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    • Martyn1981
    • By Martyn1981 5th Dec 16, 3:57 PM
    • 7,569Posts
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    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 22
    • ASavvyBuyer
    • By ASavvyBuyer 12th Oct 18, 1:47 PM
    • 893 Posts
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    ASavvyBuyer
    Another point to note is that the rates they charge on Agile are twice the wholesale rate that they pay for most of the time. Except that during the peak period they also add on about another 20p/kWh.


    Therefore, if you are thinking of B2G or V2G, remember that you are only likely to get a maximum of half the rates shown in the downloaded rates.
    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.
    • orrery
    • By orrery 12th Oct 18, 5:06 PM
    • 575 Posts
    • 487 Thanks
    orrery
    Therefore, if you are thinking of B2G or V2G, remember that you are only likely to get a maximum of half the rates shown in the downloaded rates.
    Originally posted by ASavvyBuyer

    I've just applied to Ovo for their V2G trial, but baulked when I came to subscribe - they are almost £200 more expensive than per year than Bulb, who I'm with at present.
    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
    • Martyn1981
    • By Martyn1981 13th Oct 18, 9:19 AM
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    Martyn1981
    Great news (sarcasm font needed). Tesla have upgraded their PWII, and also the price.

    I'm getting a bit bearish now on storage prices which don't seem to reflect expanding production and falling costs, but instead reflect the fact that storage demand around the world is rising even faster, especially amongst EV's.

    Hot: Tesla Powerwall To Get New Features, Higher Prices


    Found this out by accident, but S. Korea's expansion into grid storage has been so enormous that it's skewed all the world figures!

    We need more storage production, so Mart can have a battery.

    Global battery storage pipeline hits record 10.4 GW in first quarter of 2018
    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.
    • orrery
    • By orrery 13th Oct 18, 10:09 AM
    • 575 Posts
    • 487 Thanks
    orrery
    I'm getting a bit bearish now on storage prices which don't seem to reflect expanding production and falling costs, but instead reflect the fact that storage demand around the world is rising even faster, especially amongst EV's.
    Originally posted by Martyn1981

    Indeed, the short term direction appears to be increased prices. That's the second battery supplier that I've seen increase their prices recently, but that may have more to do with the Brexit effect.


    The government, in cutting EV grants from next month, have stated that the reason is because EV prices have been falling - another theoretical effect which doesn't appear to have been borne out in reality, where EV prices have just been firming up. This in itself, is probably due to the lack of battery production capacity.
    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
    • NigeWick
    • By NigeWick 13th Oct 18, 10:10 AM
    • 2,934 Posts
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    NigeWick
    I've just applied to Ovo for their V2G trial, but baulked when I came to subscribe
    Originally posted by orrery
    And, one can't be on Economy 7 either. Why would I want to pay more for my electricity in order to help them out with their trial?
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
    • NigeWick
    • By NigeWick 13th Oct 18, 10:19 AM
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    • 1,244 Thanks
    NigeWick
    We need more storage production, so Mart can have a battery.
    Originally posted by Martyn1981
    I'm feeling just a little smug that I've already got my PW2. But, disappointed that production has not ramped up enough to bring prices down.

    Since early April, 3143 kWh produced by solar, 769kWh to/from PW2, 223kWh from grid. Home & car have used 1983 kWh, a lot of which will be for the 9kW shower as PW2 only whacks out 5kW.
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
    • orrery
    • By orrery 13th Oct 18, 6:38 PM
    • 575 Posts
    • 487 Thanks
    orrery
    And, one can't be on Economy 7 either. Why would I want to pay more for my electricity in order to help them out with their trial?
    Originally posted by NigeWick

    Several reasons I can think of ... get a free 7kW V2G charger, make money from selling power back to the grid and getting a free subscription to the Polar charger network (worth £7 odd per month)..
    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
    • NigeWick
    • By NigeWick 14th Oct 18, 9:24 AM
    • 2,934 Posts
    • 1,244 Thanks
    NigeWick
    Several reasons I can think of ... get a free 7kW V2G charger, make money from selling power back to the grid and getting a free subscription to the Polar charger network (worth £7 odd per month)..
    Originally posted by orrery
    The V2G charger would be tempting if it were as smart as the Zappi already in the garage using solar to charge the car. I already have a"free" subscription to the Polar network. How will I make money if my night time electricity price goes up by 7.1p per kWh?
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
    • orrery
    • By orrery 14th Oct 18, 6:15 PM
    • 575 Posts
    • 487 Thanks
    orrery
    The V2G charger would be tempting if it were as smart as the Zappi already in the garage using solar to charge the car. I already have a"free" subscription to the Polar network. How will I make money if my night time electricity price goes up by 7.1p per kWh?
    Originally posted by NigeWick

    Well, I'm not you, and I don't have a Zappi, and I couldn't justify the expense of one, as I'd never recover the cost of one from the savings by charging from my solar PV. Note, just as you were doing, I'm talking from my perspective not yours. We all have different starting positions and your starting position isn't any use to me.



    I'd delighted to hear you have a 'free' subscription to Polar - please tell us all how we can get one!



    Night time electricity cost? The answer is I don't know until I see the terms of the trial - maybe it will make sense if they intend to pay me 50p per unit I export to the grid? In any case, I won't go ahead with it unless it does make sense to me.
    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
    • gefnew
    • By gefnew 14th Oct 18, 8:31 PM
    • 126 Posts
    • 136 Thanks
    gefnew
    Hi mart
    Maybe of interest take a look at tesla batts in aus.
    https://www.bbc.co.uk/news/av/world-australia-45648303/world-s-biggest-battery-a-look-around-tesla-project
    regards
    • NigeWick
    • By NigeWick 16th Oct 18, 8:47 AM
    • 2,934 Posts
    • 1,244 Thanks
    NigeWick
    I'd delighted to hear you have a 'free' subscription to Polar - please tell us all how we can get one
    Originally posted by orrery
    Ovo's EV-everywhere tariff which has Economy 7 gets two years Polar subscription included in the cost.
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
    • orrery
    • By orrery 17th Oct 18, 8:23 AM
    • 575 Posts
    • 487 Thanks
    orrery
    Ovo's EV-everywhere tariff which has Economy 7 gets two years Polar subscription included in the cost.
    Originally posted by NigeWick

    Err ... isn't this where we came in?


    Surely I was posting to say that I'd need to take a £100 plus hit on my bill to switch to OVO (so it would be far from 'free' for me, or anyone else for that matter).
    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
    • NigeWick
    • By NigeWick 17th Oct 18, 9:23 AM
    • 2,934 Posts
    • 1,244 Thanks
    NigeWick
    Err ... isn't this where we came in?
    Originally posted by orrery
    My bad. I had a senior moment and thought you were on about saving money with the V2G charger.
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
    • ASavvyBuyer
    • By ASavvyBuyer 21st Oct 18, 3:26 PM
    • 893 Posts
    • 2,649 Thanks
    ASavvyBuyer
    It has been our first full week on Octopus Go Tariff since getting the EV.

    We also have access to the data from the api Octopus provide, giving the following results:

    Just over 70% of our elecricity imported at the 5p/kWh rate; so working out at an average of 7.725p/kWh for all the electric we import.

    Having Solar PV helps during the day, as it lowers the % import.

    Also hoping for V2H to become available in the UK at a reasonable cost.

    However, I still can't currently justify getting a home battery, if I can import electricty at an average cost of less than 8p/kWh.
    From the costs I have seen so far, for even the cheapest home batteries, each kWh costs at least 8p (if you divide the total cost of the fully installed battery by how many kWh you can expect to get out of it during it's lifetime).
    Last edited by ASavvyBuyer; 21-10-2018 at 3:29 PM.
    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.
    • Martyn1981
    • By Martyn1981 21st Oct 18, 4:28 PM
    • 7,569 Posts
    • 12,088 Thanks
    Martyn1981
    This seems relevant:

    Lessons Learned From 6 Months With The Tesla Powerwall
    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.
    • NigeWick
    • By NigeWick 22nd Oct 18, 9:54 AM
    • 2,934 Posts
    • 1,244 Thanks
    NigeWick
    This seems relevant
    Originally posted by Martyn1981
    My PW2 is in the garage. I thought about having it on an outside wall to save space in the house. Then I decided that it doesn't take up that much room and it will stay in better condition out of the weather.

    Although I can't justify it on a cost basis, I am pleased with it as it has certainly reduced the amount of electricity I import. 223kWh since early April when the PW2 was fitted.
    The mind of the bigot is like the pupil of the eye; the more light you pour upon it, the more it will contract.
    Oliver Wendell Holmes
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