Output from 4KW panels on hottest/sunniest day of the year.

• • #19059 Reply
    
    Bernie

    Guest

    The panels on our roof are approximately 3 years old. Do they lose their efficiency? They are south facing.
    Initially we were getting 3.9Kw. Now today, 15/9/2016, and yesterday, in CM0 postcode, Essex, the reading is 2.4Kw. Surely we should be expecting a higher reading? We have no idea who to ask for advice, hence our posting here.
    Any opinions please.

  • #19060 Reply
    
    Stuart

    Guest

    Contrary to popular belief, pv solar panels work more efficiently in cooler and sunnier weather.

    External air temperature does not make the panels work better. Peak time of the year will be summer solstice time (Jun 21st) and any other time either side of that date will reduce the amount of sun exposure and thus your systems generating capacity.

    The sun rises (6.48am) and sets later (7.26pm) at the moment so you’re potentially getting 4 hours less sun exposure time. With that said, if you do feel your system is not as it was, then I would recommend getting it assessed for potential issues:

    https://www.powermyhome.uk/consultations/

  • #19061 Reply
    
    Stuart

    Guest

    P.S.

    Most good modern photovoltaic panels should still be producing at 95% of their original generating capacity 20 years from their installation date.