Adding battery storage and optimisers to my PV system

• • #17951 Reply
    
    Jayson

    Guest

    Hi there – I installed a 3.92kW system with 12 SunPower Corp 327w panels back in March 2014 and am now looking at storage using batteries cells.

    Was given a quote today by PV Solar UK who claims to be the largest installers around. Job would include replacing the current invertor to one that is compatible with energy storage and lead type cell batteries to store upto between 8 to12kW (to be confirmed). They also recommended an additional optimiser that can generate an additional 20% output by eliminating cut outs in the system.

    Overall quoted savings of £17000 over 20 years.

    All in price quoted was £5500. A couple of questions:

    1) Is PV Solar UK a recognised company with good reputation?

    2) Does the investment in the battery makes sense

    Thanks in advance.

    Jayson

  • #17952 Reply
    
    Tech for Energy

    Guest

    Answer:

    1/ Unknown to me as a 6 year PV installer but if they are that good and big, they should be on review sites like CheckATrade or Which ? Trusted Trader and great reviews of their service should be easy to find.

    2/ Not as they have specified – I would run a mile from that. Batteries are more about maximising your PV usage, making system ownership easier to manage and energy security. Batteries cannot really be viewed as an investment and lead batteries can only discharge to 50% to maintain the life of the battery, so the amount of storage capacity is half of what is advertised.

    Also lead battery technology is not suited to high peak demands or charging. Lithium is much better suited to this.

    Batteries are a good idea if your eyes are open going into it and you know what to expect, but they are not a simple thing to buy, your installer should be open and frank about the technology.

  • #17953 Reply
    
    Norman Scottish Installer

    Guest

    Hi Jason

    PV Solar I think are owned by the same people that run HELMS. They are based just south of Glasgow.

    I hadn’t noticed them around under the PV Solar banner for a few years.

    I would recommend reading this guide before committing to spending a further £5500 on batteries and VO.

    http://www.bre.co.uk/filelibrary/nsc/Documents%20Library/NSC%20Publications/88166-BRE_Solar-Consumer-Guide-A4-12pp-JAN16.pdf

    If I were you the questions I’d be asking:

    1. How long till I need to change the batteries and at what potential cost.

    2. How much am I likely to save off my electricity bill. This is the difficult one. You’ve had solar for a couple of years so you will have figures for what your system has generated. In the normal course of events you will be using say 30%. So do your sums based on this.

    If you have a hot water cylinder rather than a Combi boiler then I’d be looking at a power diverter for your surplus power rather than a battery storage system. The cost is approx £550 rather tan £5500 and will give you free hot water during the brighter months.

    See: https://www.immersun.co.uk/

  • #17954 Reply
    
    Stuart

    Guest

    Be wary of the claims of voltage optimisers devices and be very wary of the claims they will tell you about. The Solar Association ran a six month test and warned its members against selling them on the basis of any substantial savings. WHICH listed them as one of the five biggest wastes of money in saving energy.