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Solar PV DIY

  • 06-09-2022 2:50pm
    Registered Users Posts: 32

    Hi All, As the title suggests, I’m looking to do a DIY install of Solar PV in the coming months. I am a qualified electrician with enough skills to do the roof work, however, I’m new to PV, so need some guidance to ensure I’m on the right track. I have decided that it is more cost-effective to install it myself than to use a registered installer and receive a grant. My annual usage is ~6000kwh single tariff, with a family of 5 (3 kids 4, 8, and 10 years old), consumption is only going to go up in my house.

    Everything below is what I think I know, or need help with, but please feel free to correct my ignorance 

    The House/Roof:

    I’m located in Galway City with an SW-facing roof (azimuth 239°). The roof has a 30° slope and measures 8900mm X 5050mm. I believe that regulations require the panels to be installed 500mm from any edge, therefore, giving me a usable space of 7900mm X 4050mm.

    The plan is to fill this usable space with panels (I believe this is referred to as DC oversizing?) to get the most out of dull days. All panels will be located on this roof section, but I will need optimizers on some of the panels. I’ll get into this in more detail in a future post once the specific panels are chosen and I determine how many are shaded, but to give an idea of what’s ahead, hypothetically, if I have an array consisting of 2 rows of 7 panels, at least the last 2X2 panels will have a shadow from my neighbor's chimney at some point during the day, then as the evening progresses and the sun begins to set, the entire bottom row of 7 panels will be cast into shadow first from my neighbor's roofline. The Neighbour is non-movable 😉. 


    I’ll start with the inverter. I'm planning on a hybrid inverter with a battery. I know people are divided on whether or not a battery is economical, but I'm thinking that as I'm saving money doing this DIY and the current pending energy crisis and rising costs, that I’m better off investing in a battery, and with that, switching from single tariff to day/night and configuring the system as best I can to use the battery to tie me over until night rate kicks in. I think I read a post previously about ESB Networks having a list of specific inverters that they’ll accept on the network, is that right or did I imagine it?

    From what I have read previously, there is a 6kw export limit that ESB networks require installers to abide by, is it possible to get a bigger rated inverter but limit the export only to 6Kw? will the inverter size need to be matched to or greater than the PV array (i.e.) hypothetically, a 6kw inverter will work with 4kw of panels, but would a 4 Kw inverter work with 6kw panels? should there be some margin between both (i.e.) 5880w of panels is too close/risky to use on a 6kw inverter 

    Panels: I know little about what makes a good panel or manufacturer. Are there some manufacturers I should avoid? am I better off going with the highest-watt panels available and trusting the manufacturer's warranties?

    Lastly, is it mandatory to get a smart meter when you have PV? I’m not too keen on them.

    Any and all input is appreciated to help spec out a system, and once I pull the trigger on this, I’ll keep the post fully updated for any other users

    Regards Dave



  • Moderators, Sports Moderators Posts: 17,883 Mod ✭✭✭✭slave1

    I'll try and help...


    If you are not applying for a grant then I suggest you could creep closer to the edge (if it has impact on number of panels you can fit)

    then as the evening progresses and the sun begins to set, the entire bottom row of 7 panels will be cast into shadow first from my neighbor's roofline.

    I'd question the economics to optimise setting sun, if midday then sure but there's much less to be gained off a setting sun (and you 30degree roof)


    It's actually voltage and not kW that limits the amount of panels you can attach to your inverter, your chosen inverter and panels will both have their max voltages in their spec sheets


    I went with highest wattage, I think named panels are priced too premium with little to offer over cheaper ones

    Smart Meter

    Not mandatory, a lot on this Forum will advise to stay away and keep your D/N meter (I'm one of them)


    Do the math on battery, given your background you would me mad not to go the DIY battery route (separate ever growing thread on it). You'll get a 20kWh pack for ~€2.5k or less

  • Registered Users Posts: 1,595 ✭✭✭Citizen  Six

    Can you sign off the NC6 form yourself, or have someone that can? You'll need that to get any feed in tariff.

  • Registered Users Posts: 858 ✭✭✭allinthehead

  • Registered Users Posts: 32 D.flynn


    on the roof, I might creep a little bit into that 500mm if it means an extra panel on the roof, but otherwise id maintain it.

    on the shadow, i suppose it wouldnt have to much impact as it's the days end anyway. would it be best to keep the 2 rows on seperate strings then?

    Panels: which panels would be considered named? could you PM me your suggestions please. once i determine the panels, i can look to a matching inverter

    Smart meter, AFAIK, ESB networks try to install a smart meter in every property once they receive a NC6, can I still decline? unfortunately i dont currently have a D/N meter, just the old single tariff, so thats a decision for another day.

    could you also send me a link to the DIY battery thread, as thats right up my alley alright.


  • Registered Users Posts: 32 D.flynn

    Hi Citizen Six, thanks for the reply. do I only need the NC6 submitted for FIT? I thought that ESB Networks wanted them so they could have some knowledge of the level of export to the grid to ensure their grid can handle it so to speak

    I had previously been a registered contractor but canceled it when I went to work for a company. I was debating about registering again so that I could start doing a few small jobs again

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  • Moderators, Sports Moderators Posts: 17,883 Mod ✭✭✭✭slave1

    Always best to use separate strings when possible...

    I'm no expert, I've used JA Solar 410w and Jinko 455w, my criteria was whatever panel maxes space and inverter

    Never heard of ESB trying to install a SM once in receipt of a NC6. You switch to a D/N meter via your supplier and it's easy peasy, just a call to them and they take care of it.

    Long read

    Solar PV battery options — - Now Ye're Talkin'

    Shorter read

    10kWh LifePO4 DIY Battery Addition..... Here is my write up. — - Now Ye're Talkin'

  • Registered Users Posts: 1,595 ✭✭✭Citizen  Six

    I'm aware of that, which is why I asked. Not all electricians are registered.

  • Registered Users Posts: 1,595 ✭✭✭Citizen  Six

    Yeah, you are supposed to let the ESB know that you are connecting a generator to the grid, and you also need the form to get FIT.

    I used to be registered myself, but that was a long time ago. Regs are a lot tighter these days, in terms of needing to be registered for small jobs alright.

  • Registered Users Posts: 32 D.flynn

    Am i right in saying that the first couple of steps in my plan should be as follows:

    1. Select a panel type that would give me the best/most wattage for my roof space.
    2. based on the supply voltage of the panels selected above, i can then select my hybrid inverter to match said voltage and wattage?
    3. install (not that easy, i know 😊)

    has anyone had success/good experiences with international (EU) suppliers ? or is it much of muchness to just stick with local ?

  • Moderators, Home & Garden Moderators Posts: 4,423 Mod ✭✭✭✭graememk

    Get a trade account setup with midsummer or get in contact with solartricity,

    Solartricity was who my installer users

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  • Registered Users Posts: 1,595 ✭✭✭Citizen  Six

    Don't forget to check what the rules and regulations are in terms of what you need to do as well.

    Places like solartricity will have package deals, but you can also swap stuff around on it. Friend of mine got stuff from them, but I had him return the firemans switch and the din rail meter that sits in the fuse board.

  • Registered Users Posts: 32 D.flynn

    Thanks, those are the 2 i was looking at. @Citizen Six why did you return those particular components if i might ask?

  • Registered Users Posts: 1,595 ✭✭✭Citizen  Six

    The cable run from panels to isolator and inverter was short, as they were located in the attic beside panel location. There's a max length specified where it's not necessary if less than that, but I'm not 100% sure what it is exactly. It's posted elsewhere in the main forum in one of the threads.

    The inverter gives a reading of how much energy it generates, so no need for the separate meter at the board. But it's a requirement for the SEAI grant I believe.

  • Registered Users Posts: 72 ✭✭Punchin A Keyboard

    For what it's worth here is the seai installer guidance. big thanks to whomever posted it in a different thread

  • Registered Users Posts: 291 ✭✭spose

    “I had previously been a registered contractor but canceled it when I went to work for a company. I was debating about registering again so that I could start doing a few small jobs again”

    id say you’d nearly get enough work from the diy gang here just signing nc6 forms and doing the inverter connections!

  • Registered Users Posts: 1,022 ✭✭✭kabakuyu

    My sparks got a good price from CT in Galway in April, got panels, roof kit, micro inverters, and other bits and bobs.

  • Registered Users Posts: 32 D.flynn

    Hey all,

    I haven't done much on this in 2022, but am getting to it now.

    A rental property I own is becoming vacant in the coming weeks so I'm taking the opportunity to get some panels on this first as the roof is more accessible and the installation would be easier because, in my infinite wisdom, I previously ran a 6mm2 twin and earth as well as multiple cat 5's between the distribution board and the attic space prior to converting it.

    This kit will be purchased locally from CT's (Galway).

    the roof on this property has 3 Velux windows installed, but keeping back 500mm from the edges of the roof, I am able to install 8 panels as follows:

    2 rows of 3 panels in landscape orientation (beneath the Velux's)

    2 between the Velux's.

    The panels: Jinko Tiger Neo N-Type 420w Full Black (1722mm x 1134mm)

    does STC or NOCT apply to my situation ?

    either way, am I correct in saying that on a single string (all on panels on the same roof space with no shading) , my max voltage would be 256.32V

    what then are my criteria for the inverter? a single MPPT inverter capable of at least 256V and 3.36kWP ?

    Definitely not installing a battery, but may futureproof with a hybrid if it doesn't cost too much more.

    CT's supply the following inverters if someone can give any thoughts on them:

    Standard: SMA SunnyBoy, Trannergy, Huawei

    Hybrid: Huawei, Sunsynk, Sonnen

    I may opt for these panels on my own property which i plan to have done by the summer, but not sure of my own inverter choice yet

    Thanks in advance

  • Registered Users Posts: 808 ✭✭✭Mr Q

    On the inverters SMA and Huawei will be much more expensive than Trannergy. Last year I contacted Kellihers electric in Waterford about SMA equipment and they actually only had one model size. They couldn't get any other versions or Sunny Islands they told me.

    On the newer SMA inverters part of the software locks 10 hours after first powering the unit up so some changes can only be made if you have an SMA installer code. These are mostly related to the grid settings so you would be fine once you set these after powering up.

    But they are well built and once running I have only had one minor recurring issue on one inverter that I eventually fixed.

    I never owned any of the other two brands for comparison.

  • Registered Users Posts: 1,110 ✭✭✭DC999

    Huawei needs an installer code too to make changes to the inverter. But that code is available if doing DIY on it. Or an installer may give an account with more access, like an installer account.

  • Registered Users Posts: 808 ✭✭✭Mr Q

    I have an installer account on my SMA's but depending on the year of the inverter some will lock the grid settings. Most of the other settings are available to me on the newest version (AV41), all on the older version (AV40)

    SMA will sell me the code if I fill in a form and state I am an electrician, plus send them about €70.

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  • Registered Users Posts: 32 D.flynn

    Does anyone have any thoughts on a SAJ(H1-6K-S2) hybrid inverter versus Huawei(SUN6KTL-L1)?

    there's a difference of €1600 when choosing between these (both with a 5kWh battery)

  • Registered Users Posts: 519 ✭✭✭PCDub

    Going down the DIY route and have bought 6 x 405 suntech panels and growatt 3.6kw standard inverter.

    Before i start fitting them to the roof I was wondering do you have to inform your insurance company and will they accept diy install?

    Also how easy or difficult will it be to get a sparks to connect the inverter to the consumer unit and set it up to feed into the grid?

  • Registered Users Posts: 1,595 ✭✭✭Citizen  Six

    Insurance companies wont want to touch you I'd imagine. And sparks are hard to get to do a job, so can't see them certifying a job they didn't do, unless they are someone you know.

  • Registered Users Posts: 519 ✭✭✭PCDub

    Cheers for the reply Citizen. So who wants to buy a few solar panels. :)

    Just out of interest are professionally installed solar systems declared on house insurance?

    I can use a couple of the panels I've bought to upgrade my small offgrid system but I'll hold fire on roof mounting them.

    Might be posting in the for sale thread soon....

  • Registered Users Posts: 1,110 ✭✭✭DC999

    Yeah. I told house insurance company I got around 10 grand of solar and no change to cost of policy. I got an installer.

  • Moderators, Sports Moderators Posts: 17,883 Mod ✭✭✭✭slave1

    I simply increased the value of my home by current equipment and installation costs

  • Moderators, Sports Moderators Posts: 17,883 Mod ✭✭✭✭slave1

    Super stuff, great to have a low roof like that to DIY tackle. I'd say the electrician will be fine with hooking you up if you're already paying him for what I assume is panels on the house. I see the dog was inspecting your work along the way so no issues on quality of DIY.

    With 30 panels you're going big from the word go for sure, now we got to tempt you into filling the N part of that roof....

  • Registered Users Posts: 519 ✭✭✭PCDub

    That's a tidy install. My house is a bungalow so was thinking the DIY route to but will have to check with house insurance before commencing. I might also contact a few installers and see if they'll use my panels and reduce the cost a bit.

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  • Registered Users Posts: 3,054 ✭✭✭irishchris

    Nice work and very tidy install. Looking forward to hearing how the official switch on day goes. Good choice of inverter too and recently added that to my DIY install and delighted with it compared to the solis.