Adding More Solar to Existing System

NigeWickNigeWick Forumite
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I have a question. FiT maxes at a 4kW home system which is what I've got on my South facing roof. I have read that East and West facing systems with no shadowing should get about 86% of optimum.

What happens to my FiT if I were to add say a 3kW system to each of those East and West facing rooves?
The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
Oliver Wendell Holmes

Replies

  • warrenbwarrenb Forumite
    140 Posts
    Seventh Anniversary 100 Posts Combo Breaker
    I am thinking of doing the same on my W facing garage roof. I will have the extension going through a separate meter though, so it shouldn't affect my FIT at all. Will need DNO approval of course.
    Living in supposedly sunny Kent
    14*285 JA Solar Percium Panels
    Solis 4kw inverter
    ESE facing with a 40 degree slope
  • Martyn1981Martyn1981 Forumite
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    Hiya guys, this came up recently, so some info on this thread:

    Adding more solar panels

    Basically, extensions are no longer eligible for FiTs, so you won't get any subsidy, and I suspect you won't get paid for export.

    Your 'old' FiT is safe, and locked in, but if any new PV goes through the TGM, then you need to tell your FiT provider so that they can apportion it out.

    If you install a totally separate system, then you are fine, but as Warren points out, you will need DNO prior approval if the total export exceeds 3.68kW, or to be more correct, if the theoretical export exceeds 3.68kW. Eg, for my system as the inverters aren't capped, my potential export is 5.58kW, despite it being E/W, and only peaking at 4.2kW (spikes to 4.9kW).
    Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)

    For general PV advice please see the PV FAQ thread on the Green & Ethical Board.
  • NigeWickNigeWick Forumite
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    Martyn1981 wrote: »
    Hiya guys, this came up recently, so some info on this thread
    Oops, should have done a search but brain was in neutral.
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
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