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LG315N1K-V5 panel WITH IQ7 or Panasonic VBHN330SA17E with IQ7X. panasonic is 17c more

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  • LG315N1K-V5 panel WITH IQ7 or Panasonic VBHN330SA17E with IQ7X. panasonic is 17c more

    my worry is with lg panel it comes with iq7 andnot iq7+. installer is saying not worth spending more on iq7+

    so both same size systems and panasonic ends up being 17 cent watt more expensive.

    is the panasonic worth the extra $2k or stick with lg.
    both companies offering 25 year triple guard warranty.

    based on your input i'll decide.

  • #2
    315 panel vs 330

    experts what do you think

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    • #3
      larger system or more efficiency system. im told i have the roof space

      but the iq7x more efficent vs the regualr iq7. 60 cell vs 92 cell?

      Comment


      • #4
        Originally posted by GOTO35 View Post
        larger system or more efficiency system. im told i have the roof space

        but the iq7x more efficent vs the regualr iq7. 60 cell vs 92 cell?
        More efficient or lower DC to AC ratio? I have the IQ7plus and the only reason I used them is I have 96 volt panels with higher voltage. I did not want to exceed the specs on the regular IQ7s and void the warranty. My cells will never put out their rated capacity so I paid for unused inverter capacity. If you have the roof space go with the larger system and don't worry about the clipping because it will disappear in a few years and you will only see it on perfect days. If you want a more detailed explanation post the inverter specs and the panel specs and I can calculate the DC to AC ratios.
        9 kW solar, 42kWh LFP storage. EV owner since 2012

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        • #5
          I'm assuming that both companies are very strong, well-established outfits that you can trust in the long run. You probably will never need them, but it's nice to know that someone will be there 10 years down the road. Also, it's important to know that they won't take shortcuts and will do the job carefully. There are some flakes installing solar these days.

          Both panels and microinverters are good. You won't go wrong with either hardware. If the cheaper one meets your needs, I wouldn't spend extra.

          The iQ7, iQ7+ and iQ7x are equally efficient. They just have different power ratings. Most of the time, they are roughly 95% efficient. At some ideal power level, they will be a bit higher, and at other power levels, a bit lower. The real difference is that above a certain power, they will limit total power output. The panel will be able to produce 290 watts or 310 watts, but the iQ7 will only allow 250 watts to flow. Think of it like a speed governor on a car with a big engine. If you remove the governor, you still have the same engine and the same 0-60 time, but you'll be able to hit 100 MPH on the highway. We almost never have a chance to drive 100 MPH, so it won't matter.

          Depending on your exact situation, you'll probably find that your panels are only putting out 315 watts for an hour at noon on a clear day. The rest of the time, they're putting out less and the inverter won't be a limit. This picture graphically shows what I mean. Is it worth extra money for the energy shown in the red peak?

          lost-energy.jpg
          That's my opinion. If you want to be really careful, go to the web and try out the PVWatts model at pvwatts.nrel.gov with both situations. It can show you exactly how much energy you're giving up per year by not getting the iQ7+ microinverters.

          As a wild guess, I think that an installer would want $50-$60 more for the iQ7+ vs the iQ7 assuming that they were willing to let you upgrade. How long will that extra $50 per panel extra take to pay you back? Probably a long time.
          7kW Roof PV, APsystems QS1 micros, Nissan Leaf EV

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          • #6
            thanks so what would you choose, lg315 panel with iq7, iq7+ or panasonic 330 panels with iq7x?

            Comment


            • #7
              Originally posted by GOTO35 View Post
              thanks so what would you choose, lg315 panel with iq7, iq7+ or panasonic 330 panels with iq7x?
              Thanks to @bob-n for that detailed explanation that implied that the less expensive system was going to be more cost effective. At least that was how i interpreted his comments.
              That was what I would also choose.
              9 kW solar, 42kWh LFP storage. EV owner since 2012

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              • #8
                Yes, I think the LG315 with iq7 is a good choice.
                7kW Roof PV, APsystems QS1 micros, Nissan Leaf EV

                Comment


                • #9
                  One way to get a bit more information that may be useful:

                  Run PVWatts for each system.
                  Get the hourly output for each system with the appropriate panel/micro match.
                  See how much energy above 250 W/panel or 320 W/panel each system collects over a year by hour.
                  For hours where modeled system output > (micro output) * (# of panels), subtract the difference.
                  Sum the hours' differences.That sum will be a SWAG for what each system may lose as a result of inverter clipping.
                  Figure out if the clipping loss difference between systems is worth $ 2K.

                  A rough guess, but I've done it a few times for neighbors and the method seems to point in the right direction.

                  Take it FWIW.

                  Comment


                  • #10
                    Originally posted by J.P.M. View Post
                    One way to get a bit more information that may be useful:

                    Run PVWatts for each system.
                    Get the hourly output for each system with the appropriate panel/micro match.
                    See how much energy above 250 W/panel or 320 W/panel each system collects over a year by hour.
                    For hours where modeled system output > (micro output) * (# of panels), subtract the difference.
                    Sum the hours' differences.That sum will be a SWAG for what each system may lose as a result of inverter clipping.
                    Figure out if the clipping loss difference between systems is worth $ 2K.

                    A rough guess, but I've done it a few times for neighbors and the method seems to point in the right direction.

                    Take it FWIW.
                    jpm any way you can help me do it? I went to the website and got lost with all technicalities. hoping you can help. my email in case you want to email me goto35march@gmail.com

                    Comment


                    • #11
                      or could you tell me the advanced parameters? again newbie and not sure for each panel.

                      Comment


                      • #12
                        Once you fiddle with the tool and read some help screens, it will be pretty easy. We all started blind and muddled our way through it. You can as well. If you hit a confusing question, read the help by clicking the "?".

                        Here's a jump-start that will get you going well enough. It doesn't go through every feature of the tool, but gives you what you need to make these judgments.

                        Start with your address or zip code. Hit Go>>
                        Optionally you can fine tune the location or just accept it as close enough. Hit "Go to".
                        For System Info, enter all 8 items. You can leave losses at default. Some prefer 10% to the default 14.08%. It won't matter.
                        Before moving on, select Advanced Parameters.
                        Change "DC to AC Size Ratio" for your inverter choice. This is the critical thing that models inverter power limiting.
                        Hit "Go to". You'll see monthly and yearly production in kWh and $. You're done!

                        Go back and change DC to AC Size Ratio, hit "Go to", and you'll see the difference in energy generated in a year with a different inverter.
                        7kW Roof PV, APsystems QS1 micros, Nissan Leaf EV

                        Comment


                        • #13
                          Originally posted by GOTO35 View Post

                          jpm any way you can help me do it? I went to the website and got lost with all technicalities. hoping you can help. my email in case you want to email me goto35march@gmail.com
                          The short answer to your question is yes, but nothing would come of it that would be, IMO called progress.

                          In my rush to get that post out, I left out the usual suggestions I make to new users of PVWatts. I add them now with apologies to you for an incomplete post.

                          - Before you start, read all the help screens a couple of times. They provide an education. That education in itself is worth the price of admission if for nothing more than to help see through vendor's B.S. The probability is also higher that with more education you'll also wind up with a more fit for purpose system.
                          -GIGO. The closer your input is to your particular situation and the better you understand what it is, and why it's important, the higher the probability is that the model will spit out something close(r) to what you wind up with.

                          Without the prep. of reading/learning, using PVWatts, or any model for that matter, will be a bit like trying to get into an elevator that's already gone up 6 ft.

                          The method I outlined is actually a bastardization of the main intent of the model. You may want to start out by using the model for it's common purpose of 1st approx. modeling of a residential PV system before using it as I suggested. What I described is a SWAG/dart throw way to get a rough approximation of output of two different systems to compare possible lost system output as a result of micros that have max. output < a panel and so a system's modeled output.

                          If you want, after reading/studying up and doing a few runs, you have some specific questions to fill in some gaps in your newly acquired knowledge, I'll do my best to answer those specific questions as correctly and thoroughly as I am able.

                          I'm sure other's here would be willing to do the same. Just take all of it (including and maybe even particularly my brain spoor) with a skeptic's eye. The more you learn the more you'll appreciate some posters are dangerous.

                          However, and with no offense meant, I'm not a spoon feeder or an enabler, and probably not much of a teacher either. But I'm also quite sure - maybe even more than you - that you are as capable as anyone to learn anything you choose to learn. I and others can help. but IMO only, the student must do the heavy lifting required for the learning process. Sort of GIGO.

                          Take what you want of the above. Scrap the rest.
                          Last edited by J.P.M.; 05-19-2020, 12:13 PM.

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                          • #14
                            thanks got it did some research and clipping would effect me $20 a year lol. so not worth it.

                            now question is are the panasonic panels worth the $1500 more than LG or stick with the lg (both companies excellent)

                            what would you do my people?

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                            • #15
                              The same tool can help with the panel choice question. How much extra $ per year will you get with 330 watt panels vs 315 watt panels? How long until that pays for $2K extra cost up front. Are you willing to invest $2K now for that promise of money in the future?

                              Another way to calculate is to note that you would be getting 5% extra power. Is $2K more or less than 5% of the total system cost? If $2K is more than 5% of the total system cost, then the extra 15 watts will take longer to pay back than the rest of the system, so a worse investment. If same, then it is a comparable investment. Same means that the total system cost to you is $40K.
                              7kW Roof PV, APsystems QS1 micros, Nissan Leaf EV

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