Your browser isn't supported
It looks like you're using an old web browser. To get the most out of the site and to ensure guides display correctly, we suggest upgrading your browser now. Download the latest:

Welcome to the MSE Forums

We're home to a fantastic community of MoneySavers but anyone can post. Please exercise caution & report spam, illegal, offensive or libellous posts/messages: click "report" or email forumteam@.

Search
  • FIRST POST
    • Martyn1981
    • By Martyn1981 5th Dec 16, 3:57 PM
    • 9,654Posts
    • 14,541Thanks
    Martyn1981
    On-grid domestic battery storage
    • #1
    • 5th Dec 16, 3:57 PM
    On-grid domestic battery storage 5th Dec 16 at 3:57 PM
    Hello!

    Right, as discussed elsewhere, battery storage for self generation (typically PV) is interesting (to some), and gathering momentum in the UK. So here's a thread to discuss it, and watch it develop.

    I've called it on-grid, as off-grid is so much more specialised. And domestic as commercial scale storage, or grid scale can be chatted about on the Green & Ethical energy issues thread.

    So, where are, well this article lists about 20 systems that are available or should be available soon:-

    Introducing CleanTechnica’s New Home Battery Overview Page

    Jumping straight in with personal opinions:-

    Economical - Not yet. Prices are falling fast, the range of products is expanding fast, and large numbers are being deployed in some countries, either because the price of leccy is high (Australia & Hawaii) or because subsidy schemes exist (Sweden & Germany).

    Where are we today. My needs are a 4kWh system. That's 4kWh of useable capacity, which would mean about 8kWh of lead acid (LA), or about 5kWh of lithium ion (Li-ion). My research has found batts in the high £2k and up range. I need the price to be nearer to £1.5k.

    The Tesla Powerwall II, installed is approx £6.5k, which works out at about £2.2k for 5kWh, but of course, it doesn't work quite like that, as smaller systems will cost proportionately more.

    Environmental - Tricky one this (to say the least). Until storage is needed, it's not environmental. Renewable energy (RE) generation currently displaces gas generation, which is a demand follower. Once gas generation is pushed down to zero (at times) we need storage, but we aren't there yet.

    However, to push gas generation down to zero, we need more RE, and to ensure it is viable/economic/profitable, we will need storage - chicken and egg situation.

    The advantage of storage to the environment, is to take peaks of RE and timeshift them to peaks in electricity demand. On a domestic level, this works quite well as PV generates during the day into the afternoon (or evening) depending on the month, so any stored leccy is available for the evening peak 5pm to 7pm.

    That's the background, and now here's a thread to discuss options, prices, economics, and watch things unfold. Enjoy.
    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.
Page 67
    • EVandPV
    • By EVandPV 7th Nov 19, 7:43 PM
    • 73 Posts
    • 26 Thanks
    EVandPV
    I'll check with the guy who's doing the install.
    I just took it that 25a was probably recommended to maximise battery lifespan and 50a for max performance.
    Tbh, 2500w would still be fine for our average useage.
    Scott in Fife, 3kwp pv, Fronius inverter installed Jan 2012
    Renault Zoe R110 40kwh, Zappi 2 charger, arduino immersion controller
    4.8kwh Pylon battery storage with Lux ac controller due to be installed 17/12/19
    • 1961Nick
    • By 1961Nick 7th Nov 19, 9:55 PM
    • 1,119 Posts
    • 3,676 Thanks
    1961Nick
    Yeah, I take that as 25a not what it can do for 15 seconds, not the recommended max tbh.

    I'm just slightly concerned you might be disappointed with the performance of the lux using two batteries, as everything I've read says you want to use 3.

    As a comparison for the sofar. With 2 batteries. You set the internal software for a max charge and discharge of 50a. So taking a nominal 50v, that's only 2500w output.

    I'm sure they could run the 50a each, but I'm not sure for how long, nor how it would do for battery health long term.

    I say this as someone who has been trying to wrangle a way to get the lux parallel system and going to 4 batteries between the 2, and it just would seem very limiting.

    Though this is all my opinion only... happy to be wrong, not least as it will save me £1500
    Originally posted by Solarchaser
    The recommended power for 2 pylons & a Sofar ME3000 is 2400w charge & discharge. I can't imagine there's much point in exceeding that because with a maximum of 4.08kWh available, they'll soon be depleted & you'd be back to importing anyway.
    4kWp (black/black) - Sofar Inverter - SSE(141°) - 30° pitch - North Lincs
    Installed June 2013 - PVGIS = 3400

    Sofar ME3000SP Inverter & 5 x Pylontech US2000B Plus Batteries - 12kWh
    • Solarchaser
    • By Solarchaser 8th Nov 19, 2:28 AM
    • 199 Posts
    • 264 Thanks
    Solarchaser
    Ahh, see I took nominal 50v, you have taken it as 48v.
    In reality what you limit is current at 50a.
    So you can argue that when the battery is at 52v its outputing more kw than at 48v, and you would be right, but generally you state the middle that's why I said 50v nominal.

    However I would say you want as much output as possible to cover things like washing machines, the heat up cycle might be 30 mins, so take a quarter of your battery.... then the clouds clear and it gets replenished again.
    • EVandPV
    • By EVandPV 8th Nov 19, 8:24 AM
    • 73 Posts
    • 26 Thanks
    EVandPV
    I'll see how it goes with the 2 batts, can always add a 3rd if need be.
    My wife is taking early retirement in 18 months and will no doubt burn more leccy through the day so we may need a bit more capacity at that point anyway.
    Scott in Fife, 3kwp pv, Fronius inverter installed Jan 2012
    Renault Zoe R110 40kwh, Zappi 2 charger, arduino immersion controller
    4.8kwh Pylon battery storage with Lux ac controller due to be installed 17/12/19
    • orrery
    • By orrery 8th Nov 19, 9:57 AM
    • 631 Posts
    • 546 Thanks
    orrery
    I'll see how it goes with the 2 batts, can always add a 3rd if need be.
    My wife is taking early retirement in 18 months and will no doubt burn more leccy through the day so we may need a bit more capacity at that point anyway.
    Originally posted by EVandPV

    But that may lead to you being better positioned to make use of solar anyway. e.g. sticking the washer or wishdasher on because you have the power.
    4kWp, Panels: 16 Hyundai HIS250MG, Inverter: SMA Sunny Boy 4000TL, SolarImmersion
    Location: Bedford, Roof: South East facing, 20 degree pitch
    Nissan Leaf, TADO Central Heating control
    • gzoom
    • By gzoom 8th Nov 19, 10:18 AM
    • 367 Posts
    • 399 Thanks
    gzoom
    I'll see how it goes with the 2 batts, can always add a 3rd if need be.
    My wife is taking early retirement in 18 months and will no doubt burn more leccy through the day so we may need a bit more capacity at that point anyway.
    Originally posted by EVandPV
    You need as big battery as you can afford.

    Well I learnt yesterday even a Tesla PowerWall 2 is no match for in-laws + no sun!!

    Started at 8am with full PowerWall charged off E7, by 8pm it was dead.





    Today even with more sun than yesterday I suspect the PowerWall will be emptied by 5pm at the rate electrons are been gobbled!!


    • EVandPV
    • By EVandPV 8th Nov 19, 10:19 AM
    • 73 Posts
    • 26 Thanks
    EVandPV
    But that may lead to you being better positioned to make use of solar anyway. e.g. sticking the washer or wishdasher on because you have the power.
    Originally posted by orrery
    Very true, certainly in the summer. Not so much in the winter.
    And of course, I'd have to train my other half to align her useage with the surplus.
    Last edited by EVandPV; 08-11-2019 at 10:43 AM.
    Scott in Fife, 3kwp pv, Fronius inverter installed Jan 2012
    Renault Zoe R110 40kwh, Zappi 2 charger, arduino immersion controller
    4.8kwh Pylon battery storage with Lux ac controller due to be installed 17/12/19
    • EVandPV
    • By EVandPV 8th Nov 19, 10:25 AM
    • 73 Posts
    • 26 Thanks
    EVandPV
    You need as big battery as you can afford.
    Originally posted by gzoom
    Budget's pretty much blown at 4.8kwh having already bought an EV and Zappi this year.
    Sounds pretty easy to upgrade though once more funds become available.
    Scott in Fife, 3kwp pv, Fronius inverter installed Jan 2012
    Renault Zoe R110 40kwh, Zappi 2 charger, arduino immersion controller
    4.8kwh Pylon battery storage with Lux ac controller due to be installed 17/12/19
    • joefizz
    • By joefizz 8th Nov 19, 12:13 PM
    • 408 Posts
    • 365 Thanks
    joefizz
    Budget's pretty much blown at 4.8kwh having already bought an EV and Zappi this year.
    Sounds pretty easy to upgrade though once more funds become available.
    Originally posted by EVandPV

    I agree with both. I thought 4.8kw would have been enough for me but after using it for 6 months thought what extra I could do with double that!
    Took longer to build the frame for the 4 batteries than it did to add them in physically.


    The addition of other batteries also helps when you arent at max input/output, the larger number of batteries, the lower the rate of charge/discharge of each, so less heating, less effect on longevity.
    Saying that though from what Ive noticed with the sofar it does a pretty good job managing that sort of thing, been quite impressed with it really.



    Im probably there or thereabouts now.


    One thing I dont know if Ive expanded on is my reason for placing the batteries in the spare room. All to do with battery temperature/performance curves.

    I can limit the SOC in the software but one of the other main influencers of longevity is the temperature range exposure, so if you can place it somewhere with not much temperature fluctuation and within the published preferred temperature range then youve done all you can with that one.
    Main reason I didnt put it in the loft.
    The pylontechs are at the safer/more longevity end of the battery chemistry spectrum and whilst their cells are bespoke it wont be difficult to find replacements for depleted cells.
    The tesla uses more power with less longevity type cells but they are cheaper per unit and again should be easy to find replacement cells/modules.


    Went away for 4 days at the start of the week and expected to come home to a fully charged battery, 32%!
    Getting some charge in it today but in reality they will be mostly dormant now until mid Feb.
    I bought the upgrade batteries this Jan but it took almost 2 months for the management system to get up to speed fully with them so bear that in mind with any winter install.
    • Zarch
    • By Zarch 8th Nov 19, 12:53 PM
    • 310 Posts
    • 690 Thanks
    Zarch
    Using the excellent Agile app from OpenEnergyMonitor, using the data collected from my emonPi.

    https://guide.openenergymonitor.org/applications/octopusagile/

    It shows over the past month that my average import price on Agile is around 10p-11p per unit.



    So as much as I'd love the geekyness of owning batteries, i'm struggling with the maths/justification again for them.

    My budget would be around £2.5k, so maybe get 4.8kWh of Plyontech with inverter and installation for that?
    https://thinkrenewables.co.uk/lux-ac-48kw-battery-storage-system

    Say 4kWh usable on the Plyontech?
    4kw x 10p = 40p saved per day x 365 days = £146

    £2500 / £146 = 17 years.

    This seems to confirm.
    https://great-home.co.uk/solar-battery-calculator-likely-bill-savings/

    But feel free to correct me if those figures are wrong.

    Maybe I just need to sit tight and wait of the prices to fall some more? But they'd have to almost half to get under ten years ROI?

    Seems like time of use tariffs, with cheaper pricing outside of Solar generation periods is making the battery justification even more difficult than if on a fixed tariff say around 14p per unit?

    I'm wondering if the 'battery money' would be better invested in an EV or some other consumption device to make use of the cheaper pricing?
    17 x 300W panels on a 3.68 SolarEdge system in Sunny Sheffield.
    • joefizz
    • By joefizz 8th Nov 19, 1:27 PM
    • 408 Posts
    • 365 Thanks
    joefizz
    Seems like time of use tariffs, with cheaper pricing outside of Solar generation periods is making the battery justification even more difficult than if on a fixed tariff say around 14p per unit?
    Originally posted by Zarch

    Your figures are a reasonable ballpark to go off. At 11p a unit its really not feasible in monetary terms. Im optimistic about the lifetime of mine but with family history 17 years might outlast me!



    Thats cheap for electric, Im paying 18.34p a unit import and getting about 4p export although thats gone up over 20% since I got the batteries bringing the ROI in a bit.


    The calculator shows a loss for me of about 160 quid over the warranty period but the battery allowed me to install an ashp and use the immersion to cut down on oil usage so have probably saved that over the time already. Add in compound interest if youd just saved the money and thats back up again.
    Then again electricity/oil prices fluctuate so back to square one.
    The calculator also doesnt take account of the drop off over the warranty period (down to 60% over 10 years for the pylontechs), so likelihood is that its a fair bit longer.

    Ive changed usage patterns to use more of the normally exported electricity during the summer, using the battery so might go through 2 or more cycles during summer, but again thats pretty marginal at those prices.

    You could flog it half way through warranty and so on...
    Or treat it as a share you are never going to sell but gives you a good dividend every year ;-)



    Its definitely not going to make you money, thats for sure...
    • EVandPV
    • By EVandPV 8th Nov 19, 3:56 PM
    • 73 Posts
    • 26 Thanks
    EVandPV
    I think someone already mentioned it up-thread but there's also the general satisfaction of being nearly self sufficient and closer to 100% green that I'm quite looking forward to.
    Scott in Fife, 3kwp pv, Fronius inverter installed Jan 2012
    Renault Zoe R110 40kwh, Zappi 2 charger, arduino immersion controller
    4.8kwh Pylon battery storage with Lux ac controller due to be installed 17/12/19
    • ASavvyBuyer
    • By ASavvyBuyer 8th Nov 19, 4:12 PM
    • 1,060 Posts
    • 3,101 Thanks
    ASavvyBuyer
    Using the excellent Agile app from OpenEnergyMonitor, using the data collected from my emonPi.

    https://guide.openenergymonitor.org/applications/octopusagile/

    It shows over the past month that my average import price on Agile is around 10p-11p per unit.



    So as much as I'd love the geekyness of owning batteries, i'm struggling with the maths/justification again for them.

    My budget would be around £2.5k, so maybe get 4.8kWh of Plyontech with inverter and installation for that?
    https://thinkrenewables.co.uk/lux-ac-48kw-battery-storage-system

    Say 4kWh usable on the Plyontech?
    4kw x 10p = 40p saved per day x 365 days = £146

    £2500 / £146 = 17 years.

    This seems to confirm.
    https://great-home.co.uk/solar-battery-calculator-likely-bill-savings/

    But feel free to correct me if those figures are wrong.

    Maybe I just need to sit tight and wait of the prices to fall some more? But they'd have to almost half to get under ten years ROI?

    Seems like time of use tariffs, with cheaper pricing outside of Solar generation periods is making the battery justification even more difficult than if on a fixed tariff say around 14p per unit?

    I'm wondering if the 'battery money' would be better invested in an EV or some other consumption device to make use of the cheaper pricing?
    Originally posted by Zarch

    I'm on Octopus Go, with an average cost of about 8p/kWh for ALL electric we import. That makes the justification for a battery system not worth it. IMHO it is better to support a company providing RE electric, as the Co2 impact is currently less than buying a new battery system. Especially as at least parts of it would need replacing before a ROI was achieved.

    What for us would be ideal is a V2H inverter/charger, (for under £1k) so that we can store and use electric from less than 30% of the EV battery, charged from PV or the 5p/kWh rate at night.
    Rhondda Cynon Taf, 4kWp, W roof, 30° pitch, 16 x 8.33 Eternity 250w E+10 panels, Solar Edge SE4000-16A Inverter + P300 Optimisers. Inst Aug 2015.
    REUK Diverter, Toshiba RAS-10G2KVP-E Ultra High Efficiency Air Conditioner/Heat Pump, Kia Soul EV & 100% Green Electric Tariff.
    • EVandPV
    • By EVandPV 8th Nov 19, 6:29 PM
    • 73 Posts
    • 26 Thanks
    EVandPV
    The Pylons arrived today but like I say, we won't get the ac controller fitted for a few weeks yet.
    Am I ok to switch the batteries on briefly to check they're ok ?

    Edit : Actually, after opening one of the boxes, the power switch was already at 'on' and the green light below the
    switch is lit.
    Is it ok to check the SOC by pressing the red button without them connected to anything and should they not be switched off when not connected ?
    Last edited by EVandPV; 08-11-2019 at 7:12 PM.
    Scott in Fife, 3kwp pv, Fronius inverter installed Jan 2012
    Renault Zoe R110 40kwh, Zappi 2 charger, arduino immersion controller
    4.8kwh Pylon battery storage with Lux ac controller due to be installed 17/12/19
    • Solarchaser
    • By Solarchaser 8th Nov 19, 8:19 PM
    • 199 Posts
    • 264 Thanks
    Solarchaser
    Yeah no issues.

    If you wire a plug up to the power connector you can plug in the sofar, and connect up the batteries to play with the settings.

    Look on YouTube for Michael gaughan, he is actually who you speak to at think renewables, and has made a series of videos on how to set up the sofar etc.

    But in short, if you want to check the batteries, switch on, then press red button, that lights it all up, when light beside button is flashing they are "live" and soc bars will be lit.... from memory I think they come half charged.

    I would switch them off when you are done playing
    • EVandPV
    • By EVandPV 8th Nov 19, 8:37 PM
    • 73 Posts
    • 26 Thanks
    EVandPV
    Yeah no issues.

    If you wire a plug up to the power connector you can plug in the sofar, and connect up the batteries to play with the settings.

    Look on YouTube for Michael gaughan, he is actually who you speak to at think renewables, and has made a series of videos on how to set up the sofar etc.

    But in short, if you want to check the batteries, switch on, then press red button, that lights it all up, when light beside button is flashing they are "live" and soc bars will be lit.... from memory I think they come half charged.

    I would switch them off when you are done playing
    Originally posted by Solarchaser
    Thanks for that.
    Don't have the ac controller yet, it's the Lux 3K we're getting.
    I've actually been emailing Michael at Think Renewables for some info.
    He was saying they don't stock the Sofar anymore as they favour the Lux.
    Given that the extended warranty brings the Sofar to about the same price as the Lux, I doubt many people will go for them now anyway.

    Pressed the red button, green light next to red button is flashing but no SOC lights ??
    Haven't unboxed the other one yet.

    Edit : Took a meter reading from the terminals and got 49.2 volts.
    Sounds about 60-70% from what I gather ??
    Last edited by EVandPV; 08-11-2019 at 9:09 PM.
    Scott in Fife, 3kwp pv, Fronius inverter installed Jan 2012
    Renault Zoe R110 40kwh, Zappi 2 charger, arduino immersion controller
    4.8kwh Pylon battery storage with Lux ac controller due to be installed 17/12/19
    • 1961Nick
    • By 1961Nick 8th Nov 19, 9:57 PM
    • 1,119 Posts
    • 3,676 Thanks
    1961Nick
    Thanks for that.
    Don't have the ac controller yet, it's the Lux 3K we're getting.
    I've actually been emailing Michael at Think Renewables for some info.
    He was saying they don't stock the Sofar anymore as they favour the Lux.
    Given that the extended warranty brings the Sofar to about the same price as the Lux, I doubt many people will go for them now anyway.

    Pressed the red button, green light next to red button is flashing but no SOC lights ??
    Haven't unboxed the other one yet.

    Edit : Took a meter reading from the terminals and got 49.2 volts.
    Sounds about 60-70% from what I gather ??
    Originally posted by EVandPV
    The SOC indicator doesn't work properly until the battery is connected to the controller & either charging or discharging.
    4kWp (black/black) - Sofar Inverter - SSE(141°) - 30° pitch - North Lincs
    Installed June 2013 - PVGIS = 3400

    Sofar ME3000SP Inverter & 5 x Pylontech US2000B Plus Batteries - 12kWh
    • joefizz
    • By joefizz 9th Nov 19, 7:28 AM
    • 408 Posts
    • 365 Thanks
    joefizz
    Pressed the red button, green light next to red button is flashing but no SOC lights ??
    Originally posted by EVandPV

    Patience padawan, patience.
    • EVandPV
    • By EVandPV 9th Nov 19, 9:37 AM
    • 73 Posts
    • 26 Thanks
    EVandPV
    So I linked up the 2 batts as per the manual and on powering up the first batt, the second one also powered up and the SOC lights are now lit up.
    The first batt is at 49.2v and the second is 49.7v.
    The SOC lights on the first batt are flashing which I presume means it's charging from or balancing out against the second batt.
    Is this normal and ok to leave them until they balance ?

    Really appreciate all the help and advice here by the way guys. 👍
    Last edited by EVandPV; 09-11-2019 at 10:08 AM.
    Scott in Fife, 3kwp pv, Fronius inverter installed Jan 2012
    Renault Zoe R110 40kwh, Zappi 2 charger, arduino immersion controller
    4.8kwh Pylon battery storage with Lux ac controller due to be installed 17/12/19
    • ASavvyBuyer
    • By ASavvyBuyer 9th Nov 19, 7:08 PM
    • 1,060 Posts
    • 3,101 Thanks
    ASavvyBuyer
    I'm on Octopus Go, with an average cost of about 8p/kWh for ALL electric we import. That makes the justification for a battery system not worth it. IMHO it is better to support a company providing RE electric, as the Co2 impact is currently less than buying a new battery system. Especially as at least parts of it would need replacing before a ROI was achieved.

    What for us would be ideal is a V2H inverter/charger, (for under £1k) so that we can store and use electric from less than 30% of the EV battery, charged from PV or the 5p/kWh rate at night.
    Originally posted by ASavvyBuyer
    Been looking again to see if there are any V2H inverter/chargers available now. Found this Quaser DC Charger, by Wallbox. Have asked for a quote.
    Rhondda Cynon Taf, 4kWp, W roof, 30° pitch, 16 x 8.33 Eternity 250w E+10 panels, Solar Edge SE4000-16A Inverter + P300 Optimisers. Inst Aug 2015.
    REUK Diverter, Toshiba RAS-10G2KVP-E Ultra High Efficiency Air Conditioner/Heat Pump, Kia Soul EV & 100% Green Electric Tariff.
Welcome to our new Forum!

Our aim is to save you money quickly and easily. We hope you like it!

Forum Team Contact us

Live Stats

125Posts Today

1,273Users online

Martin's Twitter