Thread

1. nbf_1995 · 1790086541 · 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. schnevets · 1790111056 · focus · HN ↗

      Anecdotally speaking, I have heard of a massive California solar farm in an undeveloped area that has serious vandalism problems. Junkies will find ways through the fencing at night, strip copper and other materials from panels, and cause thousands in damages and lost energy just to extract enough scrap for a fix.

      Nothing short of a face-to-face security response will deter these criminals, so there it is a challenging cost-benefit balance. At least panels in parking lots and other developed spaces have the benefit of witnesses. I'm sure a 20 foot climb up a steel beam over running water is a decent deterrent as well.

      1. amluto · 1790123127 · focus · HN ↗

         I would love to see more project specs call for aluminum cable. For a given ampacity, it’s lighter, cheaper and more flexible than copper.

         The major downsides are that the exposed wire is much less corrosion resistant underground (which is irrelevant) and that you need appropriate lugs. But standard lugs can easily be purchased in aluminum-compatible variants at no additional cost.

         1. trollbridge · 1790165238 · focus · HN ↗

            The 1960s called; they want their trailer fires back.

            1. amluto · 1790171981 · focus · HN ↗

               Not really. The 1960s used small-gauge aluminum wire with inappropriate alloys and inappropriate connectors. The modern stuff doesn’t have the same problems.
            2. quickthrowman · 1790172681 · focus · HN ↗

               Aluminum wire is completely safe these days. Wiring devices and breakers have accepted both Cu/Al wire for the last 50 years.

               There was an issue with aluminum wire and terminations, the wiring devices and breakers used for copper only wire didn’t work with aluminum (wrong coefficient of expansion of the metal where the terminations were made) and caused arcing and fires. Once the termination points were made out of an alloy that worked with both Cu/Al, it’s been safe to use.

               1. amluto · 1790175812 · focus · HN ↗

                  > Wiring devices and breakers have accepted both Cu/Al wire for the last 50 years.

                  I agree with your general point, but be a bit careful here.

                  > Wiring devices and breakers have accepted both Cu/Al wire for the last 50 years.

                  It’s true that, for a little over 50 years, the UL has regulated what devices may “accept” Al wire. But devices have had markings suggesting use of Al wire for longer than that, and it was quite unwise:

                  <a href="https:&#x2F;&#x2F;inspectapedia.com&#x2F;aluminum&#x2F;Aluminum_Wiring_Repair_COALR.php" rel="nofollow">https:&#x2F;&#x2F;inspectapedia.com&#x2F;aluminum&#x2F;Aluminum_Wiring_Repair_CO...

                  Don’t get caught up in all the discussion of repair devices — AIUI this article is mostly about “repair” of old pre-8000-series Al wire. You can’t buy that stuff any more. As far as I know, modern Al listed building wire is only sold in 8 AWG and up, and this stuff doesn’t need “repair”: it’s perfectly fine in any appropriately listed connector.

                  1. quickthrowman · 1790195565 · focus · HN ↗

                     Ah I see what you’re referring to.

                     I was taught that the safe way to keep using the old pre-8000 series wire is to use the specific listed fittings for this purpose (WAGO 221 series nuts are fit for purpose) with contact paste and a copper pigtail that connects to the device.

                     1. trollbridge · 1790220049 · focus · HN ↗

                        I assume you mean 222, and Wago&#x27;s have earned a reputation for working themselves loose after enough years rather randomly to the point some reputable electrician outfits here won&#x27;t use them. I would not bother with pre-8000 wire at all in thinner gauges (10 and thinner).
               2. trollbridge · 1790219945 · focus · HN ↗

                  Alum wire isn&#x27;t any safer than it used to be. It&#x27;s just banned by the electrical code to use it in many applications, and elsewise the requirements to be UL listed to take Al wire are lot more stringent than they used to be.

                  The cost of copper for house wiring is not significant (if it were, every spec home builder would be wiring houses with #12 gauge Al instead of #14 Cu) until you get into thicker gauge stuff, and that&#x27;s almost always Al anyway.

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