with solar panels?

    And there could be community gardens and compost stations alongside, with organic cannabis vendors and special ATMs for receiving universal basic income payments.

    Wouldn't that be a wonderful world? Let's all join hands and sing so that someone, somewhere will just make it happen.

    • I understand you are an idiot. The project as proposed is financially positive. That is, it makes money by selling electricity. The entire point is that California is one of the places in the world where Solar panels make enough electricity to cover their cost. High population, lots of sun, little clouds.

      Your failure to understand that is why you try to make fun of a financial investment by throwing in a bunch of crap that will not make money.

      But it just makes you look like a moron, for failing to ca

      • The entire point is that California is one of the places in the world where Solar panels make enough electricity to cover their cost.

        That's damned near everywhere, given the alternatives. California is unusual in that you need little else, though.

      • Panels do make a lot of electricity compared to their price and are a no brainer for electricity generation BUT California is going to have a serious shortage of storage if we just keep adding panels without adding storage. Also, California has lots of places to put panels. I am not sure the extra expense of installing them over canals can be justified compared to installing them over already existing parking lots and perhaps in some cases in de-commissioned farmland, etc. This is not a repeat of solar road

        • Building storage for surplus energy generated under favorable conditions is the big problem.

          Actually it is not a problem. As you simply can let the energy go to waste ... obviously a sane person would power down the fossil fuel plants during such a situation.

          Storage is interesting when you produce far more than 100% of your need. And this project will be far far far away from that.

          • It is, in practice, with the grid we have here in California, a problem today. It is not theoretical or in the future. Taking baseline fossil fuel generators offline is not so easy. And at the moment, the utility (PG&E) does not have good control over all the solar generation. So they can't just let the solar go to waste. The solar generators relentlessly keep generating and dumping energy to the grid. If we shut down baseline, then when the sun goes down we have power outages (because baseline takes so

      • In the areas of California where they are talking about, winter can bring cloud cover for weeks at a time. Summer comes with more dust than you can imagine (due to farmers plowing and more than anything, shaking trees). So there are still challenges.

      • There are problems with relying on solar. CA has been running the public service announcements for a couple years about using less electricity 16:00 - 21:00 daily, since that is when solar generation declines. Time Of Use plans have been rolled out, making electricity more expensive 16:00 -21:00. To remain on a tiered plan one had to sign and mail in a form to not be switched to TOU. We are already short.

        To go all solar, we need a more panels, a lot more. To replace gas usage in LA County alone, we nee

  • The fossil fuel industry will create a few astro turf groups that will imagine some sort of vague negative impact to some group. They will be funded way out of proportion to the real or imagined grievances. Most negative reaction about this is mostly ridiculing the idea in particular, and all green tech in general. So it looks like the focus groups have not zeroed in on the talking points yet. Soon they will find one. The shade will reduce/increase algae growth that will reduce/increase oxygen levels in wat

    • So you are probably aware of this, but the US government asserts control over a lot of land. A LOT of land. One of the ways the government makes money is to lease this land to private industries. I'm sure you've at least heard stories about controversy regarding leasing wildlife preserve areas to fossil fuel companies and suchlike...

      Well just over a week ago, Feb 25th, they concluded what is the largest auction of federally controlled property rights in US history: Six leases totaling $4.37 billion and repr

      • Re: (Score:2)

        by Whibla ( 210729 )

        That was very informative, thanks. Please don't take the rest of this post as an attack on you, or anything you've written. I genuinely do appreciate the info.

        The rest of what follows could be considered paranoid hyperbole.

        If I were channelling my inner conspiracy theorist though, I might suggest an alternative motivation for the following:

        The planned use for that land? Wind power. Nobody is going to spent $4.37 billion to buy a chunk of ocean without expecting they can turn a handy profit. Among the winners are (by way of join ventures): National Grid whose main business is natural gas; Shell New Energies which is a division of Shell Oil Company, and ENGIE which is a French oil and gas company. The fossil fuel industry is seeing the dollar signs on the wall. It's no longer safe to assume that the fossil fuel industry will be opposing renewable energy tooth and nail, because they're making big investments in it.

        So these companies that produce fossil fuels now have the exclusive rights to site wind turbines in these littoral areas. Wind turbines that might cut into their fossil f

    • Re: (Score:2)

      by EvilSS ( 557649 )

      The fossil fuel industry will create a few astro turf groups that will imagine some sort of vague negative impact to some group.

      Pretty sure half the people on /. commenting on this story are trying out for those positions.

  • The panels are Phase I.

    The cu.ft. of water flow is measured in thousands. Inserting purpose designed generators the length of 4000 miles is a drop in the bucket at each generator that adds a dam worth of constant power to the grid.

    That Piggyback is PhaseII

    • Inserting purpose designed generators the length of 4000 miles is a drop in the bucket at each generator that adds a dam worth of constant power to the grid.

      Interestingly, these were built in the 70s, and already exist at places along the canals. However, they are not used for some reason (only in case of emergency).

  • Increase in West Nile? Zika?

    • You're thinking too small. Home for homeless Californian encampments.

    • The canals aren't a growing place for mosquitos because the water is flowing.

      • Depending on how fast it is flowing, it is.
        Also depends on the waters edge, is it earth and covered with plants? Or just concrete?

        The main reason for low mosquito count are fish.

        On the other hand most mosquito grow in puddles after rain.

        • The canals in this area are earth-banked, lined with concrete on the inside. The banks outside the concrete are bone-dry in summer. In winter they get muddy, because it is raining, and the canals are empty. When the canals have first been emptied, there are little puddles with all kinds of strange bugs in them, but they dry up soon enough. (Also, in winter it freezes so mosquitos die a different way). This is the area where I grew up (in the Turlock irrigation district), so I've seen a lot of these canals,

  • I don't understand how the economics of this is supposed to work. It's not like we're running out of places to put solar panels. Putting them on rooftops or over parking lots would probably be cheaper. If you want to shade canals to reduce evaporation and algae growth, some canvas should work just as well. It'll cost so much less than the solar panels, it basically adds nothing to the total.

    • I don't understand how the economics of this is supposed to work. It's not like we're running out of places to put solar panels. Putting them on rooftops or over parking lots would probably be cheaper. If you want to shade canals to reduce evaporation and algae growth, some canvas should work just as well. It'll cost so much less than the solar panels, it basically adds nothing to the total.

      Similar thought to what I had. I guess there's some benefit in that it's a large area of "disturbed land" which makes it less likely people will complain or environmental groups will try to kill the project to save a spider or turtle. But yeah, on a cost basis this is going to be way more expensive than just installing them at utility scale on a flat patch of dirt... and there's some risk that the humidity under the panels could damage the panels themselves or the connections to the other hardware that ha

      • I guess there's some benefit in that it's a large area of "disturbed land" which makes it less likely people will complain or environmental groups will try to kill the project to save a spider or turtle.

        There will still be NIMBY issues. My county recently proposed piping miles of our open flume system to reduce evaporation, and the locals were immediately up in arms about how it would take away a potential source of firefighting water and affect the local animals and generally ruin their view. The idea was

    • Actually studying the economic feasibility would be _capitalism_. That may not be welcome in California politics.

    • Re: (Score:2)

      by EvilSS ( 557649 )

      Putting them on rooftops or over parking lots would probably be cheaper.

      Can you quantify those savings in hard numbers for us?

    • Rooftops and parking lots are a form of "urban warfare"... Negotiate with HOW many people/entities?!

      This is why net metering uses a middle man (taking a big bite) to sell energy to the utility and the homeowner.

    • Putting them on rooftops or over parking lots would probably be cheaper.

      Actually, this is already happening. When I last visited California for work, I parked my car under a solar panel in the work parking lot.

      Of course, parking lots are generally privately owned, so the owner of the land decides to do or not do it without any public debate. But canals are public, so every decision becomes a news article (or many articles).

      If you want to shade canals to reduce evaporation and algae growth, some canvas should work just as well. It'll cost so much less than the solar panels, it basically adds nothing to the total.

      Yes installing mounted solar panels is more expensive than installing canvas, but you earn money back by selling the solar power. How much do you earn back?

  • The solar panels on my room did decrease the heating in the attic.

  • We put PV panels over the 386,604 lane miles in California!

    The number came when I asked google how many miles of freeway are in California

    • The canals are a much better place to put them because if you need to do maintenance you don't have traffic issues.

      Big parking lots first, canals second

  • So, dryer air passing over forests, increased evapotranspiration resulting in dryer forests. More likely to catch fire.

  • I'm guessing from their misuse of the word "canal", which is a waterway for carrying boats, that their first language isn't English. Do they mean the *aqueducts* carrying water around California?

  • What if we put solar panels on supermarket car parks

  • I'm Canadian.

    Americans built the Hoover dam, the Golden Gate Bridge and the interstate highway system. They put men on the moon and rovers on Mars and did a thousand other amazing things.

    Fast forward to today and when it comes to solar panels on frames over a canal the Americans on this thread are saying "this is impossible" and "it'll be too expensive" and "we won't be able to run the power lines."

    What the hell happened to America? Why have you all gone from "CAN DO!" to "meh, can't do."

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