Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)

Categories



Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.
Buy individually or both books together. Delivery is free!


powered by Surfing Waves




Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
 Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.

The AECB accepts no responsibility or liability for any errors or omissions in the content of this site. Views given in posts are not necessarily the views of the AECB.



Renewable Energy: Batteries

Bottom of Page

31 to 43 of 43

  1. <
  2. 1
  3. 2
  4. >
    •  
      CommentAuthordjh
    • CommentTimeMay 16th 2026
     
    Posted By: WillInAberdeenIt's no different from if you have 16 panels and a bunch of microinverters on your roof, if the mains goes off they all trip.
    When we installed ours there was a length of SMA coming down from the roof and lying in a coil for a while. The installer said I could put the end of the cable in my mouth and be quite safe. I was never that brave but I did check the voltage on the end of the cable - nothing.
  2.  
    >>>AIUI standard domestic UK MCBs / RCBOs only cut the live pole of a circuit. In Europe (or at least France) they cut live and neutral to provide full circuit isolation

    Interesting comment, prompted weekend reading! (Sorry this is off topic:)

    France, Germany, UK and most of the world all use the same MCBs, designed to IEC60898.

    In France they will be labelled NF EN 60898, in UK they are BS EN 60898, in Germany DIN EN 60898, so on. But same device.


    Like light switches, you can get multiples of the same MCB stuck together to give single pole, double pole, single pole +neutral, 3-pole, so on.

    France apparently likes to use 1p+n for domestic MCBs where Germany and UK just trip L and leave N connected. There are good historical reasons for both setups. In some places eg UK hospitals we disconnect both L+N.

    Similarly RCBs/RCBOs are 1p+n in France, but elsewhere they can be either kind : leave the neutral connected, or disconnect both L+N. The ones in my house disconnect both L+N.



    Unlike the mains, plug-in solar microinverters don't have one connection grounded to Earth so they don't really have a L or N connection polarity as such, either connector could be L or N. Their Schuko plugs can safely be plugged in either way round in countries with reversible sockets.

    You can disconnect the inverter on either the live and/or the neutral side and the inverter will stop, as unlike the mains it cannot circulate current through Earth, or through somebody standing on Earth.
  3.  
    Some movements from government on plug in solar, fast-track consultation launched today:

    https://www.gov.uk/government/consultations/plug-in-solar

    "We are proposing changes to the Plugs and Sockets etc. (Safety) Regulations 1994 (PSSR). The aim is to allow consumers to connect plug-in solar systems (without batteries) directly to a standard mains socket, provided products meet defined safety requirements."

    "DESNZ is also proposing an interim product specification to ensure that only safe and compliant products can be placed on the UK market during a transitional period, while enduring standards are developed"



    They also commissioned some laboratory testing that tested some plug in solar systems on UK circuits in every combination of faults they could think of. The much-discussed areas were fine (ring circuits, anti islanding, breaker masking etc) but some surprises about radio interference
    https://www.gov.uk/government/publications/plug-in-solar-electrical-safety-study
  4.  
    Just spotted this product:

    https://www.windfallenergy.com/windfall-battery

    2.5kWh, £1,200 RRP

    Which is aimed at the rental market as a small format 'plug-and-play' battery. The idea is you charge up during cheap rate periods and then use it to offset peak energy usage.

    Looks like it could be compatible with the plug-and-play solar panels, but they aren't committing to that yet.

    They also state 'one battery per household' but I wonder how you could even begin to control that.
    • CommentAuthorrevor
    • CommentTimeJun 17th 2026
     
    Another electricians view (more balanced and detailed ?) on balcony solar PV.

    https://www.youtube.com/watch?v=Na4LTD1M6nw
    • CommentAuthorGreenPaddy
    • CommentTimeJun 17th 2026
     
    just checking "out loud" that my calcs make sense...considering payback for for the Windfall battery

    Charge 2.5kW every night @ 7pence
    Displaces 2.5kWh every day @ 30 pence
    Saving 0.23 x 2.5 = £0.58 per day

    Cost of £1200 div by £0.58 = 2070 days = 5.6 years to pay back at today's elect prices.
    • CommentAuthorrevor
    • CommentTimeJun 18th 2026
     
    Posted By: GreenPaddyjust checking "out loud" that my calcs make sense...considering payback for for the Windfall battery

    Charge 2.5kW every night @ 7pence
    Displaces 2.5kWh every day @ 30 pence
    Saving 0.23 x 2.5 = £0.58 per day

    Cost of £1200 div by £0.58 = 2070 days = 5.6 years to pay back at today's elect prices.


    Nothing wrong with the sum but you need to include the efficiency of conversion AC to DC and DC back to AC and if you are lucky 90%.( I presume this is what is claimed by the battery round trip of 90%) My experience with a "PowerStation" it can be as low as 50% if you only have a low wattage load. Thing like fans and the electronics take up power. The windfall battery to me is like a power station except in the case of something like an Eco Flow you plug the appliance into that whereas with the Windfall you plug that into your house circuit.
    The efficiency comes from using a solar panel as DC to DC is the most efficient way to charge a battery and the sun is free but then there is the cost of the panel to take into account.
    I am not sure how easy it is to get night tariff if you have an EV it is quite easy. A neighbour has just had a solar plus battery install and is having difficulty getting the tariff. Things may change when plug in devices become more mainstream.
  8.  
    Seems that plug in batteries will remain illegal or the time being, the govt announcements and consultations yesterday exclude anything with a battery in it :-(


    My main head scratch about this small battery is that my peak time loads are either very small (fridge, TV, router, 10W each) or very large for short time (cooker, kettle, 2kW each). This 2.5kWh battery is limited to 800W, so is too big for fridge and yet also not powerful enough for the cooker!

    Ideally I would have about three of these for 2400 W, but that's beyond what should be 'plugged in'.
    • CommentAuthorrevor
    • CommentTimeJun 18th 2026
     
    Posted By: WillInAberdeenIdeally I would have about three of these for 2400 W, but that's beyond what should be 'plugged in'.


    What are you trying to achieve reduce you bill or cover outages?. Have you or can you get the night time tarriff. If you can do without the capability of getting up to 800 W out of every socket a portable powerstation could be the answer they have several 13A plug outlets and you could run extension leads off them. I have 2 such devices the 1st I bought is 1500 Wh and will deliver 3000W for 30 mins. I bought this for using 230V tools outside where no power access available. It is permanenty in use, since getting night tarriff it sites next to the TV and powers it for a few days before charging at night. I take it outside every so often to power mains tools. It weighs 16kg so goes in a wheel barrow for transport! The other is 600Wh and powers LED lights in a shed or anything else within its spec. Whilst you can get large capacity power stations and add to extramodules to them they will struggle to power a cooker for long and delivering the kW depends on the capacity of the inverter. Even though following upgrading our solar PV and adding 35kWh of battery the inverter at 6kw is the limiting factor in terms of powering the house.
  10.  
    In my case, I'd like to have a battery that covers all my peak time kWh and also kW, feeding all my house wiring and automatically controlled, at a low enough price that it pays back from time shifting!

    That would be something like 2-4 kWh and a couple of kW and would have to be under £1k, pro installed at that kW rating.

    Unfortunately that's not going to happen soon..!

    Maybe the next best would be to cover only the steady state loads (fridge etc) - say 0.5 kWh, 0.2kW, under £300 installed. Obvs an electrician cant install something for that price but maybe a DIY plug-in device from a supermarket could come along before long, fingers crossed. I could even add a plug in solar kit if it includes that kind of battery as the solar would fill the battery for free.

    Still vaguely hoping for vehicle- to- home to happen

    Am on Agile, it usually has two cheap periods day and night and an expensive peak in the early evening.
    • CommentAuthorrevor
    • CommentTimeJun 20th 2026
     
    Think you are up against it in trying to achieve your spec. As ball park figure the cheapest batteries per kWh are solar batteries which depending on size (bigger the better) work out at around £250 to £300 per kWh and weigh about 10kg per 1kWh. To make them work you need inverter/charger solar panels and install but give you more bang for your buck. At moment for a self-home install the best bet is the PowerStation approach which there are lots of choices sizes and makes that can give you what you want but not a full house system unless you were to have trailing leads. Again with these the bigger they are in capacity the greater the capable output but start weighting a lot more. The balcony systems coming to the market potentially, are restricted to the 800w. As for V2H or V2G are concerned there are costs and safety challenges associated with this but V2L is available on quite a few vehicles now but to my mind I do not think offer any advantage over PowerStation they are just different ways of doing the same thing and can hold more juice. At least you have a good start point in your agile tariff.
  12.  
    Octopus launched 'Octopus Nook' battery today, apparently a 2kWh cube that you plug in., or plug in several of them.

    No word on kW (guessing it will only be 0.8) or price

    Possibly they do clever remote controls like they do with Intelligent Go


    Claiming a short payback period!
  13.  
    The rumour on other forums is that the Nook is just a rebadged Fox ESS MiniQube:

    https://fox-ess.uk/miniqube/

    If true, that appears to offer up to 1.2kW output and is modular up to 10.5 kWh

    I'm waiting to see the price...

31 to 43 of 43

  1. <
  2. 1
  3. 2
  4. >
Add your comments

    Username Password
  • Format comments as
 
Back to Discussions Top of Page
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press