Solar PV Quote Advice

I've been looking into installing solar for a little while now. I've had a quote in today for the following system.

Supply and fit 10 x 410 watt all black JA Solar PV panels.

Supply and fit of Growatt 3.6kWp hybrid inverter with WiFi Dongle

Renusol Varisol Mounting kit including Aluminium roof hooks.

6.5kWh DC Growatt battery’s including CT

All DC electrical installation materials to connect the Solar PV to the Inverter

Installation Labour

Total £9,900.00

VAT 0% £0.00

Total payable £9,900.00

Deposit 20% £1,980.00

Balance due upon completion £7,920.00

I'm on the price cap with Shell Energy (Flexible 7) after being moved by Ofgem after PurePlanet went into administration in December 2021.

These are my current rates:

Unit rate 27.838p per kWh

Standing charge 49.64p per day

Annual usage 3,422 kWh (Taken from my most recent April bill)

Currently paying £223.00 per month for dual fuel, thanks to the recent increase.

I'm home during the day as I'm medically retired through disability. I use an iMac and NAS on my home network. I also have the TV and Soundbar on most days. My house was renovated about 9yrs ago now so my kitchen appliances are all new A to above A rated, my combi boiler is a Worcester Bosch 38CDi. My lighting throughout the house is also fully LED.

I'd be interested in any advice.


  • markin
    markin Posts: 3,841 Forumite
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    Get more Quotes, And work out the actual Annual usage from 2 bills a year apart not just their estimate.
  • EcoScruples
    EcoScruples Posts: 389 Forumite
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    Sounds ok, with that usage per year you should easily cover most of your imports except for the 3 worst winter months of course.
    One thing that sticks out is you maybe able to get a slightly bigger battery for that price, 9kw or 10kw maybe.

    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.
  • QrizB
    QrizB Posts: 13,822 Forumite
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    I agree; in general terms the quote seems consistent with others we've seen recently; a bit higher than we'd normally expect, but prices have crept up recently.
    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.
  • Heedtheadvice
    Heedtheadvice Posts: 2,456 Forumite
    First Anniversary Name Dropper First Post
    edited 8 June 2022 at 11:05AM
    The thing that sticks out most to my mind (accepting the above responses) is that you mention the A rating efficiency of appliances etc and house renovation but have not mentioned the biggest single aspect of how well the house is insulated.

    I am very keen on renewable generation and storage in the home and wish there were lots more installed and better incentives to encourage it! However there ought to be priorities in improving ones situation.

    It may well be that a bigger battery is useful and I am all for efficient devices. You probably will generate as much energy as you consume (and maybe more) from the system you are considering but this will mostly be in the 9 best months of the year when you will only consume a smaller percentage of that generation and any payment you receive for excess exported will not compensate for the energy cost you still have to purchase. It will however still make a significant inroad into the "summer" purchase cost of electricity.

    Unfortunately the maximum power use and thus cost is in those other three months of low generation, you will still have to purchase electricity to make use of battery power time shifting and supplying/augmenting peak loads; you mention dual fuel and I presume the non electric part of that purchase provides the heating and that will be by far the greatest overall power consumption. At a guess something like your 3400kWhours of electricity over the whole year and maybe  three times as much power from your other source just to heat your property for those three low generation months. I.e. solar and batterieswill not then have a big impact.

    That was a long winded reason to come round to ask about insulation! Has you renovation included maximisation of insulation? Reducing heat losses (in that winter period) will have the greatest impact on cost saving, being more comfortable (especially as you are home mostly) and is the greenest investment you can make. Without detailed knowledge and some estimation then one cannot determin if extra (or even reduced) battery capacity will be best for you but if you can get more insulation there is hardly any argument against it and posibly a far better spend than thinking of a bigger battery. The only exceptions that springs to mind is if the batter will help supporting a medical electrical device need during power failures or if the insulation improvement is cavity wall fill that might be a very bad move in wetter areas as it prevents the prime reason there is a cavity!

    You are paying currently £90+ per month for electricity (and should save some of that) and about 130 per month on your gas but will save little of that given your plan. As a pure guess £40 per month saving. Ensure that is acceptable to you but also plan for more energy purchase costs that will likely be in the pipeline! I hope you still feel you can go ahead as I have not painted the rosy picture!
  • Screwdriva
    Screwdriva Posts: 1,155 Forumite
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    I'd be interested in any advice.

    Doesn't sound like you need the battery. Also, with respect to those already installed these, I would strongly recommended non-Chinese owned brands like Hyundai 400W panels, SolarEdge or GivEnergy inverters/ batteries.  

    Much better chances of getting quality aftersales support, quality components and them fulfilling the term of their warranty.  Growatt as an example, has been panned multiple times on these forums.

    Here is a quote for a system with a 25 year warranty on quality components my neighbours installed last month (DM me if you'd like an introduction to the installer who services the Greater London area)


    10 x 400w Hyundai panels, 25 year warranty to 86.2% efficiency and a 25 year product warranty

    10 x Solar optimizers. 25 Year warranty

    1 x Solar Edge HD Wave single phase inverter[Battery ready inverter] 25 year product warranty

      1 x All cable run’s isolators and fitting’s

      1 x Micro generation meter

      1 x System monitoring  

      1 x MCS and G98 Certificates

    All service and maintenance under the terms of the warranty.

     Fully fitted price of £5,350.00

    -  10 x 400w LG + 6 x 550W SHARP BiFacial Panels + SE 3680 HD Wave Inverter + SE Optimizers. SE London.
    -  Triple aspect. (22% ENE/ 33% SSE/ 45% WSW)
    -  Viessmann 200-W on Advanced Weather Comp. (the most efficient gas boiler sold)

    Feel free to DM me if I can help with any energy saving!
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