Residential Solar System - Is It a Good Idea to Add More Panels?

gregoinc on 06/05/2024 - 16:01

We have an existing solar system on our home - 9 panels in total (facing north). I have no idea the capacity of the existing panels, but on sunny days the inverter can often peak at around 2500 watts. Some time ago I managed to acquire 6 x Trina Solar 300 watt panels. I think the model of the panels is TSM-300DD05A and the panels have been in storage for some time.

The inverter I have is a 5kw Goodwe DNS series, which was installed recently but happy to upgrade as I am not thrilled with how it interfaces into my Home Assistant system. There is more than adequate roof space on the west facing side of our roof with no overhang.

So, my question… rather than try and sell the panels, for which I am likely to get nothing. I thought it might be a good idea to mount the additional Trina panels on my roof and hook them into my existing solar system. Other challenge, who would do the installation work? I've heard there can be cowboys around, so how do I find someone that knows what they are doing, and for a reasonable price?

Thoughts, suggestions? Much appreciated.

Home & Garden Solar Energy System

Comments

  • AustriaBargain on 06/05/2024 - 16:14
    +1

    With so many competing solar resellers out there I'm sure you can get a free quote.

  • Montyjpm on 06/05/2024 - 16:15

    It would be helpful if you can state your location/city so people can put in their recommendation.

    • gregoinc on 07/05/2024 - 12:46

      Melbourne west based location.

  • 87percent on 06/05/2024 - 17:28

    If you’re in Melbourne, I’d be interested on your inverter if you decide to upgrade it!

  • Ezekiel2320 on 06/05/2024 - 17:30
    +1

    Dont know the answer to mix and match panels but can report Fronius inverter and energy consumption monitor work perfectly in Home Assistant

    • gregoinc on 07/05/2024 - 12:48
      +1

      Separate string it shouldn't be a problem with a decent mmpt solar inverter.

      I should have purchased a Fronius… perhaps I should consider an upgrade. How are you connecting the inverter to HA?

      • Ezekiel2320 on 07/05/2024 - 14:25

        I paid extra for a Fronius just for Home Assistant, and specified a consumption meter ($150) definitely worth it for whole home energy monitoring.

        There's a setting on the inverter webui to enable local API access, then it just showed up immediately as discoverable in home assistant alongside the consumption meter. Infinitely better than the fronius app and website

        • gregoinc on 07/05/2024 - 16:23

          Thanks. Can I ask what model Fronius you purchased?

  • Drakesy on 06/05/2024 - 20:26

    Mixing and matching panels can get dicey, yes your system is rated to 5kw, but the different wattage of panels pushes the inverter/regulator as it struggles to maintain a steady voltage, it's not advised.

    Just get a new system (if it's more than say 10 years old (2.5kw systems would date back to then) it might be more economic to run a brand new 6.6kw system given the rebates.

    • gregoinc on 07/05/2024 - 12:56

      Whilst I get what you are saying, and it makes sense. To upgrade the whole system might be a bridge too far cost wise, which is why I am looking at other options.

      Yes the upgrade would replace the existing panels, but I suspect there's a charge for disposal of the old panels… which I assume would be paid by me.

  • Euphemistic on 08/05/2024 - 09:57
    +1

    Been wondering the same thing since our last bill. Usage not risen much, prices risen stupidly.

    Anyway, in my case i have 2 strings. Id like to try and move some panels to increase the wattage on one string and then get some new panels, with higher wattage, for the second string. The first string would then have more panels, but the same.

    Our system is a 4kw panels with 5kw inverter. 6 panels nortb facing and 8 pa els west. Was recommended at the the time but with lower panel prices and higher power prices its time to consider updating.

    In your case, you'd probaly want to be able to put the north and west panels on separate inputs as they'll get different sun at different times.

    Try to find local, smaller business installer. The big mobs tend to use subbies and wont think outside the box.

    • gregoinc on 15/05/2024 - 16:43

      Thanks for the info. Issue I have is finding a local installer that… a) knows what they're doing, and b) wont charge me above what should be a reasonable price.

      No doubt for most installers this job wouldn't be worth it, and I get that, but it'd be nice to find someone (maybe one of the large installers subbies) that is skilled and would do it for cash.

      The inverter has capacity for additional strings, so apart from the roof works it's just DC work to hook them up.

      • Euphemistic on 15/05/2024 - 17:49

        It is tough finding an installer.

        This reply has prompted me to email my brother whos returning to work in the industry to see what his thoughts are.

Login or Join to leave a comment
Login Join