back to article California to try tackling drought with canal-top solar panels

California is ready to try out something that could help it save water and generate electricity at the same time: solar panels over irrigation canals. For this proof-of-concept experiment, some 8,500 feet of photovoltaic panels will be installed over waterways just north of Turlock, central California, generating electricity …

  1. Russ T

    372 miles

    By my rough calculations that's how many miles they'd need to cover to generate 1.21 Gigawatts.

    1. Dimmer

      Re: 372 miles

      How about one step further, use ocean water and solar panels. Quick web search:

      “The theoretical absolute minimum amount of energy required by natural osmosis to desalinate average seawater is approximately 1 kilowatt-hour per cubic meter (kwh/m3) of water produced, or 3.8 kilowatt-hours per thousand gallons (kwh/kgal). The actual SWRO energy requirement in the 1970’s was 7.0 to 9.0 kwh/m3 (26-34 kwh/kgal). With recent technological advancements and innovations in high efficiency pumps, energy recovery systems and overall higher efficiency plants, the actual expected consumed energy has reduced to 2.5 to 3.5 kwh/ m3 (10-13 kwh/kgal)”

      1. Trollslayer

        Re: 372 miles

        As long as you allow for the waves.

      2. Anonymous Coward
        Anonymous Coward

        Re: 372 miles

        And dump all the salt at the local fast food joints?

      3. Anonymous Coward
        Anonymous Coward

        Re: 372 miles

        Pick a unit system and be a dick about it. That kwh/kgal figure is an abomination!

        1. John Robson Silver badge

          Re: 372 miles

          I don't know - I quite liked it.

          Both sides are seriously oddball, non SI units - but both are also fairly well understood (particularly in USland)

          1. Yet Another Anonymous coward Silver badge

            Re: 372 miles

            So instead of kwh/kgal would kg/m/s^2 make more sense ?

        2. TheRealRoland
          Devil

          Re: 372 miles

          Psh. Remember what site you're posting on...

          https://www.theregister.com/Design/page/reg-standards-converter.html

          1. Agamemnon
            Pint

            Re: 372 miles

            Thank you for reminding our friends of El Reg measurement Standards. ----> on me.

        3. GBE

          Re: 372 miles

          Pick a unit system and be a dick about it. That kwh/kgal figure is an abomination!

          Many years ago, I worked on fire-control software for a US Navy project. It had a bunch of different input devices: INS (3D heading/velocity, location), Sonar (for ground speed), Wind speed/direction, Odometer ticks (also for ground speed), Temperature, and so on) as well as a bunch of data input by the operator (starting lat/long/elev, barometric pressure, and whatnot). Absolutely everything was in metric except for one internal value that was calculated based on various inputs: air density was in slugs/m^3. I asked why, and was told that's just the way it's done in the US Navy.

  2. Anonymous Coward
    Anonymous Coward

    How about floating on reservoirs?

    <quote>

    The solar photovoltaic (PV) system, developed by Israeli startup Xfloat, is designed to move and track the sun while floating on reservoir water. The project is being carried out in cooperation with Mekorot, Israel’s national water company,

    </quote>

    1. Roger Greenwood

      Re: How about floating on reservoirs?

      Done

      https://www.lightsourcebp.com/uk/projects/queen-elizabeth-ii-reservoir-solar-project/

      1. anothercynic Silver badge

        Re: How about floating on reservoirs?

        Yes, this one's a great thing to spot when you depart westwards from Heathrow, or if you are being brought into the airport from the west. :-)

    2. H in The Hague

      Re: How about floating on reservoirs?

      Done.

      https://solarmagazine.nl/nieuws-zonne-energie/i24664/profloating-installeert-5-000-drijvende-zonnepanelen-bij-plantenkwekerij-bernhard

      And several other projects.

    3. adam 40 Silver badge
      Flame

      Re: How about burning on reservoirs?

      Done...

      https://www.pv-magazine.com/2019/09/09/japans-largest-floating-pv-plant-catches-fire-after-typhoon-faxai-impact/

      1. DarkRookie

        Re: How about burning on reservoirs?

        About as smart as putting them in Lake Okeechobee

    4. jngreenlee

      Re: How about floating on reservoirs?

      Brings up a good point. This will impact waterfowl, whether anyone likes it or not. This in turn means that this project will be held up for 10-15 years by Environmental Impact Statements, attempts to create exemptions, and related lawsuits on all sides. Cost magnitude will be 10-25X by the time it is all settled. The budget allocation will be enough for a 100-foot section after legal fees are paid.

  3. John Smith 19 Gold badge
    Thumb Up

    13GW

    That's an actually useful amount of power.

    It's one of those "So obvious why didn't anyone think of it before?" ideas.

    But yes in principle max sunlight --> max risk of evaporation so there's a nice sens of tracking.

    Now the notion is out there let's hope more organisations roll it out.

    1. Anonymous Coward
      Anonymous Coward

      Re: 13GW

      2010 was the only time I have been in that area of the world and I mentioned the idea to everyone I met who might pass it on (mainly large land and business owners, and park rangers rather than government officials as I was there on vacation) - the idea originally formed to retain water by covering the canals, but it was obvious to gain electricity by using solar panels to do the shading.

      Also panels on stilts on the sides of storm drains to gain electricity from underused land.

      1. Screwed

        Re: 13GW

        Over car parks!

        While they wouldn't have the evaporation benefit, think how much less cooling of vehicles by A/C would be required - especially when they have been roasting under the midday sun.

        1. XSV1
          Thumb Up

          Re: 13GW

          In South Africa (with all its sunshine) there are a number of shops/stores and office parks that do exactly this. The solar panels also provide protection to the vehicles in the event of inclement weather (e.g. hail storms that are all too common in the summer months).

          1. Paul Crawford Silver badge

            Re: 13GW

            How well do the PV panels stand up to the hailstones?

            I'm thinking the golf-balls sized ones I believe SA gets!

            1. XSV1

              Re: 13GW

              Good question. I have 24 solar panels on the roof of my house as well as two solar geysers. We have had no breakages yet (still holding thumbs). I live in Joburg, an area with regular hail storms in the summer months. The nice thing about the storms is they wash all the dust off the panels... it helps improve the efficiency of the cells. In the dry months we have to manually clean the dust off.

              1. anothercynic Silver badge

                Re: 13GW

                Solar hot water is brilliant... we had this in the eighties a couple of thousand kilometres north west of you ;-)

                The panels designed at the time were heavy as hell because they actually used glass and steel plating, but it provided some seriously hot water even in winter (although there we still had to backfill with an electric tank heater once the sun set).

            2. Filippo Silver badge

              Re: 13GW

              I'd also be interested in that. I'm planning to put PV on my roof, but we do get golf ball hail every now and then. I heard that the panels can resist it just fine, but I'd love to find an authoritative source.

            3. TRT Silver badge

              Re: 13GW

              There are some nice photos of this coming out of Spain today. They just had a damaging, unfortunate and tragic hail storm.

              1. Version 1.0 Silver badge
                Unhappy

                Re: 13GW

                Unfortunately a young child almost two years old was killed by the Spanish hail - but she would have been just fine if she had been under a solar panel.

        2. sitta_europea

          Re: 13GW

          "Over car parks!"

          The car parks at Perpignan airport have been covered that way for years.

          1. XSV1

            Re: 13GW

            "Perpignan airport"

            Sounds like a great idea. I want to propose the same idea to our local airports. I had a look at the Google Earth images of the Perpignan airport in southern France, but I don't see any solar panels on images that are dated 2022. Am I looking at the wrong airport?

            https://www.google.com/maps/search/Perpignan+airport/@42.7397636,2.8672996,221a,35y,39.47t/data=!3m1!1e3

          2. TRT Silver badge

            Re: 13GW

            And of course you can increase the incident radiation by crash-diving a remote controlled space ship into the heart of a nearby sun, thereby causing massive solar flares... Just make sure that your robotic car park attendant doesn't accidentally end up onboard the stunt ship.

        3. Locky

          Re: 13GW

          Already being done

          https://www.cnet.com/google-amp/news/solar-parking-lots-are-a-win-win-energy-idea-why-arent-they-the-norm/

        4. bombastic bob Silver badge
          Devil

          Re: 13GW

          "Over car parks!"

          that is actually done a LOT. The local Walmart has several rows of covered parking with solar panels on top. Not the entire lot, but a significant portion of it. It has to make cost sense though.

          Even without the panels, covering the canals with "something" has been discussed for DECADES.

          There are many other issues outside of the scope of the article and related discussion, though, that could actually make a MUCH BIGGER difference in water usage and availability... related to the Sacramento river and a certain kind of fish. And maybe better drip irrigation systems for farmers, too.

          1. Yet Another Anonymous coward Silver badge

            Re: 13GW

            A lot of reservoirs in California were covered in black plastic balls to stop evaporation

            Of course it turns out that making 100Million plastic balls uses a lot of oil / energy /water - but if you are building the solar panels anyway

        5. Captain Scarlet Silver badge
          Holmes

          Re: 13GW

          Are you sure you aren't from EEVBlog, his been saying this over and over especially when pointing at SolarRoadways and going wtf

    2. jmch Silver badge
      Boffin

      Re: 13GW

      That IS actually both a useful amount of power, and a good use of a space that otherwise can't really be utilised. Clever.

      But.... not sure that the protection from evaporation will help so much with drought. All that evaporated water eventually would have fallen as rain (even though probably somewhere else). So you're only 'exporting' the drought to some other place. Depending on prevailing winds and weather patterns this could be disastrous for some other adjacent area that would get an even more severe drought.

      OR it could reduce rainfall in an adjacent area tat is otherwise prone to flooding.

      If good enough models can be constructed to anticipate the latter and only cover the canals in those areas it would really be a giant win.

      1. TRT Silver badge

        Re: 13GW

        I suppose the evaporation rain cycle also helps purify the water... I've never got why solar evaporators aren't used more to alleviate water shortages during a drought. Data centre... sea water... I mean CDNs are best placed near to undersea cable heads, aren't they? And they're putting power plants near the sea...

  4. hoola Silver badge

    Reduced Evaporation

    Now I have limited understanding of the science on this but:

    How does covering water with solar panels reduced evaporation by that much?

    The ambient temperature is pretty much the same.

    The panels have reduced the direct sunlight but on water, it is not sunlight that causes most of the loss, it is wind.

    Now I can see that the panels should reduce wind speed to some extent but they may also increase it with a tunnel effect.

    In terms of a useful place to put the panels, then I can see that is worthwhile but I am not sure how much of a saving in water loss there will be.

    1. Stoneshop Silver badge
      Boffin

      Re: Reduced Evaporation

      The ambient temperature is pretty much the same.

      However, the surface temperature as well as the air temperature immediately above it is not

      1. Anonymous Coward
        Anonymous Coward

        Re: Reduced Evaporation

        Also, its supposed to be floating, so, if the surface area of the float covers most of the water way (directly on the water), there is little surface area for evaporation to occur, which occurs with low temps also, due to low humidity.

        1. hoola Silver badge

          Re: Reduced Evaporation

          In the California case they are built on a framework above the waterway if the image is correct.

          This will reduce the direct sunlight but not the wind.

          I can see how floating panels could be a benefit but these are not.

    2. Dave 126 Silver badge

      Re: Reduced Evaporation

      >How does covering water with solar panels reduced evaporation by that much? The ambient temperature is pretty much the same.

      The water temperature is a factor in the evaporation loss. And evaporation cools the water. So direct sunlight will keep the water warmer than it otherwise would be (that sunlight energy doesn't just disappear).

      One would expect the ground through which the canal flows to keep the average water temperature cooler than it otherwise would be... but complex fluid dynamics are complex, duh, so I wouldn't be shocked if there was a warmer surface layer, warmed by the sun.

      https://www.engineeringtoolbox.com/evaporation-water-surface-d_690.html

    3. hoola Silver badge

      Re: Reduced Evaporation

      After all the downvotes I researched this some more rather than relying on the experience of what I see in my pond!

      Wind & temperature are both critical:

      The higher the temperature, as one would expect, the higher the evaporation.

      The higher the wind speed the higher the evaporation.

      The reason for this is that the in still conditions the air above the water will contain more water molecules as they evaporate, reducing the rate of evaporation (high humidity). If the wind is constantly blowing the water molecules away from the surface, humidity is lower so there is greater evaporation.

      I would assume that California is both hot and has some wind, even if it is just a few mph that gives you the worst case.

      So, yes covering the water will reduce the temperature (shaded) and reduce evaporation. Crucially in this scheme, the panels are not on the surface but are on a framework over the waterway.

      What is rather more interesting is that increasing the depth to reduce the temperature of the water may have a greater effect.

      This probably provides the most concise summary without spending hours:

      https://www.globalseafood.org/advocate/evaporation-affected-by-sunlight-temperature-wind/

  5. Anonymous Coward
    Anonymous Coward

    Isn't this a good "shady" idea in general?

    I have been wondering how much the shade thrown by solar panels if mounted as a sort of second roof would contribute to keeping the house underneath more cool.

    If I'm not mistaken a double roof (i.e. one to throw shade on the other and an air gap to vent any heat buildup) is already in use in countries far warmer than ours and I even found links that seem to confirm this. The disadvantage is that you need an extra construction and that it needs to be far more gust proof (due to the airgap), but it strikes me that we could take more advantage of those basic physics in play

    Sadly it's not going to work on my own house as it's listed, solar panels are apparently not deemed a period feature :). But hey, I also have a man cave shed :).

    1. H in The Hague

      Re: Isn't this a good "shady" idea in general?

      "Sadly it's not going to work on my own house as it's listed, solar panels are apparently not deemed a period feature :)."

      Same here (though conservation area rather than listed), and roof just the wrong size and shape too :(

      1. Mishak Silver badge

        Compensation

        Is it time that people who are told they can't improve the energy efficiency of their property "due to planning restrictions" are given compensation to cover the extra costs they have to cover?

        1. 9Rune5

          Re: Compensation

          Wasn't that already baked into the price when the property was bought? Caveat emptor?

          1. Mishak Silver badge

            Re: Compensation

            Not when the restriction is placed on the property after it has been purchased.

    2. Caver_Dave
      Unhappy

      Re: Isn't this a good "shady" idea in general?

      Been contacting local companies and brokers since February this year. So far I have had one vague quote for 23Q2 installation (i.e. full of caveats that the price may change) and another company planned to visit in a week. It's almost as though a 5 bed, south facing house is too small a deal for them!

    3. Toni the terrible

      Re: Isn't this a good "shady" idea in general?

      As far I can see my solar panels are an inch or two above the roof tiles fixed to the joists through the roof proper, I know this cos pigeons get in there to make nests sometimes (yes must be a squeeze), so do I have a double roof? Its been there for 10 yrs so far no problems - except for the WIFI montoring which wont connect to my (sob) eero6 network

    4. Martin an gof Silver badge

      Re: Isn't this a good "shady" idea in general?

      Sadly it's not going to work on my own house as it's listed

      Two solutions spring to mind. Firstly, solar panels don't have to be on the house roof. Build a verandah or gazebo or something out of them. Put 'em on the shed roof (I realise this isn't doing the "shade the house to keep it cooler" thing). Even a greenhouse - not all panels block all sunlight, and thin-film flexible PV materials are now apparently available which while not as efficient as traditional panels have the potential to be significantly cheaper and can be applied to glass instead of the sorts of security and shading films often fitted.

      Secondly, if the problem is aesthetic, there are such things as solar slates which can look very much like natural slate (not cheap mind), though I realise listed buildings can have a range of roofing materials which are not slate!

      Disclosure - a friend works for the company I linked.

      M.

      1. Anonymous Coward
        Anonymous Coward

        Re: Isn't this a good "shady" idea in general?

        That was very helpful - I didn't know there were more companies out there making solar slates. I was not inclined to buy anything Musk has his hands in as warranty doesn't seem to be part of his business ideas so good that there's a 'local', so to speak although I my have to see how expensive and troublesome Brexit has made this..

        1. Martin an gof Silver badge

          Re: Isn't this a good "shady" idea in general?

          I my have to see how expensive and troublesome Brexit has made this

          Assuming you are in the UK, there are some prices on that site, for example:

          The standard 500x250 PV Slate unit has a peak output of 28W and an ex-works price of £59.50. Each 500x250 unit replaces four natural 500x250 slates, covering an area of 0.2sqm. That gives PV Slate an overall roof kit price of £294/sqm or £8,449.00 for a 4kW system.

          which I believe to be fairly up-to-date. Brexit has affected some prices, but this company does a lot of its own manufacturing. Their biggest problem at the moment (my friend tells me) is sourcing inverters, particularly for larger systems. This isn't a brexit issue, it's the current semiconductor supply problems.

          M.

  6. deadlockvictim Silver badge

    Switzerland & Glaciers

    This Swiss should try this to help mitigate the massive glacier loss as well as help mitigate the loss of electricity brought about the impending closure of nuclear power plants.

    1. jmch Silver badge

      Re: Switzerland & Glaciers

      a) It's relatively easy to build structures either on the canal sides to support panels over the canal if the canal is a few metres wide. It's not gonna happen for a glacier that's a few hundred metres wide.

      b) on water you can make the panels floating, over ice they have to be supported, so you run into problem (a). Building the supports directly into the glacier wouldn't work since the glacier moves and will break the supports

      c) It would be a lot of awful-looking massive infrastructure introduced into pristine mountain areas

      If the intention is to cover the glaciers, it's already done with white tarp-like material that combines high reflectivity with looking rather similair to the ice, protecting it without ruining the landscape. Although for space reasons I think it's done only on glacier tongue where there is most melt rather than the entire glacier (covering which would be prohibitive eg Rhone glacier is 16 km2)

  7. sitta_europea

    13GW from four thousand miles of solar panels...

    ... is about what you could get from ten reasonably large wind turbines. And they wouldn't stop freight running along the canals in barges.

    Am I missing something?

    1. wobball

      Re: 13GW from four thousand miles of solar panels...

      Irrigation canals, never used for freight in the states.

      1. Francis Boyle Silver badge

        Re: 13GW from four thousand miles of solar panels...

        There were plenty in the east, just not California.

        wikipedia.org/wiki/Erie_Canal.

    2. Francis Boyle Silver badge

      Probably

      the fact that these are irrigation canals, California being California (i.e. dry). Neither the native American or the Spanish population showed much interest in transport by canal and by the time the Usanians arrived they had railroads to do the job.

      (Dammit, ninjaed!)

    3. lidgaca-2

      Re: 13GW from four thousand miles of solar panels...

      I'd like to know where you get your wind turbines from ...

      I thought the largest ones in the world that have been commercially deployed were rated at about 10 MW ...

      1. Boothy Silver badge

        Re: 13GW from four thousand miles of solar panels...

        I wondered the same, I watched a video a few months back of physicist Helen Czerski visiting the worlds largest wind turbine, and that was 13MW, but it's a prototype off-shore unit, mounted on shore for testing, so not yet commercially deployed.

        I did a quick look up, it's the Haliade-X in Rotterdam port. 260m tall, each blade is 107m long! Seems they expect these to hit 14MW for the production versions.

        Looks like they plan to install 100s of these at the Dogger Bank Wind Farm project (along with other similar sized units from different manufacturers), for a total generating capacity of 4.8 GW.

        So not even half of the 13GW, and that's going to be the largest offshore windfarm ever built (till the next one of course) :-)

    4. Anonymous Coward
      Anonymous Coward

      Re: 13GW from four thousand miles of solar panels...

      Am I missing something?

      A calculator I think. 13GW is 1000 large 13MW windmills

      1. TRT Silver badge

        Re: 13GW from four thousand miles of solar panels...

        A solar calculator?

    5. Toni the terrible

      Re: 13GW from four thousand miles of solar panels...

      Not all irrigation canals are sized for barges.

  8. Auntie Dix Bronze badge
    Facepalm

    Costs and Corrosion

    Key paragraph:

    "Still, the costs to construct canal-top solar systems can become much more expensive. Among the costs that Indian officials have run into is the need to galvanize panel supports with zinc due to increased risk of corrosion, and finding canals that are not too narrow, which would be inefficient, or too wide, making construction costs too high."

    California could instead eliminate its "sanctuary cities" and repatriate its millions of illegal aliens, which would reap promptly greater returns, including profoundly reduced water usage.

    1. xyz

      Re: Costs and Corrosion

      Think of the MOSQUITOES!!!

      1. Trollslayer
        Trollface

        Re: Costs and Corrosion

        I am - it was a great aircraft!

        1. Toni the terrible

          Re: Costs and Corrosion

          wooden you know it

    2. Androgynous Cupboard Silver badge

      Re: Costs and Corrosion

      I suspect this hasn't happened because when it comes to repatriating Aliens, typically either their engines have broken or no-one get through to anyone that can offer them a lift home.

      Although you're certainly right about the water - that Alien that looked just like David Bowie turned up a few years ago, he was definitely after the water.

      1. Auntie Dix Bronze badge
        Alien

        Re: Costs and Corrosion

        The term illegal alien, as defined by U.S. law, is dispassionate. Its context is well understood.

        Its deliberate rewording by agenda-driven activists and the media is flagrant propaganda and should be called out as such.

        Regarding Bowie's character: The extraterrestrial was not an economic refugee. The United States would likely bend over backward, as much as practicable, to help such an alien and his people, assuming, of course, that they were not the predatory lizards from "V" or the like. The last unhingeable jaw that anyone here wanted to see was Linda Lovelace's.

        Good movie (his, not hers)!

  9. Potemkine! Silver badge
    Flame

    This article would be interesting and understandable by most if it didn't mention those medieval units used everywhere except in most countries

    == Bring us Dabbsy back ==

    1. Anonymous Coward
      Anonymous Coward

      Yes, I was a bit puzzled why you would measure a quantity of solar panels by length (feet) rather than by area (metres squared).....

      1. Crypto Monad

        A typical domestic solar panel is 1.85m2 with 370W output (peak).

        Using those figures, your 13GW (peak) will be 35.1 million panels, with an area of 65 million m2, or 6500 hectares.

        We don't know the width of the canals, but if we're talking 4000 miles ~= 6400km, that means roughly a 10 metre span on average.

        What nobody seems to have mentioned is the cost. 35 million panels, even at $100 each, is $3.5 billion. That's without 4,000 miles of supporting structure, or the inverters, or the electrical interconnections.

        Still - a lot cheaper than HS2, and probably more benefit. (Thinks: train tracks are uncovered most of the time. You could lay solar panels on the sleepers?!)

        1. Anonymous Coward
          Anonymous Coward

          You could lay solar panels on the sleepers. I wonder how many days (hours?) it would be after they were installed that the first person was hit by a train whilst trying to steal them? (Thieves on the line is quite a common a problem. in the UK...)

          1. adam 40 Silver badge

            They wouldn't steal them though after they are covered in shit and piss.

        2. fidodogbreath Silver badge

          A typical domestic solar panel

          Home-grade solar panels are not used on jobs of this scale.

    2. DarkRookie

      We have many , many, many more problems in this country than what units of measure we are using.

      It isn't like there isn't a bunch of agreed upon formulas for converting between them.

  10. chivo243 Silver badge
    Joke

    Nexus? Nexux?

    Roy, where have I heard that name before?? Or am I going Batty?

  11. that one in the corner Silver badge

    Won't somebody think of the ducks

    bouncing off with surprised look on their beaks "it was softer than this last year"!

    1. John Brown (no body) Silver badge

      Re: Won't somebody think of the ducks

      Well, it's California, so the eco-freaks will be out protesting about ecology or wildlife being affected or something.

  12. Anonymous Coward
    Anonymous Coward

    Once completed they will rename to Turlock Undercover Reticulation District.

  13. Charlie Clark Silver badge

    Saving water for more abuse?

    Irrigation in California, especially Central Valley, is an example of abuse of a scarce resource: water. If there is less irrigation, you need fewer canals for the water and will thus lose less to evaporation.

    In the meantime by all means cover the canals. Also, install panels over the fruit trees in the above mentioned Central Valley and elsewhere. This will provide power for the warms and protect the trees

    1. Trollslayer
      Facepalm

      Re: Saving water for more abuse?

      And how do the trees get light on the leaves?

      1. ElPedro100

        Re: Saving water for more abuse?

        Could install electric lights under the panels?

      2. Charlie Clark Silver badge

        Re: Saving water for more abuse?

        Panels don't block all the light and you don't go for 100% coverage. See this report (in German but with pictures).

  14. Pascal Monett Silver badge
    Trollface

    "enough to irrigate 50,000 acres of farmland"

    Great.

    That'll be another 10 almond farms in California then.

  15. john.w

    GW or GWh?

    These panels will not be generating and GW at night so they will need to build lots more Gas generation plant to run on those rare cloudy days and all night.

  16. Mark 85 Silver badge

    One of the comments above mentions "needing to remove the dust". So, given where these canals run, I would think dust would be an issue. How do plan to remove it and keep the efficiency levels high enough?

    1. John Brown (no body) Silver badge

      Maybe give Lu-Tze a call?

  17. Hurn

    Microclimate?

    "Because the microclimate adjacent to irrigation canals is somewhat cooler than the surrounding air, TID said the project will also keep solar panels cool, fighting heat-based efficiency losses. "

    Not to rain on their parade, but the reason for the cooler microclimate is due to the evaporative cooling effect of the water.

    Assuming the cover results in a greatly reduced amount of evaporation, the microclimates will be greatly reduced in size and delta temp.

    On the other hand, having slowly moving water somewhat close to the back sides of the PV arrays does create an opportunity: a network of tubing on the backsides, and the occasional PV powered pump, can circulate water from the cooler canal water, chill down the PVs, and deposit the warmer water back into the canal.

    Tests would need to be done to see whether the cooling is worth the extra $ - maybe just have the little pumps run in the summer?

  18. Tempest
    Thumb Down

    Stop Watering The Grass!

    Anyone who lived in the States will realise a lot of water is wasted because Americans want picture prefect gardens and lawns.

  19. MonsieurTM

    ..... Blah blah blah......

    Why not just build a quality 2GW nuclear reactor?

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