Upgrading Solar Panels - Cost to Replace - Melbourne

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  highon2str on 22/10/2021 - 10:39

  what inverter do you currently have?

  • 

    bluntman on 22/10/2021 - 10:45

    I have a Growatt 5kw that has the 20X250w panels.
    Also a Growatt 4.2kw that i would like to upgrade to a 5kw. Seem to be able to pickup 5kw inverters for around 500, wondering if electricians are typically happy to swap these over?

    • 

      avoidfullprice on 22/10/2021 - 10:48

      So you have two solar power systems?

      Are both inverters 7 years old?

      • 

        bluntman on 22/10/2021 - 14:04

        yep, 2 systems. the 4.2kw is less than 5 years old.

        Was curious whether upgrading the 250w panels would mean on a cloudy day i would generate say 3kw as opposed to 2.5kw? Does it make a huge difference i guess is the questions.

        Today is super sunny, so it is maxing out at around 4.6kw so the superior panels in full sun isnt going to make much of a difference

        • 

          Drakesy on 22/10/2021 - 14:21

          +2

          @bluntman: Just a heads up the 300w panels are larger versions of the 250w panels.
          If you have the roof space then yes you'll get more sun, but as far as efficiency per m2 you'll be looking at marginal gains in technological efficiencies over 7 years (maybe 3-4% if you're lucky),

          Worth ripping off the whole system and starting again?
          I would say no from a cost perspective.

          If you have more free roof space to cover then go ahead, but ripping off the existing wouldn't be worth it.

          • 

            bluntman on 22/10/2021 - 15:22

            @Drakesy: Thanks Drakesy. That is the sort of common sense that i was looking for. Would be nice to know i am maximising my roofspace but the gains look like they will be marginal. Perhaps worth waiting another 7 years and see what the landscape is like then :)

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  MilkDrinker on 22/10/2021 - 10:48

  +1

  A few that I talked to, didn't want to know me if I was only doing a partial install (ie only panels replaced). They wanted the whole system replaced due to warranty issues (and maybe more money?).

  • 

    netjock on 22/10/2021 - 13:09

    They wanted the whole system replaced due to warranty issues

    Think it needs to be CEC certified. It is hard to certify previous person's job or maybe rules have been revised and no longer compliant.

    • 

      resisting the urge on 22/10/2021 - 13:41

      +2

      Technically, yes.

      Replacement can be a simple operation sometimes, but you can risk falling off roof, failing to notice an inadequate connection/insulator/seal, or getting killed by a violent short, just some of the risks for the uninitiated.

      Safety gear and good access is very helpful, strength and skill are also required.

      If doing this, look out for new panels sold cheap as their credits are already used, or call an installer and ask if they'll do you a deal on some panels that they have used the credits on. And check everything from connections to mountings for long-term safety.

      Installers won't want to talk about partial installs because they get thousands back from the gov. (each connected residence has a maximum amount of credits, (usually 10-15kW) that can be used), so so long as there are enough left, they can install new system and make more than you might think they are.

      $100/panel for 350W panels is reasonable, new can be bought for something like $150 pp last time I looked.

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  highon2str on 22/10/2021 - 10:54

  We have an 8 yo, 3kW Fronius and a 1 yo, 6kW Growatt. We had the most recent system installed and selected Growatt over SMA/Fronius as the plan was to match the lifespan of both systems such that in 7 years or so, we would decommission both systems and replace it with a larger Fronius system.

  If your Growatt is already 7 yrs old, I would not be re-using it. Get the entire system replaced, inverter and panels. We have our 6kW Growatt in the garage and I've installed 3 x 92mm DC fans under the heatsink but even then it runs hot (you can check temps in the app, temp5 is internal temp).

  A system is commissioned and certified based on inverter size - you can replace a like for like model, but not a higher capacity one as far as I understand it.

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  brad1-8tsi on 22/10/2021 - 10:55

  +1

  You can only over-feed 30% (6.5kw on a 5kw inverter). Unless you have absolutely ideal placement you still won't max out the inverter (we only hit 4.5kw on a good day).

  Because you want something that isn't a complete package, you'll have to ring around the installers and get quotes.

  Now is probably the worst possible time as panels are in short supply. Some installers have stopped quoting as they can't get panels.

  • 

    bluntman on 22/10/2021 - 14:11

    Good info, thanks

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  Hithere on 22/10/2021 - 10:57

  +1

  Most installers will refuse because regulations have changed since your panels were installed and they will not meet current safety standards and warranty conditions. It could probably cost more to upgrade your early system than to install a completely new system.

  I have the same issue and I'm considering if the outlay is worth it anymore due to lower FIT's and Australians with rooftop solar panels could soon be charged for exporting power into the grid under proposed changes recommended by the Australian Energy Market Commission.

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  JimB on 22/10/2021 - 11:36

  What output are you getting from your current panels?

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  Drakesy on 22/10/2021 - 12:43

  +1

  Have you done the numbers on a full new system vs continuing to operate your current system? a 5KW panel system is still fairly large, ripping the whole thing off to install another 1.6kw seems nonsensical.
  Also you'd most likely find the 'newer' 300kw panels are the 250kw panels but larger.

  The cost benefit ratio for your legacy feed in tariff may not apply anymore to a new system.

  • 

    netjock on 22/10/2021 - 13:00

    The panels are meant to last for 25 years. The cost of replacing / upgrading is not worth the extra benefit. Inverts would probably last 10 years+ if it isn't mounted badly and getting overheated (west facing)

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  lgacb08 on 22/10/2021 - 23:21

  +1

  With the ever falling in FIT price, unless you have really good reason to use extra energy generated (and can actually do so) I doubt you'll be making any money by the time the old one gives up.