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  • Three estimates - Different Panels

    I am looking into getting solar panels, not too familiar with all the lingo, but I have received at least three estimates. I use approximately 7050 kwh per year, and from what I have been told I need to upgrade my panel since it is 100 amps.

    LG Electronics - LG440QAC-A6 (14 panels) with Enphase IQ7a Inverter 124% Bill Offset $17,548

    REC Alpha REC370AA (11 Panels) with Enphase Energy IQ7PLUS IQ7PLUS-72-x-US-240 Inverter 97% Bill Offset $14,961

    Panasonic EverVolt WBS EVPV360 (12 Panels) with SolarEdge Technologies Single phase SE7600A-US [240V] Inverter 102% Bill Offset $11,732

    Huge differences in prices, but which one will give me a better bang for my buck?










  • #2
    Dollars per watt is the name of the game in PV panels. They all have the same ultra reliability, the same 25 year warranty, about the same risk of the company surviving as long as the warranty does. Just divide the price by the published ptc rating and you have your answer. The Asian brands will be the lowest but some domestic brands like Mission Solar and Silfab are just about as good.
    BSEE, R11, NABCEP, Chevy BoltEV, >3000kW installed

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    • #3
      Is there a reason new system comparisons always seem to be "Enphase" vs "SolarEdge"? I know the OP didn't say anything about shading, but an SMA inverter with Tigo's optimizers would work fine in almost any situation.

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      • #4
        Originally posted by oregon_phil View Post
        Is there a reason new system comparisons always seem to be "Enphase" vs "SolarEdge"? I know the OP didn't say anything about shading, but an SMA inverter with Tigo's optimizers would work fine in almost any situation.
        I have also been approached by solar installers and just about all of the "equipment" that they are pushing have micro inverters instead of string inverters. Maybe Enphase and SolarEdge just have more influence on them then other equipment suppliers.

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        • #5
          Every situation is different, use what works for you. But micro inverters are a
          dumbed down, fits all solution, looking for a problem. String inverters fit in here,
          and are producing some performance not practical with a micro inverter.
          Bruce Roe

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          • #6
            Originally posted by bcroe View Post
            Every situation is different, use what works for you. But micro inverters are a
            dumbed down, fits all solution, looking for a problem. String inverters fit in here,
            and are producing some performance not practical with a micro inverter.
            Bruce Roe
            I agree, I would not purchase a system with Micro Inverters. Your just going to be paying year after year for an installer to go up on your roof and replace a Micro Inverter that dies. I would rather stick with one Failure point in Garage than have 14 of them on my roof !
            I suspect that this is one of the things that also attracts Installers as they will have maintenance money flowing in year after year once they get enough clients using Micro Inverters.

            Also I am still confused on the Benefits of pairing 440W Panels with 350W Inverters. I get what they are saying but just like the puzzling "New Tech" behind SMA's shade fix I would love to see some long term real world data that backs up the claim that this pairing does not affect the average monthly KWH output.

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            • #7
              As a dealer, I won't install microinverters because I know down the road I'll be having to do truck rolls to replace them one at a time. I too marvel at how they have become so common in the solar industry. A big part is the 2017 code requiring "module level shutdown" (promulgated by the microinverter companies...) But I find that microinverters are seen as attractive by a culture that just loves cell phones and view microinverters like a cell phone attached to every solar panel. "Oh - I can see on my phone just how each of my solar panels is doing." Ya that's right, now when the less reliable microinverter fails - you'll at least know about it right away.
              BSEE, R11, NABCEP, Chevy BoltEV, >3000kW installed

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              • #8
                I don't want to start anything here, but I do find it interesting when people embrace their gut feelings about something as facts.

                Case in point: can anyone provide any non-anecdotal, unbiased, evidence-based data on the failure rate / TCO of micro-inverters vs string inverters? I have searched exhaustively and am unable to find actual peer-reviewed studies on the subject. Lots of FUD and manufacturer-sponsored stuff available though...

                Comment


                • #9
                  Originally posted by solarix View Post
                  As a dealer, I won't install microinverters because I know down the road I'll be having to do truck rolls to replace them one at a time. I too marvel at how they have become so common in the solar industry. A big part is the 2017 code requiring "module level shutdown" (promulgated by the microinverter companies...) But I find that microinverters are seen as attractive by a culture that just loves cell phones and view microinverters like a cell phone attached to every solar panel. "Oh - I can see on my phone just how each of my solar panels is doing." Ya that's right, now when the less reliable microinverter fails - you'll at least know about it right away.
                  To your last sentence: As someone who keeps track of solar installs in my HOA, ~ 150+ to date, I get feedback from users.
                  Seems to me:
                  1.) Most folks could not care less about monitoring.
                  2.) Most folks wouldn't know what they were looking at if they did check array/panel output.
                  3.) Those who do monitor and have a clue what they're looking at quickly get bored doing so as the novelty quickly wears off. That usually lasts less than a month or so.

                  At least when a string inverter fails, the hapless owner will only need to wait until the next billing - if they bother to read the bill or pay attention to it - many around here don't - to get hit upside the head.
                  Last edited by J.P.M.; 06-03-2021, 10:27 AM.

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                  • #10

                    I certainly understand why many installers don't like microinverters due to more difficult replacement work but from a solar owner perspective I like microinverters because I don't want to have an inverter failure to take my entire system down for weeks or longer which seems relatively common for some string inverter brands.

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                    • #11
                      I agree that finding hard data about failure rates is difficult. None of the manufacturers want their failure rates to be known. I can tell you that I have replaced many microinverters and optimizers including a few systems where all the units were replaced under warranty. Of course, this is in hot Arizona - but never the less, it is way too high a failure rate for me.
                      Yes, very few customers actually utilize their monitoring beyond the initial "christmas toy" phase of ownership and I recommend against choosing an inverter based on this feature.
                      BSEE, R11, NABCEP, Chevy BoltEV, >3000kW installed

                      Comment


                      • #12
                        Originally posted by solarix View Post
                        I agree that finding hard data about failure rates is difficult. None of the manufacturers want their failure rates to be known. I can tell you that I have replaced many microinverters and optimizers including a few systems where all the units were replaced under warranty. Of course, this is in hot Arizona - but never the less, it is way too high a failure rate for me.
                        Yes, very few customers actually utilize their monitoring beyond the initial "christmas toy" phase of ownership and I recommend against choosing an inverter based on this feature.
                        Hot running electronic devices are always going to have a shortened life. Real data from these companies is never going to be forth coming and I doubt that any third party would want to take on the task. In some cases you just have to go with your own experience with similar devices.
                        I have owned lots of Inverters over the last three decades and they always lasted the longest when kept cool and were run at no more than 70% of their rated load. Micro Inverters are working way outside of what I would call an ideal operational environment. If my panels were ground mounted it might be an option but on a high roof it becomes a logistical nightmare. I would rather keep whats on the roof as simple and reliable as possible.

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                        • #13
                          I received a new quote today that wouldn't need to update my 100amp electrical panel. The only catch is that I wouldn't be able to meet the 7100 kwh I use per year. They would install 13 REC370AA panels which gives 4.810 kW Total Solar Power or 6,318 kWh per year at $12,361. What do you guys think?

                          Comment


                          • #14
                            Originally posted by J-P View Post
                            I received a new quote today that wouldn't need to update my 100amp electrical panel. The only catch is that I wouldn't be able to meet the 7100 kwh I use per year. They would install 13 REC370AA panels which gives 4.810 kW Total Solar Power or 6,318 kWh per year at $12,361. What do you guys think?
                            Well the math comes to $12361 / 4810 watt = $2.57/watt. If that is your final cost then it might be worth while but it still depends on what it costs you per kWh, what that comes to in $$ savings and how long you feel it is worth the investment.

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                            • #15
                              Originally posted by J-P View Post
                              I received a new quote today that wouldn't need to update my 100amp electrical panel. The only catch is that I wouldn't be able to meet the 7100 kwh I use per year. They would install 13 REC370AA panels which gives 4.810 kW Total Solar Power or 6,318 kWh per year at $12,361. What do you guys think?
                              First off, is that $12,361 before of after fed. tax credit ?

                              You've got to do the math with more than a back of the envelope analysis.
                              Assuming the 6,318 kWh/yr (BTW, probably +/- 10 % or so due to weather variation yr./yr.) is a reasonable working #, , dig into your POCO's rate structure(s) and see what you'll pay for those 6,318 kWh if you didn't have PV. The digging into the POCO rates is probably necessary because the highest rates are not what you probably pay for most of your electricity, and lots of other things like T.O.U. rates and other stuff makes the digging necessary for a reasonable guess. Most folks give up on that analysis and screw themselves by paying too much/STC watt for what are usually oversized systems.

                              Anyway, divide that guess of annual electricity cost into $12,361 (less any tax credit) for a real sloppy guess at how long it'll take to recoup the investment of $12,361 (less fed. tax credit). Then, compare that to the rate of return you might get if you put that $12,361 into another form of investment.

                              To do a proper financial analysis is a lot more involved than the above, but that will get you started.

                              BTW, in many cases the most cost effective use of the money for a PV system is for one that supplies less than 100% of the annual load. Also, oversizing a system is usually the short straight road to a non cost effective system. When buying PV, what you don't know will cost you money. Get informed.

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