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  • Questions/ concerns about site plan

    I received the following site plan from my installer for my new system. It is a 5.28 kw system using 16 330W panels. I have some questions and concerns about the layout and was hoping I could get some input. I am located in Northern CA.

    According to the plan, 9 panels are installed on roof section 1, 110 degrees azimuth. The other 7 panels are on roof section 2, 200 degrees azimuth.

    1. Would it be more efficient if the majority or all of the 16 panels be installed on roof section 2, provided all 16 fit? There are no shading concerns on any of the roof sections.
    2. The inverter is located on the outside. I know this is common, but the location is facing the street for everyone to see and I don't believe there is much shading on that side of the house if any. Is it possible to request that it be installed in the garage? It is literally the other side of the wall. I don't know if I should be concerned at all about how easy it would be to tamper with the inverter.

    Thanks,
    Attached Files

  • #2
    yes you would produce more with the 200 degree azimuth roof section.

    Also if that is the HDWave version of the SE5000h (the H at the end) then it has automatic rapid shutdown and can be placed inside the garage with no problem, just needs an AC disconnect outside (would need that no matter where the inverter is placed though).
    Last edited by ButchDeal; 04-25-2018, 11:40 AM.
    OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

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    • #3
      Assuming the tilts are equal, panels at the 200 deg. az. will produce more annual output than panels at the 110 deg. az. However, the loss of production due to azimuth will probably not be as great as you might think because the 10 deg. tilt will tend to bring the 200 deg. az. output closer to the 110 deg. az. output (in the limit, horizontal array's output is unaffected by azimuth) Still, moving as many panels to the 200 deg. az. will most likely result in greater annual output, but you may not have enough roof area to put all the panels there. Often, CA/local fire setback regs. reduce available area as the sketch seems to show.

      Run PVWatts for both azimuths for an idea of possible penalty for the 110 vs. the 200 deg. azimuths.

      As for inverter placement, here's how it works: You tell the vendor where you want it and if that location is not possible the vendor provides good and valid reasons why you can't get what you want. BTW: What's cheaper/easier for the vendor is not a good reason even though that's often one of the (unspoken) reasons for inverter placement. Excess/waste heat production in a normal garage is also a B.S. reason. So is the excess heat red herring. Over the course of a year, a 5kW inverter will reject heat into a garage at an average rate of something like 50 BTU/hr. That's peanuts. An adult human easily puts rejects 100-200 BTU/hr. to the surroundings just walking around. A car coming into a garage after a drive on a hot day will put a couple orders of magnitude more heat into a garage than an inverter, or something like about as much as that inverter will put into the garage in a week.

      My 5 kW inverter is in my garage. Many feel that is a better place for several reasons, including less exposure to the elements, security and aesthetics. Greater than half the string inverter equipped systems in my HOA have the inverters in the garage. Happens all the time.

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      • #4
        Not sure what type of Utility Interconnection programs there are in California, but here in Hawaii for example now with netmetering gone, we design on different pitches and azimuths so that the system produces throughout the day. It really depends on when you need that energy. Are you getting batteries with the system ? Are there different rates that you get paid depending on when you export ? or do you get paid the same no matter what time of day you export and can you export all day ?

        I'm sure the installer has their reasons for why they designed it in that specific way.

        Comment


        • #5
          Originally posted by camilo View Post
          ......I'm sure the installer has their reasons for why they designed it in that specific way.
          Easy and Profit is usually the only concern in most vendors minds. Doing it elegantly and right is secondary.

          Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
          || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
          || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

          solar: http://tinyurl.com/LMR-Solar
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          • #6
            Originally posted by camilo View Post
            Not sure what type of Utility Interconnection programs there are in California, but here in Hawaii for example now with netmetering gone, we design on different pitches and azimuths so that the system produces throughout the day. It really depends on when you need that energy. Are you getting batteries with the system ? Are there different rates that you get paid depending on when you export ? or do you get paid the same no matter what time of day you export and can you export all day ?

            I'm sure the installer has their reasons for why they designed it in that specific way.
            I'm sure they do as well. I'm also quite sure at least one of those reasons, and probably the one that trumps all other reasons (if others exist at all) is to maximize their profit.

            Vendors/Installers make money by putting equipment on property, not optimizing cost effectiveness or saving customers money.

            The more equipment placed/sold per application, the greater the profit. Quality, good design and elegance are not part of that business model. Maybe an afterthought or at best treated like a stepchild in the pecking order.

            A lot/most of the time the owners/customers/marks solar ignorance is the catalyst for increasing system sizes and peddlers' profit margin.

            It's just business.

            Still, the low tilt angles for this application may the make off south orientation penalty somewhat less than higher tilts might.

            Comment


            • #7
              Originally posted by ButchDeal View Post
              Also if that is the HDWave version of the SE5000h (the H at the end) then it has automatic rapid shutdown and can be placed inside the garage with no problem, just needs an AC disconnect outside (would need that no matter where the inverter is placed though).
              It seems that there is room for interpretation of the location of the AC disconnect, depending on the POCO.

              Section 690.15(A) indicates that AC and DC disconnects must be "within sight of or in each inverter," so for a garage mounted inverter the AC disconnect should be inside the garage as well. To enable emergency responders or utility workers to disconnect the PV system, SCE guidelines suggest that this can be done via the main circuit breaker board and by removing the SCE meter (source of interpretation).

              So in my case I have a SolarEdge HD-wave inverter and the AC disconnect inside the garage, and my system passed inspection with no issues just a few weeks ago. There is a plague on the outside wall of the garage where the main CB panel and utility meter are indicating the location of the inverter.

              Comment


              • #8
                Originally posted by Kendalf View Post

                It seems that there is room for interpretation of the location of the AC disconnect, depending on the POCO.
                Possibly but the real point is the AHJ and fire code. Not the PoCo.

                Originally posted by Kendalf View Post
                Section 690.15(A) indicates that AC and DC disconnects must be "within sight of or in each inverter," so for a garage mounted inverter the AC disconnect should be inside the garage as well. To enable emergency responders or utility workers to disconnect the PV system, SCE guidelines suggest that this can be done via the main circuit breaker board and by removing the SCE meter (source of interpretation).
                In the case of the HDWave inverter pulling the meter will trigger the rapid shutdown but that is not the case with all inverters.
                Further DC disconnect is not really needed if there is rapid shutdown and a way to trigger it (which is NOT using the DC disconnect).


                Originally posted by Kendalf View Post
                So in my case I have a SolarEdge HD-wave inverter and the AC disconnect inside the garage, and my system passed inspection with no issues just a few weeks ago. There is a plague on the outside wall of the garage where the main CB panel and utility meter are indicating the location of the inverter.
                "plaque" In most case this needs to also indicate that the system is Rapid shutdown capable and how to trigger it.
                OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

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                • #9
                  Originally posted by ButchDeal View Post
                  "plaque" In most case this needs to also indicate that the system is Rapid shutdown capable and how to trigger it.
                  LOL didn't notice the typo till you mentioned it.

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                  • #10
                    Originally posted by Kendalf View Post
                    LOL didn't notice the typo till you mentioned it.
                    There are areas that require a plague of plaques, and one inspector that requires them to be riveted to the inverter even though that voids the warranty.
                    OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

                    Comment


                    • #11
                      Originally posted by J.P.M. View Post

                      I'm sure they do as well. I'm also quite sure at least one of those reasons, and probably the one that trumps all other reasons (if others exist at all) is to maximize their profit.

                      Vendors/Installers make money by putting equipment on property, not optimizing cost effectiveness or saving customers money.

                      The more equipment placed/sold per application, the greater the profit. Quality, good design and elegance are not part of that business model. Maybe an afterthought or at best treated like a stepchild in the pecking order.

                      A lot/most of the time the owners/customers/marks solar ignorance is the catalyst for increasing system sizes and peddlers' profit margin.

                      It's just business.

                      Still, the low tilt angles for this application may the make off south orientation penalty somewhat less than higher tilts might.
                      Well if that was the case it would be much easier to fit all panels on one roof plane, and not have mixed landscape and portrait panels. They can all fit on the 200 az roof face.

                      Out of curiosity, how old are you J.P.M.? and what's your trade? Are you an electrician? solar installer?

                      Comment


                      • #12
                        Originally posted by Mike90250 View Post

                        Easy and Profit is usually the only concern in most vendors minds. Doing it elegantly and right is secondary.
                        for most im sure that's the case. not everyone does it like that though. especially not if you plan to stay in business for a considerable amount of time.

                        Comment


                        • #13
                          Looking at your roof plan I have a question. Is the pitch 12 degrees or 12 in 12, (45 degrees)? There is a big difference between the two. From the style of your roof I'm guessing it's 12 in 12.
                          2.2kw Suntech mono, Classic 200, NEW Trace SW4024

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                          • #14
                            Originally posted by littleharbor View Post
                            Looking at your roof plan I have a question. Is the pitch 12 degrees or 12 in 12, (45 degrees)? There is a big difference between the two. From the style of your roof I'm guessing it's 12 in 12.
                            Might be, but it would make the house look kinda funky. Also, and not necessarily saying that the sketch considers projection, and assuming ~~ 65" X 39" panel size, the panel dimension ratios scale closer to a lower elevation angle. Certainly a question worth asking however.

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