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What California is learning from solar panels built over irrigation canals

372 points · 744 comments · Jtsummers

  1. nbf_1995 · · focus · HN ↗
    It seems like it would be more effective to simply put all the solar panels in a field, and construct a cheap shade over the entire canal no? The supports in the picture are massive and don't look cheap. Also I would imagine the solar array uses more copper than a similar capacity array just built in a field. You can't daisy chain multiple miles of solar panels together, so you need an extra power line to run alongside the whole thing.

    Put the solar panels in a field: The solar array uses less copper. The shade supports don't have to hold up solar panels: Shade supports cost less.

    The best reasoning they give is that California has insane permitting requirements, and it takes 1/6 the time to build on developed land compared to undeveloped land.

    1. burnte · · focus · HN ↗
      > It seems like it would be more effective to simply put all the solar panels in a field, and construct a cheap shade over the entire canal no?

      No because now you're using land that could be used for other things, which is exactly what this avoids. This takes existing land that loses water and costs money, and makes it lose less water and make money.

      1. skybrian · · focus · HN ↗
        That’s true of everything you build. The cost of land has to be taken into account, but land is much cheaper in some areas than others.
        1. zdp7 · · focus · HN ↗
          In California most of the land around the aquaduct is valuable cropland. The other side of it is at risk of wildfire.
        2. cryptolobster · · focus · HN ↗
          That's true in general, but California aqueduct land is mostly valuable cropland, and the other side is at wildfire risk
          1. fhdkweig · · focus · HN ↗
            Did anyone else get weird deja vu from the sibling comment? And I can't figure out which one is the clone. cryptolobster posted about 1 hour after zdp7, but they both have good posting history.
        3. burnte · · focus · HN ↗
          The land over a canal is free to the state. And shades the water.
      2. dietr1ch · · focus · HN ↗
        You are assuming that land is expensive and forgetting that building and maintaining panels over long a canal is harder than building over a large plot.
        1. [deleted] · · focus · HN ↗

          [deleted]

        2. asdff · · focus · HN ↗
          Harder but obviously not physically impossible either. From the image I can't imagine what the showstopper would possibly be. Technician on a little dinghy instead of a stepladder doesn't seem like a big deal. Presumably they make it where you can pull the panel off easily if you need to.
          1. fckgw · · focus · HN ↗
            You're talking about something that is probably at least 10x the cost to build and maintain. You're making something simple, like swapping a single solar panel, from a ground-level one-man job into now a multi-person job with specialized equipment and water hazards.
            1. asdff · · focus · HN ↗
              Thats 10x the cost somehow? I doubt it. They put solar in all kinds of awkward areas where a technican can't just show up and turn a screwdriver from ground level. Seems it works somehow. Chances are if they go with this, they will have some maintenance craft like a barge platform I'd guess, where the job would be made effectively no different than a ground level job (aside from bringing over the barge which could be quite simple in design, e.g. wood platform raft made from drums and a cheap outboard motor on one end, it's only in the aqueduct after all not in any open water or current.)
              1. lazide · · focus · HN ↗
                Many of those installations end up abandoned when the cost to repair them exceeds the value of the output of the panel.

                You just typically don’t notice it because unless the panel is severely damaged, a non-functional panel doesn’t look much different than a functional one.

          2. s1artibartfast · · focus · HN ↗
            The showstopper is spending $1,000 of tax payer money for what could be accomplished with $10.
            1. asdff · · focus · HN ↗
              We are just making up numbers now
              1. s1artibartfast · · focus · HN ↗
                I haven't seen anyone cite the project costs, so I think we all are
        3. burnte · · focus · HN ↗
          No I'm not. I'm assuming that existing unused land should be reserved for better projects when we have currently used land that both can do more and where this helps save water. My comment had absolutely nothing to do with the price of land. Everyone else is missing the "water conservation" part because they're distracted by the solar panels and are getting nerd sniped. This isn't a solar first project, it's a water first project.
      3. onlyrealcuzzo · · focus · HN ↗
        You're also not getting the free cooling capacity of the water which makes the panels more efficient - though that probably only drops the total cost 5% or so, but how much extra the heavier supports cost may not be much more...
      4. suncemoje · · focus · HN ↗
        In Switzerland, which is quite densely populated, they even have a pilot project with putting solar panels between rail road tracks:

        <a href="https:&#x2F;&#x2F;www.swissinfo.ch&#x2F;eng&#x2F;emissions-reduction&#x2F;solar-energy-from-railways-shows-first-positive-results-in-switzerland&#x2F;91628036" rel="nofollow">https:&#x2F;&#x2F;www.swissinfo.ch&#x2F;eng&#x2F;emissions-reduction&#x2F;solar-energ...

        1. gregoriol · · focus · HN ↗
          Of all the ideas ever tried, this one seems to be the worst
          1. burnte · · focus · HN ↗
            Yeah, feels worse that solar roadways.
          2. suncemoje · · focus · HN ↗
            Why?
      5. ck45 · · focus · HN ↗
        The concept of <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Agrivoltaics" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Agrivoltaics still sounds more promising than putting solar panels on top of the canal.
        1. burnte · · focus · HN ↗
          Not if the goal is preventing evaporation. Vertical panels in farmland solve a different problem than this does.
          1. ck45 · · focus · HN ↗
            Yes, you are right. There&#x27;s a comment further above to cover the canal but not with solar panels and have the panels in a solar park. The covered area in that solar park could then be used for agriculture - and maybe irrigated with the water from the covered canal.
            1. burnte · · focus · HN ↗
              Yes, we could also put the canal underground in a tunnel and build a nuclear plant, but none of that is relevant either. The article isa bout what we learned by putting panels on canals, not looking for alternatives.
        2. [deleted] · · focus · HN ↗

          [deleted]

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