PV Output - Ageing system

Hi all 
Does age affect maximum output? 

Any quantifiable maintenance that can improve output, ie cleaning? 

My panels are about 7 years old. 4kW system, appears to be running ok. I’ve never cleaned my panels as it’s a 3 storey house. 

I admit I rarely check daily output so I’ve lost touch with what the peak should be in certain scenarios. 

It’s 4:40pm, early May and the house is 184 degrees south with a close to ideal pitch. Output right now is 2,800watts in direct sun, it’s fairly hot so panel temperature might be around 37c looking at my direct sun thermometer and 18.5c on the inverter. 

I thought it was a tad low, expected >3kW but maybe it’s because it’s 4pm. 

Thanks 
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Comments

  • EcoScruples
    EcoScruples Posts: 389 Forumite
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    Check it against Solcast, use the efficiency reduction for 7 years and you should see roughly what you will get.
    2.8kw at 4pm doesn't sound bad at all.
    4.3kwp JA panels, Huawei 3.68kw Hybrid inverter, Huawei 10kw Lunar 2000 battery, Myenergi eddi, South facing array with a 15 degree roof pitch, winter shade.
  • oldskoo1
    oldskoo1 Posts: 616 Forumite
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    Check it against Solcast, use the efficiency reduction for 7 years and you should see roughly what you will get.
    2.8kw at 4pm doesn't sound bad at all.
    Thanks, what a great tool. Looks like I’m exceeding the forecast even without adjusting the efficiency factor. 
  • gefnew
    gefnew Posts: 876 Forumite
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    I have had panels since 2011 and can say looking at records do not see any major reduction in output.
    Original quote stated 3470Kwh a year, averaged 3700Kwh per year with no cleaning or maintenance required on any part of the installation (touch wood now).
  • oldskoo1
    oldskoo1 Posts: 616 Forumite
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    That’s very encouraging, thank you
  • Martyn1981
    Martyn1981 Posts: 14,755 Forumite
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    Yep, 11yrs in and can't see any obvious drop yet. Not even a gut feeling that there's a downward trend, perhaps UK sunshine levels just aren't enough to wear the PV ..... much?
    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.
  • QrizB
    QrizB Posts: 13,822 Forumite
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    Yep, 11yrs in and can't see any obvious drop yet. Not even a gut feeling that there's a downward trend, perhaps UK sunshine levels just aren't enough to wear the PV ..... much?
    My system was 10 in January and, like Martyn, I can't see a trend.
    There's some variation year-to-year but an overall tendency? I can't tell.
    Yes 2021 was my worst year ever, but 2020 was my best!

    Annual-Generation
    N. Hampshire, he/him. Octopus Go elec & Tracker gas / Shell BB / Lyca mobi. Ripple Kirk Hill member.
    2.72kWp PV facing SSW installed Jan 2012. 11 x 247w panels, 3.6kw inverter. 30MWh generated, long-term average 2.6 Os.
    Taking a break, hope to be back eventually.
    Ofgem cap table, Ofgem cap explainer. Economy 7 cap explainer. Gas vs E7 vs peak elec heating costs.
  • EcoScruples
    EcoScruples Posts: 389 Forumite
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    That's pretty consistent, really encouraging that after a decade, panels still perform at pretty much peak levels.
    Like all things, as long as they're well installed I don't think people will have too much to worry about.
    What about inverters? They should last longer than 10 years but how do you know when they need changing? Do they just give up?
    4.3kwp JA panels, Huawei 3.68kw Hybrid inverter, Huawei 10kw Lunar 2000 battery, Myenergi eddi, South facing array with a 15 degree roof pitch, winter shade.
  • Spies
    Spies Posts: 2,029 Forumite
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    edited 8 May 2022 at 7:31PM
    You could actually browse www.pvoutput.org and check out the older systems to see if they've recorded any considerable degradation. 
    4.29kWp Solar system, 45/55 South/West split in cloudy rainy Cumbria. 
  • QrizB
    QrizB Posts: 13,822 Forumite
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    What about inverters? They should last longer than 10 years but how do you know when they need changing? Do they just give up?
    I think they just give up, although there's probably some uncommon failure mode that would see them run at half power or whatever.
    I'm still on my original one.
    N. Hampshire, he/him. Octopus Go elec & Tracker gas / Shell BB / Lyca mobi. Ripple Kirk Hill member.
    2.72kWp PV facing SSW installed Jan 2012. 11 x 247w panels, 3.6kw inverter. 30MWh generated, long-term average 2.6 Os.
    Taking a break, hope to be back eventually.
    Ofgem cap table, Ofgem cap explainer. Economy 7 cap explainer. Gas vs E7 vs peak elec heating costs.
  • ispookie666
    ispookie666 Posts: 1,179 Forumite
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    I would say yes due to two factors 
    1. personal experience.  I did add a few posts to this thread 
    2. There is a large solar farm (started generating 2015) close to my home and they have changed all their panels this year. The panels used to be the old blue colour and are black.  I'm sure as a business they probably did all sort of calculations to reach at this conclusion.  
    “Don't raise your voice, improve your argument." - Desmond Tutu

    System 1 - 14 x 250W SunModule SW + Enphase ME215 microinverters (July 2015)
    System 2 - 20 x 330W Jinko Panels + Enphase IQ7+ microinverters (Jan 2022) + Givenergy AC Coupled inverter + 2 * 8.2KWh Battery (May 2022) + Mitsubishi 7.1 KW and 2* Daikin 2.5 KW A2A Heat Pump
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